HILL: GEOLOGY OF JAMAICA. 57 
Minho Beds. 
Metamorphosed conglomerate “of subsequent date to that of the 
Cretaceous limestone,” composed of “various crystalline rocks embed- 
ded firmly in a hard crystalline base; the whole is of a greenish color ” 
(Tufr?), 
The Richmond formation outerops in many places a short distance 
back of the sea along the north coasts of the parishes of St. Ann and 
Trelawney. It is well exposed beneath the Cambridge beds south of 
Cambridge along the highway on the west side of Great River, as seen 
by the writer, It also occurs on the south side of the Blue Mountain 
Ridge in St. Andrews and St. Thomas. According to Sawkius,! in the 
latter parish at Blue Mountain Valley it consists of “alternate bands of 
red clay, yellow sandstone and light gray shales, 1,000 to 1,200 feet in 
thickness.” 
In general, this formation underlies nearly all the later rocks, and, in 
Pur opinion, prior to the Montpelier subsidence it occupied an area 
as large or larger than that of the island of to-day. 
From data presented in the paleontological chapter of this work, the 
age of these beds is undoubtedly old Eocene, although it is impossible 
to draw an exact line between these beds and those of the lower division 
Which we have termed Cretaceous, and they are no doubt stratigraphi- 
Cally continuous. 
The uniform alternations of the Richmond beds indicate that they 
Were rapidly deposited over a considerable shallow area of deposition ; 
Since much of this area was the present locus of the island, it is difficult 
to infer the situation of the near-by land from which the material was 
derived ; some of it may have come from the old nucleus of Blue Moun- 
tain Ridge, but in our opinion this was not of sufficient size to afford 
all the material. These facts, together with the presence of foreign 
Material, are at least strongly suggestive of the occurrence of land areas 
during this epoch, concerning the locality of which present knowledge 
18 wholly wanting. 
Tun CAMBRIDGE FORMATION. 
The beds are named after the typical locality of their occurrence at 
Cambridge, between Ipswich and Montpelier, in the parish of St. 
ames, in the northwestern portion of the island, near the junction of 
the boundaries of St. James, Hanover, and Westmoreland. 
1 Jamaican Reports, p. 105. 
