STRATIFIED BEDROCK GEOLOGY OF THE AXIAL, EASTERN, AND SOUTHERN SIERRA NEVADA: A COLLAGE OF TECTONOSTRATIGRAPHIC TERRANES AND MESOZOIC OVERLAP ASSEMBLAGES

A bedrock geology compilation for the Sierra Nevada Earth Science Digital Atlas reveals a suite of accreted tectono-stratigraphic terranes and overlap volcanic arc assemblages.

The principal Paleozoic continental-margin arc terranes are the early and middle Paleozoic Northern Sierra and El Paso terranes. The principal Paleozoic craton-margin terranes are the Paleozoic and early Mesozoic Snow Lake, Kernville, Owens, Pastoria, and Tehachjapi-San Emigdio terranes.

The principal Mesozoic volcanic arc terranes are: (1) the Late Triassic to Early Jurassic volcanic: Walker Lake terrane; (2) the Late Triassic High Sierra terrane; (3) the Middle Jurassic to Early Cretaceous Sierra Crest terrane; and (4) the Late Triassic to Early Jurassic Kings terrane.

The principal late Paleozoic and early Mesozoic subduction zone terranes are: (1) the Merced River terrane containing the late Paleozoic and Triassic Calaveras Complex and associated serpentinite mélange; the middle and late Paleozoic Kings-Kaweah ophiolite and serpentinite mélange; and (2) the Cretaceous and early Cenozoic Pelona Schist terrane.

The major younger volcanic arc assemblages are: (1) the middle to late Paleozoic Sierra Buttes and Robinson arcs and the Early and Middle Jurassic Tuttle arc overlying the Northern Sierra terrane; (2) the Early to Middle Jurassic Don Pedro arc overlying the Calaveras Complex; and (3) the mid-Cretaceous Monarch arc overlying the Goddard arc in Sierra Crest terrane.

Major sutures east of the Melones Fault, some only preserved as remnants in roof pendants, are from west to east the Calaveras-Shoo Fly Thrust, the Kings River and Gem Lake Faults. Some sutures, such as the Calaveras-Shoo Fly Thrust, contain remnants of oceanic lithosphere preserved in the Feather River terrane.