青藏高原钙华沉积属性特征及其地质意义

 钙华分为大气成因钙华和热成因钙华两类，不仅具有景观价值，而且具有重要的的科研价值。青藏高原广泛发育热成因钙华，主要形成于泉水和湖泊环境中。青藏高原钙华的形成主要与高原内部的热水活动有关，而热水活动则受控于印度大陆碰撞俯冲所引起的伸展作用和区域大断裂的走滑拉分作用。钙华不仅记录高原的古气候学信息，同时也是区内大多数盐湖矿床成矿过程记录者，但是已有的研究尚不足以充分解读这些信息。形成热成因钙华的CO₂一般来自地热过程或地壳深部，其成因机制因时因地而异，远比大气成因钙华更加复杂，并不是所有热成因钙华都记录有古气候信息，因此，只有在充分明确热成因钙华成因机制的基础上，方可重建其古气候和盐湖矿床学信息。

Sedimentary property and the geological significance of travertines in Qinghai-Tibetan Plateau

The Travertines may be divided into two groups, the meteogene travertines and the thermogene travertines, with not only a landscape value, but also a scientific research value. We have a wide distribution of the travertines in the Qinghai-Tibetan Plateau, mainly in springs and in the lacustrine environment. The formation of travertines is related with the hydrothermal activity in the interior of the Qinghai-Tibetan Plateau, controlled by the crust extensional activity caused by the subduction of the Indian continent and the strike-slip pull-apart process of regional faults. The travertines provide records of the paleoclimatic information and the ore-forming processes of the saline lake deposits. However, a good interpretation of the information of travetines remains a research issue. Generally, the carrier CO₂ of the thermogene travertines originates from the thermal processes or even from the processes below the Earth' crust. The genetic mechanism of the thermogene travertines is related with the time and the location and is more complex than that of the meteogene travertines. Not all travertines keep records of the paleoclimatic information. So, it is on the basis of understanding the genetic mechanism of the travertines that one may rebuild the information of the paleoclimate and the lake deposits.