BULL. DEPT. GEOL. UNIV. CALIE 



VOL. 3, PL. 46. 



Weathered surface of orbicular facies of the gabbro showing feldspathie 

 core encased in concentric shells. The thick shells abound in olivine radially 

 disposed and stand out in relief. The deformation of the orbules is well 

 shown to affect the entire series of shells indicating growth in the present 

 relative position. Size ■} nat. 



Thin section of an orbule showing concentric and radial structure and 

 two facies of the interorbicular matrix. Size nat. x 2i. 



