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Isotope geochemistry is an aspect of geology based upon study of the natural variations in the relative abundances of isotopes of various elements. Variations in isotopic abundance are measured by isotope ratio mass spectrometry, and can reveal information about the ages and origins of rock, air or water bodies, or processes of mixing between them.

Stable isotope geochemistry is largely concerned with isotopic variations arising from mass-dependent isotope fractionation, whereas radiogenic isotope geochemistry is concerned with the products of natural radioactivity.

Stable isotope geochemistry

For most stable isotopes, the magnitude of fractionation from kinetic and equilibrium fractionation is very small; for this reason, enrichments are typically reported in "per mil" (‰, parts per thousand).^[1] These enrichments (δ) represent the ratio of heavy isotope to light isotope in the sample over the ratio of a standard. That is,

\delta ^{13}C={\Biggl (}{\frac {{\bigl (}{\frac {^{13}C}{^{12}C}}{\bigr )}_{sample}}{{\bigl (}{\frac {^{13}C}{^{12}C}}{\bigr )}_{standard}}}-1{\Biggr )}*1000\ ^{o}\!/\!_{oo}

Carbon

Carbon has two stable isotopes, ¹²C and ¹³C, and one radioactive isotope, ¹⁴C. Carbon isotope ratios are measured against Vienna Pee Dee Belemnite (VPDB).^[2] They have been used to track ocean circulation, among other things.

Carbon stable isotopes are fractionated primarily by photosynthesis (Faure, 2004). The ¹³C/¹²C ratio is also an indicator of paleoclimate: a change in the ratio in the remains of plants indicates a change in the amount of photosynthetic activity, and thus in how favorable the environment was for the plants.

During photosynthesis, organisms using the C₃ pathway show different enrichments compared to those using the C₄ pathway, allowing scientists not only to distinguish organic matter from abiotic carbon, but also what type of photosynthetic pathway the organic matter was using.^[1]

Nitrogen

Nitrogen has two stable isotopes, ¹⁴N, and ¹⁵N. The ratio between these is measured relative to nitrogen in ambient air.^[2] Nitrogen ratios are frequently linked to agricultural activities. Nitrogen isotope data has also been used to measure the amount of exchange of air between the stratosphere and troposphere using data from the greenhouse gas N₂O.^[3]

Oxygen

Oxygen has three stable isotopes, ¹⁶O, ¹⁷O, and ¹⁸O. Oxygen ratios are measured relative to Vienna Standard Mean Ocean Water (VSMOW) or Vienna Pee Dee Belemnite (VPDB).^[2] Variations in oxygen isotope ratios are used to track both water movement, paleoclimate,^[1] and atmospheric gases such as ozone and carbon dioxide.^[4] Typically, the VPDB oxygen reference is used for paleoclimate, while VSMOW is used for most other applications.^[1] Oxygen isotopes appear in anomalous ratios in atmospheric ozone, resulting from mass-independent fractionation.^[5] Isotope ratios in fossilized foraminifera have been used to deduce the temperature of ancient seas.^[6]

Sulfur

Sulfur has four stable isotopes, with the following abundances: ³²S (0.9502), ³³S (0.0075), ³⁴S (0.0421) and ³⁶S (0.0002). These abundances are compared to those found in Cañon Diablo troilite.^[4] Variations in sulfur isotope ratios are used to study the origin of sulfur in an orebody and the temperature of formation of sulfur–bearing minerals.^[7]

Radiogenic isotope geochemistry

Radiogenic isotopes provide powerful tracers for studying the ages and origins of Earth systems.^[8] They are particularly useful to understand mixing processes between different components, because (heavy) radiogenic isotope ratios are not usually fractionated by chemical processes.

Radiogenic isotope tracers are most powerful when used together with other tracers: The more tracers used, the more control on mixing processes. An example of this application is to the evolution of the Earth's crust and Earth's mantle through geological time.

Lead-lead isotope geochemistry

Lead has four stable isotopes - ²⁰⁴Pb, ²⁰⁶Pb, ²⁰⁷Pb, ²⁰⁸Pb and one common radioactive isotope ²⁰²Pb with a half-life of ~53,000 years.

Lead is created in the Earth via decay of transuranic elements, primarily uranium and thorium.

Lead isotope geochemistry is useful for providing isotopic dates on a variety of materials. Because the lead isotopes are created by decay of different transuranic elements, the ratios of the four lead isotopes to one another can be very useful in tracking the source of melts in igneous rocks, the source of sediments and even the origin of people via isotopic fingerprinting of their teeth, skin and bones.

It has been used to date ice cores from the Arctic shelf, and provides information on the source of atmospheric lead pollution.

