The Toarcian (Early Jurassic) sediments are regarded as the most significant hydrocarbon source rocks in the Qiangtang Basin, Qinghai–Tibet Plateau. In this study, geochemical and mineralogical data are reported from the Middle to Late Toarcian organic-lean sediments in the Qiangtang Basin, eastern Tethys. Combined with previous studies, the factors that control organic matter (OM) accumulation during the Toarcian are investigated. The Early Toarcian organic-rich sediments were deposited in stratified water column with oxygen-deficient bottom water, which was conducive to OM preservation. A warm and humid paleoclimatic condition favored the growth of organisms, which in turn could enhance the surficial biotic productivity. During the Middle to Late Toarcian, oxic waterbody was widely distributed in the Qiangtang Basin. This condition was unbeneficial to the preservation of OM. During this interval, a cold–arid climate had an adverse effect on organism growth, which in turn would reduce the initial productivity of surface water. The consistently low Ti/Al and Si/Al ratios revealed restricted but rather homogeneous clastic influx conditions during the Toarcian. This may suggest that the dilution of terrigenous material input had a little influence on OM accumulation. In addition, the differential enrichment of OM between shales and marls should attribute to carbonate dilution. These studies emphasize that redox conditions and paleoclimatic conditions were likely responsible for OM accumulation during the Toarcian.

在青藏高原the塘盆地，早侏罗世沉积物被认为是最重要的烃源岩。在这项研究中，报告了特提斯东部the塘盆地中至晚Toarcian贫有机沉积物的地球化学和矿物学数据。结合以前的研究，研究了在Toarcian时期控制有机质（OM）积累的因素。早Toarcian富含有机物的沉积物在缺氧的底水下沉积在分层水柱中，有利于OM的保存。温暖潮湿的古气候条件有利于生物体的生长，反过来又可以提高表面生物的生产力。在上至下Toarcian期间，有氧水体广泛分布在Qian塘盆地。这种情况不利于OM的保存。在这段时间内，寒冷干旱的气候对生物体的生长有不利影响，反过来又会降低地表水的初始生产力。一直以来较低的Ti / Al和Si / Al比显示出在Toarcian期间受限制但相当均匀的碎屑涌入条件。这可能表明稀释陆源物质输入对OM的累积影响很小。此外，页岩和泥灰岩之间的OM差异富集应归因于碳酸盐的稀释。这些研究强调氧化还原条件和古气候条件可能是Toarcian期间OM积累的原因。反过来会降低地表水的初始生产率。一直以来较低的Ti / Al和Si / Al比显示出在Toarcian期间受限制但相当均匀的碎屑涌入条件。这可能表明稀释陆源物质输入对OM的累积影响很小。此外，页岩和泥灰岩之间的OM差异富集应归因于碳酸盐的稀释。这些研究强调氧化还原条件和古气候条件可能是Toarcian期间OM积累的原因。反过来会降低地表水的初始生产率。一直以来较低的Ti / Al和Si / Al比显示出在Toarcian期间受限制但相当均匀的碎屑涌入条件。这可能表明稀释陆源物质输入对OM的累积影响很小。此外，页岩和泥灰岩之间的OM差异富集应归因于碳酸盐的稀释。这些研究强调氧化还原条件和古气候条件可能是Toarcian期间OM积累的原因。页岩和泥灰岩之间OM的差异富集应归因于碳酸盐的稀释。这些研究强调氧化还原条件和古气候条件可能是Toarcian期间OM积累的原因。页岩和泥灰岩之间OM的差异富集应归因于碳酸盐的稀释。这些研究强调氧化还原条件和古气候条件可能是Toarcian期间OM积累的原因。