Newland and LaHood Formations

Newland Formation (Yn): Dark bluish gray limestone. Thickness as much as 2,000 m (6,562 ft). LaHood Formation (Yla): Dark gray, dark brown, reddish brown, coarse, arkosic conglomerate locally with very large clasts derived from crystalline metamorphic rocks. Grades from mega-clast conglomerate to shale or argillite over short distances. Thickness as much as 3,000 m (9,842 ft).
State Montana
Name Newland and LaHood Formations
Geologic age Middle Proterozoic
Lithologic constituents
Sedimentary > Clastic > Conglomerate (Bed, Arkosic)
Sedimentary > Carbonate > Limestone (Bed)
Sedimentary > Clastic > Mudstone > Shale (Bed)
Metamorphic > Metasedimentary > Metaclastic > Argillite

Vuke, S.M., Porter, K.W., Lonn, J.D., and Lopez, D.A., 2007, Geologic Map of Montana - Compact Disc: Montana Bureau of Mines and Geology: Geologic Map 62-C, 73 p., 2 sheets, scale 1:500,000. This map was digitized in 2012 as a result of a contract between the U.S. Geological Survey and the Montana Bureau of Mines and Geology.

NGMDB product
Counties Madison - Silver Bow