REPORT OF THE STATE GEOLOGIST. XXXI 



in them. Those so far observed in Texas formations will be found 

 enumerated in the general description. 



A reference to the table on Plate III will give at a glance the general 

 relation existing between each formation and those adjacent. From 

 this table it will be seen that we have in Texas representatives of 

 nearly every group and system known in the United States, and also 

 the Lower Cretaceous and Lower Permian series, which are rarely rep- 

 resented elsewhere on this continent. The detail and full definition 

 of the boundaries, character, and resources of each of these formations 

 remains as the future work of the Survey. 



The work of the past year has mainly been directed to the acquire- 

 ment of a knowledge of the different formations occurring in the 

 State, the character of materials composing them, their economic pos- 

 sibilities, and some idea of their extent, as a basis for our future work. 

 The work was necessarily of the character of a reconnoissance, and 

 there still remains much of the same kind of work to be done, but the 

 main facts as here presented give us a good working knowledge of 

 these conditions, and enable us to formulate our plans in such manner 

 as will secure more rapid and satisfactory returns in the future. 



In a general geologic description of a region it is customary to begin 

 with its older rocks, as being not only the first in time of formation but 

 in a measure the source from which were derived the greater part of 

 the materials entering into the composition of those that succeed them. 

 In reversing this method, as is done in the following pages, respect has 

 been had merely to convenience of description by beginning at those 

 formations the main features of which are best known to our general 

 public, and therefore most readily explainable in a simple manner. 



GULF COAST FORMATIONS. 



The exposed portions of those formations which occupy the Coast 

 District (which is, as has been stated, the continuation of that bordering 

 the Gulf shore of the States east of us) comprise the Coastal Clays, the 

 entire Ghilf Tertiary Section, and part of the Cretaceous System, and 

 these are arranged in belts, the general boundaries of which are ap- 

 proximately parallel to the present coast line. The normal dip or in- 

 clination of the strata of these formations is towards the southeast, and, 

 while it is very gentle, it is greater than the average slope of the pres- 

 ent surface in the same direction, and therefore the newest beds are 



