MANSFIELD: ROXBURY CONGLOMERATE. 187 
(4) Banding is the prevalent type of bedding and is displayed in 
some form in most of the outcrops. 
(5) Lenses are not common and no definite arrangement of them 
has been observed. 
(6) Cross-bedding, ripple-marks, and mud-cracks are relatively 
rare. ‘They indicate that the strata have not been inverted. 
(7) Contemporaneous erosion during deposition is indicated by the 
inclusion of portions of the sediments as pebbles in the conglomerate. 
(8) The sediments were deposited on a surface long exposed to 
subaerial disintegration. There is no evidence of ancient glacial 
scoring. 
Tae NARRAGANSETT Basin SERIES. — Distribution: — Arkose. 
Areas of arkose occur at several places along the border of the Nar- 
ragansett Basin. Exposures are found near Fall River, along the east 
shore of Narragansett Bay south of Tiverton, at Sachuest Neck, along 
the western border of the basin from Natick into Cranston, and on 
some of the islands in the bay. In some localities, as at Steep Brook 
(near Fall River), it does not appear to be actually the basal mem- 
ber of the series (Foerste, b, p. 269) but in all the cases noted it 
forms one of the basal members. According to Shaler the arkose is 
irregularly distributed in patches rather than in extended masses fol- 
lowing an ancient shore line (Shaler et al., p. 53). 
——:—Conglomerate. Conglomerate occurs at varying horizons in 
the series from the base to the top but coarse conglomerates form the 
upper members. ‘The latter rock in the northern part of the basin is 
confined to somewhat elongated synclinal areas extending east-north- 
east. The principal exposures are at Attleboro, Somerset, Dighton, 
and Swansea, Mass. (Woodworth, d, p. 184-185). The coarse con- 
glomerate at Seekonk (Providence VIII, G 18) resembles that at 
Attleboro and Dighton and may perhaps be correlated with the lower 
member of the Dighton group (ibid., p. 174). In the southern part 
of the basin coarse conglomerates occur again at Purgatory, Paradise 
Rocks, and Miantonomy Hill near Newport. 
——:— Sandstone. Sandstone accompanies the coarser and finer 
sediments at varying horizons. It does not form masses extensive 
enough to be correlated and mapped as units but it is interbedded 
with other sediments in each of the major groups of the series. The 
sandstone presents several facies. An important and interesting mem- 
ber known as the Attleboro sandstone is well exposed west of the water 
tower in North Attleboro and again south of Goat Rock and north of 
