古地理学报2017，Vol.19Issue(3)：525-540,16.DOI:10.7605/gdlxb.2017.03.041
珠江口盆地L凹陷裂陷期始新统文昌组沉积充填模式
Depositional filling model of the Eocene Wenchang Formation in rift stage of L sag,Pearl River Mouth Basin
摘要
Abstract
The exploration of the Eocene Wenchang Formation in L sag,Pearl River Mouth Basin, is in the initial-exploration stage.Due to limited drilling data and their uneven distribution,the conven-tional multiple-data research methods of sedimentary facies is restricted in this area,resulting in the lack of systematic analysis on sequence stratigraphy and depositional system.Based on cores, well logs and seismic data,the integrated seismic facies analysis was carried out in this area.The integration of well and seismic data was applied to predict the distribution of the Paleogene rift sedimentary system,and the sedi-mentary model of the Wenchang Formation in rift period has been established.The results show that the Wenchang Formation developed three 3rd-order sequences,consisting of 8 system tracts.According to the differences between externel form and internel reflection characteristics in the sequence system tracts,five seismic facies types were identified in the study area, which are filling type, mat type, wedge type, massive type and hummocky type.Seismic facies were converted to sedimentary facies based on the com-bined analysis of core facies,well-log facies and seismic facies.Braided-river delta,fan delta and lacus-trine facies were identified.The study area developed the model of small basin with small lake in the initial syn-rift stage,when several small isolated sags were mostly filled with near-source fan delta clastic depos-its.Model of large basin and shallow lake was developed in the early rift-climax stage,when the sags be-came connected with each other,filled with braided river delta originated from the southwest.Large basin with deep lake model was formed when the tectonic stage entered middle-late rift-climax,therefore deep lake mudstone was widespread.The model of large basin and shallow lake in the late syn-rift stage was de-veloped,when the accommodation was gradually filled by a large-scale braided-river delta originated from the northeast along the long axis of L sag.关键词
断陷湖盆/文昌组/沉积相/沉积模式/珠江口盆地Key words
rift lake basin/Wenchang Formation/sedimentary facies/sedimentary model/Pearl River Mouth Basin分类
天文与地球科学引用本文复制引用
贾浪波,纪友亮,钟大康,严锐涛,刘君龙,米立军,易震,余加松,张鹏程..珠江口盆地L凹陷裂陷期始新统文昌组沉积充填模式[J].古地理学报,2017,19(3):525-540,16.基金项目
国家自然科学基金项目(编号:41672098)资助.[Financially supported by the National Natural Science Foundation of China (No.41672098)] （编号:41672098）
