30 GEOLOGICAL RECONNAISSANCE OF THE DOMINICAN REPUBLIC. 



South of the Vega Real, extending from Loma de los Palos eastward 

 nearly to Sabana de la Mar, there is a plateau that stands 100 meters or 

 more above the surrounding land. From a distance this plateau appears to 

 be nearly flat, but closer inspection shows that it is deeply pitted with large 

 cavities. It rises somewhat toward the east, and near Sabana de la Mar it 

 attains an altitude of about 200 meters above sea level. This plateau is 

 underlain by massive coralliferous limestone, probably of Miocene age, and 

 is drained through underground passages. A trail from Cevicos to Villa 

 Rivas, by far the most difficult trail travelled by any member of the ex- 

 pedition, crosses this plateau. From a point several kilometers south of 

 Cevicos, where it first climbs to the plateau, the trail follows the course of 

 an underground stream, which is marked by a chain of deep sinkholes con- 

 nected by low passes. The surprised traveller scrambles down one side of a 

 sink and up the other, over jagged masses of sharp limestone, only to find 

 another sink, equally difficult and dangerous, just before him. There are 

 said to be 24 of these holes to be crossed, but the weary traveller loses count 

 long before he emerges upon the level plain of the Vega Real. 



The part of the Cibao Valley that lies east of Santiago is abundantly 

 watered (PL IV, A), but the part west of Santiago becomes progressively 

 more arid westward, and open grassy meadows give way to cactus and mes- 

 quite clad plains (PI. IV, B). Most of the water used for domestic pur- 

 poses in this western area is carried on the backs of burros from Rio Yaque 

 or its tributaries, in some places for as much as 20 kilometers. 



The Cibao Valley is thickly settled, progressive, and prosperous. 

 Santiago de los Caballeros, the second largest city in the country, is the 

 metropolis of the region. It has direct rail connection with Puerto Plata 

 by the Ferrocarril Central Dominicana, a government-owned railroad, 

 which connects at Moca with the Ferrocarril de Santiago y Samana, giving 

 access to the port of Samana. Other towns worthy of mention are Moca, 

 La Vega, San Francisco de Macoris, and Villa Rivas on the east, and 

 Navarrete, Valverde or Mao, Guayubin, and Monte Cristi on the west. 



CORDILLERA CENTRAL. 



GENERAL FEATURES. 



The great mountainous backbone of the Dominican Republic, the Cordil- 

 lera Central, starts from low hills at the extreme east end of the island, rises 

 gradually towards the west and attains its greatest height in the west- 

 central part of the island. Its westward extension forms the north range 

 of the Republic of Haiti and is connected by the Montagne Noir with the 

 Sierra de Neiba. The range is widest in the middle, where it attains a 

 width of 130 kilometers, extending from a point near Santiago to the 

 latitude of Azua and sending a spur to the shore of the Caribbean Sea at 

 Sabanabuey. 



