Study on Influential Factors of Terrigenous Seguence Formation and Development in Fault-depressed Lacustrine Basin

Key words: 
• structural subsidence /
• source recharge /
• palaeoclimate /
• lacustrine level /
• influential factors /
• terrigenous seguence /
• Biyang fault-depression

Abstract: Mesozoi。-Neozoic terrigenous sequence of Bivang fault-depression in Nanxiang Basin is treated as a case to study influential factors of terrigenous sequence formation and development. Basement structural suhsidence, sedimentary source recharge, palaeoclimate transformation and lacustrine level change are the four factors which are very important to control terrigenous sequence development in fault-depressed lacustrince basin.In Bivang fault-depressed lacustrince hasi, regional tectonism brought about the formation of basin-fill sequence and tectonic sequence and pulsation of basin boundary faults led to the development of sequence sets/sequence.And the rate of source recharge and accommodation variation determined stacking styles of terrigenous sequence units.Palaeclimate influenced the development of terrigenous sequence by the change of sedimentary source and lacustrine level, and its cyclical transformation determined the formation and evolution of high Erequenev sequence.Lacustrine level change which is an important subject to study terrigenous sequence in fault-depressed lacustrince hasin, directly controlled the terrigenous sequence geometrical characteristics.There is a specific dialectical causality between the four factors which are basic to control terrigenous sequence development.