Wave characteristics and tectonic-sedimentation evolution of foreland thrust fault of Micang Mountain

Abstract

In this paper, the technology of wave process method for sedimentation is first adopted in the research of the foreland thrust fault of Micang Mountain with respect of oil and reservoir’s formation and tectonic and sedimentary evolution. From the fluctuation characteristics, we could make conclusions in the foreland thrust belt of Micang Mountain that, there existed 2 first-order sedimentary cycles (220 Ma), corresponding to Caledonian-Hercynian and Indo-Chinese-Yanshan-Himalayan tectonic cycles respectively; there existed 4 second-order sedimentary cycles (10 Ma), corresponding to two sedimentation peak period and two denudation peak periods in research zone; there existed 12 third-order sedimentary cycles (35 Ma) and 21 fourth-sedimentary cycles (20 Ma). These 33 cycles in the research zone corresponded to the sedimentation-denudation process in different periods, furthermore, their fluctuation characteristics bore the genetic relationship with the development law of source, reservoir and cap rocks: the source rock had the tendency to develop at the turning part between wave crest and wave trough, or at the superposition of wave turning part in different periods, presenting like “X”; most reservoir rocks developed at the place of wave peak; the development of cap rock was located in the wave trough on the right of sedimentation-denudation datum line. As a result, through the application of wave process method for sedimentation, we could rediscover the understanding of the tectonic and sedimentary evolution from another prospective, meanwhile, it enables to make prediction about the development rule of source, reservoir and cap rocks, which means a significant importance to the research of oil and reservoir’s forming condition.