Geochemical characteristics of cryptoexplosive breccias in the western part of Leimengou Mo deposit in western Henan and their geological significance

Leimengou Mo deposit is a super large deposit recently discovered in the western Henan Province, and Mo ore was present mainly in the cryptoexplosive breccia. In order to find out the genesis of the cryptoexplosive breccia and its relationship to metallogenesis, the major elements, trace elements, and rare earth elements of the breccias and cements in the cryptoexplosive breccia was analyzed. The values of major elements of the breccias show the peraluminous high potash calc-alkaline and alkaline series and of cements weak peraluminous high potassium tholeitic series. The total values of rare earth elements of the breccias and cements varied relatively widely, both showing enriched LREE and obviously negative Eu anomaly in different degrees. The spider diagram of trace elements shows the cements exhibits the enriched characteristics of LILE ( Cs, Rb, Ba, K, Pb), and relatively depleted HFSE (Ta, Nb, Ti), similar to Archaean gneiss of the Taihua Group and the granite porphyry. Combined with the geochronological data of the East Qinling and the regional tectonic evolution, it was inferred that the Leimengou cryptoexplosive breccia was possibly formed in the postorogenic extensional setting, and the cryptoexplosive process was accompanied by the molybdenum mineralization.