薇拉·凯瑟作品的南方主题

薇拉·凯瑟在弗吉尼亚度过了她生命中最初的九年。她的作品中不乏南方主题。然而评论界对此一向冷漠。通过解读她的三部南方小说,对它们的南方主题进行梳理,指出南方特质和南方情怀其实早渗透到凯瑟的心中,并深深地影响了她的创作。

Tectonic Evolution and Geological Characteristics of Hydrocarbon Reservoirs in Marine Mesozoic-Paleozoic Strata in the South Yellow Sea Basin

The South Yellow Sea Basin is the main body of the lower Yangtze area in which marine Mesozoic–Paleozoic strata are widely distributed.The latest geophysical data were used to overcome the limitation of previous poor-quality deep data.Meanwhile,the geological characteristics of hydrocarbon reservoirs in the marine Mesozoic–Paleozoic strata in the South Yellow Sea Basin were analyzed by comparing the source rocks and the reservoir and utilizing drilling and outcrop data.It is believed that the South Yellow Sea Basin roughly underwent six evolutionary stages:plate spreading,plate convergence,stable platform development,foreland basin development,faulted basin development,and depression basin development.The South Yellow Sea Basin has characteristics of a composite platform-fault depression geological structure,with a half-graben geological structure and with a ‘sandwich structure' in the vertical direction.Four sets of hydrocarbon source rocks developed – the upper Permian Longtan–Dalong formation,the lower Permian Qixia formation,the lower Silurian Gaojiabian formation,and the lower Cambrian Hetang formation/Mufushan formation,giving the South Yellow Sea Basin relatively good hydrocarbon potential.The carbonate is the main reservoir rock type in the South Yellow Sea area,and there are four carbonate reservoir types:porous dolomitic,reef-bank,weathered crust,and fractured.There are reservoir-forming horizons similar to the typical hydrocarbon reservoirs in the Yangtze land area developed in the South Yellow Sea,and there are three sets of complete source-reservoir-cap rock assemblages developed in the marine strata,with very good hydrocarbon potential.

Mesozoic tectono-magmatic activities in South China:Retrospect and prospect

The South China Block was formed through the collisional orogeny between the Cathaysia Block and the Yangtze Block in the Early Neoproterozoic.The northern,western and southern sides of the South China Block were affected by disappearance of the Paleo-Tethyan Ocean during the Paleozoic.The southern and northern sides of the South China Block were respectively collided with the Indo-China Block and North China Block in the latest Paleozoic to form the basic framework of the Eastern China.The Eastern China has been affected by the westward subduction of the Pacific Plate since the Mesozoic.Therefore,the South China Block was influenced by the three major tectonic systems,leading to a superposed compound tectonics.The comparative study of the Mesozoic geology between the South China Block and its surrounding areas suggests that although the Mesozoic South China Block was adjacent to the subduction zone of the western Pacific,no juvenile arc-type crust has been found in the eastern margin.The main Mesozoic geology in South China is characterized by reworking of ancient continental margins to intracontinental tectonics,lacking oceanic arc basalts and continental arc andesites.Therefore,a key to understanding of the Mesozoic geology in South China is to determine the temporal-spatial distribution and tectonic evolution of Mesozoic magmatic rocks in this region.This paper presents a review on the tectonic evolution of the South China Block through summarizing the magmatic rock records from the compressional to extensional tectonic process with the transition at the three juncture zones and using the deformation and geophysic data from the deep part of the South China continental lithosphere.Our attempt is to promote the study of South China’s geology and to make it as a typical target for development of plate tectonic theory.