南极半岛地质特征及其西北边缘的油气资源潜能

THE GEOLOGICAL STRUCTURAL CHARACTERISTICS OF ANTARCTIC PENINSULA AND THE OIL & GAS POTENTIAL IN ITS NORTHWESTERN MARGIN

本文较全面地综合了南极半岛西北缘60年代以来各国的调查和研究成果,较全面地概括该地区的地质构造和盆地特征,并对区内5个盆地的油气前景进行了讨论,指出图拉断裂带以南的陆架至上陆隆有较好的油气前景,有适当开展调查工作的必要。

This article comprehensively formulates the research and survey results since 1960s at the north- western margin of Antarctic Peninsula and outlined the geological features and basin characteristics of this region as well as discussing the oil and gas prospects of five basins on the south of Tula Fracture Zone. The Antarctic Peninsula had linked with the sourthem area of South America before Oligocene when a magma arc which had begun to active since Triassic stretched from South Ameriea to Antarctic Peninsula. The complicated geological structure of the Antarctic Peninsula can be roughly, at present, classified into a Mesozoic magma arc and a Cenozoic magma arc and three Mesozoic and Cenozoic fore-arc basins on the Peninsula and at its northwestem margin. The evolution of the Antarctic Penin- sula was related to the subduction of Phoenix Plate. The ocean ridge gradually moved to south during the process of subduction and then collided with sea trench (the initial collision occurred before 50Ma south of Alexander Island, the final collision occurred during Pliocene west of Smith Island). The Drake Plate, as the remains on north of the Hero Fracture Zone, ceased to colliding with sea trench before 4Ma, therefore the Bransfield Basin had been stretched into present form. Five Mesozoic and Cenozoic basins were discovered so far in the whole region. It is suggested that the South Shetland Basin and Closed Back-arc Basin are significant of oil and gas potential and the FBG Basin, Camara Basin and Bransfield Basin are of possibly moderate prospecting.