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

摘要ATM-9528062约翰逊，托马斯C. 明尼苏达大学题目：维多利亚湖古湖沼学和古气候的理想研究：化石无脊椎动物组合作为气候和人为变化的代理 IDEAL倡议是一项多国努力，旨在研究东非大湖的湖沼学、现代和过去生态学以及古气候学。 原位沉积物剖面的原状恢复是古湖沼学研究成功的先决条件。该奖项支持深水冷冻取芯技术的发展，以应对热带湖泊带来的取样挑战，特别是深生产性湖泊，在这些湖泊中，沉积甲烷的回收后脱气可能会破坏未冻结岩心样品中的精细地层。 该装置将用于收集IDEAL 1996年实地活动期间访问过的维多利亚湖深水和亚沿岸地区新近沉积物的岩芯。 这些未受干扰的沉积物档案与约束良好的210 Pb年代学相匹配，将允许以最好的时间分辨率重建维多利亚湖的19和20世纪的历史。 对冻芯样品的研究将侧重于底栖和水生无脊椎动物群落物种组成的自然和人为变化，目前没有这方面的长期数据。 IDEAL收集的维多利亚湖长活塞岩芯记录中的无脊椎动物化石分析将产生关于该湖晚第四纪历史的有价值的独立信息，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.