摘要
定量恢复高大地形的古高程是地质学家一直以来追求的目标,将自生矿物中氢氧同位素用作古高程计的历史不长,这种方法还有很大的应用潜力,可用到比新生代更古老的时期。根据与气团上升和水汽凝结的热动力学性质相关的瑞利平衡分馏原理,建立了这种古高程计的热动力模型,这个模型应用简便,适用于纬度小于35°的地区。区域性经验关系的方法误差较小,但也有计算繁琐、适用区域有限的不足。以上两种方法的计算精度均有待于提高。研究中使用方解石作为样品最普遍,在方解石、高岭石、蒙脱石和针铁石等矿物中,究竟使用哪种推算古高程产生的误差更小,还需进一步研究。
Quantitative Estimation of paleoaltitude is the objective that geologistes have always sought. The research history of paleohypsometry which uses oxygen and hydrogen isotopic composition of authigenic mineral is overviewed. This method has much more potential to be applied to older periods than Cenozonic. According to equilibrium fractionation during Rayleigh distillation linked to the thermodynamics of atmospheric ascent and water vapor condensation, thermodynamics model has been established. The model is a kind of simple and convenient calcula- tional method, which can be used for relatively low latitude （≤35 °） area. Regional experiencial relationship method is not simple and has limited application region, but the error of this method is relatively little. Both of the two methods mentioned above need precision enhancement. Calcite, smectite, goethite and kaolinite has been used as mineral proxies in the past researches. Calcite has been used as mineral proxy most frequently. However, it is not certain which mineral can produce the least error of predicted paleoaltitude.
出处
《地球科学进展》
CAS
CSCD
北大核心
2007年第9期960-968,共9页
Advances in Earth Science
基金
国家重点基础研究发展计划项目"白垩纪地球表层系统重大地质事件与温室气候变化"(编号:2006CB701400)资助
关键词
古高程计
氢同位素
氧同位素
Paleohypsometry
Hydrogen isotope
Oxygen isotope.
