THE FAYETTE BEDS. 51 



in the sand beds many impressions of leaves very much resembling those of 

 the palmetto which grows on many parts of the Gulf shore of to-day, together 

 with numerous fragments of stems and trunks of the trees.* 



The resemblance of these Fayette Beds to the Grand Gulf Beds of Louis- 

 iana, Mississippi, and Alabama is very remarkable. There are only two 

 striking differences, (1) the increase of calcareous matter in the Texas beds; 

 (2) the greater thickness of the clays at the base of the series in Texas than 

 in the other Gulf States. The first difference has already been explained ; the 

 second is accountable, as suggested before, by the fact that as we go west 

 from the Mississippi River the land or non-marine character of the stratigraph- 

 ical equivalents of the Vicksburg Beds rapidly increases, and in the region 

 of the Brazos and Colorado rivers very few species of the characteristic 

 fauna of that epoch are found. ^Therefore it is possible that part of the clays 

 of the Fayette Beds represent the era of the Vicksburg strata. In all other 

 respects the Fayette Beds are identically similar to those of the Grand Gulf. 

 They both overlie the marine strata of the region, and both occupy the strati- 

 graphical position on the Gulf coast that is held by the Miocene and Pliocene 

 strata of the Carolinas and other Southern States on the Atlantic coast. Both 

 are composed of sands and clays in equally variable stages of induration, both 

 contain impressions of land flora, and both are equally barren of all traces of 

 animal life. 



Hilgard, in speaking of this last fact, says: "I have heretofore * * * 

 remarked that such absolute dearth of fossils in a formation whose materials 

 are so well adapted to their preservation staggers belief, and that I interpret 

 the calcareous seams and concretions found in some portions of the formation 

 as derived from the long continued maceration of an apparently copious 

 fauna, as is exemplified in the Quaternary Beds of Cote Blanche on the 

 Louisiana coast, and notoriously in the limestone of the coral reefs." 



The prairies underlaid by the Fayette Beds vary from a hilly, rolling 

 country to a flat plain This character of topography is to be expected in a 

 formation differing so much in its degree of induration. The soft strata tend 

 to form the flat country, while the interbedding of alternate hard and soft 

 beds produces a region of rolling or abrupt hills. As a rule the lower part 

 of the formation appears to be harder than the upper, the natural result of 

 age in such strata. Consequently, as we enter the region underlaid by the 

 Fayette Beds we meet with hills, abrupt slopes, steep river bluffs, and a roll- 

 ing country. As we go southeast — that is, towards the upper part of the 

 formation — we come into a more gently rolling, and then a slightly undulating 



*Hilgard speaks of palm wood and other vegetable remains at Bayou Pierre, Rocky Spring, 

 and elsewhere in Mississippi. " Geology and Agriculture of the State of Mississippi," 1860, 

 p. 149. 



