Structures in the southern part of the Cabrach Igneous Area, Banffshire

Bordering the gabbro area of the Cabrach on the south, a belt of serpentine extends for nearly five miles (8 km.) from west to east, and is faulted against Dalradian schists at its southern margin. The ultrabasic rocks are extensively sheared, on predominantly vertical surfaces which lie between 075 ° and 095 ° , and are crossed by north-east faults. Structures within the serpentine belt indicate that it was subjected to sinistral wrench movements, after the emplacement of the serpentines. Many intrusive acid vein-rocks occur in the serpentines. The ultrabasic masses are faulted against hypersthene-gabbos which adjoin on the north; transitional types between gabbro and serpentine have not been recorded. The serpentines occupy a fault-zone, which is considered to be a continuation of the dislocation boundary of the Insch Igneous Complex, as seen to the east of the RhynieBogie Old Red Sandstone outlier.