ITS ADVANTAGES! ITS CONDITrONS ! ITS PROSPECTS I 



calities, it is found south of tlie rnil- 

 rond in jjiojit alinndirii'p. irciiorally on tlie 

 coutnct o£ tlie roil sandy clays and undci'- 

 lyinij' forniatiiius. I'fri-ii.siinoiis fossils 

 are frequently found, fd'tou assotdated 

 wdtli jdiosidiatic iiodnles in feirugiiious 

 clay.stoues. (Jceupyinjr more tliau one- 

 half of north F^onisiana, they impart to 

 the country largely its eharacteristie 

 topoj^raphy and \egetation. The liills of 

 the territory they underlie are eansed 

 by erosion in this format Ion. thousli fore- 

 shadowed ill tlie older terli;'.ry strata and 

 the short-leaf pine, o;ik varieties and 



sums and hickory grow most luxuriant- 

 ly on soils derived from it. In the eenlral 

 part they almost solely make up the 

 surface material, in the western, eastern 

 and sonlhern parts they are more or les.s 

 maiked hy the sands and jrravels of the 

 drift and by diluvial loam deposits along 

 the larger river courses. The coujitry iu 

 which their deposits predominate is 

 easily tilled, and by far richer than any 

 of the other regions of north Louisiana, 

 with the exception of the alluvial bet 

 toms of rivers and creeks, and tlie black 

 prairies. 



'■Cji 





si The Sands and Gravels of the Dpift Sm 





Not alone one of the most interesting for- 

 mations from a scientilic point of view, 

 but also of the highest economic interest, 

 especially on .iccount of its stratigraphi- 

 ca! position, forming the covering mantle 



over all that is beneath. Its sanda 

 spread in a thin sheet over the northern 

 portion of Louisiana, forming immense 

 deposits centi'ally from M-est to east, and 

 thinning out and spreading again, sheet- 

 like, over the grand gulf rocks. Two 

 gravel streams, many miles in extent, 

 accoinjiany the diluvial valleys of the 

 Red river and Ouachita (Mississippi) river 

 to join about fifty miles south of the 

 Vicksburg, Shreveport and Pacific llail- 

 road, and to spread from there over the 

 whole territory. Its sands are a compo- 

 nent part of all the soils of the region. 

 The alluvium along the present river 

 courses, the loam sheets of ancient river 

 bottoms and recent swaniiJS. the soils of 

 the hilly uplands, all with the exception 

 of the red lands, centrally located from 

 north to south, from \vliich recent erosion 

 has removed them, are partly derived 

 from these deposits. The well waters 

 are cleared and filtered by them, espe- 

 cially ill sections where these sands have 

 reacluHl sullicier.t thickness, all certainly 

 features which make them worthy of our 

 consideration. "Wherever they are exposed 

 they show stratiticatiou lines like in the 

 underlying formation of irregularity, 

 however not nearly as irregular as found 

 in those deposits. In their lower portions 

 they gradate into the underlving red 

 sandy cla.vs which are some times found 

 restratitied in the drift, though generally 

 the contact line of both these formations 

 is well and sharply defined. Their direc- 

 tion is from north to south, and their 

 stratification and material (well-rounded 

 gray and ferruginous quartz sands and 

 gravels) leave no doubt that they were 

 ■deposited in waters flowing in a generally 



southerly direction. Silicilied corals, 

 favosites and cyathopilum have been 

 found among the gravels north of Alex 

 jindria. Mostly they consist of quartz 

 varieties and hard silicious sandstone 

 pebbles, and on reaching the grand gulf 

 rocks they are mixed with bowlders de 

 rived from this formation. A few granite 

 bowlders have been found, and also worn. 

 They consist of a gray granite, with 

 black mica and hornblende; and al.so sev- 

 eral smaller pieces of gray and flesh-col- 

 ored granite. The sands consist general- 

 ly of alrao.'^t pure quartz grains, well- 

 rounded, and then again of deep, loose 

 red-colored quartz sands, the grain being 

 coated with peroxide of iron. In the 

 northern portion of the formation con- 

 glomerates have been found in extensive 

 layers, consisting of the pebbles of the 

 drift imbedded in an iron matrix, due to 

 a process of lixiviation of overlying 

 sands. 



There can be no doubt that these sands 

 and gravels represent the southern drift. 

 Probably the glaciers reached to their 

 northern boundary and the waters arising 

 beneath them carried the sands and grav- 

 els, spreading them over the southern 

 territory. The uniformity and thickness 

 of the gravel deposits show that currents 

 of gi eater force, likely derived from the 

 main glaciers, rolled them southward to 

 the drainage channels of the country, 

 preceding the glacial period, were filled 

 \j-ith the sands washed out from the 

 northern mo-aines till they seem to have 

 coveied north Louisiana completely, with 

 the two larger currents, the Red river 

 AW i Mississippi river, west and east. 

 When finally the streams derived from 

 tlie subsiding ice sheets censed to fur- 

 nish new material, a large amount of the 

 gravels and sands were removed to the 

 sea. and the narrowing rivers, still of 

 enormous size and lake-like appearance, 

 deposited at their bottoms gradually the 

 fine mud. forming now the loam slwets 

 of our upl.ind flats, skirted with the peb- 

 bles of former more violent floods. 



