Characteristics and evolution of sedimentary facies of the Eocene of Paleogene in Baise Basin,Guangxi
Chen Yuanzhuang Wu Mingrong Liu Luofu Lei Shenggang
1Faculty of Natural Resources and Information Technology,University of Petroleum,Beijing 102249
2Faculty of Georesource and Information,University of Petroleum,Dongying 257061,Shandong
3Research Institute of Southern Company of Exploration and Development,SINOPEC,Nanning 530023,Guangxi
Based on the identification of sequence boundary through outcrops,seismic data,well logs and analytical data,the Nadu Formation and Baigang Formation of the Eocene of Paleogene in the Baise Basin can be divided into one secondorder sequence,and further into three third order sequences The Member 3 of the Nadu Formation forms Sequence Ⅰ,the Member 2 and Member 1 of the NaduFormation form Sequence Ⅱ,and the Baigang Formation forms Sequence Ⅲ Sequences Ⅰand Ⅱ were deposited during the faulting period of the basin,during the period alluvial fan facies,fluvial facies,delta facies,fan delta facies,shore shallow lake subfacies,and deep lake subfacies were developed Sequence Ⅱis characterized by a wide range of lake sedimentation with a great thickness,and the thick bedded mudstones of deep lake subfacies are the main source rocks and regional cap rocks in the basin Sequence Ⅲ was deposited during the depression period of the basin,during the period alluvial fan facies,fan delta facies,fluvialfacies,delta facies,and shore shallow lake subfacies were developed The Paleogene in the Baise Basin experienced a process from the deposition of fluvial facies or alluvial fan facies to fluvial and delta facies,and then to lake facies (fan delta facies),and finally to fluvial facies This indicates that the Baise Basin experienced a complete cycle of evolution from the early rifting stage to expansion,and then to shrinkage In the lowstand system tracts of sequences Ⅰ andⅡ,sandstones of fluvial and delta facies are well developed in the central faulted sag,the southern subsag of the Tiandong Sagand the northern faulted nose of the Nabi Uplift along the long axis These sandstones are in mature source rock areas with a favorable condition for reservoir formation,and are in the potential areas for the exploration ofchannel lithologic pools In the transgressive and highstand system tracts of sequence Ⅱ,fan delta facies were developed along the northern steep slope and their sandstones are interfingered with source rocks which are favorable for the formation of hydrocarbon pools,and are easy to form a great deal of updip pinching lithologic reservoirs
About author: Chen Yuanzhuang,born in 1965,is a senior engineer and a candidate for PhDdegree in University of Petroleum (Bijing),and is engaged in petroleum geology and exploration
Cite this article:
. Characteristics and evolution of sedimentary facies of the Eocene of Paleogene in Baise Basin,Guangxi[J]. JOURNAL OF PALAEOGEOGRAPHY, 2004, 6(4): 419-433.
. Characteristics and evolution of sedimentary facies of the Eocene of Paleogene in Baise Basin,Guangxi[J]. JOPC, 2004, 6(4): 419-433.