第25卷第3期 2011年6月
现代地质 GEOSCIFNCE
晚自垩世介形类壳体稳定同位素尝试
一以松科1井南孔样品为例万晓樵，王焊，司伟民
（中国地质大学地球科学与资源学院，北京100083）
VolL 25 Na.3 Jen 2011
摘要：白纪中期的全球温室气候引发的迅速同位索波动具有全球的同期性，可作为地质历史中气候变化的替代指标。在诸多陆相沉积体系中，潮泊沉积记录保存了相对连续的古气候信息，是恢复陆相高分辨率古环境和古气候演变的有利依据。松辽盆地为大型白垩纪沉积盆地，对其研究可以提供大陆内部的古气候信息。对白垩纪稳定同位素的研究常采用全岩样品的分析手段。然面，陆相湖盆同位素组成复杂，全岩样品难免受多种因素的干扰。尝试利用松科1井连续的介形类光体为材料获取原生碳酸盐，为稳定同位素的高精度古气候恢复提供有效指标。尝试的首要工作是仔细开展采样分析、化石壳体挑选和受成岩影响样品的排除的每一步骤。在实体显微镜下精心利离出纯净的化石壳体，然后对纯净壳体、含充填物壳体和围岩3种样品进行抽样对比，印证实验所用的介形类化石样品的可靠性，明确化石材料受成岩作用影响微弱。测试结果显示，松科1井介形类壳体碳氧同位素保存了长期连续的气候历史记录，深人研究能
为中国基至东亚白垩纪同期陆相研究提供稳定同位素标准序列。关键词：松科1井；介形类壳体；稳定同位素；白垩纪
中图分类号：P532；P597.2
文献标患码：A
文章编号：10008527(2011)03040108
AttempttotheLateCretaceousOstracodCarapaceStableIsotopeMeasurement
-CaseStudyontheSK1DrillCores
WAN Xiao-qiao,WANG Zhuo,SI Wei-min
(School of Earth Sciences and Resouroes, China Uriernsity of Geosciences, Bejing100083, China)
Abstract: Rapid isotopic variation affected by Late Cretaceous green-house is of globe implication, and can be used as proxy of climate change in the Earth's history. In continental sedimentary system, relatively continuous paleoclimate signal is recorded in lacustrine sediments. It is an ideal record to recover high-resolution paleoen-vironment and paleoclimate changes. The Songliao lacustrine basin is a large Cretaceous sedimentary basin. A coring program, the"Cretaceous Continental Scientific Drlling Programme of China (SK1)", was initiated to the study of Cretaceous climate change. Under this programme, an ambitious effort is now underway to develop an oxygen and carbon isotopic record for a nearly complete Cretaceous lacustrine section in the Songliao basin to reveal paleoclimate change in inner-continental area. Bulk samples were normally used to the Cretaceous stable isotope analysis. The compositions of terrestrial stable isotopes are complicated and can be affected by various factors, The present authors attempt to select ostracod carapaces as analytical materials, As a result, ostracods were handpicked from samples collected from drill cores. After removing them from rock matrix, the ostracod carapaces, matrix and flling materials were then visually examined for possible secondary calcite, such as spar-ry calcite, respectively. The result indicates that ostracod carapaces are avoided from secondary calcite and /or diagenesis, They are reliable materials for the isotopic study. Specifically, we demonstrate that the carbon and
收稿日期：2011-03-14；改回日期：2011-04-26；责任编辑：楼亚儿。
基金项目：国家自然科学基金项目（40872016）；中国地质调查局科研项目（1212011120145）；国家重点基础研究发展计划"973"
项月(2006CB701400)。
作者简介：万晓植，男，教授，博士生导师，1950年出生，地层古生物学专业，主要从事微体古生物学、古海洋与古期泊学的
教学与研究。Email；wanxq@cugh.educn。