XXV111 REPORT OF THE STATE GEOLOGIST. 



the district and the determination of the probability of their existence 

 in workable quantities, and finally the discovery of the existence of tin, 

 which is in itself one of the most important of all. 



TRANS-PECOS TEXAS. 



Prof. W. H. Streeruwitz, having practically completed the topographic 

 mapping of an important area, including the Quitman and Sierra Blanca 

 mountains, parts of the Eagle, Diabolo, and Carrizo mountains, and the 

 foot hills adjacent to them, was instructed to investigate its geology, 

 with special reference to the valuable deposits of precious metals already 

 determined as existing in it. He accordingly went to Fort Davis and 

 got together his teams which had been at pasture, and after some 

 trouble in securing assistants, finally started work with Mr. Ralph 

 Wyschetzki as Assistant Topographer, and Mr. J. A. Taff as Assistant 

 Geologist. Mr. Taff was given the study of the Cretaceous strata of 

 the region, Prof. Streeruwitz working on the crystalline and older strati- 

 fied rocks. The winter having been an unusually dry one, great diffi- 

 culty was experienced in getting water at places convenient to the work 

 without long hauling. The summer heat was also excessive, and 

 lacked the invigorating breezes which are usual in that section. Taking 

 it altogether, the work was done under very considerable disadvantage 

 and even hardship, and it required the best of good nature and all the 

 enthusiasm which the intensely interesting features of the geology of 

 that region evokes to overcome them and succeed as fully as has been 

 done. 



The work that has been done includes the tracing and mapping of 

 the various mineral veins of that district, specimens of all of which 

 were taken and are now in the laboratory for analysis. Of the value 

 of the district as a mining region there can be no doubt, and since ex- 

 cellent water occurs in the deeper workings and is found in the Quitman 

 Valley, there is no longer any fear of a lack of this important item. 



Besides this, the general geology of the region has been studied, and, 

 as far as the limited time permitted, compared with similar adjacent 

 areas ; and while it is not possible to fully correlate the older rocks 

 with those of other regions, much has been done towards the clear un- 

 derstanding of the structure and the stratigraphic relations of the various 

 granites, porphyries, quartzites, marbles, etc. The fine porphyries and 

 marbles have been collected for the purpose of showing their great 

 beauty as building and ornamental stones. 



