摘要： 通过对四川盆地龙门山区甘溪石沟里剖面实测,建立了石沟里剖面泥盆系养马坝组风暴沉积的识别标志,进而对其风暴岩进行了系统研究。石沟里养马坝组风暴沉积的重要标志包括冲刷面、渠模等风暴侵蚀构造和粒序层理、平行层理、丘状交错层理等风暴浪构造。该区养马坝组发育了6种类型的风暴沉积单元组成序列,据此建立了完整的风暴序列模式,由粒序层理段(Sa)、平行层理段(Sb)、丘状交错层理段(Sc)、波状层理段(Sd)和泥岩段(Se)组成,底部常发育冲刷面和渠模构造。龙门山区甘溪石沟里养马坝组风暴沉积可分为近源风暴和远源风暴2种类型,依据风暴沉积的剖面结构类型和沉积构造特点,建立了该区风暴沉积序列的分布模式。龙门山区甘溪石沟里养马坝组发育的风暴沉积是该区混合沉积发育、抑制生物礁发育的重要控制因素,对于该区古地理重建具有重要的指示意义。

关键词: 风暴沉积, 沉积序列, 沉积模式, 养马坝组, 泥盆系, 龙门山区, 四川盆地

Abstract: A comprehensive measurement on Shigouli outcrop section of Devonian Yangmaba Formation in the Longmenshan area of Sichuan Basin,was carried to identify the major characteristics of storm deposition and detail study the tempestite depositional system. The major features of storm deposits in the Yangmaba Formation include storm scouring surface,gutter cast structure,graded bedding,parallel bedding,and hummocky cross-stratification. The Yangmaba Formation developed six different composites of storm sedimentary units. A complete storm sequence pattern in the area is established,including the graded bedding section(Sa),the parallel bedding section(Sb),the hummocky cross-stratification section(Sc),the wave bedding section(Sd)and the mudstone section(Se). The bottom often developed the scour surface and gutter cast structure. Generally,there are two types of tempestites developed in the study area,the near-source storm deposits and far-source storm deposits. According to the profile structure type and sedimentary structure characteristics of storm deposits,the distribution pattern of storm sedimentary sequence in this area is established. The storm deposits developed in the study area have great implications for the reconstruction of palaeogeography,because it indicates that the storm deposits is an important control factor for the development of mixed deposits and the inhibition of the development of reefs in this area.

Key words: storm deposits, sedimentary sequence, sedimentary mode, Yangmaba Formation, Devonian, Longmenshan area, Sichuan Basin

中图分类号: 

• P512.2+1