176 DE. C. E. TILLET ON THE PETEOLOGT OF [vol. lxxix, 



form an intimately related group of rocks : for. in the upper 

 portions of the mica-schists and in the lower bands of the Green 

 Schists, there are intercalations of Green Schists and mica-schists 

 respectively. 



One of the best sections for studying the relations of the Green 

 Schists and the mica-schists in this area is the coast-section south 

 of Biddle-Head Point. At Sunny Cove there are evidences of 

 interbanding of mica-schist with the Green Schists, and in the 

 main mass of the Green Schists at this place the dip is 33° south- 

 westwards, overlying the mica-schists on the north. This south- 

 westward to southward dip is continued along the coast, becoming 

 less steep, until at Limebury Point the beds show evidence of 

 rolling, and contain narrow bands of mica-schist and chlorite- 

 mica- schist. 



The continuity of the Green- Schist outcrop along the southern 

 coast is broken at Rickham Sands, where faulting has brought into 

 contact the mica-schists and the Green Schists. This fault, as 

 Ussher mapped it, is a dip-fault which can be traced inland to 

 Piickham Farm. A second fault is developed at the eastern end of 

 Seacombe Sands, and from that point to Moor Sands the coast is 

 formed of mica-schists. 



The northern boundary of the great mass of the Prawle Green 

 Schists is exposed in Moor Sands on the west, and at Horseley Cove 

 on the east. Inland the boundary-line is for its greater length 

 obscured, its approximate position being in cultivated fields. 



At Moor Sands the junction -beds are highly inclined, but the 

 superposition of the Green Schists is maintained. Between this 

 point and Prawle Point the high inclination obtains, until at the 

 signal-station the Green Schists dip at 40° to 45° in a direction 

 slightly west of north. 



In the eastern coast-section at Horseley Cove, the beach-reefs 

 display low dips and undulations, finally passing southwards into a 

 northward dip at Langerstone Point, where there are numerous 

 intercalated sedimentary bands exposed on the shore. It is, 

 therefore, probable that, in the Prawle mass of the Green Schists, 

 a compressed synclinal structure is developed. 



Igneous bands are developed in the mica-schists north of 

 Horseley Cove, and narrow bands of basic ashes are present in the 

 rnica-schists below the Start Point Lighthouse. 



The first evidence of the Green Schists forming the northern 

 band of the anticlinorial fold along the Salcombe estuary is 

 furnished by a narrow band dipping northwards close to the 

 Portlemouth Ferry-steps, and the southern outcrop of the northern 

 Green-Schist band is revealed at various points along the southern 

 shore of Southpool Creek. A great development of the Green 

 Schists, with intercalations of mica-schist, follows north (with 

 a dominant northward dip) to the junction with undoubted 

 Devonian rocks in the inlet almost opposite Tosnos Point. The 

 Green Schists are again exposed in Waterhead Creek, and on both 

 sides of the Southpool Creek near Gullet Farm. 



