Multiple origins for flatpebble limestones and sedimentary environments of the Upper Cambrian Gushan
Formation at Tangwangzhai in Shandong Province
1 School of Earth and Space Sciences,Peking University Beijing100871
2 College of Geoinformation Science and Engineering Shandong University of
Science and Technology Qingdao266510,Shandong
The Upper Cambrian Gushan Formation in North China Platform is characterized by abundant deposition of flatpebble limestones(flatpebble conglomerates). The flatpebble limestone refers to the socalled edgewiselimestone. Based on the systematic investigation of the sedimentology of the Gushan Formation at the Tangwangzhai Section,Shandong Province,8 rock types,namely calcareous shale,nodular micritic limestone,muddy banded micritic limestone,thinbedded micritic limestone,bioturbated micritic limestone,skeletal wackestonepackstone,oolitic grainstone,and flatpebble limestone,have been recognized in this formation,and have been grouped into 3 rock associations,which were deposited in the shaly basin,deep subtidal zone and shallow subtidal zone. The characteristics of pebbles and matrix and sedimentary successions indicate different provenances for the pebbles and matrix,and suggest that flatpebble limestones in the Gushan Formation were originated from multiple sedimentary environments. Flatpebble limestones in the Gushan Formation are grouped into 4 types according to their origins. 1)Both pebbles and matrix were probably formed in situ or transported only for a short distance; 2)Both pebbles and matrix were eroded and transported for a long distance from nearshore regions or experienced a sealevel rising process; 3)Matrix might be transported from nearshore regions,and mixed with pebbles and lime mud formed in situ; 4)Pebbles might be eroded and transported from micritic limestone on far offshore regions,and mixed together with matrix in situ,such as lime mud and skeletal grains.
About author: Ding Yu,born in 1981,graduated from Shandong University of Science and Technology in July,2004, with a bachelor degree. Now she is engaged in sedimentology,palaeontology and stratigraphy in Peking University as a Ms. candidate. Address:School of Earth and Space Sciences,Peking University,Beijing 100871; Email:dingyumm@163com.
Cite this article:
. Multiple origins for flatpebble limestones and sedimentary environments of the Upper Cambrian Gushan
Formation at Tangwangzhai in Shandong Province[J]. JOURNAL OF PALAEOGEOGRAPHY, 2008, 10(2): 125-138.
. Multiple origins for flatpebble limestones and sedimentary environments of the Upper Cambrian Gushan
Formation at Tangwangzhai in Shandong Province[J]. JOPC, 2008, 10(2): 125-138.