10 Geological Survey of Alabama. 



The few fossils which have been obtained from this division are mostly 

 in the form of casts. They do not appear to differ specifically from those 

 of the overlying division. 



4. The Lignitic. This is the most massive of the subdivisions of the 

 Tertiary, having a thickness which can hardly be less than 900 feet. It 

 also presents a greater variety in mineral composition, as well as in fossils, 

 than the other divisions. In the most general terms, the Lignitic strata 

 are cross-bedded sands, thin-bedded or laminated sands, laminated clays 

 and clayey sands, and beds of Lignite as well as Lignitic matter, which 

 merely colors the sands and clays. 



With these are interbedded, at several horizons, strata containing 

 marine fossils. For the sake of greater convenience and clearness of 

 description, we present the Lignitic in seven sections, each of which 

 includes, and is characterized by, one or more beds of marine fossils. 

 These sections are as follows : 



1. The Hatchetigbee Section. 175 feet in thickness; made up of sandy 

 clays of prevailing brown or purplish color, containing three or four beds 

 of marine fossils in the upper 75 feet, and of somewhat similar purplish- 

 brown, sandy clays, nearly devoid of marine fossils, in the lower 100 feet. 



All these brown, sandy clays become much lighter colored upon drying 

 and exposure to the weather. 



The following is a more detailed 



Section at Hatchetigbee Bluff. 



1. Light-colored, aluminous rocks, lowermost of the Buhrstone 



20 to 30 ft. 



2. Sandy clays of brown, yellowish and reddish colors interstratified... 



15 to 20 ft. 



3. Heavy-bedded, dark-brown clays (similar to 2), but of darker color 

 when dry 10ft. 



4. Yellowish, glauconitic marl (marine shells) 2 to 3 ft. 



5. Purplish-brown, sandy clays, in the middle of which is a projecting 

 ledge of dark-colored clays, which are harder, but which break up into 

 small prismatic fragments upon weathering 15 ft. 



6. Yellowish-gray sands, striped with thin streaks of brown, sandy 

 clay, indurated in places ..5 to 6 ft. 



7. Bluish-brown, sandy-clay marl, containing many new forms of 

 shells 5 to 6 ft. 



8. Laminated, grayish sands, interstratified with thin beds of brown 

 or black lignitic olay, indurated in places 4 ft. 



