石笋碳酸盐假性热释光:古环境的新指标  

Spurious Thermoluminescence from Stalagmite:A New Paleoenvironmental Proxy

作　　者：廖金[1] 胡超涌[1] 李成展[1] 张格格[1] 高金荣[1] 黄俊华[2] 

机构地区：[1]中国地质大学生物地质与环境地质国家重点实验室,湖北武汉430074 [2]中国地质大学地质过程与矿产资源国家重点实验室,湖北武汉430074

出　　处：《地球科学（中国地质大学学报）》2014年第4期443-450,共8页Earth Science-Journal of China University of Geosciences

基　　金：国家重点基础研究发展计划"973"项目(No.2011CB808800);国家自然科学基金项目(Nos.41072262;41030103;41130207)

摘　　要：海相碳酸盐热释光灵敏地响应冰期-间冰期地球气候变化,是一个新的古海洋代用指标,但是否适用于陆地沉积物,尚缺少研究.通过测定湖北清江穿心洞石笋(CX-1)碳酸盐热释光和氧同位素组成,探讨石笋热释光的发光机制,开发热释光作为陆地古环境的替代指标,发现空气环境中检测的石笋碳酸盐热释光主要是发光有机质氧化产生的化学发光,为假性热释光.石笋中发光有机质来源于土壤中有机物的降解,其含量与太阳辐射调控的土壤温度有关;热释光曲线与其对应的氧同位素曲线变化趋势相似.因而,石笋碳酸盐假性热释光是反映过去环境变化的一个新指标.Thermoluminescence from marine carbonate is found to be sensitively responding to the earth climate change ofglacial-interglacial stage, which implies a novel proxy for paleoceanography. Yet it is to be confirmed by studies as to whether it is suitable for the terrestrial sediments. In this study, thermoluminescence and oxygen isotopic composition have been carried out on stalagmite CX-1 from Chuanxin cave, Qingjiang valley, Hubei Province, China, to determine the physical links between the climate and thermoluminescence intensity. It is found that thermoluminescenee glow in air environment is mainly contribu- ted by chemiluminescence derived from oxidation of the organic matter from stalagmite carbonates. Therefore, thermolumines cence is closely related to organic matter content of stalagmite derived from the degradation of organic matter in soil and the degradation rate is related to soil temperature controlled by the insolation. The variations of TL （total luminescence intensity） and show similar features which can reasonably be associated with climate change. Therefore, stalagmite thermolumines cence can act as a new proxy for terrestrial paleoenvironment.

关 键 词：石笋 热释光 发光有机质 氧同位素 太阳辐射 气候变化 沉积物 

分 类 号：P532[天文地球—古生物学与地层学]