Method of quantitatively restoring maximum paleo-water depth of lake basin through seismic profiling

Abstract

The invention discloses a method of quantitatively restoring the maximum paleo-water depth of a lake basin through seismic profiling, comprising the following steps: (1) a 3D seismic profile deltaic progradational reflection configuration is found, and the top interface time t1 and the bottom interface time t2 are calibrated; (2) the top interface time and the bottom interface time are converted into corresponding top and bottom interface depth H1 and H2 through a time depth conversion scale; (3) the average sandstone thickness h1 and the average mudstone thickness h2 in a 3D seismic profile progradational layer are calculated; (4) the sandstone compaction rate K1 and the mudstone compaction rate K2 are obtained using a graphical method or an experimental method; and (5) before compaction, the sandstone thickness h10=h1 / (1-K1), the mudstone thickness h20=h2 / (1-K2), and the total thickness of the formation before compaction h0=h10+h20, namely, in the delta sedimentation period, the paleo-water depth thickness of the lake basin is h0, and the maximum paleo-water depth h of the lake basin at the moment is greater than or equal to h0. Through the method, the maximum paleo-water depth of a continental lake basin in the geological history period can be restored quantitatively, and the calculation result is real and reliable and is unique.

Description

technical field [0001] The invention belongs to the technical field of geological exploration, and in particular relates to a method for quantitatively restoring the maximum ancient water depth in the geological history period of continental lake basins by using three-dimensional seismic sections. Background technique [0002] Paleo-depth is an important research content of paleo-sea level restoration and basin analysis, but the quantitative determination of paleo-depth is still in the groping stage. Foreign scholars initially used methods such as paleontology, geochemistry, seismology, and mathematical modeling to semi-quantitatively determine the paleowater depths of marine carbonate rock platforms and deltas, such as Chappell et al. (1991) and Lawrence (1993) through C 14 The water depth, sea level and glacier melting level changes of the Huon Peninsula coral reefs were discussed with the U-Th method for more than 10,000 years; Bard et al. (1996) studied Barbados Tahiti b...

AI Technical Summary

Problems solved by technology

Based on previous studies, whether it is marine or continental strata, the determination method of paleowater depth is both ambiguous and unreliable

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