44 



LOWER EOCENE FLOIUS OF SOUTHEASTERN NOI!Tll A.MEUR'A. 



of havino; been nearly if not entirely contiinious 

 at the time of formation and furnishes strikina; 

 evi(h>nce of the pakistrine character of the early 

 Wilcox, the low surface of the Wilcox mainland, 

 the absence of terrigenous materials m the 

 Wilcox lagoons at this time, and tlie liighly 

 ferruginous character of I lie run-off, jiossibly 

 derived from the glauconite of the Upper Cre- 

 taceous mamland to the east. 



Iron salts in the presence of carbonic acid and 

 certaiji bacterial organisms are converted into 

 ferrous carbonate and deposited directly from 

 solution. The ferric hvdroxide formed would 



So far as I have observed, these iron carbon- 

 ates arc unfossilif(>rous, and they lie somewhat 

 above the leaf-bearing ferruginous sandstone 

 at Hurleys. 



More than two l(>vels are developed at other 

 localities, and these levels are probably not 

 exactly synclironous throughout northeastern 

 Mississipi)i. 



SECTIONS IN TENNESSEE. 



GRAND .JUNCTION, KAYETTE COUNTY. 



The beds numberetl 1 to 6 m the following 

 section were measured about 1 mile south of 



be reduced to ferrous hydroxide by the action Grand Junction, Fayette County, Tenn., at an 



of the decaying organic matter and the carbon elevation of about 570 feet above sea level, 



dioxide freed m the accompanying reactions The rest of the section (beds numbered 7 to 9) 



woidd unite with the ferrous hydroxide, form- is taken from a well record at Grand Junction 



ing the normal ferrous carbonate. given by L. C. Glenn.' 



Section of beds of Wilcoz age near Grand Junction. Fni/ettc Counti/, Tenn. 



1. Yellowish loamy stmtifiod .«aud becoming coarser below, in places purplish; contains a few Feet. 



ferruginous .sand-fillod ' ' bombs " ; thickens to the east 2-15 



2. Small white clay lens 0-2 



3. Buff to gray stratified sand 3 



4. Gray clay, more or less sandy and generally thinly laminated, with ferruginous films or a few 



thin iron crusts; in places a pure hard ringing white clay 15-20 



5. Iron crust not far above base of formation -iV~ i 



6. Coarse gray to brown sand similar to lower part of bed No. 1 . with here and there argillaceous 



bands an inch or two in thickness 



7. \Mute sharp sand 



§. Wiite plastic clay 



9. Reddish sand, coarse at top and l>ottom and finer in the middle, penetrated 



5- 6 



20 



2 



139 



Brown compact sand 10' 



xReworked gray clay l'-4' 



Cross-bedded brownish sand with much angular 

 pea gravel and iron crusts 5'-lo' 



Pinkish ferruginous leaf impressions are (lis- The plant-bearing daj- is obviously a lens, 

 tributed throughout bed No. 4, usually between since it thins within a short 'distance both to 

 the clay laminie, and arc as a rule poorly pre- the north and to the east. There is a gradual 

 served. A few better-preserved remains have horizontal transition to the east from this clay 



to brownish sand, and the sands 

 contahi transported masses of 

 the gray clay, indicating two 

 local unconformities at different 

 levels in the beds of Wilcox age. 

 Some geologists consider these 

 reworked clays as proof that 

 the upper part of the section 

 represents a thin stratum of the 

 socaUcnl Lafayette lying nn- 

 conformably upon the Wilcox. 

 Those who arc^ disjiosed to accept this interpre- 

 tation are confronted in the ])receding sectitni 

 by two Lafayette formations separated from 

 each other by an unconformity fuUy as marked 

 as that at the base. 



PI 



Plaht^bearing~gray^jay£"- 



Gray loosesand 



Transition tocoarse brown 

 sand with some reworked 

 gray clay 



FiGUEE 3.— Diagrammatic section of Wilcox deposits near Grand Junction, Tenn 



furnished the following determinabh^ species, 

 among which Euonymus splendcnn in all sizes is 

 by far the most abundant form: 



Cercis wlcoxiana, Grewiop.sis tonno.sseensis. 



Combretum ovalis. Oreodaphne obtusifolia. 



Euonymus splendens. Tcrminalia lesleyana (?). 



About 100 feet southeast of tlu> plant-bearing 

 section the gullies expiise the section showTi diti- 

 grammatically in figure 3. 



1 Glenn, L. C Un(ioi(,Toiiii<I waters of Tennessee and Kentucky west 

 of Tennessee Kiver and of an adjaeent area in Ulinois: U. S. Geol. Sur- 

 vey Water-supply Paper lil-l, p. 79, 190(5. 



