The continuous Cenozoic strata are well outcropped in the Mazar Tagh, the central Tarim basin and the Quaternary are mainly thin lacustrine sediments, which are perfect basis of paleoclimate and paleoenvironment researches. A total of more than two hundreds of bulk samples were collected from the ～ 140m long sedimentary section. Here the result of field survey together with oxygen and carbon stable isotopic data is given; the paleoenvironment variation and its tectonic significances are also introduced. The Mid-Pleistocene climate transition is characterized by significant sediment assemblage change and drastically fluctuated stable isotopic data. Near the top of the section, the pronounced positive δ13C drift and negative δ18O excursion might indicate a extreme climate change and possible increasing influence of ice-snow melting water. The widely developed Quaternary lacustrine sediments in Mazar Tagh are distinctly different from the corresponding huge conglomerates and aeolian sandstone in the piedmont regions, which suggest the significant heterogeneity of regional tectonic activities. Acting as the front of the West Kunlun northern marginal thrust fault, Mazar Tagh fault might active in the Late Pleistocene or Holocene and currently remains active.%塔里木盆地腹地玛扎塔格地区最近发现了完好出露的新生代连续沉积地层,其中第四系主要为细粒湖相沉积,从而提供了最新的来自盆地内部的古气候古环境研究载体.在详细野外考察基础上,沿厚约140m的剖面采集两百多块样品,本文报道了野外考察结果和样品碳氧稳定同位素数据,以期初步探讨盆地新生代晚期环境变化及相应的构造意义.中更新世气候转型期在玛扎塔格地区有清楚显示,主要表现为沉积组合的显著不同,湖相沉积物氧碳同位素数据(δ18O和δ13C)则呈现周期性波动震荡特征,并呈现出明显的反相关特征,尤其剖面最上部出现显著的δ18O负偏和δ13C正偏,可能暗示了一次较为极端的气候异常事件,或说明冰雪融水的影响逐步加深,说明积雪源区向沉积区的扩展.玛扎塔格地区广泛发育的第四纪湖相沉积和山前地带沉积特征明显不同,说明了区域构造运动的显著不均一性,作为西昆仑北缘冲断带的前锋部位,玛扎塔格断裂的最新活动时间为更新世晚期或全新世,且目前可能仍在持续进行.
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