Sequence stratigraphy of Jurassic-Cretaceous boundary strata in Luanping, Northern Hebei, China  

作　　者：TIAN Shugang LIU Yongqing LI Peixian PANG Qiqing NIU Shaowu 

机构地区：[1]Institute of Geology,Chinese Academy of Geological Sciences,Beijing 100037,China [2]Shijiazhuang Economic College,Shijiazhuang 065000,China [3]Tianjin Institute of Geology and Mineral Resources,Tianjin 300170,China

出　　处：《Science China Earth Sciences》2004年第7期607-617,共11页中国科学（地球科学英文版）

摘　　要：A sediment-continuous section of Jurassic-Cretaceous (J-K) boundary strata was found in Zhangjiagou of Luanping, northern Hebei Province, China. The boundary strata were systematically divided into 5 sequences, 13 subsequences and 139 parasequences by sedimentary cyclicities and facies analysis. According to stable time-ranges of subsequences and parasequences, some boundary ages can be marked as 142.90 Ma of the SQ I (Dabeigou Fm) basal bound, 141.16 Ma of the SQ II basal bound, 140.00 Ma of the SQ III (Dadianzi Fm) basal bound, 138.24 Ma of the SQ VI (Zhangjiagou Fm) basal bound and 135.34 Ma of the SQ V (Zhangjiagou Fm) top-bound. A sequence-stratigraphic framework of the Dabeigou-Zhangjiagou Fms has been constructed by tracing sequence-bounds, marker-beds and fossil zones. The basin-development and tectonic activities are studied based on sequence-stratigraphic evidence. 5 sequences represent 5 tectonic cycles and all the 6 sequence-bounds reflect tectonic activities. Tectonic activities clearly influence the basin-development that can be divided into 3 stages in the J-K transitional period. Each stage consists of a down-faulting-rising process, i.e. from strongly rising of basin-bottom, then violently faulting down (with volcanic eruptions) and to gently rising. The development shows a pattern of bottom down-faulting with basin narrowing and rising with spreading. Keywords sequence - stratigraphy - terrestrial stratotype - Jurassic-Cretaceous bound DOI: 10.1360/03yd0451A sediment-continuous section of Jurassic-Cretaceous (J-K) boundary strata was found in Zhangjiagou of Luanping, northern Hebei Province, China. The boundary strata were systematically divided into 5 sequences, 13 subsequences and 139 parasequences by sedi-mentary cyclicities and facies analysis. According to stable time-ranges of subsequences and parasequences, some boundary ages can be marked as 142.90 Ma of the SQ I (Dabeigou Fm) basal bound , 141.16 Ma of the SQ II basal bound, 140.00 Ma of the SQ III (Dadianzi Fm) basal bound, 138.24 Ma of the SQ VI (Zhangjiagou Fm) basal bound and 135.34 Ma of the SQ V (Zhangjiagou Fm) top-bound. A sequence-stratigraphic framework of the Dabeigou- Zhangjiagou Fms has been constructed by tracing sequence-bounds, marker-beds and fossil zones. The ba-sin-development and tectonic activities are studied based on sequence-stratigraphic evidence. 5 sequences represent 5 tectonic cycles and all the 6 sequence-bounds reflect tectonic activities. Tectonic activities clearly influence the basin-development that can be divided into 3 stages in the J-K transitional period. Each stage consists of a down-faulting-rising process, i.e. from strongly rising of basin-bottom, then violently faulting down (with volcanic eruptions) and to gently rising. The development shows a pattern of bottom down-faulting with basin narrowing and rising with spreading.

关 键 词：sequence STRATIGRAPHY terrestrial stratotype Jurassic-Cretaceous bound DOI: 10.1360/03yd0451 

分 类 号：P534[天文地球—古生物学与地层学]