Method for quantitative calculation of water body depth of basin in deposition stage through field outcrop profile

Abstract

The invention discloses a method for quantitative calculation of a water body depth of a basin in a deposition stage through a field outcrop profile. The field outcrop profile is a profile exposed out of the earth's surface after a deposition stratum of the basin in a geological historical period is subjected to a bedding effect, a diagenesis effect, an architecture uplifting effect and a denudation effect. The method comprises the following steps: 1, a delta progradational reflection structure in the field outcrop profile is sought, and a top interface and a bottom interface are calibrated; 2, elevations corresponding to the top interface and the bottom interface are recorded; 3, an average thickness h1 of sandstone and an average thickness h2 of mudstone in a foreset bed of the outcrop profile are counted; 4, compaction rate K1 of the sandstone and a compaction rate K2 of the mudstone are respectively solved by use of an experiment method; and 5, before a compaction effect takes place, a thickness h10 of the sandstone h10=h1 / (1-K1), a thickness h20 of the mudstone h20=h2 / (1-K2), and a total stratum thickness h0 before compaction h0=h10+h20, i.e., the maximum paleo-water depth h of the basin is greater than or equal to h0. According to the invention, the maximum paleo-water depth of the basin in the geological historical period can be quantitatively recovered, and the calculation result is real and reliable and is of uniqueness.

Description

Technical field [0001] The invention belongs to the technical field of geological exploration, and specifically relates to a method for quantitatively calculating the depth of a basin during a sedimentation period through a field outcrop profile. Background technique [0002] Ancient water depth is an important research content of ancient sea level restoration and basin analysis, but the quantitative determination of ancient water depth is still in the exploratory stage. At first, foreign scholars mainly used paleontology, geochemistry, seismology, and mathematical simulation to determine semi-quantitatively the paleo-water depth of marine carbonate platform and delta. For example, Chappell et al. (1991) and Lawrence (1993) passed C 14 The U-Th method and the U-Th method discussed the changes in water depth, sea level and glacier melting level of the HuonPeninsula coral reef over the past 10,000 years; Bard et al. (1996) studied Barbados Tahiti barriers and changes in sea depth th...

AI Technical Summary

Problems solved by technology

It can be seen that the quantitative recovery of basin sedimentary paleo-depths, especially continental lacustrine basins, still has multiple solutions.

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