
E beds, or No. 1. They consist of a series of layers of yellow and grey, 
- more or less fine-grained sandstones and pudding-stones, with some 
intercalated layers of arenaceous clays. In almost all cases there is 
associated with these beds a thin series of carbonaceous clays, which some- 
times become impure coal, and contain masses of silicified wood, &c.” Also, 
“on the eastern slope of the Big Horn Mountains, I observed this same 
series of beds in the summer of 1859, holding a position between Cre- 
taceous No. 2, and the Jurassic marls, with a considerable thickness of 
earthy lignite,” and large quantities of petrified wood.* Fresh water shells 
of the genera Unio, Planorbis, and probably Paludina, have been found in 
association with Ostrea, in beds apparently belonging to this part of the 
formation in the Black Hills region. It preserves a very similar charac- 
ter as far south as Colorado, and there appears to have been somewhat 
definitely correlated with the lowest Cretaceous of the eastern Missouri, 
by the discovery of certain plant remains. The conditions implied 
throughout, are those of deposits forming in shallow, salt, or brackish 
waters, with neighbouring extensive land surfaces, and a marked ten- 
dency toward the accumulation of carbonaceous beds or lignites. 
4y 336. To this division of the Cretaceous, Dr. Hector is inclined to 
| refer the group which in his general section he has designated by the 
detter E.,{ and which is characterized by great deposits of lignite. The 
proviso, however, is made, that the region which he had examined did 
not afford sufficiently clear evidence, to render it certain that under the 
same title, he had not included some Tertiary rocks as well as Cretaceous. 
The rocks of Series E., are thus described: “Sandstone, coarse and friable, 
or argillaceous and concretionary, indurated shales and soft limestones, 
ironstone nodules, beds of lignite 3 to 10 feet. Silicified wood, Tazites 
and sedge-like stems in the sandstones.” § 
337. It is highly probable that some at least of the coal and lignite 
bearing beds, described by Dr. Hector, are really Cretaceous, in view of 
some of the fossils which he has found associated with them.|| The 
question might indeed be considered as definitely settled in that sense, 
but for the remarkable mingling of Cretaceous fossils with those of the 
5 Lignite Tertiary, in the far west; a subject more fully noticed on a sub- 
sequent page. If then, it be admitted that a part of the carboniferous 
beds belong to the Cretaceous properly so-called, it would appear that they 



*U. S. Geol. Surv. Territ., 1857-59., p. 113. + U.S. Geol. Surv. Territ., 1873. 
t The lettering affixed to Dr. Hector’s general sections, in his Official Report, and in his paper in 
Vol. XVIL, of the Journal of the Geological Society, differs. I have adopted that of theformer. _ 
_ § Exploration of British North America, p. 227. || See especially Foot Note to p. 233, Op. cit. 
ag é CRETACEOUS AND TERTIARY—GENERAL ARRANGEMENT. 137, 

