Paleolimnology of mid-elevation lakes in the Kenya Rift Valley
Paleolimnology of mid-elevation lakes in the Kenya Rift Valley
复制标题
肯尼亚大裂谷中海拔湖泊的古湖泊学
作者：
J. Richardson;R. Dussinger
肯尼亚高地的三个小湖已经进行了50多年的间歇性古环境调查。在这份报告中，地层，核心为基础的历史奈瓦沙湖（elev。1890米）向后延伸到20 000 B. P.，并与附近的纳库鲁湖和埃尔门泰塔湖不太完整的30 000年的核心地层。古湖泊重建，主要是基于地球化学参数和第一介形虫地层从热带非洲。所有三个湖泊的分析都集中在过去大约4500年的低水位和波动水位的历史上，之前是一个主要的全新世高水位（约1500年）。10 000-6 000 B.P.）在晚更新世（13000 - 30000 B. P.），湖泊大多非常低，尽管在这段时间的早期可能出现了适度的升高。介形虫的记录，包括至少15种，是相对连续的纳库鲁核心，但仅限于从其他湖泊的核心急剧划分的区域。
Three small lakes of the Kenya Highlands have been subject to intermittent paleoenvironmental investigation for more than 50 years. In this report, the stratigraphic, core-based history of Lake Naivasha (elev. 1 890 m) is extended backward to 20 000 B.P. and is related to less complete 30 000-year core stratigraphies from nearby lakes Nakuru and Elmenteita. The paleolimnological reconstructions, primarily diatom-based, include geochemical parameters and the first ostracode stratigraphies from tropical Africa. The analyses from all three lakes converge on a history of low and fluctuating water levels over approximately the past 4 500 years, preceded by a major Holocene high stand (ca. 10 000-6 000 B.P.) and a brief earlier rise centered on 12 500 B.P. The lakes were mostly very low during the late Pleistocene (13 000–30 000 B.P.), though modestly elevated levels may have occurred early in this time period. The ostracode record, comprising at least 15 species, was relatively continuous in the Nakuru core but was restricted to sharply demarcated regions in cores from the other lakes.