由高密度洪水河流潜入低密度水体底部形成的异重流（hyperpycnal flow）沉积已成为近年来国外地质学研究的前沿领域，与异重流相关的深水储集砂体、有机质富集及岩性油气藏吸引了国外石油地质学家的广泛关注。虽然深水湖盆比海洋盆地更有利于形成异重流，但国内外关于异重流沉积机制及中生代湖相异重流沉积的研究鲜有报道。鄂尔多斯盆地南部晚三叠世深水湖盆异重流沉积（延长组长7油层组）的发现，为探索陆相湖盆异重流沉积机制、深水储集砂体的成因与储层分布规律创造了客观条件。 本项目将通过大比例尺岩心-露头测量、系统采样和样品分析，结合现代沉积考察，分析湖相异重流沉积特征与砂体发育控制因素，探索湖相异重流沉积机制，建立湖相异重流沉积识别标志与沉积模式，研究异重流沉积砂体的物性特征。异重岩作为一种特殊类型的浊流沉积，不仅具有重要的地质学理论研究价值，而且对于深水储集砂体预测和油气勘探具有重要的现实意义。

Hyperpycnal flow deposits generated from high-density flooding river diving into the bottom of low-density water has become the frontier research field of geology abroad in recent years. Deep-water sandbodies, organic matters accumulation and lithologic hydrocarbon reservoir relating to hyperpycnal flow have attracted wide attention of petroleum geologists. Although deep lacustrine basin is more conducive to forming hyperpycnal flow than ocean basin, depositional mechanisms of hyperpycnal flow and hyperpycnite in Mesozoic lake has been rarely reported both at home and abroad. Discovery of hyperpycnal flow deposits (in the seventh section of Yanchang formation) in the southern part of the late Triassic deep lacustrine Ordos basin create the objective conditions for the probing of depositional mechanism of hyperpycnal flow, genesis and distribution rule of deep-water sandstone reservoirs in continental lacustrine basin. Applicants may pay attention: ① to analysis sedimentary characteristics of hyperpycnal flow deposition and controlling factors of the development of sandbodies, ② to probe for hyperpycnal flow depositional mechanism in lacustrine environment, ③ to establish identification symbols and sedimentary model of lacustrine hyperpycnite,and ④ to study on physical properties of sandstone reservoir deposited in hyperpycnal flow, based on measurement of drill cores and outcrops with large scale proportion, serially sampling and sample analysis, combining with investigation on modern sediments. As a special turbidite current deposition, hyperpycnal flow deposition not only has the value of scientific theoretical research, but also has important practical significances for sandbody prediction and exploration on oil and gas reservoir in deep-water basin.