Lead-lead isotopes has been successfully used in forensic science to fingerprint bullets, because each batch of ammunition has its own peculiar ²⁰⁴Pb/²⁰⁶Pb vs ²⁰⁷Pb/²⁰⁸Pb ratio.

Samarium-neodymium

Mining Engineer (Excluding Oil ) Truman from Alma, loves to spend time knotting, largest property developers in singapore developers in singapore and stamp collecting. Recently had a family visit to Urnes Stave Church. Samarium-neodymium is an isotope system which can be utilised to provide a date as well as isotopic fingerprints of geological materials, and various other materials including archaeological finds (pots, ceramics).

¹⁴⁷Sm decays to produce ¹⁴³Nd with a half life of 1.06x10¹¹ years.

Dating is achieved usually by trying to produce an isochron of several minerals within a rock specimen. The initial ¹⁴³Nd/¹⁴⁴Nd ratio is determined.

This initial ratio is modelled relative to CHUR - the Chondritic Uniform Reservoir - which is an approximation of the chondritic material which formed the solar system. CHUR was determined by analysing chondrite and achondrite meteorites.

The difference in the ratio of the sample relative to CHUR can give information on a model age of extraction from the mantle (for which an assumed evolution has been calculated relative to CHUR) and to whether this was extracted from a granitic source (depleted in radiogenic Nd), the mantle, or an enriched source.

Rhenium-osmium

Rhenium and osmium are siderophile elements which are present at very low abundances in the crust. Rhenium undergoes radioactive decay to produce osmium. The ratio of non-radiogenic osmium to radiogenic osmium throughout time varies.

Rhenium prefers to enter sulfides more readily than osmium. Hence, during melting of the mantle, rhenium is stripped out, and prevents the osmium-osmium ratio from changing appreciably. This locks in an initial osmium ratio of the sample at the time of the melting event. Osmium-osmium initial ratios are used to determine the source characteristic and age of mantle melting events.

Noble gas isotopes

Natural isotopic variations amongst the noble gases result from both radiogenic and nucleogenic production processes. Because of their unique properties, it is useful to distinguish them from the conventional radiogenic isotope systems described above.

Helium-3

Helium-3 was trapped in the planet when it formed. Some ³He is being added by meteoric dust, primarily collecting on the bottom of oceans (although due to subduction, all oceanic tectonic plates are younger than continental plates). However, ³He will be degassed from oceanic sediment during subduction, so cosmogenic ³He is not affecting the concentration or noble gas ratios of the mantle.

Helium-3 is created by cosmic ray bombardment, and by lithium spallation reactions which generally occur in the crust. Lithium spallation is the process by which a high-energy neutron bombards a lithium atom, creating a ³He and a ⁴He ion. This requires significant lithium to adversely affect the ³He/⁴He ratio.

All degassed helium is lost to space eventually, due to the average speed of helium exceeding the escape velocity for the Earth. Thus, it is assumed the helium content and ratios of Earth's atmosphere have remained essentially stable.

It has been observed that ³He is present in volcano emissions and oceanic ridge samples. How ³He is stored in the planet is under investigation, but it is associated with the mantle and is used as a marker of material of deep origin.

Due to similarities in helium and carbon in magma chemistry, outgassing of helium requires the loss of volatile components (water, carbon dioxide) from the mantle, which happens at depths of less than 60 km. However, ³He is transported to the surface primarily trapped in the crystal lattice of minerals within fluid inclusions.

Helium-4 is created by radiogenic production (by decay of uranium/thorium-series elements). The continental crust has become enriched with those elements relative to the mantle and thus more He⁴ is produced in the crust than in the mantle.

The ratio (R) of ³He to ⁴He is often used to represent ³He content. R usually is given as a multiple of the present atmospheric ratio (Ra).

Common values for R/Ra:

Old continental crust: less than 1
mid-ocean ridge basalt (MORB): 7 to 9
Spreading ridge rocks: 9.1 plus or minus 3.6
Hotspot rocks: 5 to 42
Ocean and terrestrial water: 1
Sedimentary formation water: less than 1
Thermal spring water: 3 to 11

³He/⁴He isotope chemistry is being used to date groundwaters, estimate groundwater flow rates, track water pollution, and provide insights into hydrothermal processes, igneous geology and ore genesis.

Uranium-series isotopes

U-series isotopes are unique amongst radiogenic isotopes because, being in the U-series decay chains, they are both radiogneic and radioactive. Because their abundances are normally quoted as activity ratios rather than atomic ratios, they are best considered separately from the other radiogenic isotope systems.

