Quantitative estimates of time-averaging in terebratulid brachiopod shell accumulations from a modern tropical shelf

作者：Monica Carroll, Michał Kowalewski, Marcello Guimarães Simões, Glenn A. Goodfriend · 发表于：Paleobiology · 年份：2003 · DOI：10.1666/0094-8373(2003)029<0381:qeotit>2.0.co;2 · 被引用次数：124 · 研究领域：Geology and Paleoclimatology Research、Isotope Analysis in Ecology、Paleontology and Stratigraphy of Fossils

Abstract Quantitative estimates of time-averaging in marine shell accumulations available to date are limited primarily to aragonitic mollusk shells. We assessed time-averaging in Holocene assemblages of calcitic brachiopod shells by direct dating of individual specimens of the terebratulid brachiopod Bouchardia rosea. The data were collected from exceptional (brachiopod-rich) shell assemblages, occurring surficially on a tropical mixed carbonate-siliciclastic shelf (the Southeast Brazilian Bight, SW Atlantic), a setting that provides a good climatic and environmental analog for many Paleozoic brachiopod shell beds of North America and Europe. A total of 82 individual brachiopod shells, collected from four shallow (5–25 m) nearshore (<2.5 km from the shore) localities, were dated by using amino acid racemization (D-alloisoleucine/L-isoleucine value) calibrated with five AMS-radiocarbon dates (r2 = 0.933). This is the first study to demonstrate that amino acid racemization methods can provide accurate and ...