226 abstracts: hydrology 



parallels the general course of the Matanuska river. The nearly parallel 

 northern edge of the Chugach mountains may also be determined by 

 faulting. In the valley the sedimentary rocks have been strongly folded. 

 In most places definite structual details could not be determined. Two 

 broad simple synclines which are modified by bounding fault planes are 

 known. 



The coal of the Matanuska Valley occurs in several isolated fields, 

 only part of which are included in the area here described. The coal 

 ranges in character from low-grade bituminous to a good grade of semi- 

 bituminous, there being a progressive increase in degree of alteration 

 from west to east. F. J. K. 



HYDROLOGY. — Ground water in Juab, Millard, and Iron comities, 

 Utah. 0. E. Mehstzer. Water-supply Paper, U. S. Geological 

 Survey, No. 277, pp. 162, with maps and diagrams. 1911. 



Juab, Millard, and Iron counties which lie in western Utah, are occu- 

 pied by desert plains interrupted by Basin ranges, and are bounded on 

 the east by the Plateau province. The formations exposed range from 

 Pre-Cambrian to Recent. Much of the desert was covered by ancient 

 Lake Bonneville and is underlain by lake beds. 



Water is found chiefly in unconsolidated sediments confined within 

 rock basins, igneous rocks forming more impervious basins than lime- 

 stones. Alkali flats indicate the water level and therefore serve as guides 

 in prospecting for underground supplies. Flowing wells are obtained 

 from the unconsolidated sediments but not from the rock formations. 



Characteristic of the region are large "pool" and "knoll" springs that 

 yield warm water and are apparently related to faults. The pools are 

 deep reservoirs bordered by projecting shelves formed of vegetable fibers 

 and wind-deposited sand and dust. The knolls are a development of 

 these shelves. Their flow is inversely proportional to their height, and 

 their growth is limited by the hydrostatic head of the water. 



0. E. M. 



HYDROLOGY. — Geology and water resources of Eastancia Valley, New 

 Mexico, with notes on ground-water conditions in adjacent parts of 

 central New Mexico. 0. E. Meinzer. Water-Supply Paper U. S. 

 Geological Survey No. 275, pp. 69, with maps and illustrations. 

 1911. 

 The drainage basin of Estancia Valley, New Mexico, has an area of 



about 2000 square miles and forms a depression that has no outlet. 



Pre-Carboniferous crystallines, Carboniferous and Cretaceous sediments, 



