Iron-Formation (SDXif;0)

Iron-Formation

Banded, dark-green, reddish-brown, and white iron-formation, ferruginous chert, and minor mica schist. Includes three or more ages of oxide-, carbonate-, silicate-, and sulifide-facies iron-formation and interbedded tuffaceous rocks. Thickness 20-500 ft (6-152 m).

State	South Dakota
Name	Iron-Formation
Geologic age	Early Proterozoic
Lithologic constituents	Major Sedimentary > Chemical > Banded-iron-formation (Bed) Sedimentary > Chemical > Chert (Bed) Minor Metamorphic > Schist > Mica-schist
References	Martin, J.E., Sawyer, J.F., Fahrenbach, M.D., Tomhave, D.W., and Schulz, L.D., 2004, Geologic Map of South Dakota: South Dakota Geological Survey, GM 10, scale 1:500,000.
NGMDB product	NGMDB product page for 72317
Counties	Custer - Lawrence - Pennington

Iron-Formation

Martin, J.E., Sawyer, J.F., Fahrenbach, M.D., Tomhave, D.W., and Schulz, L.D., 2004, Geologic Map of South Dakota: South Dakota Geological Survey, GM 10, scale 1:500,000.