Experimental Study of Migration of Gabbro Elements during Deformation

Gabbro is selected as a sample for experimental deformation to investigate and validate the migration of elements during rock deformation. Samples are deformed for 3 h under a strain of about 5 % at T =700 ℃, p =100 MPa, σ =50 MPa. It is shown that there are 4 areas with different colors in the section of the samples parallel to σ₁: the extensional, contractional, and strongly compressional areas and a ductile shear zone, respectively on the basis of the stress states and the direction of material movement. The chemical components such as K, Na, Al and Fe from materials in different areas have changed. The four elements mentioned above in pyroxene grains decrease in content from the extensional area through the ductile shear zone, the contractional area, to the strongly compressional area. The contents of the same elements in feldspar grain vary in a reverse direction.