Ⅰ. INTRODUCTION Volcano-sedimentary system of the Dengfeng Group metamorphosed to the amphibolite facies, central Henan, is considered as an E-W extending greenstone belt on the southern margin of the North China Craton (Sino-Korean Craton). I. INTRODUCTION Volcano-sedimentary system of the Dengfeng Group metamorphosed to the amphibolite facies, central Henan, is considered as an E-W extending greenstone belt on the southern margin of the North China Craton (Sino-Korean Craton).