关键词: 闽中裂谷, 块状硫化物型铅锌矿床, 找矿标志, 找矿前景

Abstract:

Investigations on the paleo-tectonic setting, major characteristics and origin of deposits in central Fujian Province are key parts to a better understanding of the Precambrian tectono-magmatic evolution and further ore explorations in the Cathaysia Block. The stratigraphic sequence and petrography indicate that the Dongyan Formation of the Mamianshan Group underwent at least three generations of bimodal volcanism instead of the result of one period of volcanism.Geochemical analysis suggests that the protoliths of the Dongyan Formation, host strata of the major deposits, were marine spilite-quartz keratophyre series, which resulted from the continental rifting during the Meso-Neoproterozoic. Detailed analyses on the typical deposits reveal that the massive sulfide deposits or mineralization embryos were formed by seafloor volcanic exhalation in Neoproterozoic. These deposits underwent tectonic deformation and magmatic-hydrothermal superposition in later Mesozoic and led the formation of some deposits. Based on the research mentioned above, the relationships between the origin of the massive sulfide deposits and the Meso-Neoproterozoic rifting tectonic settings are discussed.The geologic features and markers which could be used as clues for deposit exploration have been summarized and the favorable prospecting regions are discussed.

Key words: central Fujian rift, massive sulfide Pb-Zn deposits, prospecting criteria, explorative prospect