Writers : Etemad Khah, Z.; Khatib, M. M.; Zarin Kub, M. H.
Refference : The Forth National Geological Conference of Payam Noor University(PNU)
Publishing Year : 1389

Abstract :

Ring complex of Givshad in south of Birjand is located in northern part of Sistan structural zone, east of Iran. It belongs to Eocene. Field studies shows that this mass near the surface with ring structure and mechanism of subsidence caldera collapse piston type has appeared. In this complex, ring faults trapped the central block. With near magma chamber to surface, the maximum value of the shear stress (Sigma1-Sigma2) occur at the outer margins of the magma chamber, hence first fractures are created. The minimum value of the tensile stress ( Sigma3 ) must be located at a radial distance at surface. The maximum tensile at surface must peak at surface of the magma chamber or the angle a should be in the range or lower than (Ө=10-15).Finite element model, it is possible that equal to the ratio between the size (V magma in fault + V magma in surface earth= V volume caldera collapse) calculate the volume of the magma, deep faults calculate, with data processing Field, Block Central collapse value was obtained(h≈27m) .Hence,the deep of ring fault, was estimated(h=2756m) .

Subject List : ring complex