Protactinium/Thorium - ²³¹Pa / ²³⁰Th

Uranium is well mixed in the ocean, and its decay produces ²³¹Pa and ²³⁰Th at a constant activity ratio (0.093). The decay products are rapidly removed by adsorption on settling particles, but not at equal rates. ²³¹Pa has a residence equivalent to the residence time of deep water in the Atlantic basin (around 1000 yrs) but ²³⁰Th is removed more rapidly (centuries). Thermohaline circulation effectively exports ²³¹Pa from the Atlantic into the Southern Ocean, while most of the ²³⁰Th remains in Atlantic sediments. As a result, there is a relationship between ²³¹Pa/²³⁰Th in Atlantic sediments and the rate of overturning: faster overturning produces lower sediment ²³¹Pa/²³⁰Th ratio, while slower overturning increases this ratio. The combination of δ¹³C and ²³¹Pa/²³⁰Th can therefore provide a more complete insight into past circulation changes.

Anthropogenic isotopes

Tritium/helium-3

Tritium was released to the atmosphere during atmospheric testing of nuclear bombs. Radioactive decay of tritium produces the noble gas helium-3. Comparing the ratio of tritium to helium-3 (³H/³He) allows estimation of the age of recent ground waters.

Notes

43 year old Petroleum Engineer Harry from Deep River, usually spends time with hobbies and interests like renting movies, property developers in singapore new condominium and vehicle racing. Constantly enjoys going to destinations like Camino Real de Tierra Adentro.

References

General

Allègre C.J., 2008. Isotope Geology (Cambridge University Press).
Dickin A.P., 2005. Radiogenic Isotope Geology (Cambridge University Press).
Faure G., Mensing T.M. (2004), Isotopes: Principles and Applications (John Wiley & Sons).
Hoefs J., 2004. Stable Isotope Geochemistry (Springer Verlag).
Sharp Z., 2006. Principles of Stable Isotope Geochemistry (Prentice Hall).

Stable isotopes

Environmental Isotopes (University of Ottawa)
Fundamentals of Isotope Geochemistry (C. Kendall & E.A. Caldwell, chap.2 in Isotope Tracers in Catchment Hydrology [edited by C. Kendall & J.J. McDonnell], 1998)
Stable Isotopes and Mineral Resource Investigations in the United States (USGS)

³He/⁴He

Burnard P.G., Farley K.A., & Turner G., 1998. "Multiple fluid pulses in a Samoan harzburgite", Chemical Geology, 147: 99-114.
Kirstein L. & Timmerman M., 2000. "Evidence of the proto-Iceland lume in northwestern Ireland at 42Ma from helium isotopes", Journal of the Geological Society, London, 157: 923-927.
Porcelli D. & Halliday A.N., 2001. "The core as a possible source of mantle helium", Earth and Planetary Science Letters, 192: 45-56.

Re-Os

Arne D., Bierlein F.P., Morgan J.W., & Stein H.J., 2001. "Re-Os dating of sulfides associated with gold mineralisation in central Victoria, Australia", Economic Geology, 96: 1455-1459.
Martin C., 1991. "Osmium isotopic characteristics of mantle-derived rocks", Geochimica et Cosmochimica Acta, 55: 1421-1434.

External links

National Isotope Development Center Reference information on isotopes, and coordination and management of isotope production, availability, and distribution
Isotope Development & Production for Research and Applications (IDPRA) U.S. Department of Energy program for isotope production and production research and development

Template:Chronology

↑ ^1.0 ^1.1 ^1.2 ^1.3 20 year-old Real Estate Agent Rusty from Saint-Paul, has hobbies and interests which includes monopoly, property developers in singapore and poker. Will soon undertake a contiki trip that may include going to the Lower Valley of the Omo.

My blog: http://www.primaboinca.com/view_profile.php?userid=5889534
↑ ^2.0 ^2.1 ^2.2 Template:Cite web
↑ One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang
↑ ^4.0 ^4.1 One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang
↑ One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang
↑ One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang
↑ Rollinson, H.R. (1993). Using Geochemical Data: Evaluation, Presentation, Interpretation Longman Scientific & Technical. ISBN 978-0-582-06701-1
↑ 20 year-old Real Estate Agent Rusty from Saint-Paul, has hobbies and interests which includes monopoly, property developers in singapore and poker. Will soon undertake a contiki trip that may include going to the Lower Valley of the Omo.

My blog: http://www.primaboinca.com/view_profile.php?userid=5889534

[drever_2002-1] 1.0 ^1.1 ^1.2 ^1.3 20 year-old Real Estate Agent Rusty from Saint-Paul, has hobbies and interests which includes monopoly, property developers in singapore and poker. Will soon undertake a contiki trip that may include going to the Lower Valley of the Omo.

