摘要：

应用自然伽玛测井（GR）曲线反演古气候和古环境的方法在国际上逐渐得到重视并取得了进展，柴达木盆地第四纪应用其反演2.85Ma B.P来的古气候变化也取得了成功。本文以柴达木盆地侏罗系冷科1井和雨33井自然伽玛曲线并结合孢粉等地质资料进行了古气候与沉积环境分析，证明GR曲线是有价值的古气候研究参数。GR值的大小及古气候的干湿变化和沉积水体的深浅变化均有内在联系，GR曲线振幅与频率的变化快慢反映出沉积环境动荡与稳定的相对特征，据此对两口井的沉积环境演变作了具体分析。结合古气候与沉积环境综合分析，GR曲线的异常波动还具有特殊的指相意义。GR值增大-古气候加湿-沉积水体加深的同步表现特征是一般性规律，构造-古地理背景的变动可改变这一对应关系，因而提供了研究古地理演变的信息，进一步丰富了GR曲线研究的地质涵义。说明在侏罗纪古气候和古环境研究上，GR曲线是一有价值的参考指标。

Abstract:

 Inversion of climate and paleoenvironment using gamma ray (GR) log is being highlighted and improved increasingly in the world. Application of inversing paleoclimate change before 2.85 Ma has been succeeded in Quaternary in Qaidam basin. This paper shows gamma ray log is an important parameter for paleoclimate research, making an analysis of paleoclimate and paleosedimentary environment combining gamma ray log with sporopollen data and other geological data from two wells in Quaternary Qaidam Basin. Both Value sizes of GR and dry/wet changes of paleoclimate have internally related to the depth of dipositional water body. Quick/slow variations of frequency and amplitude of GR log show relatively active and stable characteristics of sedimentary environment. For this, specific analysis to an evolution of sedimentary environment from the two wells was made. Integrating paleoclimate with sedimentary environment, abnormal varying of GR curve is of a special implication in sedimentary facy. Variations on tectonic -paleogeography background could change the corresponding relation which is characterized as a general regularity by a synchronization of the GR log value-increasved, the paleoclimate-wetting, and the depositional water-deepen. Therefore, information of researching a paleogeography development can be presented, enriching a geological implication of GR log investigation further. This demonstrates GR log is a significant indicator in studying of the Jurassic paeoclimate and paleoenviroment.