THE BLOCKUP, YARROW CREEK NEAR GLEN INNES NSW AUSTRALIA
In the Blog on “Sue’s Favourite Spot”, I included an image showing the long “straight”,
in Yarrow Creek, which finishes where the creek makes a right angle bend into the Blockup. This is an area of granite
where the water flows through a narrow (30-40 cm) channel and continues under
granite boulders before emptying into a long pool. This pool finishes at the
spot we know as “The Bottom End”.
Much of the creek bed above the Blockup consists
of submerged rocky areas and lengthy reedy sections. It looks uninviting and so
we have generally left it alone. Those few places where we have fossicked have
been the most accessible ones and they have basically had a flat granite bottom
(sometimes entirely weathered) with few cracks or holes. I don’t think we left
much behind in these spots.
Nevertheless, there is a long section of
unprospected creek waiting for a dry season to lower the water level. It can
drop more than a metre, so there must be other channels in the Blockup for the
water to escape through.
The finds have been the same as elsewhere, that
is, sapphire, zircon and garnet in amongst heaps of black spinel with an
occasional piece of topaz. Waterworn clear and smoky quartz turns up
frequently. There must be heaps more of these amongst the rocks and beneath the
reeds.
Check out my video of fossicking at the Blockup here .
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
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Shoalhaven District Geology.
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| 6 carat "jelly bean" sapphire from the Blockup |