Method and system for predicting shortening amount of earth crust structure based on rock magnetic experiment

Abstract

The invention discloses a method and system for predicting the shortening amount of an earth crust structure based on a rock magnetic experiment, and the method comprises the steps: selecting a target rock sampling region, and carrying out the collection of a standard rock sample in the sampling region; performing a rock magnetic experiment on the standard rock sample in a preset experiment environment, performing residual magnetism analysis on the standard rock sample by adopting a principal component analysis method, and combining a residual magnetism analysis result and a rock magnetic experiment result to obtain a palaeomagnetic pole and a palaeolatitude of the standard rock sample; and performing wrinkle inspection on the standard rock sample to verify the accuracy of the palaeomagnetic pole and the palaeolatitude, and predicting the crustal structure shortening amount by using the palaeomagnetic pole and the palaeolatitude. According to the method, the rock magnetic experiment is performed on the standard rock sample in the preset experiment environment, and the accurate paleomagnetic pole and paleolatitude of the standard rock sample are obtained by combining the residual magnetism analysis result and the rock magnetic experiment result, so that geological mineral engineering is guided through the paleomagnetic pole, the paleolatitude and the crustal structure shortening amount.

Description

technical field [0001] The invention relates to the technical fields of structural geology and applied geophysics, in particular to a method and system for predicting crustal structure shortening based on rock magnetism experiments. Background technique [0002] The formation of the Qinghai-Tibet Plateau experienced plate compression, collision, and later uplift and shrinkage. At present, a large number of scholars have conducted in-depth research and discussion on it, but there has been great controversy over the collision time, collision process and post-collision crustal shortening of the India-Asia continent. For example: paleomagnetism, significant changes in terrigenous clastics in foreland basins, great changes in sedimentary lithofacies or paleontology, ultra-high pressure metamorphic eclogites formed by plate subduction, regional unconformity contact between Linzizong Group volcanic rocks and underlying strata, Significant changes in the speed of the northward drif...

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Problems solved by technology

[0004] The purpose of the present invention is to overcome the problem existing in the prior art that rocks are not fully analyzed before performing paleomagnetic calculations, leading to unclear main magnetic minerals and types of rocks, and the obtained paleomagnetic data may be affected by later remagnetization Influenced by the lack of reliable paleomagnetic tests in the later period, the obtained paleomagnetic data are inaccurate, and the amount of crustal shortening cannot be accurately estimated. A method and system for predicting crustal tectonic shortening based on rock magnetic experiments is provided. This method Carry out rock magnetism experiments on standard rock samples in the preset experimental environment, and obtain the results of rock magnetism experiments. According to the results of rock magnetism experiments, the main magnetic-carrying minerals and types in rock samples can be obtained; after obtaining the main magnetic-carrying minerals in rock samples and type, adopt principal component analysis method to carry out remanent magnetism analysis to described standard rock sample, combine described remanent magnetism analysis result and rock magnetism experiment result, obtain the accurate paleomagnetic pole and magnetic pole of described standard rock sample Paleo-latitude: After obtaining the paleo-magnetic pole and paleo-latitude, the accuracy of the paleo-magnetic pole and paleo-latitude is ensured through the fold test, and the shortening of the crustal structure is predicted by using the high-accuracy paleo-magnetism and paleo-latitude data that have passed the fold test. Guiding geological and mineral engineering through paleomagnetic poles, paleo-latitudes, and crustal structure shortening

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