“构造杂岩"及其地质意义——以西准噶尔为例

"STRUCTURAL COMPLEX" AND ITS GEOLOGICAL SIGNIFICANCE --IN THE CASE OF WEST JUNGGARIAN COMPLEXES

构造杂岩是构造地层学的重要研究内容之一。以西准噶尔为例,三个不同时期形成的构造杂岩:科克沙依杂岩、玛依勒杂岩和达拉布特杂岩,代表了古生代不同时期洋盆与火山弧的残迹。现今西准噶尔的构造格局,可能是多个地体的拼合.

'Structural complex'-an assemblage or mixture of rocks of two or more genetic classes-is very important for tectonostratigraphic research in erogenic belts. In West Junggar of northern Xinjiang, three complexes of different ages were distinguished. They are the middle-late Ordovician or earliest Silurian Kekeshayi Complex, late Silurian Mayile Complex and late Carboniferous Dalabut Complex. However, assemblage of the rock types and tectonic settings of these three complexes are very similar. All are mixture of ophiolitic rocks, pelagic pelitic sediments and clastic turbidites relating to volcanic arcs. This means that in the wide area of ancient central Asia the complicated environment for oceanic basins along with volcanic island arcs lasted a long period from Ordovician to Carboniferous. Intra-oceanic subduc-tion occurred and these complexes represent the remnants of intra-arc, fore-arc or back-arc terranes of different ages. Today's West Junggar may be composed of many displaced terranes.