Private Property
Please note that this public reserve was sold into private hands
during the Kennett years.
The land owner has kindly granted us permission to access the
reserve on foot, so be sure to respect this private property by not
driving onto the land (the gate a little further along the road is
padlocked).
Also, leave your pets outside the property as sheep and
cattle occasionally graze in the paddocks on the mountain's western
slopes.
There is a deep unprotected quarry near the crest, so please
take extra care with young children who may want to race ahead to
the marker above the first waypoint.
Entering the Reserve
To enter the reserve, use the indicated stepping stone to cross
over the fence as this provides the best approach to the summit.
There is room to pull off the road and park directly beside this
waypoint.
As you climb to the summit, on the ground you'll see a
scattering of olivine basalt, together with light-weight pumice,
and a heavy iron-ore rich red rock, as well as the odd Paddy
Melon or two (Cucumis myriocarpus, a weed with a small
bitter fruit, introduced from Africa, found growing here in late
autumn).
This is Mount Consultation (elevation 377 metres), and it
contains two of my favourite things; a great view and a
triangulation station survey marker.
For those of you in a hurry, find the trig marker's five digit
stamped ID (723[AA]), and proceed directly to the cache, a 1
litre Sistema container hidden in the traditional manner at
S 37° 05.[902-AA] E 144° 10.[076+AA].
For the remaining slow-cachers, catch your breath here at the
crest and read on for a brief discussion of this area's long
geological history.
Mount Consultation: The Volcano
While Mount Franklin (standing proudly to the South) is 220
thousand years old, Mount Consultation has been dated at
approximately 3.5 million years, which makes it about 16 times
older.
Being a volcano, the mountain consists of Igneous rocks,
which are formed when molten rock, or magma, cools and solidifies.
If this occurs at the surface, the molten rock is lava from a
volcano, and we get volcanic (extrusive) rocks such as basalt. If
the molten rock cools deep under the ground we get plutonic
(intrusive) rocks such as granite.
Mount Alexander in Harcourt is composed of granite, which
has a course crystal from very slow cooling below the surface,
while Mount Franklin and Mount Consultation are
composed of basalt, which has a fine grain from rapid cooling at
the surface.
This rapid cooling does not allow time for the atoms to arrange
themselves into larger crystalline structures, rather, it gives
rise to many centres of crystallisation, and smaller crystals
result. When very rapid cooling occurs (not seen here) there
is no time for the atoms to arrange themselves into a space-lattice
of crystals, and glass occurs.
This volcano was probably much higher originally, but at some
point its top blew off, and you can see some larger boulders from
this event down the southern side.
There is pumice on one side of the mountain only, so it's also
likely that there was a strong North-West wind blowing at the time
of the eruption.
The volcano's top would have formed a typical pyroclastic
cone (actually a composite cone), but then a breach
occurred in the North-West side.
Lava flowed from this breach for several kilometres to the
North-West towards the golf course (in the direction of Mount
Tarrengower), and the basalt is visible from the summit of the
volcano. The basalt tongue can also be seen from the Pyrenees
Highway near the golf course.
As the lava flow slowed and cooled, a basalt plug formed
which capped the volcano off. This is unusual, as the hot magma
typically retreats back down the conduit leaving a crater (Mount
Franklin is a breached volcano with a crater, and the road to
the picnic area passes through the breach).
The South-Eastern side of the mountain is actually
sedimentary rock (not volcanic).
The View
Let's take a look at the vista from this fine vantage point, so
pull out your binoculars and point them Due South.
-
Mount Franklin lies 18km almost Due South, standing 611
metres high, which is 234 metres higher than your current vantage
point.
-
Just behind, and touching the left edge of Mount
Franklin, is Daylesford's Wombat Hill, which is 27km
away (and not to the right of the mountain as you may have
expected).
-
Continuing left to about SSE, but below the skyline, you will
see two white mullock heaps which are 5km away in Guildford.
