MOTHER LODE GOLD ORE
Mother Lode Gold Ore (above & below) - these are samples of hydrothermal
quartz-gold veins from California, USA.
This gold occurrence is part of the Mother Lode Gold Belt in the
Sierra Nevada foothills. The Au-quartz mineralization occurred during the
late Early Cretaceous, at about 108-127 million years ago, in the Melones Fault
Zone (= the boundary between the Foothills Terrane and the Don Pedro
Terrane). To the east of the fault zone is Jurassic slate. To the
west of the fault zone is a Jurassic serpentinite melange. The Melones
Fault Zone was active principally in the late Jurassic and early Cretaceous.
Above:
quartz-gold vein sample (3.2 cm across) from the Harvard Open Pit Mine,
northwestern side of Rt. 49/Rt. 108, western side of Woods Creek, just west of
Jamestown, western Tuolumne County, central California, USA. 37° 56'
50" North , 120° 36' 20" West.
Below:
quartz-gold vein sample from an
unspecified mine at or near Grass Valley, Nevada County, northeast-central
California, USA. (Cranbrook Institute of Science specimen, Bloomfield
Hills, Michigan, USA)
Mother Lode Gold Ore