High Country History
A bizarre geological formation
in an otherwise lush area of steep, heavily timbered mountainsides is the
location for a cache originally placed for the History, Mystery, High Country
event cache of Feb 2005.
"The scenery is wild and
rough and grand in the extreme. In no place else in Victoria are there such
dizzy precipices, such sheer bluffs, or gorges with such vertical sides. In
places the river is hemmed in between rocks which leave but a 30ft waterway."
(W.H. Ferguson in the Snowy Gorge,
Geological Survey of Victoria Progress Report No. 11, 1899)
| Dating back to the last ice age
some in Pleistocene times over 10,000 years ago this periglacial
geological formation is what is referred to as a basalt block stream.
Volcanic activitiy laid down the basalt here as it did in many places in
the Alps before this time.
Ice broke up the basalt and ice flow moved it
over the frozen subsurface. As the climate warmed through the Holocene age,
water flow over many years removed any sediment, gravel and smaller material to
leave what you see today – a block stream or rocky scree slope. Downstream the
rivers widened with erosion, and gravels and silt from high up was deposited in
lower land to create the river flats such as those nearby here in the
Wonnangatta Valley. |
Nice spot - apologies for the
jeep.... |
Periglacial (not quite glacial, generally not
as steep,) processes during the Great Ice Age made a major contribution to the
present day alpine and subalpine topography. Periglacial features such as
terracing, soil movement, shattered boulders and rock rivers are the product of
low temperatures, frequent frosts and persistent snow, and are much more
extensive than glacial features in the Australian Alps.**
Once thought to be a very recent geological
formation it is now known that the Australian Alps predates the European Alps,
Himalayas and the Andes of South America.
“Note.
For much of the twentieth century, the highland areas of south-eastern Australia
were presumed to have originated from a substantial phase of uplift over the
last 5 million years. This was known as the 'Kosciuszko Uplift' and the
highlands were described as being recent geological features. Since the early
1970s the 'Kosciuszko Uplift' theory has been challenged by researchers offering
a number of different theories. It is perhaps best just to accept that an uplift
occurred. The geological time scale illustrates the generally accepted
sequence.”**
**(©
Australian Alps national parks)
For more info try
AANP -
Click here
It was in the same sort of terrain as this
that it was realised that the Burramys Parvus or Mountain Pygmy Possum
was to be found. After discovery in 1966 at University Ski Club it was found at
Hotham and on Bogong, when it was long thought to have been extinct. Though it
is unlikely to exist in this formation preferring altitudes above 1400m, it
cannot be ruled out without comprehensive mammal trapping studies which are
beyond budgetry constraints for DSE at this time. Forced to high altitude
"islands in the sky" over 10,000 years as climates warmed, this species is
subject to heat stroke at temperatures above 28°C. Global warming of 1-2°C would
see this species extinct. The rock scree would also play host to a range of
spiders, skinks and other creatures which if studied would almost inevitably
reveal unique species of limited distribution elsewhere.
Bear all of the above in mind as you seek this
cache, it is a fascinating location. The determination of the tree that chose
this location to take root has to be seen to be believed. That it survived as
long as it did is quite impressive. Enjoy the location, it is unusual and fairly
unique.
The cache is in an ammo box and
contains a good range of swaps. Please trade even or trade up. You may suffer
poor EPE in this area – a problem not unusual in the Alps. After the History,
Mystery, High Country event cache I will know better how close the coords are
and whether EPE is a problem, I may or may not add a hint.
This terrain is unsuitable for small
children. This area is subject to seasonal track closures from after June to
Nov, and is 4wd only access. For track closures and condition reports phone
Parks Vic on 131963 and ask for the Heyfield Office. The extremely keen could
hike down the 4wd track from the Howitt Plains Rd which provides 2wd access to
the top of the King Billy Track.
Happy caching!
djcache