34 GULF TERTIARY OF TEXAS. 



eroded bed of sand which once overlay the shell rock, and the latter probably 

 represents the lowermost Tertiary bed which once overlay this exposure of 

 Cretaceous rock in a continuous stratum. The Saline was worked for salt 

 several years ago, and some large shallow wells were sunk in the clay to col- 

 lect brine. But lately cheap Eastern salt has driven it out of the market. 

 Seven miles south of Palestine is seen a deposit of white cross-bedded sands, 

 very much like those seen at "Red Bluff:," on the Colorado River. They 

 are exposed in numerous gullies and washouts. Between here and Palestine 

 are seen many outcrops of clay and sandy strata, and occasionally the hills 

 are capped with the iron-bearing glauconitic beds. 



One mile south of Elkhart, in Anderson County, numerous fossils are 

 found in glauconitic strata in the bed of a small creek; beyond them are seen 

 clay and greensand beds belonging still higher up in the geological series. 

 From data obtained at these localities the following section can be made: 



1. Brown and black clays, plastic, containing irony pebbles, silicified wood, cal- 



careous nodules 10 feet. 



2. G-ray and yellow brown plastic clays in thin laminae 5 feet. 



3. Dark brown altered greensand, fossil casts, probably 1 foot 



4. Gray laminated plastic clay 3 feet. 



5. Greensand, bard for eight to ten inches and full of shells, interbedded with 



greenish black clay 4 feet. 



6. Gray clay like (4), base of section. 



One mile southeast of Elkhart several wells, thirty to sixty feet deep, have 

 been sunk for mineral water in strata which, geologically, belong directly 

 under these. 



HOUSTON COUNTY. 



Two miles west of Crockett, the county seat of Houston County, is Cook's 

 Mountain, a hill about six hundred yards long, rising gently from the 

 southeast and ending abruptly on the northwest. It is capped by a yellow 

 sandstone containing many shell casts, is cross-bedded, and made up of grains 

 of sand, mica and glauconite. It is underlaid by gray and brown laminated 

 clays. Nine miles northeast of Crockett, on the old San Antonio Road, is 

 an outcrop of shell-bearing rock similar to that seen one mile south of Elk- 

 hart. It is overlaid by very dark lead- black plastic clay, with white calca- 

 reous concretions, and small fragments oi silicified wood. The calcareous 

 concretions are soft and jelly-like when freshly dug, but harden on exposure 

 to the air, causing cracks which are often filled with crystalline calcite. 



MARION AND CASS COUNTIES. 



At Port Caddo, on the Big Cypress River, are found large concretionary 

 masses of limestone, varying from two pounds to two tons in weight. They 



