桐柏山—大别山地区航磁信息研究

A STUDY OF THE AEROMAGNETIC INFORMATION IN TONGBEIMOUNTAIN-DABIEMOUNTAIN AREA

笔者将桐柏山—大别山地区最新大比例尺航矿资料编制成统一航磁数据集，对其作了多种数据处理和图象处理，获得了丰富的信息，结合参考其它地球物理、化学及地质等资料，提出草店—宣化店—天堂寨中央断裂，是华北和扬子两大板块在印支—燕山期陆陆碰撞的缝合线，大别块体以此为界分成南北大别两个块体；探讨了东西碰撞不同模式和超高压变质矿物仅出现在东段的根本原因；首次提出了造山带中部的木兰山块体；华北地块和大别山块体分界线应是商城—桐城断裂；秦岭造山带和桐柏山—大别山造山带存在时空上的过渡关系。

The author has obtained a wealth of information from the new aeromagnetic data processing and image processing with good quality in Tongbeimountain - Dabiemountain area. Depending on the information analyses and interpretation combined with the other data of geophysics,geochemistry, and regional geology, some new views about the basic geological problems in Tongbei Dabie Orogen have been put out. It is the first to advance that the Caodian Xuanhuadian -Tiantangzhai centric fracture is the collision geosuture of the smallplate between Yangzi and North - China during Indosinian and Yanshanian movement. As the boundary line, this geosuture devides the Dabie landmass into two landmass - the South Dabie landmass and North Dabie landmass.The Mulanshan Landmass in the middie part of Tongbei - Dabie Orogen has been put forward for the first time. It has been also dixcussed that the different pattern of smallplate collision at the east part and west part, and the fundamental cause of which the ultrahigh - pressure metamorphic belt only exist in the east part. The boundary line between North - China plate and Dabie landmass is the Shangcheng Tongcheng fracture. Tongbei - Dabie orogen exists a time - space transitive relation to Qinling orogen.