“Longquanguan Group”, which is classically accepted as a uniform rock-stratigraphic unit, consists of two parts:gneiss granite and metasediment, and the former is called as “Yushuwan Formation”, the latter, “Paoquanchang Formation”. It distributes in the south west piedmont of Wutai Mountain. In recent years some researchers pointed out that “Longquanguan Group” is a ductile shear zone formed during the collision between “Fuping” and “Hengshan” terrains, instead of a rock-stratigraphic unit.On the basis of our studies, “Longquanguan Group” can be divided into two stratigraphic units with different stratigraphic natures: “Longquanguan Tectonic Rocks” being a tectono-stratigraphic unit and “Paoquanchang Metasediment Formation” as a rock-stratigraphic unit. “Longquanguan Tectonic Rocks” are composed mainly of gneissic granite. They experienced at least two stages of deformation and metamorphism. “Paoquanchang Metasediment Formation” consist of a series of metamorphic epicontinental sediments such as sandstone, mudstone, limestone, etc. They experienced only one stage of deformation and metamorphism. Judging from the deformation and metamorphism features of these two stratigraphic units, we believe that “Longquanguan Group” Virtually consists of two stratigraphic units of different ages and must be disintegrated.The major conclusions of this paper are the following:1)“Longquanguan Group” consists of two stratigraphic units of different ages with different natures instead of a uniform rock-stratigraphic unit.2)“Longquanguan Tectonic Rocks” are a part of the basement of the “Fuping terrain”, and “Paoquanchang Metasediment Formation” was deposited on the passive margin of “Puping terrain”.
Hao Jie,Wang Kaiyi,Zhou Shaoping. DISCUSSION ON STRATIGRAPHIC AND TECTONIC FEATURES OF “LONGQUANGUAN GROUP” IN THE SOUTH WEST PIEDMONT OF WUTAI MOUNTAIN AND RELEVANT PROBLEMS[J]. Chinese Journal of Geology, 1995, (2): 183-189.