14G 
THE TERTIARY GEOLOGY OF THE 
Considerable uncertainty still exists relative to the age and position of the deposits 
eonstitnting the Northern Lignite. Their local variability, uniformly moderate dip 
(or even horizontalitv), and dearth of fossil (animal) remains, combined with the cir- 
cumstance that at only a few localities is a superposition of strata distinctly observable, 
render a positive determination difficult, if not impossible. That the region of the 
“ Flatwoods ” bordering the Cretaceous formation on the west, and extending to the 
nortliern boundary of the State, is of the same age as the formation occurring in 
Liuderdale and Neshoba Counties, which can be distinctly traced beneath the 
Siliceous Claiborne or “ Buhrstone,” there can be but little or no doubt, and, there- 
fore, as far as the age of this section is concerned, nothing further need be said. But 
whether all the lignitic territory lying north of the marine Tertiary bomidary, and 
occupying nearly the whole northern half of the State, belongs to the same geological 
period (Eo-lagnitic), as Hilgard appears disposed to believe,* may well be considered 
doubtful. On the contrary, it appears far more reasonable to suppose, seeing the 
position occupied by the outlier of the Siliceous Claiborne in Carroll, Holmes, Attala 
and Choctaw Counties (Shongalo, Valden, etc.), that the lignitiferous deposits, or at 
least a portion of them, of these counties, as well as of Amazon, Madison and Leake, 
and possibly also of A’allabusha, belong to a much newer period, not improbably the 
Jacksonian. Hilgard clearly affirms that the marine outlier here referred to is as well 
over as underlaid by lignito-gypscous strata ;t again in a boring made in the Jackson 
penitentiary well, and i)enetrating, as stated, to a depth of 470 feet, what would 
a])pear to lx; a continuation of the Shongalo (Siliceous Claiborne) deposits was struck 
at 450 feet, or 418 feet below the strata recognized to be of Jackson age. Granting 
the correct determination of the Shongalo deposit, it is evident that the 418 feet of 
lignitic clays passed through before the 20 foot shell-bed was reached, and regarding 
which “ there can be little doid)t that it, also, is of the Claiborne age,” must represent 
something much newer than the basal lignites, and not improbably, as has already 
been suggested, the Jacksonian (at least in principal part).J Such a reference woidd 
be much more nearly in accord with the disposition of the Jackson beds in the 
adjoining State of Louisiana, where, according to Hopkins, the strata are also veiy 
lar^dy lignitic, and where they occupy the greater part of the area included between the 
ic 'sbuig line and the Arkansas boundary.§ They doubtless extend for a con- 
sidenible distance into Arkansas, largely entering into the formation of the Mississippi 
* P. 109 ; Am. J. of Science, new ser., vol. xlili, p. 35. 
the Silireo!!!! aaih„n.ri7 hTs gl^fogiclT considering it an exponent of 
and Alabama” (Am. .1 of Sci^^ r -*!^ State, m a later article, “On the Tertiary Formations of 
p. 34, and, again, on the follow iim ,.n.r« deposit in qmstion is referred to the Lower Lignite on 
and Attala. ” '’"S'* " “«***«» of “the marine outlier of the Claiborne age, in Carroll 
I A..™., .r .U. G.o,„e„., s„„,, „r Lo„, p. 8, „,o. 
