IDEAL Studies on the Paleolimonology and Paleoclimate of Lake Victoria: Fossil Invertebrate Assemblages as Proxies for Climatic and Anthropogenic Change

题目：维多利亚湖古湖沼学和古气候的IDEAL研究：化石无脊椎动物组合作为气候和人为变化的代用物。IDEAL计划是一个研究东非大型湖泊湖沼学、现代和过去生态学和古气候学的多国努力。原状地恢复原位沉积物剖面是成功进行古湖泊学研究的先决条件。该奖项支持深水冷冻取心技术的发展，以应对热带湖泊的采样挑战，特别是深海生产湖泊，在这些湖泊中，沉积物甲烷的回收后脱气可能会破坏未冷冻岩心样品中的精细地层。该装置将用于收集在IDEAL 1996野外活动期间访问过的维多利亚湖的深海和浅海地区最近沉积物的岩心。这些未受干扰的沉积档案配备了严格约束的210pb年表，可以以最好的时间分辨率重建维多利亚湖19世纪和20世纪的历史。对冷冻岩心样本的研究将集中于底栖和浮游无脊椎动物群落物种组成的自然和人为变化，目前尚无长期数据。利用IDEAL收集的维多利亚湖长活塞岩心记录对无脊椎动物化石进行分析，将为该湖的晚第四纪历史提供有价值的独立信息，并有助于限制基于沉积学和稳定同位素地球化学的古气候解释。

Abstract ATM-9528062 Johnson, Thomas C. University of Minnesota Title: IDEAL Studies on the Paleolimnology and Paleoclimate of Lake Victoria: fossil invertebrate assemblages as proxies for climatic and anthropogenic change The IDEAL initiative is a multinational effort to study the limnology, modern and past ecology, and paleoclimatology of the large lakes of East Africa. Undisturbed recovery of an in situ sediment profile is a prerequisite for successful paleolimnological study. This award supports the development of deep-water freeze- coring technology to meet the sampling challenges presented by tropical lakes, in particular deep productive lakes where fine stratigraphy can become disrupted in unfrozen core samples by post- recovery degassing of sedimentary methane. The device will be used to collect cores of recent sediments in profundal and sublittoral areas of Lake Victoria, visited during the IDEAL 1996 field campaign. Fitted with a well-constrained 210Pb-chronology, these undisturbed sedimentary archives will permit reconstruction of Lake Victoria's 19th- and 20th century history at the finest temporal resolution possible. Study of the freeze-core samples will focus on natural and anthropogenic changes in species composition of benthic and planktonic invertebrate communities, for which currently no long-term data are available. Analysis of fossil invertebrates in long piston-core records from Lake Victoria collected by IDEAL will produce valuable independent information on the lake's late Quaternary history and help constrain paleoclimatic interpretations based on sedimentology and stable-isotope geochemistry.