ITS ADVANTAGES! ITS CONDITIONS I ITS PR05PECTSI 



of the Rypsiiiii bod, it is prol)abIe Hint 

 the oi-iiriiial oxlpiit of llio rucli salt l)eil 

 was ( orresponditij^ly ^'reat, and tliat, 

 Uoi.vever it may liave been cncroaclicd 

 upon by snhition and erosion during tlio 

 tertiary and (luaternary jjeriods, it will 

 still be fouml of sullicient tliickness and 

 aeeessibility for exii'oitation at uuuierous 

 points outside of I'elite Anso." 



'!%-» same probabilities hold ffood, 

 thoush in a nineh more restricted sense, 

 of the Calcasieu sulidiur bed. The ol)vious 

 fact that the drift currents have en- 

 croached heavily iiii.^n botli deposits, ren- 

 ders the delerniiiiation of their occurrence 

 in parlicniar localities a matter of con- 

 siderable didiculty and delicacy. 



It Is, therefore. hii,'hly iirobable that 

 similar de!)osits of salt, jrypsum and sul- 

 phur to those now liiiowu may be dis- 

 covered in the near future. 



THE TERTIARY FORMATIONS. 

 At the close of the meso/.oic ago p.)\v?r- 

 ful forces produced on upheaval of this 

 cretaceous ridge, causing many fractures 

 and folds, and gave to Louisiana an out- 

 line of its future drainage ciumnels. This 

 ridge, trending diagonally across the 

 state, formed two immense shallow 

 basins, the Red on the west and the 

 Mississippi rtii the east. Into these shal- 

 low waters were deposited the sand and 

 shales of lignites of the early 



EOCENE. 



yi Louisiana tliis is known as the 

 "lower lignitic," since lignite and lignitic 

 clays abound. In DeSoto and Sabine 

 parishes beds of lignite occur in many 

 places. The country underlaid by this 

 formation covers nearly the entire north- 

 western portion of the state, but ^vhile 

 this geological formation underlies this 

 entire section, it rarely reaches the sur- 

 face, and, therefore, takes little or no 

 part in soil formation. The soils here, 

 as in other parts of the state, are being 

 formed from tlie yellow, sandy clays and 

 drift sands of the quaternary age, de- 

 posited after the state liad definite form 

 and shaiie. But this section is to be 

 emphasized by virt'ie of a large amount 

 of lignite which it '-ontains. On the Sa- 

 bine river an outcrop of 14 feet in tliick- 

 ness is reported in the banks. Nine miles 

 southwest of Manstield a lignite seam 

 3 1-2 feet thick forms the bed and bank 

 of the stream. The coal preserves its 

 woody structure, is glossy and very firm. 

 Mixed with charcoal, it is used l)y local 

 blacksmiths with success. This coal con- 

 tains, by analysis, 5.!)4 per cent, ash, 

 38.93 per cent fixed carbon, 38.52 per 

 cent volatile matter, and IC.Gl oer cent 

 moisture. It has also I.IU per ce.it sul- 

 phur. 



MARINE CLAIBORNE. 



The deposits of this group are resting 

 directly and conformably upon the lower 

 lignitic. North of the Vieksburg, Shreve- 

 port and Pacific Railroad these deposi's 

 along their western boundary trend 

 northwest. South of this railroad their 

 course is nearly due south. The eastern 

 bonndar.v of this group passes through 

 Gibbsland, in Bienville parish. This 

 formation runs as far south as Alexan- 

 dria, where it is crossed by the sands of 

 the grand gulf group. Tliis formation 

 nowhere reaches the surface, and 

 therefore, takes no part in the formation 

 of the soils, but it is characterized by 

 the presence of marls and glauconite, 

 which can, under proper conditions, be 



utilized as valualjle amendments to soil 

 fertility. 



Uri'ER LIGNITIC. 



The eastern i)ortion of tlie hills of 

 north Louisiana are uiulerl.-iid by this 

 formation, which rests conforip.ably ii-pon 

 the Claiborne sands and clavs. hi lith- 

 ological matt-rial and physical structure 

 this group is strangely similar to the 

 lower lignitic, from which it is scpar- 

 at(Hl by the marine Claiborne. Beds of 

 lignite occur also in this formation, but 

 they are rarer and not so thick as in the 

 low(>r lignitic. 



While the above groitps wore being de- 

 posited, the dry laud w.as slowlv ••niorjr- 

 ing from the gulf and the rivers and 

 creeks were sculpturing a landscape 

 similar in topographical features to that 

 presented to-day. P.ut here the scene 

 changes and a slow submergeuee takes 

 place. Muddy shallow seas prevail and 

 a heavy dPi)osit of grav clay is placed 

 over all the hills of north Louisiana. 

 These clays arc called by Dr. Lerch 



ARCADIA *CLAYS. 



"They cross the state from east to 

 west, resting upon the deeply eroded sur- 

 face of the lower lignitic, marine Clai- 

 borne aud upper lignitic formations, 

 reaching northward into Arkansas, west- 

 ward into Texas and eastward to the 

 flood-planes of the Mississippi and south- 

 ward to the calcercous marls aud lime- 

 stones of the overlying Jackson and 

 Vieksburg groups." They are of the high- 

 est economic importance, since thev form 

 the water-carrying beds for the springs 

 and wells of north Louisiana, and enter 

 largely into the composition of the soils 

 of the creek bottoms. The water coming 

 from them is remarkably pure, while the 

 soils made from them are cold, tenacious 

 and hard to drain. When mixed with the 

 sands and sandy clays of the surround- 

 ing hills, they give soils of fair fertility 

 and susceptible of great improvement. 

 In Bossier and Webster parishes they 

 constitute the soils of the large flats 

 which characterize this section of the 

 state. These clays can be used for pot- 

 tery and, when properly mixed with sand, 

 make good brick and fire clay. 



THE .TACKSON AND VICKSBURG 

 GROUPS. 



have not been clearly separated in this 

 state. They occur, resting conformably 

 upon the Arcadia clays, in the southern 

 portion of the hills of north Louisiana, 

 and constitute the "black prairies" of 

 this section. They run in a band about 

 thirty miles wide across the state. From 

 the preliminary report upon the hills of 

 Louisiana, made by Dr. Lerch, under 

 the auspices of the experimental station, 

 and published as Part II, Geology and 

 Agriculture, the following is extracted: 



JACKSON GROUP. 



They are of high economic importance, 

 not alone on account of the litholojiical 

 material they consist of. but especially 

 on account of their position. They enter 

 and frequently make up the soils of a 

 vast extent of couiitry solely, cause an 

 entirely different vegetation, of which 

 hawthorns, persimmons, black haw and 

 crab apples are et^pecially characteristic, 

 and are the cause of the black bald 

 prairies frequently mentioned. The soils 

 derived from this formation ure generally 



