F. H. Lahee — Metamorphism and Geological Structure. 257 



Districts in which the strikes are conspicuously variable are 

 as follows : Northwest of Watchemoket Cove (D : 1), Ponham 

 Rock-Riverside area (D and E : 2), southeastern Cranston (A :4), 

 Warwick Neck, Bristol Neck, Hope Island, Potter's Cove on 

 Conanicut Island (Loc. 17, E : 13), eastern coast of Mackerel 

 Cove (Loc. 21, D : 14), Beaver Tail Peninsula (Loc. 23, D : 14), 

 Coaster's Harbor Island (Loc. 29, F : 13), Sheep Point district 

 (Loc. 42, F:15), area north and northeast of Warren Neck 

 (H and 1 : 3 and 4), Brayton Point (Loc. 49, J : 5), and the east- 

 ern coast belt. 



Strikes of the western coast belt, then, are fairly regular, 

 although with some rather abrupt changes in direction. On 

 the contrary, strikes of the eastern border region are very irreg- 

 ular and, except along the coast north of Stone Bridge (Loc. 47, 

 1 : 8), have no particular relation to the eastern edge of the 

 Basin. The lack of system here is probably due in part to 

 faulting. 



Dips. — Without entering into detail, we may say that steep 

 dips predominate in the southern portion of the area, and low 

 dips in the northern. Many of the actual readings are recorded 

 on the map. 



Fitch. — A definite northward pitch is indicated in the fol- 

 lowing places : Warwick Neck, Rumstick Neck, Hope Island, 

 southeast coast of Prudence Island, Gould Island, southern 

 Swansea, and High Hill Point (Loc. 45, 1: 11-12). Southward 

 pitch was recorded near Silver Spring (Loc. 3, D-E : 2), half a 

 mile northeast of Riverside (E : 2), northeastern coast of Pru- 

 dence Island, north side of Butt's Hill (near Loc. 35, H : 9), one 

 mile west of Portsmouth Village (H : 9), Coddington Cove (Loc. 

 31, F : 12-13), Beacon Hill (Loc. 32, F : 13), probably north of 

 the Paradise tract (H : 14), and at Easton's Point. 



Pitch is more commonly low than high. In general, it is 

 high where adjacent strikes and dips are variable (Swansea, 

 Coddington Cove, Warwick Neck), or where adjacent dips are 

 steep (Gould Island) ; and it is low in the broad folds (Pru- 

 dence Island, Easton's Point) ; but there are exceptions. 



Axial planes* — Axial planes are vertical or dip either east- 

 ward or westward without regard to whether the fold is nearer 

 the eastern or western border of the Basin. That is to say, 

 with reference to these border regions as comparatively rigid 

 beams through which the forces were applied against the sedi- 

 ments, both overthrusting and underthrusting were produced. 



Continuity of the major folds. — Because of these variations 



in strike, dip, pitch, and symmetry, and especially because of 



the wide water intervals between the land areas, the identity 



of separate folds can rarely be discerned across many miles. 



* See generalized sections, figs. 5 to 7. 



