Page:EB1911 - Volume 27.djvu/655

Ordovician.
Saluda bed	20 ±	ft.
Richmond formation	300 ±	”
Lorraine formation	300 ±	”
Eden (Utica) shale	250	”
Trenton limestone	130	”

Iowa

Glacial drift.
Unconformity.
Upper Cretaceous.
Benton formation	0- 150	ft.
Dakota formation	50- 100	”
Unconformity.
Pennsylvanian.
Missouri formation	1500	ft.
Des Moines formation	250- 400	”
Unconformity.
Mississippian.
St Louis limestone	100	ft.
Osage (Augusta) formation	200- 300	”
Kinderhook formation	150- 200	”
Devonian.
Lime Creek formation	80	ft.
State Quarry beds	20-  40	”
Sweetland Creek shales	20-  40	”
Unconformity.
Cedar Valley limestone	250- 300	ft.
Wapsipinicon formation (Independence, Fayette, Davenport)	100- 150	”
Silurian.
Anamosa limestone	50-  75	ft.
Le Claire limestone	50	”
Delaware stage	200	”
Unconformity.
Ordovician.
Maquoketa shales	175	ft.
Possible Unconformity.
Galena-Trenton limestone	290	ft.
St Peters sandstone	100	”
Oneota formation (includes Shakopee, New Richmond and Oneota proper)	300	”
Cambrian.
St Croix sandstone ( = Potsdam)	1000	ft.
Unconformity.
Proterozoic.
Sioux quartzite	(?)

This section is fairly representative for much of the central Mississippi Basin.

Oklahoma

Pennsylvanian.
(Summit removed by erosion.)
Seminole conglomerate	50	ft.
Holdenville shale	260	”
Wewaka formation	700	”
Wetumka shale	120	”
Calvin sandstone	145- 240	”
Senora formation	140- 485	”
Stuart shale	90- 280	”
Thurman sandstone	80- 260	”
Boggy shale	2000-2600	”
Savannah sandstone	750-1100	”
McAlester shale	1150-1500	”
Hartshorne sandstone	150- 200	”
Atoka formation (Chickahoc chert lentil)	3200	”
Wapanucka limestone	100- 150	”
Mississippian.
Caney shale	1500	ft.
Devonian.
Woodford chert	600	ft.
Silurian.
Hunton limestone	160	ft
Sylvan shale (upper part)	50- 100	”
Ordovician.
Sylvan shale (lower part)	250	ft.
Viola limestone	750	”
Simpson series	1600	”
Arbuckle limestone	4000-6000	”
Cambrian.
Regan sandstone	50- 100	ft.
Unconformity.
Pre-Cambrian.
Tishomingo granite	(?)

Composite section. The upper part is taken from vicinity of Coalgate, the lower part from the vicinity of Atoka.

West Central Colorado

Eocene or later.
West Elk breccia	3000	ft.
Unconformity.
Cretaceous.
Ruby formation	2500	ft.
Unconformity.
Ohio formation (local only)	200	ft.
Unconformity.
Laramie formation	2000	ft.
Montana formation	2800	”
Niobrara formation	100- 200	”
Benton formation	150- 300	”
Dakota formation	40- 300	”
Jurassic.
Gunnison formation	350- 500	ft.
Unconformity.
Pennsylvanian.
Maroon conglomerate	4500	ft.
Possible unconformity.
Weber limestone	100- 550	ft.
Unconformity.
Mississippian.
Leadville limestone	400- 525	ft.
Apparent unconformity.
Ordovician.
Yule limestone	350- 450	ft.
Upper Cambrian.
Sawatch quartzite	50- 350	ft.
Unconformity.
Archean.

The Bighorn Mountains of Wyoming

Cretaceous.
De Smet formation (shale and sandstone)	4000	ft.
Kingsbury conglomerate	0-1500	”
Piney formation (shale and sandstone)	2500	”
Parkman sandstone	350	”
Pierre shale	1500-3500	”
Colorado formation	1050-1700	”
Comanchean.
Cloverly formation (upper part may be Cretaceous)	30- 300	ft.
Morrison formation (may be Jurassic)	100- 300	”
Jurassic.
Sundance formation	250- 350	ft.
Unconformity.
Triassic and Permian.
Chugwater formation	750-1200	ft.
Pennsylvanian.
Tensleep sandstone	30- 150	ft.
Amsden sandstone	150- 350	”
Mississippian.
Madison limestone	1000	ft.
Unconformity.
Ordovician.
Bighorn limestone	300	ft.
Unconformity.
Cambrian (Upper).
Deadwood formation	900	ft.
Unconformity.
Pre-Cambrian.
Granites.

This section is fairly representative for the Rocky Mountains.

Southern California

Quaternary.
Alluvium, &c.
Terrace deposits and dune sand.
Pliocene (?)
Paso Robles formation	1000 +	ft.
Unconformity.
Miocene (?)
Pismo formation (in south part of area)	3000 ±	ft.
Santa Margarita (in north part of area)	1550 ±	”
Unconformity.
Miocene.
Monterey shale	5000-7000	ft.
Vaquero sandstone	0- 500	”
Unconformity.
Cretaceous.
Atascadero formation	3000-4000	ft.
Unconformity.
Comanchean.
Toro formation (Knoxville)	3000 ±	ft.
Unconformity.