FRACTURE CHARACTERISTICS OF KRETA GRANITOID

Abstract

Ke Ga area mainly consists of geological formations as follows:

•    Cretaceous granitoid of Deo Ca suite exposes at Bau Sen area and Ta Dang Mountain.

•    Late Cretaceous leuco-granite of Ankroet suite distributed along beach follow NorthEast direction of 2km wide and 7km long. It consists of many smaller blocks which exposes at Ke Ga Cape, Blue World Resort, Da Do Resort, Da Nhay Resort, and Binh Yen Resort.

•    Cenozoic loosen sands.

In the research area, main faults were developped dominantly such as NE-SW fault - F1 creating a brecciated zone of 3km wide, 7km long, NW-SE fault - F3 in the southeast of Ta Dang mountain, and latitude fault - F2 along the streamline at Thuan Cuong, Thuan Minh areas.

Fractures developped by many directions. Especially, leuco-granite had been fractured strongly such as follows:

•    NE-SW (30-70⁰) striking, dipping towards to many directions such as SE (113^o), 80^o dipping angle. It is indicated to be the shear fractures associated with F1, SW (295⁰), 60⁰ dipping angle, and vertical angle.

•    NW-SE 293° striking, vertical.

•    This system creates thick brecciated zones

•    NE-SW 25° striking, dipping towards NW 295^o, dip angle 60^o

•    NW-SE 300 striking, dipping towards NE, 70^o dip angle

Sub-latitudinal 75-80^o striking, dipping toward SE, 80^o dip angle