Paleochemistry of V, Mo and Other Oxyanions as Recorded in Ferromanganese Deposits

小行星9416602 这项研究将利用一种新的分析技术，激光烧蚀固体，与电感耦合等离子体质谱仪（LA-ICP-MS）集成，以确定高分辨率的配置文件 铁锰矿床水合氧化铁相中的一组微量元素。 目标样品从缓慢积累的含氢结壳到快速积累的热液结壳和浅水结核，目的是研究海水中以含氧阴离子形式存在的V、Mo和其他微量/痕量元素（包括P、U、As、Se、Cr等）的古地球化学。虽然这些元素在地壳中的浓度可能是复杂的各种因素，据推测，各种含氧阴离子之间的比例清除的氧化铁相可以与它们的古海水中的比例，并可能在沉积时的环境条件。 其他元素的测定，包括稀土元素和232钍，将有助于解释地壳化学。 将在快速形成的样品的较年轻部分中测定230 Th，以完善年代学。ICP-MS的高灵敏度，加上激光烧蚀的采样分辨率（约50微米），有助于实现大幅提高铁锰结壳的利用率的长期目标， 古海洋学研究

9416602 COLLIER This study will make use of a new analytical technique, Laser Ablation of solids, integrated with an Inductively-Coupled Plasma Mass Spectrometer (LA-ICP-MS) to determine high-resolution profiles of a group of trace elements in the hydrous iron oxide phases of ferromanganese deposits. Target samples range from slowly accumulating hydrogenous crusts to rapidly accumulating hydrothermal crusts and shallow-water nodules with the goal to study the paleochemistry of V, Mo and other minor/trace elements present in seawater as oxyanions (including P, U, As, Se, Cr, and others). Although the concentration of these elements in the crust may be complicated by a variety of factors it is hypothesized that the ratios between various oxyanions scavenged by the iron oxide phases can be related to their paleo-ratios in seawater and possibly to environmental conditions at the time of deposition. The determination of other elements, including REEs and 232Th, will aid in the interpretation of crust chemistry. 230Th will be determined in the younger portions of rapidly-formed samples in order to refine chronologies. The high sensitivity of the ICP-MS, coupled with the sampling resolution of laser ablation (approximately 50 um) contribute to the long-term goal of significantly improving the utility of ferromanganese crusts for paleoceanographic studies.