Abstract:

Anthraxolite of Tanjianshan group, with high vanadium and nickel content, is widely deposited in the Qaidam Basin. Some metal ore deposits are distributed in good accordance with the anthraxolite's distribution. It is meaningful to study the formation mechanism of the Tanjianshan group anthraxolite and its interaction with metal minerals. That is conductive to the research and exploration of oil, gas and mineral in the Qaidam Basin. The distributional characteristics of anthraxolite of Tanjianshan group were clearly studied based on geological survey. Some metallic element contents and organic geochemical characteristics of anthraxolite were tested for studying the formation mechanism of anthraxolite and paragenesis metals in Tanjianshan group. It shows that anthraxolite is mainly deposited in Saishentengshan, Tanjianshan, Mangyashimiankuang and Kaimuqi of the Qaidam Basin. For Tanjianshan area, anthraxolite mainly occurs in the limestone and sandstone reservoirs, or mudstones. Oil source correlation shows that anthraxolite was generated by mudstones in interval A of Tanjianshan group. Parent material types of anthraxolite were derived from low grade aquatic organisms, e.g. algae, which were formed in the shallow seabathyal with anoxia and reducing condition and salt water. They have experienced relatively strong biological effects. With anthraxolite generating, active tectonic and magmatic activity were both beneficial to metal elements enrichment. And initial enrichment of organic matter on metal elements or fluid extraction from the outside conditions resulted in some high metallic elements contents in the anthraxolite. Therefore, there is great metal mineralization potential in Tanjianshan area of the Qaidam Basin.

Key words: anthraxolite, Tanjianshan group, northern margin of Qaidam Basin, metallic mineral deposit