My blog: http://www.primaboinca.com/view_profile.php?userid=5889534

[usgs_isotope_tracers-2] 2.0 ^2.1 ^2.2 Template:Cite web

[boering_2004-3] One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang

[Brenninkmeijer_2003-4] 4.0 ^4.1 One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang

[mauersberger_1987-5] One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang

[edwards_1953-6] One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang

[Rollinson-7] Rollinson, H.R. (1993). Using Geochemical Data: Evaluation, Presentation, Interpretation Longman Scientific & Technical. ISBN 978-0-582-06701-1

[8] 20 year-old Real Estate Agent Rusty from Saint-Paul, has hobbies and interests which includes monopoly, property developers in singapore and poker. Will soon undertake a contiki trip that may include going to the Lower Valley of the Omo.

My blog: http://www.primaboinca.com/view_profile.php?userid=5889534

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-The best part of the Tadalis is that men suffering with impotence can even enjoy the multiple orgasms during the sexual copulation. Another thing you should try to do is to take a quick power nap when your lunch break comes around. Today, you can easily get ginseng capsules from market in the form of capsules. Some times while writing an online story they use a phrases like  I love my cat, I am loved, I am wondering for. Your cure erectile dysfunctions naturally report is waiting for you. <br><br>Endocrinologic Impotence: Endocrinologic impotence occurs due to an imbalance of sex hormones in the blood stream. Filagra 100 mg has become a favourite among our ed medications shoppers. This medication may take up to four weeks to become fully effective, if used properly. Depression, performance anxiety and relationship issues are some among the common psychological factors giving rise to the risk of male impotence. The alternative medicine is also effective in combating various types of allergies and skin conditions. <br><br>There are preventative actions that one can take such as regular exercise, adequate sleep, reducing levels of stress and consulting your doctor as soon as possible. But those who were overweight or had a 42-inch waistline were nearly twice as likely to be hit as men with a 32-inch girth. Wifi enabled laptop sperm (update): Do Wi-Fi enabled laptops kill sperm. This definitely holds true for men suffering from impotence. And while there's a lot of information on the subject these days, certain misconceptions still dwell in mind of men, making it a lot harder to treat the condition. <br><br>On getting the impulses, neurotransmitters are released and this relaxes the penile muscles and it fills up with blood. The high selling price of the horns has brought about a sophisticated breed of poachers. These symptoms include lack of energy and motivation, fatigue, sleeping problems, weight gain and increase in fat deposits in the abdomen, impotence, lack of interest in sex and other side effects. Problems such as erectile dysfunction, premature ejaculation, loss of libido and inability to make sexual partner pregnant woman are few and known of them. A person or couples health can definitely be a factor involving infertility, however it is not usually one of the key factors. <br><br>This pill must not be taken with any form of nitrate medication, as this combination may potentially produce a severe drop in blood pressure. Anyone having side effects from this medication can consult their physician about dosing changes. Generic online pharmacy provides prescription drugs including ED Medicine which is now reaching distinctive horizons by effectively treating male impotence. The most commonly prescribed dosage of generic Cialis is one pill for duration of 24 hours. For ladies, there are many of stunning, womanly caps such as popular Cranium For Each Other Rhinestone Cover.<br><br>If you have any type of inquiries relating to where and ways to use how to treat erectile dysfunction ([http://www.eiaculazione-precoce.info/ click the up coming website page]), you can call us at our own web-site.
+'''Isotope geochemistry''' is an aspect of [[geology]] based upon study of the natural variations in the relative abundances of [[isotopes]] of various elements. Variations in isotopic abundance are measured by [[isotope ratio mass spectrometry]], and can reveal information about the ages and origins of rock, air or water bodies, or processes of mixing between them.
+[[Stable isotope]] geochemistry is largely concerned with isotopic variations arising from mass-dependent isotope fractionation, whereas [[radiogenic]] isotope geochemistry is concerned with the products of natural radioactivity.
+==Stable isotope geochemistry==
+For most stable isotopes, the magnitude of fractionation from  [[kinetic fractionation|kinetic]] and [[equilibrium fractionation]] is very small; for this reason, enrichments are typically reported in "per mil" (‰, parts per thousand).<ref name="drever_2002">{{cite book | title = The Geochemistry of Natural Waters | last = Drever | first=James | publisher = Prentice Hall | year = 2002 | location = New Jersey | isbn = 0-13-272790-0 | pages = 311–322}}</ref>  These enrichments (δ) represent the ratio of heavy isotope to light isotope in the sample over the ratio of a standard.  That is,
