, . a De 3 ty See Aor Soe ae a 
* =e 
CHAPTER V. 
CRETACEOUS AND TERTIARY ROCKS OF THE VICINITY OF THE 
FORTY-NINTH PARALLEL—WOOD MOUNTAIN TO THE 
ROCKY MOUNTAINS. e 
LicnitE Tertiary Rocks NEAR Woop MounTaIn—SEctions tN Bap Lanps SouTH 
oF Woop Mountain—Nature of Bad Lands—Divisions of Section—Fossil 
plants—Vertebrate fossils—Srcrions Wrst oF THE BAD LANnDs To WHITE 
Mup Rtver—Cretaceous No. 4—Fossils—White Mud River—Cretaceous 
Nos. 4& 5.—-Relations of beds, White Mud River and Bad Lands—Sgcrions 
West oF Woop Mountain SETTLEMENT TO WuitE Mup River—Bay of 
Cretaceous Rocks—Tertiary Plateau—Cretaceous No. 4. with fossils—W HITE 
Mop River To MILK RivER—Cretaceous plain—Tertiary Plateau—East Fork 
of Milk River—Section near West Fork of Milk River—Age of Beds exposed 
—Cretaceous plain—Milk River Valley—Sections in Milk River Valley— 
Upper arenaceous clays, &c.—Sandstone Zone—Lower arenaceous clays, &c.— 
Mitk River To THE West Burre—Sections North of East Butte—Nature 
and height of the Buttes—East Butte—Igneous rocks of the Buttes—Middle 
Butte—West Butte—Wesr Butrre To THE Rocky MountTarns—Synclinal west 
of West Butte—First Branch Milk River—Vertebrate fossils—Second Branch 
Milk River—Fresh Water deposits—St. Mary River—Disturbance of Beds— 
Coal Bed—Marine Fossiliferous Beds—Exposures nearest the Mountains— 
South Fork of Belly River. 

Rocks near Wood Mountain. * 
248. In the immediate neighbourhood of the half-breed settlement of 
Wood Mountain, no good exposures were observed. Where rocks were 
seen, they were generally hard greyish sandstones, which protrude here 
and there in the sides of the hills, and banks of vallies, the softer 
intervening beds being concealed. These sandstones no doubt belong to 
the Lignite Tertiary, and probably occur at several different horizons. 
They have much to do with the definite shape of the watershed plateau, 
which but for them would probably have been but a diffuse ridge. 
249. South-west of Wood Mountain, on the trail used by the half- 
breeds of that place in going to Fort N. J. Turney—a trading post south 
of the Line—ravines cut in the southern edge of the water-shed plateau 
show occasional sections of the Lignite Tertiary rocks. , At nineteen 
miles from Wood Mountain, by odometer, the edge of the plateau is 
pic 
* The name Wood, or Woody Mountain, is sometimes used to designate the whole, or an indefinite 
part, of the Tertiary watershed plateau. It is here restricted to the half-Breed settlement and its imme- 
diate vicinity. : 

