https://scholars.lib.ntu.edu.tw/handle/123456789/624746
標題: | Late Pliocene and Early Pleistocene Variability of the REE and Nd Isotope Composition of Caribbean Bottom Water: A Record of Changes in Sea Level and Terrestrial Inputs During the Final Stages of Central American Seaway Closure | 作者: | Osborne A.H Hathorne E.C Böning P Groeneveld J Pahnke K Frank M. JEROEN GROENEVELD |
關鍵字: | AMOC; Central American seaway; neodymium; Pleistocene; Pliocene; REE | 公開日期: | 2019 | 卷: | 34 | 期: | 12 | 起(迄)頁: | 2067-2079 | 來源出版物: | Paleoceanography and Paleoclimatology | 摘要: | The isotopic composition of neodymium dissolved in seawater consists of a distal, advected component that reflects water mass mixing and circulation but near land can also contain a large local component originating from terrestrial sources such as aeolian or fluvial material. In order to use Nd isotopes to reconstruct paleocirculation, it is important to detect any local influences on the seawater signal recorded in deep sea sediments. Here we present rare earth element (REE) and Nd isotope (εNd) records from the deep Caribbean for two well-studied time intervals in the Late Pliocene and Early Pleistocene. We measured trace element and REE compositions of weakly cleaned foraminifera to investigate if the Nd isotope signal from the same samples contained a local component. We find distinct changes in REE compositions across glaciations that are consistent with increases in the supply of local terrestrial material to the basin likely the results of glacially driven changes in sea level. Despite these larger terrestrial inputs, the Ce anomaly (Ce/Ce*) became more pronounced during glaciations indicating a better deep Caribbean ventilation. Short negative Nd isotope excursions occurred during three of the four studied glaciations, independently of any other proxy indicators for changes in ocean circulation suggesting that inputs from local terrigenous sources of Nd controlled the signal. We recommend that studies that aim to use εNd as a paleocirculation tracer routinely measure REE compositions of the authigenic phase to identify any possible terrestrial influence on the signal. ©2019. The Authors. |
URI: | https://www.scopus.com/inward/record.uri?eid=2-s2.0-85076720673&doi=10.1029%2f2019PA003654&partnerID=40&md5=66c49d9450afea740419d5e009900d91 https://scholars.lib.ntu.edu.tw/handle/123456789/624746 |
ISSN: | 25724517 | DOI: | 10.1029/2019PA003654 | SDG/關鍵字: | bottom water; deep-sea sediment; foraminifera; glaciation; isotopic composition; neodymium isotope; Pleistocene; Pliocene-Pleistocene boundary; rare earth element; sea level change; seawater; trace element; Atlantic Ocean; Caribbean Sea; Central Department; Foraminifera |
顯示於: | 海洋研究所 |
在 IR 系統中的文件,除了特別指名其著作權條款之外,均受到著作權保護,並且保留所有的權利。