【作者】 刁玉杰；

【导师】 魏久传；

【作者基本信息】 山东科技大学 ， 矿产普查与勘探， 2009， 硕士

【摘要】 南华北地区位于东秦岭—大别山构造带北缘,华北地台的南部,为一在华北地台基础之上发育起来的中、新生代叠合盆地,研究其古地理是重建南华北晚石炭—早二叠世海陆分布、构造背景、盆地配置和沉积演化的重要途径和手段,对于该区的油气资源远景预测评价和勘探开发实践都具有十分重要的意义。南华北地区晚古生代沉积盆地经历了由陆表海—三角洲—近海湖泊沉积的充填过程,晚石炭—早二叠世主要为陆表海充填沉积。通过对岩层宏观和微观的沉积学标志、垂向沉积序列、测井曲线和古生物方面的研究,识别出在南华北地区晚石炭—早二叠系中主要存在着碳酸盐台地相沉积体系和障壁—泻湖相沉积体系。南华北地区晚石炭—早二叠世的海平面变化经历一个上升下降的旋回,主要原因是构造沉降和气候的变化。其中,构造沉降是主要的影响因素,气候引起的冰川融化也是海平面变化的重要影响因素,这样形成了的一个陆表海盆地充填层序表现为海陆交互相多发性海侵、海退的陆源碎屑沉积。研究区上石炭—下二叠统为一个Ⅱ级陆表海充填层序,三个Ⅲ级层序(Sq1-3),其中Ⅲ级层序分别对应晚石炭世巴什基尔—格舍尔期、早二叠世紫松期和隆林期。根据层序地层学研究对Sq1、Sq2、Sq3进行古地理重建,发现陆表海充填沉积总体上为海退序列,沉积物源主要来自阴山隆起。Sq1沉积厚度北厚南薄,海侵方向来自东北方向,海侵时间短,范围小,主要发育泻湖相沉积;Sq2海侵方向由东北转变为东南,海侵范围扩大,覆盖了整个南华北地区,地层沉积厚度北厚南薄,东厚西薄,沉积中心较Sq1海侵范围南移,潮坪沉积发育:Sq3延续了Sq2的古地理格局,沉积中心南移至宿南地区,沉积相带由北向南依次为泻湖—潮坪—台地。通过晚石炭—早二叠世海平面变化研究和古地理恢复,证实了海侵转换面的存在,全球海平面上升和板缘构造运动共同塑造了南华北地区晚石炭—早二叠世特殊的古地理演化过程,二者共同作用,交替主导,在全球海平面上升的控制下,发生了研究区晚石炭—早二叠世陆表海充填沉积。更多还原

【Abstract】 The South North China is in the north marginal of east Qinling-Dabie structural belt, the south of north china platform,bestrides the north china block and whose south margin structural belt.The study of Paleogeography is important method of reconstructing land-sea distribution,tectonic background,basin configuration and sedimentary evolution of the Southern North China in later Carboniferous and early Permian.It is meaningful for oil and gas prospective prediction,exploration and development in this area.The South North China basin in late Paleozoic experienced epicontinental sea-delta-lake near the sea filling sediment.According to the study of macroscopic and microscopic sedimentological mark of rocks,silt body shapes,vertical sequences,logging curves,palaeontology,we can acknowledged that there were carbonate platform and barrier-lagoon sedimentary systems.The change of sea level in the South North China experienced a up-down cycle,because of tectonic subsidence and the variation of climate.Tectonic subsidence was the main influencing factor,and the glacier melting caused by climate was the important factor too, so there formed a epicontinental sea filling sequence which manifested errigenous clastic deposit of sea-land interbedding facies with multiple marine transgression-regression.In this paper,late Carboniferous-early Permian series was aⅡepicontinental sea filling sequence,and it was divided into threeⅢsequences(Sq1-Sq3),these threeⅢsequences are correspondence with Bashkirian-Gerschel stage of late Carboniferous, Zisong stage and Longlin stage in early Permian respectively.According to the sequence stratigraphic research,epicontinental sea was a filling sequence,material source was mainly from Kageyama uplift.In the Sq1 stage,it is thick in north while thin,marine transgression was from northeast direction in short time and small range,lagoon facies was the main sedimentary facies.In the Sq2 stage,marine transgression was from southeast direction,the range of marine transgression enlarged covering all the study area,it was thick in north and east while it was thin in south and west, sedimentation center transfer towards south compared with the earlier marine transgression,tidal flat sedimentary was developed.In Sq3 stage,paleogeography pattern was continued after Sq2,sedimentation center transfer to Sunan area,there were lagoon, tidal and flat platform facis from north to south.On the basis of paleogeographical reconstruction of key sequences,transgressive inversion surface is proved between Sq1 and Sq2,special paleogeography evolution were controlled by increasing global sea level and plate marginal tectonic movement,because of these effect,there was epicontinental sea filling sedimentary in study area in late Carboniferous-early Permian.更多还原