Deep Water Circulation During the Middle to Late Miocene Carbonate Crash

这项研究将利用中新世铁锰氧化物涂层和鱼牙中的Nd同位素组成变化来确定中新世和晚中新世深海环流的变化，这些变化可能是由中美洲海道基床深度的构造变化引起的。PI表明，根据以往的研究，这些沉积储存库中记录的ND同位素是不同古水团(NADW、AABW、AAIW)的指示物。由于巴拿马地峡的抬升和各地相继发生的一系列碳酸盐溶解事件，这一时间间隔是有意义的。这些碳酸盐崩塌间隔期归因于腐蚀性太平洋/南部组分水域的优势，以及介于非腐蚀性北大西洋深水的保存间隔期。这项研究将使用ND同位素比率来追踪一组岩芯在这一关键时间间隔内对北大西洋和太平洋/南大洋的贡献。

MartinAbstractThis study will utilize Nd isotopic compositional changes in Miocene Fe-Mn oxide coatings and fish teeth to determine Middle and Late Miocene deep ocean circulation changes potentially caused by tectonic changes in sill depth at the Central American seaway. The PI suggests that based on prior investigations Nd isotopes recorded in such sedimentary repositories are indicators of different paleo water masses (NADW, AABW, AAIW). This time interval is of interest due to the uplift of the Panama Isthmus and a series of carbonate dissolution events seen successively in various places. These carbonate crash intervals have been attributed to dominance of corrosive Pacific/Southern Component Waters and the intervening preservation intervals to non-corrosive North Atlantic Deep Water. The study will use Nd isotope ratios to trace North Atlantic vs Pacific/Southern Ocean contributions in a set of cores over this critical time interval.