地洼构造研究现状——并纪念地槽学说诞生120周年

来源期刊：中南大学学报(自然科学版)1979年第3期

论文作者：陈国达

文章页码：1 - 11

关键词：地洼构造； 研究现状； 地槽区； 地洼区； 地壳运动； 地球化学特征； 活动区； 地质资料； 地球物理特征； 构造单元

摘    要：1859年，美国学者J.赫尔(Hall，1811-1898)根据研究北美东部阿帕拉契安山脉的古生代底层的岩性、厚度和褶皱强烈情况，并与邻侧的北美中部平原情况对比的结果，提出了地槽的原始概念。至1873年J.D.德那(Dana，1813-1895)总结了当时的有关地质资料，在讨论地球冷缩与山脉成因时，发展了赫尔的思想。以后还有许多其他学者的工作，遂逐步形成了比较完整的地槽学说。

Abstract: The founding of J. Hall’s geosynclinal theory in 1859 was a major event in the history of the geological science.It propeled effectively the geotectonic researches forward and brought a great benefit to the ore-searching until now. In the 1950’s, the writer proposed a new-type mobile region of post platform stage, the third main tectonic element of the continental earth’s crust, based on the data collected chiefly in China. It has been named as the region of activation(l956) or of diwa (geodepression, 1959). The characteristics of the diwa region have been discussed systematically in previous papers(1959, 1960, 1965,etc.). Farther researches about this tectonic region, especially its geophysical and geochemical features since the last ten years mainly by the Chinese geologists will be reported in this article.The diwa region is marked by high heat flow values, sometimes up to 2.5 HFU, such as in the N. China diwa region. Low values of Bouguer anomaly are commonly met, generally-200--400 mgal, and sometimes even-550 mgal(E. Xizhaug [Tibet]). These characteristics are most typical in the middle ( intense ) period of the diwa development. The famous example is the W. China where the diwa regions belong to the Central-Asian stage whose middle period of development is in the Cenozoic.Geochemically, the diwa region has its own characteristics. For instance, in E. China, where the diwa regions belong to the Cathaysian type, the Meso-Cenozoic magmatic rocks either acidic or intemediate are rich in Si, K, Na, Li, Rb, Cs, Be, Nb, Ta, Th, U, Cu, Pb, Zn, W, Sn, Mo, rare earths, etc, while poor in Mg, Fe, Cr, Co, Ni, Ti, V, etc. Thus the metallogenesis of these tectonic regions are very important with corresponding distinguishing features.In the diwa regions, the structural influences are as deep as the Moho discontinuity. Deep fractures are widely spread,including many of lithosphe ric and even translithospheric ones. Fig.1shows the deep structural features in the N. China diwa region.The Gutenberg low-velocity layer in the diwa region may be situated in the shallow place, e. g,, only 70 km. below the earth’s surface in the Yishu great fracture belt of Shandong.According to the nature of the diwa region and its complex construc tion(with 3 structural layers),a new recognition on the regularity of the earth’s crustal development has been proposed in 1959 by the writer, namely the theory of progression(with transformation between mobile and "stable" regions). The proccess like this is supposed to be resulting from the movement of the materials within the asthenosphere.