福建东洋地区地球物理场特征

Geophysical Field Characteristics of Dongyang Region,Fujian Province

为了研究东洋地区深部地质结构,在福建东洋地区开展了综合地球物理勘查,对福建东洋地区地球物理场进行了分析,结合已有的地质资料,分析研究了区域地球物理场特征及区域深部地质结构特征.研究认为:福建东洋地区位于巨型环形构造外环带西南部,研究区处在东部沿海磁场剧烈变化带和西部内陆磁场相对平缓带的过渡区域,区域航磁ΔT异常以北东向条带状异常带为主,区内分布有2处剩余重力异常高;地球物理综合剖面范围被两条北西向深大断裂分割为3部分,结合区域地质特征,推断区域南部的浅层是一套推覆无根的变质岩系高阻体,深部为一套以中生代沉积岩石为主的低阻体,区域北部浅部主要为中生代沉积岩夹薄层火山岩组成的低阻体,深部为下古生代和元古界基底岩系共同反应的高阻体,区域中部是火山岩主要发育区.

In order to study the deep geological structure of Dongyang region, it carried out the integrated geophysical exploration in Dongyang region, analyzed the geophysical field. Combined with the existing geological data, it analyses and studies the characteristics of regional geophysical field and regional deep geological structure. The conclusion is that the Dongyang region is located in the southwest of the outer ring of the giant ring structure. The study area is located in the transition area between the eastern coastal magnetic field violent change zone and the western inland magnetic field relatively gentle zone, and the regional aeromagnetic ΔT anomaly is mainly NE trending banded anomaly zone. There are two high residual gravity anomalies in the study area. The comprehensive geophysical section is divided into three parts by two NW trending deep faults. Combined with regional geological characteristics, it infers that the southern part of the area is a set of nappe rootless metamorphic rock series with high resistivity, the deep part is a set of Mesozoic sedimentary rocks with low resistivity, the shallow part of the northern part of the area is mainly composed of Mesozoic sedimentary rocks with thin volcanic rocks, the deep part is the high resistivity body of the Lower Paleozoic and Proterozoic basement rock series, and the central part of the area is the main development area of volcanic rocks.