ST. JOHN.] PALEOZOIC AREAS — CARBONIFEROUS. 487 



dence goes, we have good grounds for the recognition of physical con- 

 ditions, accompanied by organic manifestations, representative of at 

 least two prominent formations of the Lower Carboniferous in this region, 

 ■\iz, the Keokuk and Warsaw beds of the Saint Louis. There also occur 

 in this range certain limestones which are charged with Lithostroiion 

 and Syrhujopom; but the relative position of these beds Avith those 

 above mentioned was not determined. However, in the vicinity of Sta- 

 tion IX, the Lithostroiion limestone is underlaid by a lieavy series of 

 bluish-gray cherty limestone, with Zaphrentis and crinoidal remains, 

 which may well embrace the lower horizons. If the paleontological 

 evidence in all cases holds good, then we should infer that the Litho- 

 strotion horizons correspond to the Saint Louis formation. 



It is probable that, in the Snake Eiver Eange, the Lower Carbonifer- 

 ous formations arc well developed, especially in the magnilicent natural 

 sections exi)osed along the lower course of the Grand Canon. But in 

 the northeastern belt, which alone was penetrated the past season, at 

 only one or two points iu the Pierre's Mountains are these deposits well 

 exposed. Here was noted the uppor Lithostrotion bearing limestones, 

 and it seems not imi)robable the older formations may yet be found in 

 their proper order in the ridge terminating iu Spring Point. They here 

 exhibit the same lithological and raineralogical concomitants elsewhere 

 prevalent, and wherever the rocks are much disturbed they are, in 

 common with other limestone formations above and below, traversed by 

 seams of calc-spar, which doubtless owe their origin to infiltratiou. 



Little was elicited, in the course of the hasty examination made in the 

 Teton Range, relating to the detail stratigraphy of these lower limestone 

 deposits, beyond the recognition of the various groups above alluded to 

 in the similar faunal associations which also here occur. We also ob- 

 serve in this quarter the frequent occurrence of red-stained beds, and in 

 the vicinity of Station XXXII, at the northern end of the range, these 

 lower horizons are quite siliceoiis. But at no point visited were the pas- 

 sage-beds at the base of the series satisfactorily revealed, although it is 

 api)arent, almost to a certainty, that the space intervening between the 

 Carboniferous and the Niagara limestones is occupied by soft or shaly 

 deposits. Even the Carboniferous limestones appear to be iuterbedded 

 with shales and shaly layers, Avhich give rise to the step-like steep 

 slopes of their outcrop, which usually weathers in low mural exposures, 

 alternating with narrow taluses, giATing to some of the isolated outlines 

 iu the higher portions of the range their peculiar pyramidal form. 



In theGros Ventre Mountains, particularly at Station XL VI, we gain 

 a clue to the character of the inferior deposits of this series, as also the 

 nature of the beds of passage. The latter as here exposed show yellow 

 Aveathered shaly deposits, probably made up of limestones and shales, 

 and which constitute a rather marked band AA-hercA^er the horizon is not 

 covered with debris. The lower limestones are a gTayish or bluish drab 

 color, OA'crlaid by dark broAvnish-drab magnesian layers charged Avith 

 Hemipronites cre)iistria, or a closely-allied form. The thickness of the 

 limestoues intervening between the heaA'y magnesian limestone of the 

 horizon of the ISTiagara and the upper red siliceous or arenaceous horizon, 

 which latter may be regarded as the top of the loAver series, it is impos- 

 sible to state with accuracy ; but this space appears to be of less vertical 

 extent at this locahty than in the T6ton Mountains, yet it may reach 

 1,000 feet. 



As has already been obserA^'ed, in the vicinity of Buflalo Fork Peak 

 the deposition of Umestone-making materials went on Avithout interrup- 

 tion from the time of the Upper Quebec limestone to the LoAver Carbon- 



