NOTE ON THE GEOLOGY OF THE ISLE OF PINES, CUBA 
O. E. JENNINGS 
Carnegie Museum, Pittsburg. Pa. 
It was the good fortune of the writer to be one of a party con- 
stituting an expedition of the Carnegie Museum to the Isle of Pines 
during the month of May, 1910. While primarily busily engaged 
in collecting and studying the flora of the island, the writer inci- 
dentally noted certain geologic features of the island some of which 
are erroneously reported in our present literature. 
The Isle of Pines is situated about 65 miles south and a little 
west of Batabano, a small seaport on the south coast of Cuba almost 
directly south of Havana. The area of the island is approximately 
1,200 square miles and it is divided by an east-west swamp into an 
irregularly oblong northern portion measuring about 30 miles east 
and west and a narrow southern portion about 4o miles long, east 
and west, with its western end tapering out and upcurving toward 
the northwest for a considerable distance beyond the remainder of 
the island. The general features of the northeastern and central 
portions of the island are well described by Hayes,’ who notes that 
the island ‘‘consists essentially of a level plain above which rise 
numerous isolated ridges. The plain itself consists of three distinct 
elements: (1) a low coastal fringe, (2) elevated terraces, (3) interior 
plain.” 
The writer can add little to Hayes’s description of the portion 
of the island covered by the latter; but the lower valley of the Rio 
de las Nuevas was explored to its mouth in the extreme northwestern 
point of the island, and it may be added that here the shallow sea 
is being rapidly reclaimed through the agencies of the mangroves 
and the alluvial materials washed down by the river. This river 
is the largest one in the island and for several miles back from its 
« “Report on a Geological Reconnoissance of Cuba, Made under the Direction of 
General Leonard Wood, Military Governor, by C. Willard Hayes, T. Wayland 
Vaughan, and Arthur C. Spencer, Geologists, t901,” Annual Report of Brig.-Gen. L. 
Wood, Military Governor of Cuba, 1tg01. Vol. I. 
367 
