Reconnoissance in New Mexico.—Johnson. Sr 
quartzyte sandstone bands. A 10 to 15 foot band of nodular 
lime (overlaid by 6 to 8 feet of reddish quartzyte sandstone ) 
yielded exceptionally large Productus punctatus Productus 
nebrascencis, together with some specimens of Productus cara 
and Derbya sp. This we refer (mainly on stratigraphical evi- 
dence) to the upper layers of the Permo-carboniferous lime 
suries, the Manzano group.” 
In several of the lakes, especially those of the northern por- 
tion of the basin, exposures occur showing 25 to 30 feet of im- 
perfectly lithified shales, alternating dark slate color and lighter 
yellowish red. These shales are saline to taste, and contain 
crystallized gypsum. This is of course a higher horizon than 
that exposed northwest of Berrendo springs. 
Passing still further east, and so still higher in the geolog- 
ical scale, we reach the Red Beds, which are exposed in numer- 
ous places over the plains on either side of the dividing ridge 
above referred to, in the basin of the southern Dog lake, the 
Pinos Wells basin, and in the basin 15 miles northeast of Pinos 
Wells. This horizon is exposed to good advantage in the high 
escarpment of the Jumanez mesa to the south, and the fact that 
it first appears in the basin of the southern Dog lake would 
seem to indicate that the dip is south of east, in this portion 
of the valley at least. 
A section of the escarpment of Jumanez mesa shows :+ 
Feet. 
OR a ee ee, re err eae 25 
Indurated yellowish to whitish sands........... 350 
Loose red sands, gypsiferous................... 100 
Imperfectly exposed red sands (?)............ 50-100 
The red sands are very abundant in both amorphous and 
crystalline gypsum, which in some places is quite pure, al- 
though not as remarkably so as at the southern end of the 
Nacimiento range. The massive gray lime is very firm and 
well preserved, and although some few fragments of fossils 
were seen, we were unable to secure specimens sufficiently 
well preserved for accurate identification. We noted Nautilus 
sp., seven inches across, a small gasteropod, and several 
specimens of coral. 
*Geology of the White Sands, C. L. HERRICK, Geol., Surv. Univ. of N. Mex., 
vol. ii, p. 4. 
fAll sections are given in descending order. 
