CHAPTER VII. 



GEOLOGY AND WATER RESOURCES OF THE VICINITY OF 



MONTE CRISTI. 



By Clyde P. Ross. 



CHARACTER AND PURPOSE OF THE WORK DONE. 



The town of Monte Cristi, the metropolis of the western part of the 

 Cibao Valley, is on the north side of the mouth of Rio Yaque del Norte, 

 near the seacoast, in the northwestern part of the Province of Monte Cristi. 

 The area here considered, which includes most of the irrigated country 

 under cultivation around Monte Cristi, extends about 30 kilometers east 

 of the town and is bounded on the north by the Monte Cristi Range and on 

 the south by the Cordillera Central. (See map, PI. XIV.) Reconnaissance 

 trips were made not only in the valley but through neighboring parts of 

 the Monte Cristi Range and in the foothills of the Cordillera Central near 

 Dajabon. 



The object of this investigation was to gain a general knowledge of 

 the geology of the region and to ascertain the probability of obtaining 

 supplies of groundwater, particularly artesian flows. Supplies of stored 

 water are greatly needed in this region for, according to the most reliable 

 information obtainable, the rainfall here amounts to only about 31 centi- 

 meters a year. 1 The success of the principal local industries, farming by 

 irrigation and stock raising, is therefore dependent upon water derived 

 from sources other than direct rainfall. The present principal source of 

 water is Rio Yaque. The few wells in the region are shallow, and the 

 water in many of them is salty. The water obtained from these wells is 

 used for cattle and, if not too salty, for domestic purposes. 



The examinations on which this report is based were necessarily hurried. 

 More detailed investigations, aided by the drilling of test wells, would be 

 necessary to warrant any but the most general conclusions as to the possi- 

 bility of obtaining a sufficient supply of groundwater. 



TOPOGRAPHY. 



The dominant topographic features of this region are the broad valley of 

 Rio Yaque and the two mountain ranges that bound it — on the north the 

 Monte Cristi Range; on the south the Cordillera Central and its outliers, 

 the Cerros de Jacuba. 



Rio Yaque del Norte, the largest stream in the Republic, is nearly 240 

 kilometers long and is about 100 meters wide near its mouth. In the lower 

 part of its valley the river has built an extensive delta, across which run 



1 Oral communication from Mr. D. C. Terry, of Monte Cristi. 



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