Reflection of seismic paleoevents in Mesozoic–Cenozoic terrigenous sequences of the northern Caucasus

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• 作者：Yu. O. Gavrilov
• 刊名：Lithology and Mineral Resources
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：52
• 期：1
• 页码：1-19
• 全文大小：
• 刊物类别：Earth and Environmental Science
• 刊物主题：Mineral Resources; Mineralogy; Sedimentology;
• 出版者：Pleiades Publishing
• ISSN：1608-3229
• 卷排序：52

文摘

Numerous traces of paleoseismic events (seismites) were established in Mesozoic–Cenozoic marine sedimentary sequences of the northern Caucasus. These traces are most prominent in the terrigenous Middle Miocene sandy–clayey sediments. Impact of seismic shocks upon the relatively weakly lithified sediments provoked distortion of the primary sedimentary structure, liquefaction of the sandy material, and injections of different morphologies (neptunic dikes and sills). The formation of jointing in sediments fostered their vertical permeability and promoted the migration of diagenetic solutions into the adjacent horizons, which stimulated the formation of subvertical carbonate bodies. The amount and intensity of seismic events varied at different stages of the accumulation of sequences and in different areas of the paleobasin. In the eastern sector of the northern Caucasus, seismic activity similar to the present-day general pattern was likely developed as early as the Middle Miocene: maximum activity in the Dagestan and its westward attenuation. Traces of seismic activity are also recorded in the Maikopian (Oligocene–Lower Miocene) and Lower–Middle Jurassic rocks.