GCOLOGY. 281 



not be relied on. A fact somewhat similar was first observed by Prof. 

 Daniels, in his researches at the Royal Society, where the water bar- 

 ometer indicated the change of pressure an hour earlier than the 

 usual mercurial standard barometers constantly used for observations. 



GEOLOGY AND PALEONTOLOGY OF A PART OF THE ROCKY 



MOUNTAIN REGION. 



PROF. HALL, in the Report of Stansbury's Expedition to the Great 

 Salt Lake, furnishes some notes on the Geology and Palaeontology of 

 a part of the Rocky Mountain Region, from specimens collected in the 

 course of the Expedition. 



The first specimens furnished are from the west side of the Missouri 

 River, near and above Fort Leavenworth (39 21' N., 94 44' W.) 

 They are all from limestone of the Carboniferous period, and appar- 

 ently from the upper of the two great limestones of this period in the 

 West. The most conspicuous fossils are Productm and Terrebratula. 

 The route from the Missouri westward, shows a continuation of this 

 limestone as far as the Big Blue river. Here it disappears, and is soon 

 succeeded by strata of the Cretaceous age, which extends for a consid- 

 erable distance on the route. Among the cretaceous fossils are a 

 species of Pholadomya, and the Inoceranaus, which is so abundant in 

 numerous localities in this region. 



It would appear that the character of the country from near Fort 

 Kearney to near Fort Laramie is uniform, and no deposites of older 

 date than the Tertiary were observed. Of the specimens collected, 

 there is but a single individual indicating the character of a marine 

 formation. From the condition of the bones it may even be ques- 

 tioned, whether the deposit containing them is not of post tertiary age. 

 The specimens from the vicinity of Fort Laramie are all from lime- 

 stone of the carboniferous period. Some of the fossils are identical 

 with species collected between the Missouri and the Big Blue, and we 

 "in only suppose, from the great similarity of the specimens, that it is 

 a continuation of the same formation. The specimens collected two 

 days' march north- west of Fort Laramie, (105 W.,) are a feldspathic 

 granite with little quartz or mica. The rocks in this locality are 

 doubtless of metamorphic origin, probably rocks of the Silurian age. 

 The specimens collected three days' march in advance of this place, 

 (105 25' W.,) are shaly sandstones and thinly laminated sandstones 

 containing fossils. These beds are recorded as dipping at the rate of 

 15 to the X. E., and are probably Devonian. The specimens col- 

 lected at 105 50' "W., are precisely like those collected at Fort Lara- 

 mie and contain the same species of fossils ; red and gray sandstones 

 were also seen here. On the following day, (near 106 W.,) is 

 recorded a bed of coal, three or four feet thick, with Sigellaria and 

 Calamites. The specimens collected here are those of bituminous coal, 

 and soft shale, without any well marked vegetable remains. From the 

 proximity of limestone of the age of the coals, and the records ol 

 sigillaria and calamites occurring in the same connection, it may be 



