SCRUBBY GULLY, TORRINGTON NSW
Scrubby Gully is located on the western side of The Torrington Pendant, where the Mole Granite intrudes the overlying sedimentary rocks. In many places the boundary is notable for the presence of silexite, essentially a topaz-quartz rock. See especially my earlier blog entry “Torrington – Essential Reading” as well as the various references mentioned in the blogs on downloading from DIGS and the ALF site. Scrubby Gully may be reached by following the
Butler Mine road and then the Mystery Face road, which branch to the left several
kilometres north of Torrington from the Silent Grove road. At the Mystery Face
car park, the fence directly ahead marks the boundary between the Conservation
Area and private property. Follow the fence to the left for 15-20 minutes until
it descends into Scrubby Gully. The alluvial areas are marked by hatching on the adjoining map. (The Scrubby Gully Mine shown is a bismuth/tungsten/lead deposit.)
To the right (upstream) are the Scrubby Gully alluvial workings, dating
from the 1870’s and 80’s. Large quantities of “tin” (cassiterite) were
extracted from here and from the gully below (downstream of the boundary fence).
From the 1960’s until now fossickers have visited this area in search of topaz,
especially the sky blue variety, for which the locality is well known.
For details of the geology of the diggings, see
TWE David’s 1887 memoir on the Vegetable Creek Tin Mining Field (pages 71 and
164 especially. This can be downloaded from DIGS. The Minerama books on Topaz and Beryl also contain useful
information.
The topaz comes in two forms – very waterworn
(like the tin) and scarcely worn at all, reflecting the two likely sources - the
ancient alluvial deposits and vughs in the silexite and adjacent granite. Only
a very small proportion is the desirable sky blue variety. Along with the topaz
is black tourmaline (schorl) and the occasional sapphire and zircon (both very
worn). Pale green beryl is also found as unabraided crystals, no doubt also
derived from the same vughs and veins as the topaz crystals and the tourmaline.
Any place where sediment is accumulating in holes
and cracks is worth investigating for these gems. Remember that beryl is not a
dense mineral and does not concentrate in the sieve centres as the other minerals
mentioned do.
Typical topaz producing crack |
A good trap |
Check my fossicking videos
from around Glen Innes here .
Some choice Scrubby Gully topaz |
Beryl crystal from Scrubby Gully |
https://johnsbluemountainsblog.blogspot.com/2013/12/links-to-all-blog-entries-and-relevant.html All Blue Mountains blogs and videos
All New England and other Geology blogs and videos
Limestone Caves of NSW
Song Studies. Bible studies based on hymns and songs
Shoalhaven District Geology.
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