Marine from interglacial

Racemization Dating of Shell from Interglacial Marine Terraces in San Diego County. Numerous fossiliferous terrace deposits occur along the coast of San Diego County. Only one reliable date has been reported for these terraces a uranium-disequilibrium age of 120,000 10,000 years on coral for a locality on Point Loma in San Diego (50). This and... 

Table V. Isoleucine Racemization Dates on Total Hydrolysates of Fossil Chione from Interglacial Marine Terraces in San Diego County (20)...

Muhs DR, Kermedy G, Rockwell TK (1994) Uranitun-series ages of marine terrace corals from the Pacific coast of North America and implications for last-interglacial sea level history. Qrrat Res 42 72-87 Nozaki Y, Nakanishi T (1985) Pa and °Th profiles in the open ocean water coltrrrm. Deep-Sea Res 32 1209-1220... 

Slowey NC, Henderson GM, Curry WB (1995) Direct dating of the last two sea-level highstands by measurements of U/Th in marine sediments from the Bahamas. EOS 76(46) 296-297 Slowey NC, Henderson GM, Curry WB (1996) Direct U-Th dating of marine sediments from the two most recent interglacial periods. Nature 383 242-244... 

Atkinson TC, Rowe PJ (1992) Applications of dating to denudation chronology and landscape evolution. In Uranium-series disequilibriiun Applications to Earth, Marine and Enviromnental Sciences, Ivanovich M, Harmon RS (eds) Oxford University Press, Oxford, p 669-703 Auler AS, Smart PL (2001) Late Quaternary paleoclimate in semiarid Northeastern Brazil from U-series dating of travertines and water table speleothems. Quat Res 55 159-167 Ayliffe LK, Marianelh PC, Moriarty KC, Wells RT, McCulloch MT, Mortimer GE, Hellstrom JC (1998) 500 ka precipitation record from southeastern Australia Evidence for interglacial relative aridity. Geology 26 147-150... 

Foraminifera are also important in marine geochemistry studies, and Li isotopes have been measured in the shells of a variety of these organisms. The first report of this kind (You and Chan 1996) gave data for four Pleistocene samples of H obliquiloculata 5 Li = +19.3 to +23.0 for two glacial period samples and +26.6 to +42.4 for two interglacial samples (data without blank correction). The species effect interpreted by Marriott et al. (2004) in corals has also been suggested for forams. In the study of Rosier et al. (2001), core-top (i.e., Holocene)P. obliquiloculata samples yielded isotopic compositions close to modem seawater (5 Li = +27.8 to +31.1), whereas samples of G. tumida from the same samples had values of up to +50.5. 

The geology of the Scripps cliff has been discussed previously by Carter (44) and by Karrow and Emerson (45). The cliff is composed of Pleistocene alluvial and colluvial sediments overlying the Ardath Shale and Scripps Formation which are Eocene in age. There is a marine fossili-ferous terrace deposit at the contact between the Pleistocene sediments and the Eocene conglomerate. Shells obtained from this terrace, 40-50 m north of the area where the cliff collapsed, have been analyzed by amino acid racemization and corresponded in age to a period of high sea level during the last interglacial, i.e., 120,000 years B.P. (46,47). This... 

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