Banded veins of jasperoid and barite occur near the St. Louis Mine. They are unusual in the fine development of comb structure, often described as a signature of a true epithermal precious metal district. Iron and manganese oxides are minor and sulfides absent. Late calcite veinlets sometimes crosscut the earlier barite and jasperoid. Northeast of the Leviathan Mine monomineralic veins of white barite can be observed.
Alteration is absent.
Inclusions of brecciated host rock can be seen at many localities. Southwest of the Leviathan Mine, thin but laterally persistent veins of jasperoid with no attendant barite are present. The marked differences in mineral suites of these two vein types which lie within 300 meters of one another may be explained by their age relationships. Monomineralic barite veins represent an early stage of mineralization while jasperoid veins represent a much later stage of mineralization Barstow Barite-Silver Mineralization Mineralization within the Barstow formation is largely disseminated. Fletcher recognizes three stages of mineralization which correlate well with the paragenesis of the underlying Pickhandle barite-silver veins.