• 责任者：Wu Jiaoqi (Guangzhou Marine Geological Survey ; Ministry of Land and Resources ; Guangzhou 510760 ; China) ; Gao Hongfang
• 刊名：Marine Geology & Quaternary Geology
• 出版年：2012
• 卷期：32(5)
• 关键词：盆地分析 ; basin analysis ; 构造层 ; tectonic layer ; 南沙群岛 ; Nansha Islands
• 页码：p.1-11
• 图表：5 illus., 39 refs.
• 分类号：0300
• issnNo：ISSN0256-1492
• isbnNo：CN37-1117/P

The Wan’an Basin is a strike-slip and pull-apart basin formed by the tensile stress derived from the dextral strike-slip movement of the Wan’an fault on its east side. Based on the relationship of two-way travel time vs. depth between stacking velocities from the seismic data and drilling data from wells, four megasequence boundaries were identified: MB1, the top of the acoustic Pre-Tertiary basement; MB2, the top of the Oligocene (24 Ma); MB3, the Late Miocene (8 Ma); and MB4, the Early Pliocene(4 Ma).Above each megasequence boundary (MB), there is a megasequence (MS).