摘要
在地质记录中,大至陨星碰撞地球,小至某些外力作用下的沉积现象,虽然作用时间短促,作用次数不多,但往往比长时期的经常作用遗留更加深刻的影响。在滨岸和浅海区域,水体内一次高能量突发事件,如台风、飓风、风暴潮、或地震海啸等,可以冲毁长时期正常天气条件下的波潮流沉积和堆积风暴沉积。
The investigation of storm as important mechanism for the transportation of sediments and generation of sedimentary structures in nearshore zone and open shelf has been increasingly carried out during the last decade,because these rare high energy events have the potential of preservation in the geological record disproportionate to their frequency and duration.Owing to the difficulty of making observation of modern storm deposits,many concrete results are summarized from the studies of storm sequences in the ancient rocks.Sedimentary structures and textures used as criteria for identifying storm deposits are discussed in the light of the mechanics of storm process.A pair of basal lag deposit and laminated unit is formed,which is thought to have recorded a single storm event comprising storm peak erosion,subsequent rapid deposition and post storm reworking.Storm deposits are complex and varied in different sedimentary environments.Four principal factors seem to control the variability in facies:(1)water depth,(2)relationship between the strengths of storm process and fair weather marine processes,(3)prograding stationary and transgressive trends,(4)availability of source materials.Thus,quite different storm sequence models appear.Models interpretated by other authors are also presented.
作者
严钦尚
Yan Qinshang(East China Normal University)
出处
《海洋与湖沼》
1984年第1期14-20,共7页
Oceanologia Et Limnologia Sinica
