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greatly depressed. He bases his conclusions, (1) upon their general 
resemblance in contour to land valleys, and (2) upon their direct con- 
nection (in most cases) with existing rivers, save where such connection 
has been manifestly obliterated or obscured by recent coastal deposits. 
In many respects these depressions resemble land valleys, and the 
author’s conclusion has a strong basis of probability. The following 
consideration may, however, be urged against his view. If these 
depressions are drowned land valleys, the soundings ought to show the 
existence of great deltas at their mouths. The author makes no men- 
tion of such deltas and the inference is that they do not exist. Their 
absence, so far as known, is a serious objection to the author’s view. 
The logical inference from Mr. Spencer’s conclusion respecting 
these fjords is that the land formerly had a much greater elevation than 
at present. Assuming that the depth to which the mouths of the fjords 
are now submerged is nearly the exact measure of the former elevation 
of the continent, and making a small allowance for foldings and ampli- 
fied marginal depressions, Mr. Spencer concludes that this elevation 
was not less than 8000 feet along the northern shore of the Gulf of 
Mexico, about 12,000 feet in the vicinity of Yucatan, 10,000 or 12,000 
feet for the Greater Antilles and nearly the same for the southeastern 
margin of the continent. The soundness of this assumption will be 
considered later. Waiving for the moment this point, let us note the 
author’s conclusions. 
In the West Indies Mr. Spencer has found two series of deposits 
which he correlates with the Lafayette formation and with the older 
Columbia series. To these he gives the names Matanzas and Zapeta, 
respectively. They are separated from each other by strongly marked 
unconformities. The Matanzas is likewise separated from the upturned 
and deeply eroded Miocene beds by a great unconformity. Combining 
the data furnished by these deposits with the quantitative element fur- 
nished by the fjords, the author reaches the following conclusions as 
to the oscillations of the land. From an elevation toward the close of 
the Miocene much lower than at present, the land in the Pliocene was 
elevated according to location from 8000 to 12,000 feet higher than at 
present. The close of the Pliocene saw the Antilles and the neighbor- 
ing parts of the main land 100 to 1100 feet lower than at present. 
During this depression the Matanzas limestone was formed. This 
subsidence was followed by a re-elevation in early Pleistocene times, 
probably as great as that of the Pliocene. The fjords crossing the 
