XXIV REPORT OF THE STATE GEOLOGIST. 



important work, but it was found impracticable to complete it. Conse- 

 quently only a brief statement is made concerning it. 



THE CRETACEOUS AREA. 



In February. 1890, Mr. Robt. T. Hill, having resigned from his pro- 

 fessorship at the State University of Texas, was appointed Geologist in 

 charge of the Cretaceous area. Under this appointment he first pre- 

 pared his paper on "The Cretaceous Rocks of Texas and Their Eco- 

 nomic Uses," for the First Annual Report. 



This report comprised the material contained in the introduction to 

 Bulletin No. 4, together with some new matter which had been ob- 

 tained in tracing the Cretaceous-Tertiary parting north of the Colorado 

 River, to which was added brief mention of the economic features of 

 the formation. 



His work for the present year, as outlined in his letter of instruc- 

 tions, was the economic geology of that portion of the Cretaceous lying 

 north of the Colorado River, including its soils, marls, building and 

 paving stones, cement and lime materials, artesian water conditions, 

 and such additional work in general or special stratigraphy as might 

 be carried on with the above ends in view. 



He began field work in the latter part of March, starting from Tex- 

 arkana to make a study of the region adjacent to Red River. He con- 

 tinued to work westward, taking in such portions of the Indian Terri- 

 tory as became necessary to the proper understanding of his region. 

 With his various assistants he covered as rapidly as possible the area 

 of the Cretaceous north of the line of the Texas and Pacific Railway, 

 and also considerable portions to the south of that line such as had not 

 previously been examined. 



His work, as detailed in his letters from April 8 to July 23, proved of 

 the greatest interest both from a scientific and economic point of view. 



Among the facts thus determined were: the presence of a great fault 

 north of Denison, which has its effect on the present course of Red 

 River; the absence in North Texas of the "Alternating Beds" of the 

 Fredericksburg Division ; the separation of the Trinity Sands, between 

 Comanche and Wise counties, into two beds by a stratum of limestone, 

 which has, in some places, a thickness of two hundred feet ; and the 

 presence of greensand marls. 



On the 26th of July he was called in for consultation in regard to 



