关键词: 异重流, 异重岩, 浊流, 沉积过程, 沉积特征

Abstract:

Hyperpycnal flow, one of the most significant sediment delivery systems to deep water, has aroused a great concern for a
considerable number of marine geologists and sedimentologists in recent years. It is a kind of subaquatic flows which have higher
density than the ambient water (lakes or oceans) discharging from river mouth, and usually occurs during the flooding period of some
areas that lack of vegetation under extreme dry and hot climate. Hyperpycnal flows are sustained turbidity currents, containing
bed-loads and suspended-loads to transport sediments. They could vibrate frequently during the flowing process, but mainly wax
initially and wane later. Hyperpycnites are hyperpycnal flows deposits. The remarkable recognitions of hyperpycnites include vertical
composite rhythm, repetitive alternation of cross bedding and massive layers, organic matters, a large amount of plant debris and
internal scouring surfaces. The thickness of stacking ancient hyperpycnites vertically could be more than ten meters, and they also
behave as a point-source sand-rich or mud-rich submarine (sublacustrine) fan with channels, levees and lobes laterally. Hyperpycnites
could play crucial role in oil and gas geological merits and economic values because of extraordinary conditions to be high quality
reservoirs and could be rather promising exploring targets.

Key words: hyperpycnal flow, hyperpycnites, turbidity current, sedimentary process, sedimentary characteristic