Mafic flows and volcanic breccias

Amygdaloidal, nonporphyritic, massive flows and breccia, tuff, and tuffaceous argillite are interbedded with limestones in the Smelser Pass Member of the Augusta Mountain Formation in the Star Peak Group Triassic sedimentary rocks (TRc) in Pershing County (Nichols and Silberling, 1977b). They are well dated by abundant fossils from the surrounding rocks and range from lower Upper Triassic (Carnian) to lower Middle Triassic (Anisian) (Silberling and Wallace, 1969). They are not divided out on the 1978 State map from the surrounding Triassic carbonate unit TRc.
State Nevada
Name Mafic flows and volcanic breccias
Geologic age lower Upper Triassic to lower Middle Triassic
Lithologic constituents
Major
Igneous > Volcanic > Mafic-volcanic (Flow, Pyroclastic-tuff, Volcaniclastic-volcanic breccia)
References
NGMDB product
Counties Pershing