Writers : Etemadkhah, z.; Khatib, M.M.; Zarinloub, M.H.
Refference : 29th symposium on geosciences, p: 123
Publishing Year : 1389

Abstract :

Ring complex of Givshad in southwest of Birjand is located in northern part of Sistan structural zone, east of Iran. In this research, fault slip data is used as the main data for paleostress analysis by Multiple Inverse Method. The misfit angle is 1.54. The geometrical shape of the stress ellipsoid proved to be prolate and the shape factor around 0.1 (Ø=0.1) and the maximum principal axis is vertical. Field studies shows that this mass near the surface with ring structure and mechanism of subsidence caldera collapse piston type has appeared, the analogue experiments confirming that the magma chamber close to the surface, Maximum
shear stress (σ1-σ2) located at the edges of magma chamber and dose to the surface earth. σ3 (the maximum tensile strength) increases near the earth surface, away from the wall of magma chamber. The peak point σ3 is located with the angle θ =10-15° to the edges of magma chamber, ultimately, the sub-vertical ring fault formed. Magma channel is created, simultaneously with the central block subsidence (piston type). 3D numerical simulation allows the ratio equality that was noteworthy between (r.asnBinnrfaa-gBdBi.firib = dininwJ wnile calculates the magma volume, depth of fault is of the .data processing field, the value of central block depression was calculate Therefore, the magma volume in faults was estimated and depth of fault ring.

Subject List : Stress, ring complex