Several glacial episodes have been distinguished in the Shotover Valley.
These produced fluvioglacial aggradational deposits downvalley from the
terminii, commonly with well-preserved terrace treads, as exemplified near
Skippers. Chronological links can be determined between the Shotover tills and
sediments and assessed equivalent deposits in the Wakatipu Basin/Kawarau Valley
region through axial valley profiling. Constructed relationships suggest older
Shotover events were probably large and left little detrital deposits within the
valley. In contrast, the younger advances were smaller and valley-constrained.
They are modelled as being wholly of Waimea or Otira Glaciation age, advances
from the latter period producing the visually distinctive flights of
terraceremnants. Both the terraces and the inner gorge, now occupied by the
Shotover River, have been extensively worked for alluvial gold. Enrichments in
the former environment have predominantly been as bottom or intermediate lags
produced during degradation phases of catchment erosion. Surface lags have been
locally targeted. Placer mining in terrace areas involved both tunnelling and
sluicing techniques. In the modem river the greatest concentrations were on the
schist or false bottoms, although flood gold has always contributed to the
returns. Placer mining techniques here were highly variable.