碳酸盐热释光是指示过去气候和海洋环境的一个潜在指标,但其发光机制及其影响的因素尚不十分清楚。分别研究了海相碳酸盐、黄铁矿和普通煤的热释光特性,并通过加入法研究黄铁矿和煤(有机质)对碳酸盐热释光的影响。研究发现黄铁矿和煤的掺入对热释光谱线特征及其峰位没有影响,但是明显影响了热释光的强度。黄铁矿和煤的加入量愈多,热释光强度越小,影响的大小分别为每1%黄铁矿热释光强度减少4.034%和每1%煤热释光强度减少6.197%。黄铁矿和煤的加入并未影响碳酸盐的晶格特征;然而暗色矿物的加入,吸收了部分碳酸盐矿物释放出的光,使检测到的热释光的强度减弱。因而,对于黄铁矿或有机物质量分数高于1%的样品的热释光测定,建议对样品进行预处理。对去除硫化物和有机质后的海相碳酸盐热释光的分析数据的地质意义进行了探讨,认为热释光响应了海洋环境和生物的变化。
Natural thermoluminescence(TL) of carbonate has been proposed to be a new proxy for climate and marine environment,but the mechanism remains unclear.In this paper,the thermoluminescence of carbonate was measured in presence of pyrite and coal to investigate the influence of co-exist minerals on the charac teristics of TL.Data analysis shows that both pyrite and coal do not change the crystal lattice of carbonate but play a role of TL-killer,with TL decreasing o f 4.043% and 6.197% respectively with one percent increased of pyrite and coal i n sample.This implies that dark minerals such as pyrite and coal absorb the lig ht released from the carbonate,weakening the light that reaches the detector of TL apparatus.A pretreatment is required to remove high content of sulfite and organic matter(more than 1%) before the TL of carbonate measuring.A negative c orrelation between TL and Mo in the carbonates from Shangsi section in Guangyuan,Sichuan Province,confirms the TL as a proxy for paleoceanography reconstructi on.