Olivia Mine, Rosa de Castilla, Ensenada Municipality, Baja California, Mexicoi

Regional Level Types
Olivia Mine	Mine
Rosa de Castilla	- not defined -
Ensenada Municipality	Municipality
Baja California	State
Mexico	Country

A tungsten mine. Though listed under Rosa de Castilla, this mine is centered between Rosa de Castilla, Los Gavilanes, and Laguna Hansen, and could be considered an independent locality.

During his visit to the mine in 1964, Sinkankas described the ore body as a continuous dike, giving every appearance that it was the continuation of a pegmatite, which coarsens in grain size toward the granitic country rock contact until it resembles a pegmatite in mineralogy as well. The interior mineralogy is rather classic skarn or tactite, consisting primarily of fine-grain banded masses of diopside with grossularite garnet aggregations of various sizes. Vugs commonly contain anhedral adularia
ad reddich clay. No calcite was observed. More northerly exposures find diopside more rare, with coarse-grained quartz-grossularite-adularia. Formless masses of actinolite are found inthe diopside, and epidote
along with axinite, forms masses in the more garnet-rich sections. Along the contact zone between the garnet and the diopside, small anhedral to subhedral blebbs of scheelite occur. The edge of the dike
contains highly weathered microcline feldspar. In this area in 1964-65, pockets of large gemmy axinite crystals were found in this feldspar zone. The puzzling association of feldspar and clay in a skarn
alongside skarn mineralization of unusual size led Sinkankas to theorize that the pegmatite and the closely-associated skarn mineralization were semi-contemporaneous.

Other Regions, Features and Areas containing this locality

References