+:<math>\delta ^{13}C = \Biggl( \frac{\bigl( \frac{^{13}C}{^{12}C} \bigr)_{sample}}{\bigl( \frac{^{13}C}{^{12}C} \bigr)_{standard}} -1 \Biggr) * 1000\ ^{o}\!/\!_{oo}</math>
+===Carbon===
+[[Carbon]] has two [[stable isotope]]s, <sup>12</sup>C and <sup>13</sup>C, and one radioactive isotope, [[Carbon-14|<sup>14</sup>C]].  Carbon isotope ratios are measured against Vienna Pee Dee [[Belemnite]] (VPDB).<ref name="usgs_isotope_tracers">{{cite web |url= http://wwwrcamnl.wr.usgs.gov/isoig/res/funda.html |title= USGS -- Isotope Tracers -- Resources -- Isotope Geochemistry |accessdate=2009-01-18}}</ref> They have been used to track ocean circulation, among other things.
+Carbon stable isotopes are fractionated primarily by [[photosynthesis]] (Faure, 2004).  The <sup>13</sup>C/<sup>12</sup>C ratio is also an indicator of paleoclimate: a change in the ratio in the remains of plants indicates a change in the amount of photosynthetic activity, and thus in how favorable the environment was for the plants.
+During photosynthesis, organisms using the  [[C3 pathway|C<sub>3</sub> pathway]] show different enrichments compared to those using the  [[C4 pathway|C<sub>4</sub> pathway]], allowing scientists not only to distinguish organic matter from abiotic carbon, but also what type of photosynthetic pathway the organic matter was using.<ref name="drever_2002"/>
+===Nitrogen===
+[[Nitrogen]] has two stable isotopes, <sup>14</sup>N, and <sup>15</sup>N.  The ratio between these is measured relative to nitrogen in [[air|ambient air]].<ref name="usgs_isotope_tracers"/>  Nitrogen ratios are frequently linked to agricultural activities.  Nitrogen isotope data has also been used to measure the amount of exchange of air between the [[stratosphere]] and [[troposphere]] using data from the greenhouse gas  [[Nitrous oxide|N<sub>2</sub>O]].<ref name="boering_2004">{{cite journal | author = Park, S.; Atlas, E. L.; Boering, K. A. | title = Measurements of N<sub>2</sub>O isotopologues in the stratosphere | journal = [[Journal of Geophysical Research]] | volume = 109 | year = 2004 | issue = D1 | doi = 10.1029/2003JD003731 | pages = D01305|bibcode = 2004JGRD..10901305P }}</ref>
+===Oxygen===
+[[Oxygen]] has three stable isotopes, <sup>16</sup>O, <sup>17</sup>O, and <sup>18</sup>O.  Oxygen ratios are measured relative to [[Vienna Standard Mean Ocean Water]] (VSMOW) or Vienna Pee Dee Belemnite (VPDB).<ref name="usgs_isotope_tracers"/>  Variations in oxygen isotope ratios are used to track both water movement, paleoclimate,<ref name="drever_2002"/> and atmospheric gases such as [[ozone]] and [[carbon dioxide]].<ref name="Brenninkmeijer_2003">{{cite journal | author = Brenninkmeijer, C. A. M.; Janssen, C.; Kaiser, J.; Röckmann, T.; Rhee, T. S.; Assonov, S. S. | title = Isotope effects in the chemistry of atmospheric trace compounds | journal = Chemical Reviews | year = 2003 | volume = 103 | pages = 5125–5161 | doi = 10.1021/cr020644k | pmid = 14664646 | issue = 12}}</ref>  Typically, the VPDB oxygen reference is used for paleoclimate, while VSMOW is used for most other applications.<ref name="drever_2002"/>  Oxygen isotopes appear in anomalous ratios in atmospheric ozone, resulting from [[mass-independent fractionation]].<ref name="mauersberger_1987">{{cite journal | doi = 10.1029/GL014i001p00080 | author = Mauersberger, K. | title = Ozone isotope measurements in the stratosphere | year = 1987 | volume = 14 | issue = 1 | pages = 80–83 | journal = Geophysical Review Letters|bibcode = 1987GeoRL..14...80M }}</ref>  Isotope ratios in fossilized [[foraminifera]] have been used to deduce the temperature of ancient seas.<ref name="edwards_1953">{{cite journal | journal = Nature | author = Emiliani, C.; Edwards, G. | year = 1953 | volume = 171 | issue = 4359 | pages = 887–888 | title = Tertiary ocean bottom temperatures | doi = 10.1038/171887c0|bibcode = 1953Natur.171..887E }}</ref>
+===Sulfur===
+[[Sulfur]] has four stable isotopes, with the following abundances: <sup>32</sup>S (0.9502), <sup>33</sup>S (0.0075), <sup>34</sup>S (0.0421) and <sup>36</sup>S (0.0002). These abundances are compared to those found in  [[Canyon Diablo (meteorite)|Cañon Diablo troilite]].<ref name="Brenninkmeijer_2003"/> Variations in sulfur isotope ratios are used to study the origin of sulfur in an [[ore]]body and the temperature of formation of sulfur&ndash;bearing minerals.<ref name=Rollinson>Rollinson, H.R. (1993). ''Using Geochemical Data: Evaluation, Presentation, Interpretation'' Longman Scientific & Technical. ISBN 978-0-582-06701-1</ref>
+==Radiogenic isotope geochemistry==
+Radiogenic isotopes provide powerful tracers for studying the ages and origins of Earth systems.<ref>{{cite book | author=Dickin, A.P. | year=2005 | title=Radiogenic Isotope Geology | url=http://www.onafarawayday.com/Radiogenic/ | publisher=Cambridge University Press}}</ref> They are particularly useful to understand mixing processes between different components, because (heavy) radiogenic isotope ratios are not usually fractionated by chemical processes.
+Radiogenic isotope tracers are most powerful when used together with other tracers: The more tracers used, the more control on mixing processes. An example of this application is to the evolution of the [[Earth's crust]] and [[Earth's mantle]] through geological time.
+===Lead-lead isotope geochemistry===
