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| 陇西民和黄土CaCO3和有机碳总量的含量变化及其气候指标的局限性 | |
| 引用本文： | 谢远云,李长安 周 嘉 殷鸿福.陇西民和黄土CaCO3和有机碳总量的含量变化及其气候指标的局限性[J].中国地质,2003,30(1):99-104. |
| 作者姓名： | 谢远云 李长安 周 嘉 殷鸿福 |
| 作者单位： | 1. 中国地质大学地球科学学院,武汉,430074;哈尔滨师范大学地理系,150080 2. 中国地质大学地球科学学院,武汉,430074 3. 中国科学院长春地理研究所,长春,130040 |
| 基金项目： | 国家自然科学基金项目(49972057)和国土资源部甘肃兰州红古城、新寺乡1:5万区调项目共同资助. |
| 摘 要： | 民和黄土地处黄土高原与青藏高原东北缘的交接部位，对气候反应较敏感，对该黄土1.87-0.70Ma BP段进行了CaCO3和有机碳总量（TOC）的采样分析。民和黄土CoCO3含量在5.89%-18.63%之间变化，平均11.41%；有机碳含量较低，在0.007%-0.452%之间，平均0.088%。民和黄土中的CaCO3含量明显高于兰州、洛川和西安等地，而有机碳含量则远低于上述地区。黄土中CaCO3和有机碳含量变化反映了该区1.87Ma BP以来气候变干冷的趋向。分别受复杂的CaCO3来源与类型、困难的采样、地区上的差异对比等和有机碳保存条件、沉积速率以及“埋藏效应”的影响，黄土中的CaCO3和有机碳的波动变化作为气候变化的替代性指标存在一定的局限性。文章最后指出，在实际应用中，黄土（特别是黄土高原西北部）中CaCO3和有机碳气候指标应结合其他环境指标共同使用，才能从中提取正确的古气候信息。 |
| 关 键 词： | 陇西 民和黄土 青藏高原 CaCO3 有机碳 局限性 碳酸钙 古气候 |
| 文章编号： | 1000-3657(2003)01-0099-06 |
Variations of the CaCO3 and total organic carbon contents in the Minhe loess and their limitations as climatic proxies |
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| XIE Yuan-yun,LI Chang-an,ZHOU Ji,YING Hong-fu.Variations of the CaCO3 and total organic carbon contents in the Minhe loess and their limitations as climatic proxies[J].Chinese Geology,2003,30(1):99-104. | |
| Authors: | XIE Yuan-yun LI Chang-an ZHOU Ji YING Hong-fu |
| Institution: | XIE Yuan - yun 1,2,LI Chang - an 1,ZHOU Jia 3,YING Hong - fu 1 |
| Abstract: | Situated in the intersection area of the Loess Plateau and the northeastern margin of the Qinghai-Tibet Plateau,the Minhe loess is sensitive to the climate.Analysis of the CaCO 3 and total organic carbon(TOC)contents in the187-0.70Ma interval of the Minhe loess shows that the content of CaCO 3 in the Minhe loess ranges from5.89to18.63%,averaging11.41%and that the content of TOC is lower,ranging from0.007%to0.452%with an average of0.88%.The CaCO 3 content in the Minhe loess is notably higher than those in Lanzhou,Luochuan and Xi ' an,but the TOC content is much lower than those in the aforesaid areas.The variations of the CaCO 3 and TOC contents in the Minhe loess indicate that the climate in the area had a trend of becoming cold and dry since1.87Ma BP.The variations of CaCO 3 and TOC in loess as substitute proxies of climatic changes have certain limitations due to influences of complex sources and types of CaCO 3 ,difficult sampling and differential comparisons among areas,as well as preservation conditions,sedimentation rates and"burial-effect"of TOC.At last,the paper points out that in actual applications the climatic proxies of CaCO 3 and TOC in loess,especially loess in the northwestern part of the Loess Plateau,must be used together with other climatic proxies,and then correct paleoclimatic information can be extracted. |
| Keywords: | Minhe loess Qinghai-Tibet Plateau CaCO 3 TOC limitation |
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