河北南部石炭-二叠纪古气候演化特征

通过对河北南部的石炭二叠纪含煤岩系的岩石学、矿物学及地球化学等特征的研究表明,河北南部晚石炭世到早二叠世早期气候温暖潮湿,早二叠世晚期逐渐向半干旱气候转变,晚二叠世气候又再次向温暖潮湿转变,气候为半湿半干,至晚二叠世末则变得较为炎热、干旱.整体上研究区晚古生代气候由温暖潮湿向炎热干旱转变,但其中又存在着一定程度的波动.这种古气候演变与华北板块所处位置以及晚古生代古地中海的逐渐闭合有关,同时,华北板块晚古生代发生了多次海侵,这种海水的进退所带来的周期性湿气变化,导致了气候的波动,并于晚古生代末海水最终退出华北板块时,气候变得较为干旱.

Evolution of the Paleoclimates during Permo-Carboniferous in the Southern Hebei

Coal accumulation was closely related to the paleoclimate during Permo-Carboniferous in the northern China Plate. As shown by lithological, mineralogical and geochemical characteristics of the Upper Paleozoic, it was relatively wet during the latest Carboniferous and earliest Permian. And then the climate became wet-dry or even semiarid during the late time of the early Permian. Later in the late Permian, the climate changed to wet or wet-dry again, and the climate became semiarid or even arid at the end of the Permian. Such climate variations are attributed to the closing of the ancient Mediterranean sea and the ancient tectonic location of the North China Plate during the late Paleozoic, and under the control of tectonic movement, several transgressive and regressive events took place during this time, such transgression-regression cycles brought periodical humidity to the study area and resulted in the fluctuation of climate. And when the sea completely regressed out of the North China Plate at the end of the Permian, the climate became relatively dry.