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158 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
There is also some evidence of unconformable deposition of the later 
beds upon the Richmond, On the south side of the Clarendon Moun- 
tains the Chapelton beds of the Cambridge formation rest directly 
upon the Minho beds of the Blue Mountain Series, without the inter- 
vention of the Richmond beds; the Catadupa beds at Catadupa are 
interpolated between the Richmond and Chapelton beds; at other 
places, on the north side of the island, the Chapelton beds rest directly 
upon the Richmond, 
Furthermore, the older beds of the Blue Mountain Series, the 
Cretaceous limestones and Richmond beds, are all turned up together 
in this older and more complicated system of foldings, and inseparably 
constitute the summits of the Blue Mountain Ridge, which betwee? 
the altitude of 3,000 and 7,325 feet now protrude 4,325 feet above all 
the later Eocene and Oligocene formations. These facts, especially 
the different nature of the folding, strongly suggest an interruption 
of sedimentation and a corrugation of the strata after the close of the 
Richmond deposition period, and also indicate that mountain making 
movements were operative in Mid-Eocene time, which may have bee? 
the initiation of the uplifts, which had far reaching importance IM 
Antillean history, accompanied by active vulcanism in the Isthmia? 
and probably Windward regions. We are not prepared to interpret 
fully this particular event without further examination of the regio” 
If, on the other hand, this folding did not occur at this particular 
epoch, then the Richmond beds may mark the initiation of a grea 
subsidence so clearly traceable in the succeeding epoch. 
Lime making fossils begin to appear in the upper part of the Rich- 
mond shale where the Cambridge beds begin, — such as Foraminifer™ 
corals, and Mollusks, — and the lime they produce has been taken int? 
Solution and segregated into masses and strata of nodular limestone 
occurring in the shale. "These impure limestones of the Cambridge 
beds represent the transition between the terrigenous littoral deposits 
of the Richmond and the deep oceanic chalks of the Montpelier epoch, 
and are a step in the great subsidence that was then progressing: 
The “Yellow Limestones,” like the Richmond beds, are undoubtedly 
of Eocene age, corresponding to the later portion of that period. 
The rapidity with which the impure nodular limestones of the 
Cambridge grade into Montpelier chalks, composed of Globigerine P? 
void of molluscan fossils, indicates that the subsidence, initiated as abov? 
stated, continued to profound depths, 1,200 fathoms or more, acco 
panied in adjacent localities with great deposits of Radiolarian earths. 
