REPORT 



ON THE 



GEOLOGY OF NORTHWESTERN TEXAS. 



BY PROF. W. F. CUMMINS. 



INTRODUCTION. 



The following report is a statement of the work done in the field by myself 

 and assistants during the past two years. In order to make a full report 

 upon the different subjects it will be found necessary to repeat some things 

 that have been given in previous reports, but this will only be done where it 

 is important to a full understanding of the matter, and where it is necessary 

 to have all the facts presented together. 



In Part I, I have given a detailed statement of the general geology, stratig- 

 raphy, and paleontology of the district. 



Part II is devoted to a review of the economic geology and agriculture. 



Part 111 contains a brief description of the several counties in which coal 

 seams No. 1 and No. 7 occur. This is given for the purpose of directing 

 especial attention to the localities where the workable beds of coal may be 

 found. 



PART I. 

 STRATIGRAPHIC GEOLOGY. 



The following table will show the formations in this portion of Texas, as I 

 have observed them, as compared with the table taken from Dana's Manual 

 of Geology, which will give a definite idea of what I intend to represent by 

 the various divisions and subdivisions: 



DANA. TEXAS. 



Recent Recent. 



Tertiary Tertiary. 



Cretaceous • Cretaceous. 



Jurassic ? 



Triassic Triassic. 



Permian Permian. 



Carboniferous * Carboniferous. 



Sub-Carboniferous ? 



Devonian 



Silurian Silurian. 



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