46 



LOWER EOCENE FLORAS OF SOUTHEASTERN NORTH A.MERICA. 



Cassia eoli^iiiiica. 

 Cassia fayottonsi.s. 

 Cassia silonni. 

 Cassia mai-shallensis. 

 Cassia mississippiensis. 

 Cassia tennossoensis. 

 Celastnis eoliirnitioa. 

 Combretantliites cocenica. 

 Euonynms spliMi<lons. 

 Eiiphoit)i(iphyIliim fayettensis. 

 Launipliyllum fioruiii. 

 Laurophyllum ])refl<imiu. 

 Melastomites aiaericanus. 

 Mespilodaphne pseudoglauca. 

 Mimosites inequilateralis. 

 Mimosites lanceolatus. 

 ilimosites variabilis. 

 MyTcia bentoiionsis. 

 Myrica elaeanoides. 

 Sophora palseolobifolia. 

 Sopliora \vilcoxiana. 

 Taxodium sp. 

 Zizyphus meigsii. 



PIXSON, MADISON COUNTY. 



The following soctiou was measured at the 

 pits of the Piiison Pottery Co., on Bear Creek, 

 near Phison, Madison County, Tenia., at an 

 elevation between .3.50 and 400 feet above sea 

 level : 



Section (It pits of Pinsoa Pottery Co., on Bear Creek, near 



Finson. Madison Counti/. Tinn. 



Feet. 



1. Rcddisli loam 1-2 



2. Gray to orange sand with some thin c-lay laniiiiiv 



and numerous ferruginwis pipes 12 



3. Light-orange to brownish coarse cross-Ijedded 



sand with some fine gravel 10-1 2 



4. Thin iron crusts ^^j- \ 



5. Gray, finely sandy clay becoming brownish bel- 



low; contains scattered lignitic fragments and 

 poorly preserved leaves at some levels 18-20 



There are no well records at Pinson or other 

 means for determining the distance of the 

 plant-bearmg horizon above the base of the 

 beds of Wilco.K age, except the unreliable evi- 

 dence of the probable dip of the upper surface 

 of the Porters Creek clay (of Midway age), 

 whicli outcrops a few miles east of Pinion. 

 The tleep well at Jackson, which starts at 

 nearly the same level as the top of the Pinson 

 section, is of interest in this comiection, since 

 it is only 3 or 4 miles farther from the eastern 

 margin of the beds of Wilcox age. According 

 to Glenn ' it furnished the following section. 



The geologic names used m brackets, however, 

 are my own interpretation of the formational 

 units to which the beds belong. 



Log of deep veil at Jarkson. Tenn. 



[Wilcox gi-oup]; Feet. 



Sandy red clay (Lafayeltoi 12 



Tough blue clay IG 



Coarse white sand 12 



Tough white clay 



White sand ^v^th small gravel and iron crusts. . . . (iO 



Light varicolored clay 43 



Soft feiTuginous sandstone (base of Lagrange) 11 



[Porters Creek clay]: 



Lead-colored fine clay (Porters Creek) 170 



Hard dark rock (limestone?) (base of Porters Creek) 5 



[Ripley formation]: 



AMiito water-bearing sand 13 



^\^lite, very micaceous quicksand 28 



[Selma? chalk]: 



Dark lead-colored laminated clayand lignitic nn- 



caceous pyritiferous sand 29 



[Eutaw? formation]: 



Material similar to foregoing, with shark teeth 



at 418 feet 43 



Light water-bearing sands 77 



If correctly interpreted, this section shows 

 a thickness of about 160 feet of beds of Wilcox 

 age at Jackson, so that at the Pmson jjit their 

 thickness must be between 100 and 150 feet. 

 This would make the horizon at which the fos- 

 sil plants are found within 100 feet of the base 

 of the beds of Wilcox age in this latitude, 

 probably a maximum estimate. These plant 

 remains are neither common nor well preserved, 

 bemg more macerated than most of the mate- 

 rial from the leaf-bearing horizons in the Wil- 

 cox. The following species have been identified 

 from tiiis locality: 



CiBsalpinia wilcoxiana. 



Csesalpinites pinsonensis. 

 Chrysojihyllum ficifolia. 

 Palitu'us pinsonensis. 

 Sabalites grayanus. 

 Taxodium dubium. 



This meager flora is of interest l)ecause three 

 of the species have not been foimd at other 

 Wilco.x outcrops where the flora is much more 

 representatively preserved, although as the 

 stratigraphy is interpreted by me, the base of 

 the beds of Wilcox age at Pinson lies in the 

 abundantly leaf-bearing zone of the Holly 

 Springs sand or midtUe Wilcox of northern 

 Mississippi. 



' Glenn, L. C, op. cit., p. 



ys, ISWG. 



