四川地质学报
四川地質學報
사천지질학보
ACTA GEOLOGICA SICHUAN
2013年
4期
394-398,403
,共6页
地质剖面%飞仙关组%台地边缘滩%海槽%云阳石梁
地質剖麵%飛仙關組%檯地邊緣灘%海槽%雲暘石樑
지질부면%비선관조%태지변연탄%해조%운양석량
Feixianguan Formation section%shoal on edge of platform%west side of Chengkou-west Hubei trough
重庆云阳石梁剖面位于上扬子板块北缘南大巴山冲断带位置,早三叠世飞仙关期处于城口-鄂西海槽西侧位置。对该剖面的详细研究,有利于恢复飞仙关期川东北碳酸盐台地东缘的沉积演化过程。研究认为,该剖面飞仙关组一段属于斜坡相沉积;二段下部继承碳酸盐台地东缘斜坡相,中部发育典型的台地边缘滩沉积,其顶部则演化为局限台地潟湖环境;三段由开阔台地及局限台地潟湖沉积构成;四段属于典型的局限台地潮坪沉积。城口-鄂西海槽西侧飞仙关组由两个向上变浅的沉积旋回组成,通过与相邻位置的井剖面对比认为,相对海平面变化控制了城口-鄂西海槽西侧飞仙关期沉积相演化,台地边缘滩基本发育于相对海平面下降时期。
重慶雲暘石樑剖麵位于上颺子闆塊北緣南大巴山遲斷帶位置,早三疊世飛仙關期處于城口-鄂西海槽西側位置。對該剖麵的詳細研究,有利于恢複飛仙關期川東北碳痠鹽檯地東緣的沉積縯化過程。研究認為,該剖麵飛仙關組一段屬于斜坡相沉積;二段下部繼承碳痠鹽檯地東緣斜坡相,中部髮育典型的檯地邊緣灘沉積,其頂部則縯化為跼限檯地潟湖環境;三段由開闊檯地及跼限檯地潟湖沉積構成;四段屬于典型的跼限檯地潮坪沉積。城口-鄂西海槽西側飛仙關組由兩箇嚮上變淺的沉積鏇迴組成,通過與相鄰位置的井剖麵對比認為,相對海平麵變化控製瞭城口-鄂西海槽西側飛仙關期沉積相縯化,檯地邊緣灘基本髮育于相對海平麵下降時期。
중경운양석량부면위우상양자판괴북연남대파산충단대위치,조삼첩세비선관기처우성구-악서해조서측위치。대해부면적상세연구,유리우회복비선관기천동북탄산염태지동연적침적연화과정。연구인위,해부면비선관조일단속우사파상침적;이단하부계승탄산염태지동연사파상,중부발육전형적태지변연탄침적,기정부칙연화위국한태지석호배경;삼단유개활태지급국한태지석호침적구성;사단속우전형적국한태지조평침적。성구-악서해조서측비선관조유량개향상변천적침적선회조성,통과여상린위치적정부면대비인위,상대해평면변화공제료성구-악서해조서측비선관기침적상연화,태지변연탄기본발육우상대해평면하강시기。
The geological section at Shiliang, Yunyang, Chongqing, is located on the southern Dabashan thrust belt on the northern margin of the upper Yangtze plate, and was located on the western side of the Early Triassic Chengkou-Western Hubei trough. Study of this section in detail is favorable to the reconstruction of the sedimentary history of the eastern side of the carbonate platform in northeast Sichuan Basin. Based on the measured section, the First Member of the Feixianguan Formation consists of slope facies. The lower part of the Second Member of the Feixianguan Formation consists of the slope facies on the eastern margin of the carbonate platform facies with shoal on edge of platform in the middle and restricted platform lagoon deposits in the top. The Third Member consists of open platform and restricted platform lagoon deposits, and the Fourth Member of belongs to restricted platform tidal flat deposits. The Feixianguan Formation on the western side of Chengkou-west Hubei trough comprises two ascendingly shallowing depositional cycles. The results of section correlation show that the relative changes of sea level has obvious controlling effect over the evolution of sedimentary facies of the Feixianguan Formation. The shoal on edge of platform was almost developed in the sea level fall period.