The 61 Mile Creek hydromagnesite deposits are located within a swampy area at the headwaters of 61 Mile Creek and about three kilometres east of Goose Lake and 1.6 kilometres northwest of the head of 61 Mile creek.
The general region contains numerous semi-evaporitic playa lakes that have been termed the "Green Timber Plateau" area (EMPR Bulletin 4), a semi-arid plateau area averaging 1130 metres elevation which is part of the Cariboo Plateau. The area is underlain by alkaline plateau basalt flows of the Miocene to Pleistocene Chilcotin Group, mantled by a thin cover of glacial till and glaciofluvial sediments. Annual precipitation averages between 300 and 400 millimetres (EMPR Paper 1991-1).
Several hydromagnesite deposits are present in the area adjacent to a small swampy lake in a depression between low hills.
White hydromagnesite with what is described as a typical cauliflower-like surface texture covers about 1.1 hectares. The material has been pitted to a depth of 30 centimetres but no data is available to indicate total thickness of the hydromagnesite nor of the character of the underlying material.
Analysis of Three Surface samples:
MgO CaO Fe+Al SiO2 H2O CO2 H2O+CO2
1 38.00 1.6 1.7 9.80 16.0 32.9 -
2 34.4 1.76 0.69 11.60 - - 48.16
3 32.75 3.32 0.67 12.40 - - 47.74