大陆造山带沉积地质学研究中的几个问题

RESEARCH ON THE SEDIMENTARY GEOLOGY AND PETROLOGY OF CONTINENTAL OROGENIC BELTS

大陆造山带一直是地质科学研究的中心议题之一，在开展大陆造山带的形成与演化研究过程中首先遇到的是地层问题。由于造山带地层构成因素复杂，不能简单地使用Ｓｍｉｔｈ地层原理和法则所建立的地层学的一般工作方法，而应当使用一套新的实用于造山带的地层工作方法和原理。笔者将造山带地层划分为四种类型：（１）沉积－地层体型：沉积地层基本上呈连续的和相互叠加的，并在侧向延伸上基本连续；（２）构造－地层体型：沉积地层遭受较强烈的褶皱和冲断作用，层状岩石保持相对的独立性和完整性，构造－地层体之间多为断层接触；（３）构造－岩石体型：地层遭受强烈的褶皱和剪切作用，层状岩石的叠置和侧向连续性被破坏，仅呈断续的连接；（４）构造－混杂岩体型：沉积地层被完全破碎、混合。造山带与盆地是地球动力学作用下的统一的相互密切联系的两个方面，造山带可看作为沉积盆地演化的最终产物，深入研究沉积盆地，有助于解决造山带结构与造山作用过程研究中所遇到的一些难题。

Continental orogenic belts have been a focus of geological research.In researchon the formation and evolution of continental orogenic belts,the primary object of study isstrata.A new set of methods and principles suitable to such strata,in place of those devel-oped by Smith should be used.In view of the complexing of the strata in continental oro-genic belts. Four categories of strata in continental orogenic belts are proposed in this pa-per:(1)sedimentation-strata bodies,in which the strata are basically continuous and su-perimposed, and also continuous in lateral extension; (2)tectonics-strata bodies,in whichsedimentary strata have experienced strong folding and thrusting,but the stratified rockshave kept relatively independent and complete,with the boundaries between such stratabodies almost all marked by faults; (3)tectonic-rock bodies,in which the strata were sub-jected to strong folding and shearing,with destruction of lateral continuity and superimpo-sition of the strata,and the relationship between the two discontinuous;(4)tectonic-mix-ture bodies,in which sedimentary strata were completely broken and mmingled.Orogenic belts and sedimentary basins are closely related phenomena controlled bygeodynamics.Orogenic belts can be considered the final result of evolution of sedimentarybasins.Consequently,through the study of sedimentary basins,the structure of orogenicbelts and other problems related to the study of orogeny can be elucidated.