The Stratif/rap/ii/ of X. W. Louisiana. — ]'a>(</ha)i. 207 
stone, sulphur, and gypsum, are not infrequent. On Sees. 81 
and 32, Twp. 10 N., R. 4 W., near Atlanta, in Winn parish, 
there outcrops a hard blue limestone which is traversed by 
minute fissures. In these fissures a small amount of gold has 
been found. 
In the Cretaceous of Louisiana /'J.ro(/i/ra co.s/afrt has been 
found; as this fossil is characteristic of the Glauconitic di- 
vision of the Upper Cretaceous, the strata in Louisiana bear- 
ing this fossil should be considered of Glauconitic age. 
Hilgard* mentions Gri/pluea pifcheri also; but he is without 
doubt mistaken in his identification, as G. pifcheri is a Co- 
manche series fossil and does not occur in the Upper Creta- 
ceous. 
The relations of the Eocene to the Cretaceous, as conceived 
by Hopkins, + is shown in a section across the state, published 
in his first report. He indicates tiiat there are knobs of Cre- 
taceous, around which the Eocene was deposited, but does not 
state explicitly the relation existing between the two series. 
Dr. Lerch on page 72 of his Second Report gives the fol- 
lowing explanation : 
If Wf' connect the jibovc localities we obtuin ;iii irri'i/uhtr liiu' with a 
northwesterly I rend, re veal in. in- the distribiitioii of the cretaceous depos- 
its in north Louisiana as far as explored, over 1.000 feet in thickness. 
Nowhere outside of the outcrops bores have reached the cretaceous, not 
even in the nearest vicinity, wells of considerable deptli have penetrated 
tlie shales of the lower lignitic and marine Claiborne which surround 
these islands. It is most probable, however, that at Shreveport the ar- 
tesian bore, 1,100 feet in depth, has penetrated the tertiary strata and 
that the water flows from the upper cretaceous sands. .Iiidgini;- fniin 
the bores and exposures of this substructure of Louisiana and excludini;- 
the overlying later deposits, it rejiresents a ridLiv willi steep hillsides 
and occasional hi<;'h peaks with almost perpendicular di'cliv ities. 'I'he 
exogyra costata and the «r-ryj.ha^a pitcheri found in close proximitv in 
these outcrops, as well as the Eocene directly overlaying and restinu' 
against the cretaceous, seem ui prove that at the close of mesozoic time 
enormous plutonic forces convulsed, fractured, faulted and folded the 
cretaceous strata, throwing up mountain chains of vast extent and 
raising them far al)o\e the waters of the gulf. It seems to us more than 
possible that these grand disturbances invohe the whole of i hr southern 
cretaceous, and that the enormous downthrow along the balcones and 
the basaltic outbreaks along that fault are contemfxiraneous with the 
*Prel. Rep. of a Geol. Reconn. of La., \). II. 
fFirst Ann. Rep. of the (Jeol. Sur. of La., \>. TS. in the La. .'-itate I'niv 
Rep. for l.S()!», published 1S70. 
