In the sharpstone conglomerate, the original chert pebbles are replaced by recrystallized strained quartz, while the volcanic fragments are partially replaced by epidote, garnet, magnetite and minor sulphides. The limestone is mostly altered to garnet skarn, but banded garnet-epidote-actinolite skarn is also common. Skarn alteration of limestone and sharpstone conglomerate is fairly extensive. These dykes are found at all levels of the mine from surface down to the 152 metre level. These stratified rocks are cut by slightly skarn-altered granodiorite and feldspar porphyry (quartz syenite) dykes from several centimetres to 30 metres wide. The formation, which strikes northwards and dips steeply east, also includes a lower sharpstone conglomerate overlain by skarn-altered siltstone and lenses of Brooklyn limestone and an overlying fine-grained sharpstone. The protolith is believed to be mainly sharpstone conglomerate, calcareous siltstone and limestone. The copper skarn mineralization at the Mother Lode pit occurs in the same member of the Brooklyn Formation as the skarns at the Phoenix mine (082ESE020). The largest and most productive precious metal enriched (PME) copper skarns are in the lower part of the Brooklyn Formation, either in the transition zone between the lower sharpstone and the Brooklyn limestone, or within the Brooklyn limestone itself. The formation of skarn in the district appears to be preferentially controlled by the contact between Brooklyn limestone and underlying sharpstone and siltstone beds. Tertiary intrusions include many dykes, sills and irregular bodies of monzodiorite and other alkalic rocks. The major intrusive event is represented by the Cretaceous Greenwood stock and Wallace Creek batholith which are considered to be part of the Nelson Intrusions and genetically related to economic skarn development in the Greenwood camp (Paper 1989-3).Įarlier intrusive activity comprise small diorite, microdiorite, quartz feldspar porphyry and gabbro bodies that show varying degrees of alteration, but are not apparently associated with economic skarn mineralization. They are truncated to the north by granodiorite of the Cretaceous Wallace Creek batholith, the southern margin of which has irregular apophyses and satellite intrusions that have thermally metamorphosed the country rocks. The rocks are broadly folded and have been affected by low grade regional metamorphism. Regionally the Knob Hill Group trends east to southeast and dips moderately north, whereas the Brooklyn Group strikes north to northeast and dips steeply east. The conglomerate is overlain by the Brooklyn limestone which reaches 350 metres in thickness and comprises limestone and minor siltstone. The conglomerate is massive near its base and commonly bedded near its top, with numerous interbeds of sandstone, shale, siltstone and minor limestone. The sharpstone conglomerate contains angular fragments of chert and minor limestone, greenstone and jasper clasts set in a fine-grained chert, calcite and chlorite-rich matrix. The Brooklyn Group includes thick units of sharpstone conglomerate and limestone, as well as thinner beds of siltstone, sandstone and calcareous chert-pebble conglomerate. The Knob Hill Group consists of massive chert, greenstone and amphibolite with minor pods and thin, widely scattered beds of limestone and argillite. The Tertiary Penticton and Marron groups consisting of volcaniclastic and flow rocks unconformably overlie the Knob Hill and Brooklyn rocks. The skarn deposits are associated with the Upper Paleozoic Knob Hill Group and the unconformably overlying rocks of the Triassic Brooklyn Group. The Greyhound (082ESE050) claim lies 1700 metres to the southeast.Ĭopper and iron-skarn mineralization occurs at several locations in the Greenwood mining camp. Access is by good gravel road which connects the property to the Mother Lode Creek road and Greenwood. The property comprising the Mother Lode (Lot 704) and Sunset (Lot 788) (082ESE035) mines is centered four kilometres northwest of Greenwood at the elevation of 1050 metres. K01 : Cu skarn K04 : Au skarn K03 : Fe skarn LAWRENCE (L.1255), STANDARD (L.1463), DEADWOOD CAMP, SUNSET, WOODGREEN, GREYHOUND, MOTHERLODE MOTHER LODE (L.704), MOTHER LODE MINE, CROWN SILVER (L.789), TEN BROCK (L.1221), PRIMROSE FRACTION (L.927), ST.
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