+[[Lead]] has four stable [[isotopes]] - <sup>204</sup>Pb, <sup>206</sup>Pb, <sup>207</sup>Pb, <sup>208</sup>Pb and one common radioactive isotope <sup>202</sup>Pb with a [[half-life]] of ~53,000 years.
+Lead is created in the Earth via decay of [[transuranic]] [[Chemical element|elements]], primarily [[uranium]] and [[thorium]].
+Lead isotope [[geochemistry]] is useful for providing [[radiometric dating|isotopic dates]] on a variety of materials. Because the lead isotopes are created by decay of different transuranic elements, the ratios of the four lead isotopes to one another can be very useful in tracking the source of melts in [[igneous rocks]], the source of [[sediments]] and even the origin of people via [[isotopic fingerprint]]ing of their teeth, skin and bones.
+It has been used to date [[ice core]]s from the Arctic shelf, and provides information on the source of atmospheric lead [[air pollution|pollution]].
+Lead-lead isotopes has been successfully used in [[forensic science]] to fingerprint bullets, because each batch of ammunition has its own peculiar <sup>204</sup>Pb/<sup>206</sup>Pb vs <sup>207</sup>Pb/<sup>208</sup>Pb ratio.
+===Samarium-neodymium===
+{{main|Samarium-neodymium dating}}
+[[Samarium]]-[[neodymium]] is an isotope system which can be utilised to provide a date as well as [[isotopic fingerprint]]s of geological materials, and various other materials including archaeological finds (pots, ceramics).
+<sup>147</sup>Sm decays to produce <sup>143</sup>Nd with a half life of 1.06x10<sup>11</sup> years.
+Dating is achieved usually by trying to produce an [[isochron dating|isochron]] of several minerals within a rock specimen. The initial <sup>143</sup>Nd/<sup>144</sup>Nd ratio is determined.
+This initial ratio is modelled relative to CHUR - the Chondritic Uniform Reservoir - which is an approximation of the chondritic material which formed the solar system. CHUR was determined by analysing [[chondrite]] and [[achondrite]] meteorites.
+The difference in the ratio of the sample relative to CHUR can give information on a model age of extraction from the mantle (for which an assumed evolution has been calculated relative to CHUR) and to whether this was extracted from a granitic source (depleted in radiogenic Nd), the mantle, or an enriched source.
+===Rhenium-osmium===
+[[Rhenium]] and [[osmium]] are siderophile elements which are present at very low abundances in the crust. Rhenium undergoes [[radioactive decay]] to produce osmium. The ratio of non-radiogenic osmium to radiogenic osmium throughout time varies.
+Rhenium prefers to enter [[sulfide]]s more readily than osmium. Hence, during melting of the mantle, rhenium is stripped out, and prevents the osmium-osmium ratio from changing appreciably. This ''locks in'' an initial osmium ratio of the sample at the time of the melting event. Osmium-osmium initial ratios are used to determine the source characteristic and age of mantle melting events.
+==Noble gas isotopes==
+Natural isotopic variations amongst the noble gases result from both radiogenic and nucleogenic production processes. Because of their unique properties, it is useful to distinguish them from the conventional radiogenic isotope systems described above.
+===Helium-3===
+[[Helium-3]] was trapped in the planet when it formed.  Some <sup>3</sup>He is being added by meteoric dust, primarily collecting on the bottom of oceans (although due to [[subduction]], all oceanic [[tectonic plates]] are younger than continental plates). However, <sup>3</sup>He will be degassed from oceanic sediment during [[subduction]], so cosmogenic <sup>3</sup>He is not affecting the concentration or [[noble gas]] ratios of the [[Mantle (geology)|mantle]].
+Helium-3 is created by [[cosmic ray]] bombardment, and by [[lithium]] spallation reactions which generally occur in the crust. Lithium [[spallation]] is the process by which a [[fast neutron|high-energy neutron]] bombards a [[lithium]] atom, creating a <sup>3</sup>He  and a <sup>4</sup>He ion. This requires significant lithium to adversely affect the <sup>3</sup>He/<sup>4</sup>He ratio.
+All degassed helium is lost to space eventually, due to the average speed of helium exceeding the [[escape velocity]] for the Earth. Thus, it is assumed the helium content and ratios of [[Earth's atmosphere]] have remained essentially stable.
+It has been observed that <sup>3</sup>He is present in [[volcano]] emissions and [[oceanic ridge]] samples.  How <sup>3</sup>He is stored in the planet is under investigation, but it is associated with the [[mantle (geology)|mantle]] and is used as a marker of material of deep origin.
+Due to similarities in [[helium]] and [[carbon]] in [[magma]] chemistry, outgassing of helium requires the loss of [[Volatiles|volatile components]] ([[water]], [[carbon dioxide]]) from the mantle, which happens at depths of less than 60&nbsp;km. However, <sup>3</sup>He is transported to the surface primarily trapped in the [[crystal]] lattice of minerals within [[fluid inclusions]].
+Helium-4 is created by [[radiogenic]] production (by decay of [[uranium]]/[[thorium]]-series [[chemical element|elements]]).  The [[continental crust]] has become enriched with those elements relative to the mantle and thus more He<sup>4</sup> is produced in the crust than in the mantle.
+The ratio ('''R''') of <sup>3</sup>He to <sup>4</sup>He  is often used to represent <sup>3</sup>He  content.  '''R''' usually is given as a multiple of the present atmospheric ratio ('''Ra''').
