284 
PALEONTOLOGY OF THE EUREKA DISTRICT. 
Paleozoic section of Nevada, 
Upper Carboniferous .....-...-. 500 | Light-colored blue and drab limestones .......-.--....--..------..----+.---- 
Weber conglomerate ........-- 2,000 | Coarse and fine conglomerates; layers of reddish yellow sandstone......... 
Lower Carboniferous ...---..... 8,800 | Heavy-bedded dark blue and gray limestone, with intercalated bands of 
CARBONIFEROUS, 9,300 feet. 
White pine shale 
chert; argillaceous beds near the base. 
8,000 | Massive gray and brown quartzite, with brown and green shales at the 
summit. The quartzite is largely a fine quartzitic conglomerate formed 
of small, dark jaspery pebbles and light quartz pebbles in a grayish 
matrix. 
2,000 | Black argillaceous shales, more or less arenaceous, with intercalations of 
red, and reddish brown friable sandstone, changing rapidly with the 
locality; plant impressions. 
Nevada limestone 
DEVONIAN, 8,000 feet. 
+ 
Lone Mountain limestone 
6, 000 
Ore Lower horizons indistinctly bedded, saccharoidal texture, gray color, pass- 
ing up into strata distinctly bedded, brown, reddish-brown and gray in 
color, frequently finely striped, producing a variegated appearance. The 
upper horizons are massive, well-bedded, and pluish-b ack in color; 
highly fossitiferous. 
Black, gritty beds at the base, passing into a light gray siliceous rock, with 
all traces of bedding obliterated; Trenton fossils at the base; Halysites 
in the lower portion. 
Eureka quartzite 
Compact vitreous quartzite, white, blue, passing into reddish tints near the 
base; indistinct bedding. 
500 
Pogonip l'mestone 
SILURIAN, 5,000 feet. 
=) ] Vellow argillaceous shale, layers of chert nodules throughout the bed, but 
Hamburg shale 
2,700 
Interstratified limestone, argillites, and arenaceous beds at the base, passing 
into purer, fine-grained limestone of a bluish gray color, distinctly bedded ; 
highly fossiliferous. 
ow argillaceous shale, layers of chert nodules throughout the bed, bu 
t 
more abundant near the top. 
330 
Hamburg limestone 
1,200 | Dark gray and granular limestone; surface weathering, rough and ragged; 
only slight traces of bedding. 
Secret Cafion shale 
1,600 | Yellow and gray argillaceous shales, passing into shaly limestone; near the 
top, interstratified layers of shale and thinly bedded limestones. 
CAMBRIAN, 7,700. 
| Prospect Mountain limestone. . . 3, 050 
Gray, compact limestone; lighter in color than the Hamburgh limestone, 
traversed with thin seams of calcite; bedding planes very imperfect. 
Prospect Mountain 
Bedded brownish white quartzites, weathering dark brown; ferruginous 
near the base; intercalated thin layers of arenaceous shales; beds whiter 
near the summit. 
quartzite ...| 1,500 
Nortr.—Plane of unconformity indicated by double dividing line. 
