In the Ross goldfield area, Early Tertiary, Late Tertiary and Quaternary groups of sediments rest upon what appear to be early Palaeozoic greywackes intruded by granite. At least two major orogenic disturbances have affected the region since Oligocene times. The earlier appears to have occured at about the end of the Miocene, but the latter movements occurred after the first episode of glaciation. There is evidence of two and possibly three distinct periods of ice advance, the first two being separated by a period of intense deformation, and very probably by an amelioration of climate amounting to an interglacial period. The earliest glacial beds are probably Upper Pliocene (Nukumaruan) in age.
Alluvial gold is present in almost all the members of the Late Tertiary and Quaternary groups, and continues to be mined from several of them. There is no record of the basal Tertiary conglomerates at Ross being explored for gold. Very old claims on the eastern slopes of Mount Greenland, on which foothills the town of Ross is established, near Cameron Creek appear to have worked locally derived greywacke detritus, while on the floor of the Totara Valley gold has been worked from glacial gravels and recent reconcentrations of glacial and R.8 gravels.
Recent floodplain deposits and perched remnants in older formations have been worked in many places. The claims are mainly operating in patches of glacial and R.8 gravels left between old claims, while tailings in Jones Creek have been successfully reworked. The alluvial gold in these gravels is generally rather fine, however it has also been reported in R.6 conglomerates and R.5 sands, but not in R.7 silts. Some of the younger deposits further inland from the beaches contain very coarse, rough gold, suggesting they have not been subjected to long transportation by water.
It is evident that although some of the Ross gold deposits have been enriched by successive concentrations, at the same time workable deposits in Recent and Pleistocene beds have originated as a result of merely a single cycle of erosion and deposition of gold derived from quartz veins in the vicinity. The Ross region is well known for alluvial and hard-rock gold deposits and includes the Ross Flat deposit immediately east of the town and several alluvial gold workings around the district and along the coastline.
The Victory North property permit covers auriferous Quaternary gravel deposits 10 km along the coast line and 3 km inland and comprises gold-magnetite bearing Pleistocene beach strandlines known as blacksand leads that are adjacent to current or historical mining operations. These blacksand leads, which form part of raised beach deposits, buttress up against moraine outwash terraces. Gold, along with ilmenite, magnetite, garnet, zircon and other heavy minerals (Minehan, 1989) is concentrated into lenticular beach placers, or blacksand leads, of which a number are currently being exploited by mining operations along strike to the northeast and southwest.
In the Ross goldfield area, Early Tertiary, Late Tertiary and Quaternary groups of sediments rest upon what appear to be early Palaeozoic greywackes intruded by granite. At least two major orogenic disturbances have affected the region since Oligocene times. The earlier appears to have occured at about the end of the Miocene, but the latter movements occurred after the first episode of glaciation. There is evidence of two and possibly three distinct periods of ice advance, the first two being separated by a period of intense deformation, and very probably by an amelioration of climate amounting to an interglacial period. The earliest glacial beds are probably Upper Pliocene (Nukumaruan) in age.
Alluvial gold is present in almost all the members of the Late Tertiary and Quaternary groups, and continues to be mined from several of them. There is no record of the basal Tertiary conglomerates at Ross being explored for gold. Very old claims on the eastern slopes of Mount Greenland, on which foothills the town of Ross is established, near Cameron Creek appear to have worked locally derived greywacke detritus, while on the floor of the Totara Valley gold has been worked from glacial gravels and recent reconcentrations of glacial and R.8 gravels.
Recent floodplain deposits and perched remnants in older formations have been worked in many places. The claims are mainly operating in patches of glacial and R.8 gravels left between old claims, while tailings in Jones Creek have been successfully reworked. The alluvial gold in these gravels is generally rather fine, however it has also been reported in R.6 conglomerates and R.5 sands, but not in R.7 silts. Some of the younger deposits further inland from the beaches contain very coarse, rough gold, suggesting they have not been subjected to long transportation by water.
It is evident that although some of the Ross gold deposits have been enriched by successive concentrations, at the same time workable deposits in Recent and Pleistocene beds have originated as a result of merely a single cycle of erosion and deposition of gold derived from quartz veins in the vicinity. The Ross region is well known for alluvial and hard-rock gold deposits and includes the Ross Flat deposit immediately east of the town and several alluvial gold workings around the district and along the coastline.
The Victory North property permit covers auriferous Quaternary gravel deposits 10 km along the coast line and 3 km inland and comprises gold-magnetite bearing Pleistocene beach strandlines known as blacksand leads that are adjacent to current or historical mining operations. These blacksand leads, which form part of raised beach deposits, buttress up against moraine outwash terraces. Gold, along with ilmenite, magnetite, garnet, zircon and other heavy minerals (Minehan, 1989) is concentrated into lenticular beach placers, or blacksand leads, of which a number are currently being exploited by mining operations along strike to the northeast and southwest.