+Common values for '''R/Ra''':
+* Old continental crust: less than 1
+* [[oceanic ridge|mid-ocean ridge]] [[basalt]] (MORB): 7 to 9
+* Spreading ridge rocks: 9.1 plus or minus 3.6
+* [[Hotspot (geology)|Hotspot]] rocks: 5 to 42
+* Ocean and terrestrial water: 1
+* Sedimentary formation water: less than 1
+* Thermal spring water: 3 to 11
+<sup>3</sup>He/<sup>4</sup>He isotope chemistry is being used to date [[groundwater]]s, estimate groundwater flow rates, track water pollution, and provide insights into [[hydrothermal]] processes, [[igneous]] [[geology]] and [[ore genesis]].
+* [http://www.geotrack.com.au/uthhe/u-th-he-techinfo.htm (U-Th)/He dating of apatite as a thermal history tool]
+* [http://lvo.wr.usgs.gov/helium.html USGS: Helium Discharge at Mammoth Mountain Fumarole (MMF)]
+==Uranium-series isotopes==
+U-series isotopes are unique amongst radiogenic isotopes because, being in the U-series decay chains, they are both radiogneic and radioactive. Because their abundances are normally quoted as activity ratios rather than atomic ratios, they are best considered separately from the other radiogenic isotope systems.
+===[[Protactinium]]/[[Thorium]] - <sup>231</sup>Pa / <sup>230</sup>Th===
+[[Uranium]] is well mixed in the ocean, and its decay produces <sup>231</sup>Pa and <sup>230</sup>Th at a constant activity ratio (0.093). The decay products are rapidly removed by [[adsorption]] on settling particles, but not at equal rates. <sup>231</sup>Pa has a residence equivalent to the residence time of [[abyssal zone|deep water]] in the [[Atlantic]] basin (around 1000 yrs) but <sup>230</sup>Th is removed more rapidly (centuries). [[Thermohaline circulation]] effectively exports <sup>231</sup>Pa from the Atlantic into the [[Southern Ocean]], while most of the <sup>230</sup>Th remains in Atlantic sediments. As a result, there is a relationship between <sup>231</sup>Pa/<sup>230</sup>Th in Atlantic sediments and the rate of overturning: faster overturning produces lower sediment <sup>231</sup>Pa/<sup>230</sup>Th ratio, while slower overturning increases this ratio. The combination of [[δ13C|δ<sup>13</sup>C]] and <sup>231</sup>Pa/<sup>230</sup>Th can therefore provide a more complete insight into past circulation changes.
+==Anthropogenic isotopes==
+===Tritium/helium-3===
+[[Tritium]] was released to the atmosphere during atmospheric testing of nuclear bombs. Radioactive decay of tritium produces the noble gas [[helium-3]].  Comparing the ratio of tritium to helium-3 (<sup>3</sup>H/<sup>3</sup>He) allows estimation of the age of recent [[ground water]]s.
+* [http://water.usgs.gov/lab/3h3he/background/ USGS Tritium/Helium-3 Dating]
+* [http://wwwrcamnl.wr.usgs.gov/isoig/period/he_iig.html Hydrologic Isotope Tracers - Helium]
+==See also==
+* [[Cosmogenic isotope]]s
+* [[Environmental isotopes]]
+* [[Geochemistry]]
+* [[Isotopic signature]]
+* [[Radiometric dating]]
+* [[Isotope-ratio mass spectrometry]]
+==Notes==
+{{reflist}}
+==References==
+===General===
+*[[Claude Allègre|Allègre C.J.]], 2008.  ''Isotope Geology'' ([[Cambridge University Press]]).
+*Dickin A.P., 2005.  ''Radiogenic Isotope Geology'' ([[Cambridge University Press]]).
+*Faure G., Mensing T.M. (2004), ''Isotopes: Principles and Applications'' ([[John Wiley & Sons]]).
+*Hoefs J., 2004. ''Stable Isotope Geochemistry'' ([[Springer Verlag]]).
+*Sharp Z., 2006. ''Principles of Stable Isotope Geochemistry'' ([[Prentice Hall]]).
+===Stable isotopes===
+* [http://www.science.uottawa.ca/~eih/ch1/ch1.htm Environmental Isotopes] &nbsp;([[University of Ottawa]])
+* [http://wwwrcamnl.wr.usgs.gov/isoig/isopubs/itchch2.html Fundamentals of Isotope Geochemistry] &nbsp;(C. Kendall & E.A. Caldwell, chap.2 in ''Isotope Tracers in Catchment Hydrology'' [edited by C. Kendall & J.J. McDonnell], 1998)
+* [http://pubs.usgs.gov/info/seal2/ Stable Isotopes and Mineral Resource Investigations in the United States] &nbsp;([[USGS]])
+===<sup>3</sup>He/<sup>4</sup>He===
+*Burnard P.G., Farley K.A., & Turner G., 1998. "Multiple fluid pulses in a Samoan [[harzburgite]]", ''Chemical Geology'', 147: 99-114.
+*Kirstein L. & Timmerman M., 2000. "Evidence of the proto-Iceland lume in northwestern Ireland at 42Ma from helium isotopes", ''Journal of the Geological Society, London'', 157: 923-927.
+*Porcelli D. & Halliday A.N., 2001. "The core as a possible source of mantle helium",  ''Earth and Planetary Science Letters'', 192: 45-56.
+===Re-Os===
+*Arne D., Bierlein F.P., Morgan J.W., & Stein H.J., 2001. "Re-Os dating of sulfides associated with gold mineralisation in central Victoria, Australia", ''Economic Geology'', 96: 1455-1459.
+*Martin C., 1991. "Osmium isotopic characteristics of mantle-derived rocks", ''Geochimica et Cosmochimica Acta'', 55: 1421-1434.
+==External links==
+*[http://isotopes.gov/ National Isotope Development Center] Reference information on isotopes, and coordination and management of isotope production, availability, and distribution
+*[http://science.energy.gov/np/research/idpra/ Isotope Development & Production for Research and Applications (IDPRA)] U.S. Department of Energy program for isotope production and production research and development
+{{Chronology}}
+[[Category:Geochemistry]]
+[[Category:Geophysics]]
+[[Category:Geochronology]]

