History
Prior Ownership and Ownership Changes
The region has been actively explored and mined since the late 1800's and several mining
companies were active in the region during the early to mid-20th century. Some old
workings are presently held by individuals recovering gold from stream-beds and alluvium.
In 2003, PAMM made application for research permits covering the B7 Project area.
Exploration and/or Development
Gold was discovered at the head-waters of the Mania River system in 1888 and the government
using forced labour gangs amounting to several thousand workers to exploit gold from the
region. During the French colonial period, several small companies and entrepreneurs mined
gold from extensive alluvial deposits and from quartz veins in bedrock.
Local villages recount that the Andramasina (B7) project area is dotted with abandoned
surface mines worked mainly by French colonials between the 1930's and late 1940's.
Christopher examined five abandoned mine sites described below.
Site 1
Workings cover an area of several acres located along the margins of a small creek.
The site is situated at the head of the valley shown in Plate #1. The quarry extends
westward from a narrow creek valley where high-walls 15 m high expose shallow dipping
quartz stringers in a reddish-orange clay matrix. There is minor evidence of recent
informal mining but little work has been done since the French abandoned the area in
1945. When in operation, the mine was accessed by a pack-horse trail. Christopher
found no documentation covering this site.
Site 2
This site was mined for two kilometers along the bank of a small stream. Workings
extend 200 m. into the west bank leaving a 20m high wall composed mainly of clay-rich
alluvium. Broad zones of narrow quartz stringers are exposed in saprolite at the base
of the workings.
Informal miners currently work the headwaters of the stream on a small scale.
Christopher did not locate formal documentation describing these workings but a local
guide stated that the mine was operated by a French company between 1937 and 1938.
Site 3
This site, worked by Mr. L. Robert, a noted gold miner during the colonial period, extends
for about one kilometer along a creek and its tributaries. Plate #1 shows the over-grown
lower workings that wind beyond the yellow-flowering bushes seen on the right.
Site 4
This is the Analasotra mine discovered by L. Robert, probably in the early 1950's. Gold
is found in sulphide rich quartz lenses confined to a conformable pegmatite dyke. Quartz
lenses range in length from less than a meter to 4 meter and are generally less than a
meter in width. Country rocks consist of garnet-sillimanite schist alternating with bands
of quartzite striking variably to the northeast. A large partially collapsed pit remains
visible at the site. No record of production was found by Christopher.
A prominent north-south ridge follows a strong quartz vein system on the hill above
the Analasotra mine (Plate #4). Robert explored this system by a series of trenches but
results of his work are not available.
Site 5
A mineralized zone was traced by a series of open pits for over 500m. The workings targeted
vertical shear controlled quartz stringers occurring as several parallel zones a few meters
apart (Plates 5 & 6). Current informal mining is entirely in saprolite and extends
to a depth of 10 to 15m. Samples taken from the structure shown in Plate 5 are weakly
anomalous in gold.
