扬子克拉通继承性构造与新生构造并存的时空发育特征及其对海相油气勘探的指导

继承性构造与新生构造时空发育特征的研究,是"盆""山"耦合理论从指导含油气盆地的研究发展为指导油气勘探的道路上迈出的重要一步。以前寒武纪、加里东期、海西—印支期和燕山期4大构造阶段,重点剖析了上扬子北部地区(四川盆地)各阶段的构造线方向及其形成机制(与造山带发育的耦合演化),提出川东地区近期海相油气勘探取得重大突破的最主要经验是认识到同海相沉积期的新生构造被燕山期的新生构造高角度横跨形成了岩性—构造复合油气藏。与川东地区作比较,还分析了上扬子南部和中扬子地区各阶段的构造演化,提出前者与川东的最大不同是盆地发育与八布-PhuNgu洋(不是秦岭—大别洋)的演化耦合,且叠加了巨地幔作用的热隆升造山的影响;后者独特的基底构造对建造和改造长期有明显的制约。据上述分析探讨了上扬子南部和中扬子地区海相油气勘探的有利区块,认为黔西的贵阳—安顺一线以北(黔北盆地)尽管晚古生代及以后各期新生构造的方向与四川盆地不同,但仍是有望获得海相油气勘探突破的地区。 

Time-spatial developing features of co-existed inherited and neogenic structures and their guidance to marine origin oil-gas exploration in the Yangtze Craton

The study on time-spatial developing features of co-existed inherited and neogenic structures is an important step for the basin-orogeny coupling from a direction of petroliferous basin study to a guidance of oil-gas exploration.The exploration of marine origin oil-gas pool in China has taken a very tortuous road,and now it is in urgent need of new theoretical guiding.Taking the northern part of Upper Yangtze area(the Sichuan Basin) as an example,the paper described the orientation of structural line and its mechanism(coupled evolution with the neighbouring orogenic occurring) in the Precambrian,Caledonian,Hercynian-Indosinian and Yanshanian tectonic stages.A key knowledges for recent good progress of marine oil-gas exploration in the easetrn Sichuan Basin was lithologic-structural compound pool created by the Yanshanian neogenic structure(NE-orientation) acrossing the syn-marine sedimentary neogenic structure(NW-striking),which were named the 2nd and 3rd generation of neogenic structures respectively.In the western Sichuan Basin,the 3rd generation of neogenic structure was NEE-striking.To compare with eastern Sichuan,the paper analysed the orientation of structural line of each tectonic stage in the southern part of Upper Yangtze area(Guizhou) and Middle Yangtze area(Hubei) respectively.An obvious distinction in Guizhou might be that evolution of the epicontinental sea basin was coupled with the Babu-Phu Ngu ocean to the south(instead of the Qinling-Dabie ocean to thenorth of the Yangtze craton).In addition,Guizhou area was influenced by the plume tectonics in Late Permian-Early Triassic.The unique basemental structures(the N-S Huangling continental nucleus and the NE-striking Paleo-Tan-Lu fault zone) in Middle Yangtze area constrained the regional formation and deformation for a long time.Based on what mentioned above,the beneficial districts for marine oil-gas exploration in Guizhou and Hubei areas was discussed,which thought that the North Guizhou Basin(to the north of Guiyang-Anshun in west Guizhou) might be a hopeful area,although the orientations of Late Paleozoic and Mesozoic neogenic structures varied from the Sichuan Basin.