CHAPTER VIII. 

 GEOLOGY OF THE PROVINCE OF SAMANA. 



By Clyde P. Ross. 



The conclusions here recorded concerning the geology of the Province of 

 Samana are based on observations made by the writer during a two weeks' 

 reconnaissance between Sanchez and Santa Barbara de Samana, on the 

 north shore, and during a trip by motor boat along the south coast of 

 Samana Bay, as well as on observations made by Wythe Cooke at the west 

 end of Samana Peninsula and on observations made by T. W. Vaughan, 

 D. D. Condit, Wythe Cooke, and the writer during a day spent at San- 

 chez while en route to Santo Domingo City. 



TOPOGRAPHY. 

 SAMANA PENINSULA. 



Relatively low, rugged mountains cover almost the entire area of 

 Samana Peninsula. The mountains at the west end of the peninsula are 

 seperated from the Cordillera Septentrional by a flat, swampy area called 

 El Gran Estero, which was in relatively recent time beneath the sea, 

 when Samana Peninsula was an island. Recent species of corals and 

 oysters were found in the soil along the road between Sanchez and Matan- 

 zas, at the west end of the mountains, at an altitude of less than 15 meters 

 above sea level. As the peninsula is shown as an island on some of the 

 earlier maps the sea probably continued to occupy this area even within 

 early historic time. 



The mountains of the peninsula consist of three parallel ranges. The 

 southernmost range has a maximum altitude of about 300 meters above 

 sea level, but the central range rises to at least 480 meters. The central 

 range is drained northward. All the streams that enter Samana Bay 

 drain only the southernmost range and the narrow coastal plain. In the 

 area between Sanchez and Los Cocos the streams originate in springs at 

 the base of the southernmost range. 



The east end of the peninsula is a more or less flat limestone plateau, 

 which rises to an altitude of probably 100 meters above the sea and merges 

 westward into the mountains. The streams on this plateau disappear in 

 sink holes and flow underground to the sea, where some of them are said 

 to emerge as springs along the beach. 



A narrow strip of low, rolling country, which probably includes the dis- 

 sected remnants of a series of sea terraces, fringes the mountains along 

 the south coast of the peninsula between Sanchez and Los Cocos. (See 

 PL III, C.) The highest parts of this rolling terrane stand about 30 meters 



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