盆地陆源碎屑沉积物对源区构造背景的指示意义

盆地陆源碎屑沉积物对源区构造演化有重要的指示作用，目前利用盆地陆源碎屑沉积物示踪源区，反演源区构造演化的方法很多，包括沉积碎屑组分分析方法、地球化学分析方法及同位素年代学方法等。结合实例分析，简要介绍了这几种方法目前的研究进展及存在问题。由于盆地沉积碎屑组分、副（重）矿物及地球化学方法仅能够提供源区物质组成方面的信息，因此在应用上有很大的局限性。而同位素年代学方法则可以提供源区年龄组成方面的信息，锆石 U-Pb及FT年代学的结合，是一种新的突破。结合区域构造背景，有选择地进行多种方法综合分析应是行之有效的手段。

THE INDICATION OF CONTINENTAL DETRITAL SEDIMENT TO TECTONIC SETTING

As the product of mountain uplift-erosion, basin detrital sediment include abundant important information about source rock types and its tectonic setting, so basin continental detrital sediment is a very important indicator to the tectonic setting of sediment source. At present, there are many methods using basin detrital sediment to trace source and inverse its tectonic setting，such as detrital composition analysis method, geochemistry analysis method and isotopic chronology analysis method. Through examples, the progress and limitations of these methods are introduced. Basin detrital composition analysis and geochemistry analysis are the most fundamental methods to trace source and inverse its tectonic setting and have made great progresses, but detrital composition analysis, assemblage of accessory mineral and geochemistry analysis can only provide material composition information about sediment source. Because of the influence of provenance diversity, the different contribution of different provenance and the differentiation in the transportation process, so it is very difficult to trace source precisely only through these methods. While isotopic chronology analysis can provide chronology information about sediment source, different isotopic chronology analysis methods, such as K-Ar,Rb-Sr,Sm-Nd method, have been used in many areas and made very good results. These methods have their own priority in monitoring source denudation rate and tectonic-thermal events, but they are also often influenced by provenance diversity.  Zircon U-Pb method can solve the problem very well, different zircons coming from different sources can be separated through single-grain dating. Zircon U-Pb method can provide the information about zircon formation in igneous or high grade metamorphic environments, and FT method can provide the low-temperature information that record the thermo-tectonic evolution of sediment source. Such information is central to understanding the temporal relationships between sediment source and sedimentation in adjacent basins. So combination of zircon U-Pb and FT dating can extract the optimum amount of sediment source information. Through basin detrital sediment to trace source and inverse its tectonic setting has very important scientific significance, it can provide new ways to basin-mountain coupling research，but it is also a very complex problem including much knowledge about sedimentology, geochemistry and tectonics. According to the different tectonic setting of different regions, selecting several methods to make a comprehensive analysis will be a better way.