FEBRUARY 23, 1912] 
than at the present time. The gorge is post- 
Glacial for this reason, and does not represent the 
outflow from a glacial lake. A beach on the 
northern flank of the hill at 450 feet above tide 
has been supposed to be marine without the show- 
ing of any evidence. Upon revisiting the hill no 
evidence of the marine character was found. 
Dr. Spencer’s paper was discussed by J. B. 
Woodworth and H. L. Fairchild, and reply was 
made by the author. 
- Pre-Cambrian Formations in South-central British 
Columbia: REGINALD A. DAty. 
A reconnaissance along the Canadian Pacific 
Railway line has established the following conclu- 
sions: (1) Dawson’s ‘‘Nisconlith series’’ occur- 
ring in the Selkirk Mountains is not Cambrian, 
but represents the northern continuation of the 
‘*Beltian’’ (Belt terrane) rocks at the Interna- 
tional Boundary. (2) Dawson’s ‘‘Nisconlith 
series’? of the Shuswap Lakes area (west of the 
Selkirks) is an entirely different pre-Cambrian and 
pre-Beltian group of sediments, which unconform- 
ably underlie the ‘‘Nisconlith series’’ of the Sel- 
kirk section. (3) The Adams Lake volcanic series 
conformably overlies the thick limestones of the 
“*Nisconlith series’? in the Shuswap Lakes area 
and is of pre-Beltian age. (4) The ‘‘Shuswap 
series’’ of the Shuswap Lakes is not a distinct 
gneissie group unconformably underlying the 
“*Nisconlith series,’’ but is the facies of the 
““Nisconlith series’’ produced where that series 
was thermally metamorphosed by batholiths. (5) 
Though these pre-Cambrian rocks are typical crys- 
talline schists, their metamorphism of the regional 
type was not due to-dynamie action; it was 
‘static’? metamorphism (Belastungsmetamorphis- 
mus of Milch). (6) The pre-Cambrian rocks are 
much less deformed (upturned) than the over- 
lying Carboniferous or Triassic rocks, illustrating 
the small depth of the earth-shell which underwent 
strong folding in post-Cambrian time. (7) The 
petrography of this pre-Cambrian and pre-Beltian 
terrane strongly suggests that it furnished the 
greater part of the clastic material of the Rocky 
Mountain geosynclinal prism. 
Origin of the Sediments and Coloring Matter of 
the Eastern Oklahoma Red Beds: J. W. BEEDE. 
Recent investigations seem to show that the 
sediments of the lower red beds of Oklahoma were 
derived from the Arbuckle-Wichita Permian land 
mass, The conclusion is based on the amount of 
material removed and the geographic distribution 
of sediments bordering the mountains. Coarse 
SCIENCE 
dll 
limestone conglomerate of great thickness and con- 
glomerates of crystalline rocks—both possibly of 
subaerial origin—dovetail into red beds. Belts of 
sandstone have been found extending into the area 
of finer sediments farther away from the moun- 
tains, apparently indicating the location stream 
debouchures at the margin of the shoal sea. The 
extreme shallowness of the water is clearly indi- 
cated in the structure of the beds. The coloring 
matter is thought to have been derived from the 
solution of the 8,000 or 10,000 feet of pre-Car- 
boniferous limestone which formerly covered the 
Arbuekle-Wichita Mountains and much of the sur- 
rounding region. The solution of the limestone 
furnished optimum conditions for the oxidation of 
its iron content, as it does at the present time in 
the limestone regions of the Mississippi Valley, 
southern Europe, West Indies, ete. Moreover, the 
solution of the pre-Carboniferous limestones and 
the conglomerates of the Arbuckle-Wichita region 
now in progress produces a red residuum prac- 
tically indistinguishable from red beds sediments. 
The red granites, red porphyries and other erystal- 
line rocks of the region under discussion contrib- 
uted their share of material to the red beds. Other 
factors may have entered largely into the forma- 
tion of the red beds of western Oklahoma. 
The paper was discussed by I. C. White. 
Correlation of Rocks in the Isolated Coal Fields 
around the Southern End of the Rocky Moun- 
tains in New Mexico: WiuuIs THoMAS LEE. 
Several isolated coal fields in New Mexico, near 
the southern end of the Rocky Mountains, were 
visited, notably those near Cerrillos east of the 
Rio Grande and those on the Rio Puerco. 
Stratigraphic studies were made and fossil leaves 
and shells collected from the coal-bearing rocks 
and those stratigraphically near them, with two 
objects in view: first, of fixing the age of the 
coal beds, and second, of correlating the forma- 
tions of the great coal fields on opposite sides of 
the mountains by means of the data from these 
small fields intervening between them. 
Monument Creek Group and its Relations to the 
Denver and Arapahoe Formations: G. B. RicH- 
ARDSON. 
The Monument Creek Group, Hayden’s name for 
several thousand feet of arkosic deposits on the 
Platte-Arkansas divide in Colorado, is separated 
into two parts on the basis of a well-marked un- 
conformity. The rocks above the break carry 
titanotherium bones of Oligocene age, and the 
rocks below contain leaves of Hocene age. Tho 
