Abstract: In this paper microstructure,texture,and preferred orientations in peridotites from Fangshan have been studied and kink structure,glide systems in olivins have been measured primarily.Fangshan is a volcanoc cone which consisted of Cenozoic alkali-basalts as the substances were carried out from upper mantle by volcanic eruptions.The results indicate that crystalline plasticity and solid state flow are characteristic of upper mantle.The upper mantle physical parameters for this region have been calculated as:
Temperature T=1278-1487癒
Confining pressure P= 17.3-30.1kb
Applied stress =214-362b
Depth Z = 57-95km
strain rate = 10^-13...10^-16 strain/sec.
Viscosity =1.3?10²⁰p-1.3?10²³p.