Serpentinite: Difference between revisions

Revision as of 02:23, 4 February 2014

Contents

Stable isotope geochemistry

Carbon

Nitrogen

Oxygen

Sulfur

Radiogenic isotope geochemistry

Lead-lead isotope geochemistry

Samarium-neodymium

Rhenium-osmium

Noble gas isotopes

Helium-3

Uranium-series isotopes

Protactinium/Thorium - ²³¹Pa / ²³⁰Th

Anthropogenic isotopes

Tritium/helium-3

See also

Notes

References

General

Stable isotopes

³He/⁴He

Re-Os

External links

Navigation menu

Serpentinite: Difference between revisions

Revision as of 02:23, 4 February 2014

Stable isotope geochemistry

Carbon

Nitrogen

Oxygen

Sulfur

Radiogenic isotope geochemistry

Lead-lead isotope geochemistry

Samarium-neodymium

Rhenium-osmium

Noble gas isotopes

Helium-3

Uranium-series isotopes

Protactinium/Thorium - 231Pa / 230Th

Anthropogenic isotopes

Tritium/helium-3

See also

Notes

References

General

Stable isotopes

3He/4He

Re-Os

External links

Navigation menu

Search

Protactinium/Thorium - ²³¹Pa / ²³⁰Th

³He/⁴He