The disintegration of Kuanping Group in North Qinling orogenic belts and Neo-proterozoic N-MORB
北秦岭宽坪岩群的解体及新元古代N-MORB

Kuangping Group located in North Qinling orogenic belt which consists chiefly of metabasalts and meta-sedimentary. A new LA-ICPMS zircon U-Pb age of metabasalt of Kuanping Group is presented and gives a weighted mean 207Pb/206PbPb age of 943Ma which in the Neo-proterozoic time. However, the meta-sedimentary of Kuanping Group is limited to that in Early Phanerozoic time, but the Proterozoic, as previously considered. Therefore, this indicate that the two types of rock is not a continuous stratigraphic unit, protoliths of metabasalts were tholeiitic basalts with N-MORB geochemical characteristics, which represents a dismembered ophiolite and indicate a remnants of Greenville orogeny in the North Qinling orogenic belts.