Continental isotopic indicators of climate studied



Our knowledge of past climatic variations has greatly expanded during the last 30 years by the addition of new analytical methods that evaluate the stable isotopic composition of planktonic and benthic foraminifera. As this isotopic record of climate change is restricted to marine sediments, the information obtained from these studies has been naturally biased toward variations in oceanic climate. There are, however, numerous potential continental isotopic indicators of climate (CIIC), which have not been widely utilized either to evaluate past or to predict future climate change. Examples of such indicators are the hydrogen and oxygen isotopic ratios of cellulose, ice cores, and clays; the oxygen and carbon isotopic compositions of carbonates from cements, altered whole rock, calcretes, cave deposits, land-dwelling organisms, and authigenic lake sediments; and the oxygen isotopic composition of phosphorites.