METALLOGENY OF THE TECTONOMAGMATIC EMPLACING CONTACT STRCTURAL SYSTEMS OF THE METALLOGENIC BELT IN MIDDLE AND LOWER REACHES OF YANGTZE

With discussion on the different contact structural systems of tectonomagmatic emplacement, the metallogeny in the Middle and Lower Reaches of Yangtze is studied. This metallogenic province belongs to the Yangtze marginal tectonic region of South China ancient continental marginal tectonic belt. The tectonomagmatic emplacement is in three steps: 1) forming of the tectonomagma in the deep of crust; 2) dynamic process for the initiative emplacement of magma; and 3) forming of metallogenic sites with different types of emplacing contact structural systems in supracrust of the earth. With two examples of Daye iron deposit and Tongling copper deposit, the authors introduce the roof-foundering contact structure system, which is formed by the initiative tectonomagmatic emplacement, and roof-pendent emplaced above the country rock to form the hinged ore-controlling structures in different depths. The concept of tectonomagmatic emplacing contact structure is a new understanding for the prospecting idea of "digging deeper".