The sulfur isotopic composition of dissolved sulfate in seawater has varied through time. Distinct variations and relatively high rates of change characterize certain time intervals. This allows for dating and correlation of sediments using sulfur isotopes. The variation in sulfur isotopes and the potential stratigraphic resolution of this isotope system is discussed and graphically displayed.

a total of 40 samples from carbonates and 8 samples from silicate rocks were analyzed from the sangan iron skarn deposit to examine behavior of the oxygen and carbon isotopes. the higher values of ?18o are from metamorphic calcite and dolomite and lower ones are from granitic rocks. although the ?18o and ?13c values of calcite and dolomite in marble yield the highest values in the sangan deposi...

a total of 40 samples from carbonates and 8 samples from silicate rocks were analyzed from the sangan iron skarn deposit to examine behavior of the oxygen and carbon isotopes. the higher values of ?18o are from metamorphic calcite and dolomite and lower ones are from granitic rocks. although the ?18o and ?13c values of calcite and dolomite in marble yield the highest values in the sangan deposi...

Freshwater wetlands are a major source of the greenhouse gas methane but at the same time can function as carbon sink. Their response to global warming and environmental pollution is one of the largest unknowns in the upcoming decades to centuries. In this review, we highlight the role of sulfate-reducing microorganisms (SRM) in the intertwined element cycles of wetlands. Although regarded prim...

Studies in freshwater ecosystems are seeking to improve understanding of carbon flow in food webs and stable isotopes have been influential in this work. However, variation in isotopic values of basal production sources could either be an asset or a hindrance depending on study objectives. We assessed the potential for basin geology and local limnological conditions to predict stable carbon and...

The present work is associated with dietary reconstruction using δ13C and δ15N analysis of humans from the site of Sidon, a Middle Bronze Age (2000BC-1550BC) settlement in Lebanon. The main objective of this research is to focus on collagen extraction of 23 individual bones, discovered in a cemetery, College site (season 2001-2002) in ancient Sidon. Collagen could only be extracted from the 8 a...

There are three principal isotopes of carbon which occur naturally C, C (both stable) and C (unstable or radioactive). These isotopes are present in the following amounts C 98.89%, C 1.11%, and C 0.00000000010%. Thus, one carbon-14 atom exists in nature for every 1,000,000,000,000 or (1 in a trillion) carbon-12 atoms in living material. The radiocarbon method is based on the rate of decay of th...

Stable isotopes of carbon are commonly used to characterize dietary preferences in animals. Because turnover rates of carbon isotopes are related to metabolic rate, we wanted to determine the rates at which carbon isotopes are exchanged in tissues of two species of nectar-feeding bats (Leptonycteris curasoae and Glossophaga soricina), both of which have relatively high mass-specific metabolic r...