102 Bulletin of Laboratories of Denison University [Voi. xi. 
3 , 
THE AREA NORTH OF THE SANDIA MOUNTAINS. 
From the northern portion of the Sandia range there is a 
strong spur or isolated uplift composed of granite and schists 
intersected with dykes of diorite and of quartz. This spur 
projects westward toward the river and gives rise to springs and 
streams of beautiful water. This area has not been sufficiently 
studied but is evidently the focus of local metamorphism as de- 
scribed above. To the south of the spur a small portion of the 
same formation as that which underlies the lava beds to the 
north and west of the Rio Grande protrude through the river 
gravels and consists of the same red detrital materials. Near 
the [river in the neighborhood of Alameda is a deposit of pum- 
ice evidently from one of the craters in the neighborhood of 
Bernalillo. To the north of this place the supposed pleisto- 
cene crops in the river bed as it does at several places even fur- 
ther south. It also appears in the hills and seems to be greatly 
commingled with the river gravels. North of the Sandias to 
the river and Galisteo creek and eastward to the Jura-triassic 
area east of Thornton the surface is irregular and is worn by 
erosion into deep gullies. The material is chiefly unindurated 
sand and crag with shaly layers. This may, in all probability, 
be referred also to the Pleistocene. In fact, evidence that this 
is the case is found in the neighborhood of the little Indian 
town of San Fillipe where an outlyer of the lava on the east 
side of the river forms a small isolated mesa about lOO feet 
above the general level. The river gravels are seen on the east- 
ern aspect rising half way to the top and enabling one to ob- 
serve the contrast. It would appear that the exposed soft ma- 
terials have eroded faster than the same strata on the west side 
of the river where protected by the lava as is also the case in 
the area opposite Bernalillo on the west side of the river and 
south of the lava. This eroded country is denominated “the 
bad lands,” but has no relation to the mal pais resulting from 
the breaking down of the lava flows met in many parts of the 
territory. Going east, the country rises to about 525 feet above. 
