EASTERN AND SOUTHERN »UNITED STATES. 
153 
Immediately to the south of the Eocene, according to Loughridge, a belt of sand- 
stone, extending completely across the State, and probably referable to the Grand 
Gulf Grorrp (Miocene 1), makes its appearance. Beginning at the lower part of 
Sabine County, it outcrop.s on the Trinity River near Trinity Station, in the county of 
the same name, where it forms a bluff some 100 feet in thickness, near Chapel HiU 
and Burton in Washington County, at La Grange in Fayette, where it also forms a 
bluff 100 feet in height, and at various points in De Witt, Live Oak (passing near 
Oakville) and Duval counties, reaching the Rio Grande at Rio Grande City. 
Buckley also mentions the existence of “ hard siliceous limestones and sandstones,” 
referable to the newer Tertiary series, in Washington and Fayette counties, which 
evidently form part of the series described by Loughridge. They are stated to be 
practically devoid of fossils, only a few specimens of a bivalve {Meretrix) having been 
found near the centre of Washington County.* The formation here referred to is 
covered all along the coast hne by the deposits of the Port Hudson Group (post- 
Pliocene) . 
Tennessee. 
The Tertiary formations of Tennessee, occupying a tract some 60-75 miles in 
width in the western part of the State, consist of variously colored sands and clays, 
and lignitic deposits, from which traces of zoogene fossils are for the most part absent. 
Plant remains, on the other hand, are sufficiently abundant, clearly indicating the 
conditions under which the deposits in question were laid down. 
The following subdivisions are recognized by Safford,t although the upper and 
lower groups are but provisionally indicated : 
3. Bluff Lignite. 
2. Orange Sand, or La Grange Group. 
1. Porter’s Creek Group (oldest). 
The Porter’s Creek Group, with a stated development of 200 or 300 feet, is 
doubtless, as is suggested by Safford, the northern extension of the “ Flatwoods ” of 
Mississippi, constituting the base of Hilgard’s “Northern Lignite.” Casts of shells 
occur in some of the sandy rocks, but their bad state of preservation precludes the 
possibility of their determination. The belt of surface occupied by this group is along 
the line of the Memphis and Charleston Railroad about eight miles wide, narrowing 
towards the north. The outcrop of the Orange Sand, whose thickness is assumed to 
be about 600 feet, covers a tract some 40 miles in width, the beds dipping at a slight 
angle to the west.J Vegetable remains belonging to fourteen § or more species of 
» Buckley, First Annual Report, p. 63. f “Geology of Tennessee,” 1869, p. 423, et seq. t Salford, op. ciL, p. 425. 
§ Quereus erassinenis. Q. Saffordi, Q. myrtifoUaf, Q. Lydli, Pmnus Caroli, liana, Fagus ferrugmea, 
FAaagnm inaqualis, Andromeda mennifolia (form related to), A. dubia, Sapotacites Amerkanus, Saltx r deniOr- 
nereis, Salix Worthenii, Cemothus Meigsii, Jaglana Saffordiana. 
21 JOUR. A. N. S. PHILA., VOL. IX. 
