【摘要】 通过对南极半岛鲍威尔盆地及邻区多道地震数据、重磁数据及测井数据的综合解译,对其地层结构和沉积特征进行了研究,并对其新生代构造、沉积演化过程以及主控因素进行了分析.对地震剖面的解释共划分出4个层序界面,5个构造沉积单元.研究结果表明鲍威尔盆地是一个典型的弧后盆地,始新世以来西侧太平洋板块向南极半岛之下持续的俯冲,以及东侧新生代以来威德尔海向斯科舍地区俯冲带的后撤,导致南极半岛发生近东西向的伸展作用,南奥克尼微地块与南极半岛裂离,并最终在早渐新世末期-早中新世期间发生海底扩张作用.南奥克尼微地块一侧的东部陆缘与南极半岛一侧的西部陆缘表现为被动陆缘特征,为共轭陆缘.其南北两侧陆缘则表现为走滑-拉张特征.对研究区沉积过程的控制因素进行研究,包括构造活动和沉积物源,海平面变化,以及冰川作用.其中南极半岛新生代冰川作用的影响因素显示了高纬度区边缘海盆地独特的沉积特征.更多还原

【Abstract】 Integrated geophysical data including multichannel seismic data,gravity, magmetic,and drilling data were interpreted and analyzed in the Powell Basin, Antarctica Peninsula.Based on interpretation we worked out stratigraphic sequences,tectonic structures,and sedimentary controlling factors. Five tectonic-stratigraphic units are determined,together with four sequence boundaries.Detailed analyses reveal that the Powell Basin is a typical back-arc basin.The continued subduction of the Pacific plate under the Antarctica Peninsula since Eocene,and the slab roll-back of the Weddel Sea’s subduction under the Scotia region triggered the break-up of the Antarctica Peninsula and sea-floor spreading in Powell Basin between the end of Early Oligocene and Early Miocene.The eastern margin at the South Orkney microcontinent side and the western margin at the Antarctica Peninsula side are conjugated passive margins,while the northern and southern margin are of strike-slip features.Controlling factors on the sedimentary process are discussed,including tectonic activities,sedimentary origin,sea level changes,and glacial events.The effects of the Cenozoic glacial events in the Antarctica Peninsula on the sedimentary process mark the distinctive features of a high-latitude marginal sea example.更多还原