Stable isotope geochemistry is a branch of geology that investigates the age of natural materials, their origin and the processes they have undergone since formation [1]. Stable isotope analysis is also used in biogeochemical studies to monitor element cycling in ecosystems [2] and to identify geographical/regional differences for food provenance and archaeology. Of the elements of interest in ...

In the aftermath of the anthrax letters of 2001, researchers have been exploring various analytical signatures for the purpose of characterizing the production environment of microorganisms. One such signature is stable isotope ratios, which in heterotrophs, are a function of nutrient and water sources. Here we discuss the use of stable isotope ratios in microbial forensics, using as a database...

Natural waters’ carbon isotopes content is an important parameter in many environmental studies, as it hints to the water’s origin and history. Atmospheric water contain a certain amount of dissolved carbon dioxide, in the form of oxygen, hydrogen and carbon through their various species (CO2, HCO3 & CO3), which are commonly used for isotopic characterization of natural water [1]. Carbon posses...

[1] Eocene Thermal Maximum 2 (ETM2; ∼53.7 Ma) occurred approximately 2 Myr after the Paleocene‐ Eocene Thermal Maximum (∼55.5 Ma) and was characterized by a deep‐sea warming of >3°C, associated with massive release of carbon into the ocean‐atmosphere system. We performed single‐specimen stable isotope analyses of the planktic foraminiferal genera Acarinina (surface dweller) and Subbotina (therm...

Stable isotope analysis (SIA; carbon, hydrogen, nitrogen, sulfur, and oxygen) of human tissues offers a means for assessing diet among living humans. Stable isotope ratios of broad categories of food and drink food vary systematically, and stable isotope ratios in consumer tissues represent a composite of the isotopic ratios of food and drink consumed during an individual's life. Isotopic evide...

carbon and sulfur isotopic data are helpful in understanding environmental conditions under which soils are formed. soils from 18 sampling sites along a climotoposequence from higher laleh zar mountains (4,351 m above sea level with xeric-mesic soil moisture-temperature regimes) to shahdad depression (250 m above sea level with arid-hyperthermic soil moisture-temperature regimes) in kerman prov...

Radiocarbon analyses and stable isotope measurements are presented foro recent cores of banded corals from the Florida Straits. These values provide a record of variations in the ratio of carbon-14 to carbon-12 in the dissolved inorganic carbon in the surface waters of the Gulf Stream from A.D. 1642 to 1800. An increase in the carbon-14/carbon-12 ratio of 7 per mil for coral growth during the e...

[1] Paired benthic foraminiferal trace metal and stable isotope records have been constructed from equatorial Pacific Ocean Drilling Program Site 1218. The records include the two largest abrupt (<1 Myr) increases in the Cenozoic benthic oxygen isotope record: Oi-1 in the earliest Oligocene ( 34 Ma) and Mi-1 in the earliest Miocene ( 23 Ma). The paired Mg/Ca and oxygen isotope records are used ...

The large size of canines in saber-toothed cats suggests implicitly that they took longer to grow than ‘‘normal’’ canines. If this were the case, then juveniles may not have been able to use them for hunting. Consequently, juvenile Smilodon fatalis, for example, may have had to remain in a social group and be fed by adults longer than is the case for modern large cats. Analysis of the stable ca...

Kinetic isotope effects (KIEs) during the inorganic hydration of carbon dioxide (CO2) in aqueous solution cause reduced stable carbon and oxygen isotope ratios (C=C and O=O) in the reaction product carbonic acid (H2CO3) or bicarbonate ion (HCO 3 ), relative to CO2. While such KIEs are of importance in various physicochemical, geochemical, and biological systems, very few experimental and theore...