中国地质2018，Vol.45Issue(2)：377-391,15.DOI:10.12029/gc20180212
四川龙门山地区早—中泥盆世混积相遗迹化石及其环境分析
Trace fossils of hybrid facies from Early-Middle Devonian strata in Longmenshan area, Sichuan Province
摘要
Abstract
Abundant marine trace fossils are preserved in the Early-Middle Devonian strata of the Guixi-Shawozi section in Longmenshan area,Sichuan Province.According to the shapes,three types of trace fossils were identified that include Domichnia as Skolithos,Fodinichnia as Chondrites,Phycodes,Planolites,Rhizocorallium,Thalassinoides and Zoophycos;Food-seeking traces including Cylindrichnus and Palaeophycus;Repichnia as Cruziana and Monomorphichnus;Cubichnia as Asterichnus,Lockeia and Rusophycus.14 kinds in total trace fossils can be identified clearly.The ichnocoenoses represent types of Domichnia,Fodinichnia,Food-seeking traces,Repichnia and Cubichnia.Four ichnocoenoses representing different sedimentary environments were recognized as follows:(1) Skolithos-Thalassinoides ichnocoenosis can be explained as Domichnia from higher-energy foreshore;(2) Rusophycus-Phycodes ichnocoenosis mainly consists of Cubichnia and Fodichnia generated in higher-energy nearshore;(3)Chondrites-Palaeophycus ichnocoenosis is from shallow shelf,which suggests sub-oxic and lower energy;(4) Zoophycos-Palaeophycus ichnocoenosis is considered as Fodichnia from higher-energy shallow shelf between normal wave base to storm wave base.In terms of the ichnocoenoses,living environment and distribution pattern of trace fossils of hybrid facies were set up from Early-Middle Devonian strata in Longmen-shan area.Three kinds of Zoophycos fossils were observed,which were coexistent with concentrations of brachiopoda and shell,ripple marks,hummocky and swaley cross bedding,which reflects shallow environment sedimentary characteristics from Early to Middle Devonian in Longmenshan area and indicates that Zoophycos fossils were formed in a shallow environment.关键词
遗迹化石/古环境/混积相/泥盆纪/龙门山地区Key words
trace fossil/paleoenvironment/hybrid facies/Devonian/Longmenshan area分类
天文与地球科学引用本文复制引用
荆锡贵,李凤杰,成晓雨,杨晓琪,张昊,沈凡..四川龙门山地区早—中泥盆世混积相遗迹化石及其环境分析[J].中国地质,2018,45(2):377-391,15.基金项目
国家自然科学基金项目“龙门山地区泥盆纪土桥子组高频韵律旋回成因及古气候意义研究”(41172100)和四川省教育厅自然科学重点项目“龙门山地区泥盆纪风暴沉积及其地质意义”(12ZA012)联合资助.Supported by National Natural Science Foundation Project for Research on Genesis of High Frequency Rhythm Cycle and Significance of Palaeoclimate in Devonian Tuqiaozi Formation,Longmenshan Area (No.41172100) and Natural Science Key Project of Education Department of Sichuan of China for Geological Significance and Storm Deposit from Devonian in Longmenshan Area (No.12ZA012). （41172100）
