The basin tectonic model: it is intermont basin during late Jurassic to early Cretaceous, developed into faulted-lacustrine basin in Eogene, and evolved into depression in Neogene and Quaternary.

“”构造发育模式为：从晚侏白垩纪末发育的山“”开始、发展早第三纪断陷湖的发育、再演化为晚第三纪及第四纪陷发育阶段。