Konnarock Formation

Konnarock Formation (Rankin, 1993). Mostly moderate-red glaciogenic sedimentary rocks include massive diamictite (tillite), bedded diamictite, varve-like laminite locally containing dropstones, massive mudstone, pink arkose, and minor conglomerate. Clasts in the diamictite and laminite are dominantly granitoid, but include rhyolite and greenstone of the Mount Rogers Formation. Thickness is as much as 3275 feet; diamictite is most common toward the top of the section.
State Virginia
Name Konnarock Formation
Geologic age Proterozoic Z
Lithologic constituents
Tectonite > Cataclasitesedimentary breccia
Sedimentary > Clastic > Sandstone > Arkosesedimentary breccia
Comments In Grayson, Washington, and Smyth Counties only; Blue Ridge Anticlinorium (Southwest)

Virginia Division of Mineral Resources, 1993, Geologic Map of Virginia: Virginia Division of Mineral Resources, scale 1:500,000.

Virginia Division of Mineral Resources, 2003, Digital Representation of the 1993 Geologic Map of Virginia, Publication 174, CD ROM (ISO-9660) contains image file, expanded explanation in pdf, and ESRI shapefiles, scale 1:500,000.

NGMDB product
Counties Grayson - Smyth - Washington