沉积与特提斯地质2024，Vol.44Issue(4)：773-795,23.DOI:10.19826/j.cnki.1009-3850.2024.05007
藏北日土地区南羌塘地块晚石炭—早二叠世海相裂谷盆地沉积序列:冈瓦纳大陆北缘初始裂解的沉积响应
The marine rifted successions of the Late Carboniferous-Early Permian deposits from the South Qiangtang Block in the Rutog area,Northern Xizang:Sedimentary records of a rifting process on the northern Gondwana margin
摘要
Abstract
The South Qiangtang Block(SQB)is widely acknowledged as part of the Cimmerian Continent,which rifted away from the northern Gondwana margin during the Early Permian,marking the initial opening of the Bangong-Nujiang Meso-Tethys Ocean.However,the sedimentary response to this rifting event remains unconfirmed,leaving the event ambiguous.In this study,five sedimentary successions are identified in the Rutog area,Northern Xizang,each characterized by distinct facies that record different stages in the tectonic evolution and climatic influences on the basin,along with associated changes in the rates of basin subsidence and sediment accommodation.Succession Ⅰ,formed in the Late Carboniferous to Asselian age,shows that glaciomarine sediments compensated for the sediment accommodation generated by the basin subsidence,resulting from tectonic activities and climatic factors in the early stage of the syn-rift.During the Sakmarian to early Artinskian age,the glaciomarine retrogradational sequence represented by the Zhanjin Formation(Succession Ⅱ)and the following progradational-aggradational sequences represented by the Qudi Formation(Succession Ⅲ)mark the climax and standstill stages of the first episode of the syn-rift tectonic activities,respectively.In the late Artinskian to Kungurian age,the second episode of syn-rift is manifested by the Succession Ⅳ and Ⅴ.And the former retrogradational sequence(Succession Ⅳ),reflected in the lower part of the Tunlonggongba Formation,indicates a climax stage of syn-rift tectonic activity,while the latter aggradational-progradational sequences(Succession Ⅴ),represented by the upper part of the Tunlonggongba Formation,mark a stage of tectonic quiescence.Therefore,these Early Permian sedimentary successions in the SQB are best explained by the tectonic subsidence resulting from the rifting of the SQB from the Gondwana margin,suggesting an early Permian timeline for the initial opening of the Bangong-Nujiang Meso-Tethys Ocean.关键词
南羌塘地块/晚石炭—早二叠世/沉积充填序列/冈瓦纳北缘裂解/日土地区Key words
South Qiangtang Block/Late Carboniferous-Early Permian/sedimentary filling sequences/rifting on the north Gondwana/Rutog area分类
天文与地球科学引用本文复制引用
张予杰,翟庆国,张以春,刘一鸣,曾孝文,安显银,刘石磊..藏北日土地区南羌塘地块晚石炭—早二叠世海相裂谷盆地沉积序列:冈瓦纳大陆北缘初始裂解的沉积响应[J].沉积与特提斯地质,2024,44(4):773-795,23.基金项目
国家自然科学基金项目(42241205) （42241205）
第二次青藏高原综合科学考察项目(2019QZKK0706) （2019QZKK0706）
中国地质调查局地质调查项目(DD20240026) （DD20240026）
