AND THE SALT DEPOSIT ON PETITE ANSE ISLAM), 19 



No. 4 of this section doubtless corresponds to the fossiliferous clay stratum on the 

 opposite slope. The latter appears to be underlaid by sandy strata, which from 

 their composition and bedding might be presumed to belong to the Drift, and cover 

 the slopes of most of the interior hills. The clay band, No. 4, is traceable, with 

 several undulations, to the southwest slope of Prospect Hill, where it appears at 

 about the same level as the fossiliferous clay, but is only twelve to twenty inches 

 thick, contains some calcareous concretions, and, after showing an " uphill" slope 

 for a short distance, passes out of sight horizontally, into the body of the ridge. It 

 is directly underlaid by the sands just mentioned, often (here as elsewhere) con- 

 taining strings of pebbles; lower down appear the outcrops of the unequivocal 

 Drift materials. Above the clay band appears grayish-white hardpan, w'hich at 

 other points overlies directly the pebbly sands, and sometimes seems to replace 

 them. The lower clay bed (No. 2 of the above section) does not seem to exist in 

 the interior of the island, any more than the cypress stump stratum ; which, how- 

 ever, forms the bed of bayou Petite Anse, and doubtless underlies the surrounding 

 marsh, as it does the Attakapas prairies themselves. 



Ravines and washes on the higher portion of Prospect Hill, above the level of 

 the clay band, repeatedly exhibit irregular veins and lenticular masses of similar 

 greenish calcareous clay, in gravelly sand. But the manifest dislocation by sub- 

 sidence which has taken place here, obscures the stratigraphical relation between 

 these materials and the profile below. Occasionally, ferruginous veins and concre- 

 tions also occur, producing locally very much the appearance of a Drift outcrop. 

 On the summit of the hill there is a level platform, abruptly elevated several feet, 

 which I presume to be a work of art; although, according to the observations of 

 my traveling companion, the Rev. Ed. Fontaine, its materials are regularly stratified. 

 But they (variegated clays) are not of such a character as to make it probable that 

 they could have resisted the atmospheric influences through several geological ages. 

 Its obvious adaptation as the foundation of a "lookout" stiggcsts itself more forcibly 

 tome; but excavations alone can determine the point. Evcrywlicre else, the usual 

 brown surface loam overlies, with a thickness of four to six feet. 



