THE PRINCIPLES AND METHODS FOR PREPARATION OF TECTONIC MAPS BY USE OF THE THEORY OF PLATE TECTONICS

The tectonic map.is one of integrated geological maps.It is the special map that elucidates the lithospheric structure and the regularity of its evolution in a certain region. The tectonic map prepared under the guidance of the plate tectonic theory is obviously different from that prepared by use of the classic geosyncline and platform theory.The concept of plate tectonics advocates that Ⅰ-order tectonic units on the continents are distinguished with the paleosutures as the plate boundaries.These boundaries usually dissect geosynclines and two plarts of a geosyncline separated by a latest ophiolite belt are respectively assigned to two plates.That is to say,a plate is made up of a stable block in the core and geosynclinal fold belts of different ages surrounding the block.Therefore,as far as Ⅰ-order tectonic units in plate tectonics are concerned,a plate includes both platform and geosyncline.Ⅱ-order tectonic traits are provisionally called plate segments.Their distinction is based on the nature of their underlying crust. Thore with marine crust as the basement are called marine crustal plate segments,while those with continental crust as the basement are called continental crustal plate segments.The principle for the divison into Ⅲ-order tectonic units is largely similar to that in the concept of geosyncline-platform. Therefore,in preparing regional tectonic maps,the concept of geosyncline-plat- form is not able to be integrated with the concept of plate tectonics in relation to the division into Ⅰ-and Ⅱ-order tectonic units. This paper also concerns the main content and rsquirements and methods fot preparation of tectonic maps.Efforts have been made to break through the shackles of the classic concepts aud complie new-generation tectonic maps.