Chironomid counts for the Holocene record of Crooked Pond (US)@en

This dataset provides chironomid counts for the Holocene sediment sequence retrieved from Crooked Pond (United States). Sediment cores were retrieved from the lake using a 1-m long handheld piston corer deployed from a floating coring platform during field work in May 2009. Volumetric samples were obtained from splits of the core and processed in the laboratory (University of New Brunswick, Canada) using standard protocols. Chironomid counts are presented against both depth (cm) and age (cal yr. BP). A total of 58 downcore 1-cm-thick samples were analysed, ranging between 477.5cm depth (9056 cal yr BP) and 0.5cm depth (the present). The chironomid record provides information about changes in the chironomid fauna as well as in within-lake conditions. The dataset was produced to inform on the exact age and duration of a major lake-level lowstand during the mid-Holocene. This lowstand was compared to palynological transitions determined on pollen samples from an older core sequence derived from the same coring location.本数据集收录了从美国克罗克塘（Crooked Pond）获取的全新世沉积物序列的摇蚊（Chironomid）计数数据。2009年5月的野外工作中，研究人员借助浮动取芯平台，采用1米长手持式活塞取芯器从该湖泊采集沉积物岩芯。从岩芯分样中获取体积定量样品，并于加拿大新不伦瑞克大学实验室按照标准实验规程完成处理。摇蚊计数结果同时以深度（单位：cm）和年代（校正后距今年数，cal yr BP）两种维度展示。本次研究共分析了58个自上而下、厚度为1厘米的岩芯样品，采样深度跨度为0.5厘米（对应现代）至477.5厘米（对应9056个校正后距今年）。本摇蚊记录可揭示摇蚊群落组成的演变过程以及湖泊内部环境的变化情况。本数据集的构建旨在明确全新世中期一次显著湖泊水位下降事件的精确年代与持续时长。研究者将该水位下降事件与同一取芯位点获取的旧岩芯序列的孢粉样品所确定的孢粉演替事件进行了对比分析。