Guildford's Stone Lookout Platform (310m elevation, at the
end of Havelock Street) can be found by following the tree-line
that is level with the right-most mullock heap further South
(right), where it will appear in a gap just below this tree
line.
You may need to shift your position slightly to line up a gap in
the trees before the platform can be seen.
-
Continuing left to about ESE, high up on the skyline at 540m is
the Fryerstown Lookout Tower, about 12km away.
-
Due East is The Monk at 463m and 6.6km away, but this is
harder to spot as it is below the skyline and
tree-covered.
-
ENE is a Telstra Mobile Phone Tower, which is also below
the skyline at 370m and 5km away. This is situated in the Little
Bendigo area, where the Poverty Gully Reservoir Track meets Ross
Drive.
-
NE and 16.6km away at 746m lies Mount Alexander,
bristling with TV and Mobile Phone towers.
-
Swinging around to the NW and 15.5km away at 581m lies Mount
Tarrengower, with its distinctive fire lookout tower and other
microwave towers.
-
Finally, to the SW and 27.5km away at 670m lies Mount
Kooroocheang, with a microwave tower and a dirt road snaking up
its side.
Muckleford Fault
A little West of Mount Kooroocheang, below the skyline, the
flat cleared land about 5km away is the Guildford Plateau lava
flow. If you follow the plateau West for another kilometre it
dips then rises again into a rough tree range that is part of the
Muckleford Fault, which was formed about 440 million years
ago.
The Muckleford Fault is a major fault line in Victoria, with a
total vertical movement during the initial stages of about 1 to 2
kilometres. There has been a movement of about 15m along the fault
line since the basalt flow (in the last 4 to 6 million years), so
the fault may still be active.
To April 2007, 559 earthquakes have been located in this region,
most along the Muckleford Fault. The largest was of magnitude 4.5
well to the north near Serpentine in 1932, and several have been of
magnitude 4.0.
Over 540 of these earthquakes occurred since 1976 when sensitive
modern seismographs were first installed. Of these, about 300 were
in a large swarm of activity in the Bradford Hills north of Maldon
in 1991 with decreasing activity over the next few years. Small
earthquakes occur along the Muckleford Fault every few weeks, but
most are too small or too deep to be felt. [source: 'Geology of the Castlemaine-Maldon-Newstead
Area', Gary Gibson]
The Cache
Punch in the cache location calculated above and wander down the
hill to GZ (be careful not to step too close to the quarry's edge),
and sign the log before we continue on with the tour.
The Quarry
Part of the mountain was quarried away for use as ballast when the
Castlemaine-Maryborough railway line was built (it opened in July
1874).
If you continue to proceed down the hill past the cache and bear
left, you can walk around to the road the leads into the quarry
itself.
The rock in this mountain has been analysed and contains
olivine basalt, a very fine basalt containing a silicate of
iron and magnesium, which gives it a distinctive olive-green
colour, and is of a very high grade.
At the entrance to the quarry you can see a block of concrete
with some bolts sticking up - this is where the rock crusher was
located. At the time this quarry work took place I'd expect that
they would have used a horse & cart to haul the crushed rock
out.
Quite a while ago now, Carisbrook Quarries wanted to excavate
the entire mountain right down to the ground, and they even wanted
to quarry the basalt flow too.
Fortunately there was a big public uproar about this, so the
operation didn't proceed, but you're very lucky not to be standing
in a big hole here today.
Witches Coven
In the mid 1980's Guildford was home to quite a large practice of
witches, and some used this mountain to hold celebrations of the
Sabbat here in the quarry.
They would bring smooth river washed, tumbled white quartz rocks
from the Guildford area and arrange them here in a huge circle to
perform Circle Casting. Most of these white quartz rocks
have now been taken away, however a few remnants still remain
(Quartz is not native to this mountain).
Rumour: I'm not sure if they were Skyclad ("Clad only in
the sky", i.e. naked) during these rituals, but some say magick is
more powerful when performed in this way.
It was apparently quite an active group for 3-4 years, and I
believe that some seasonal celebrations, such as Ostara
(Spring Equinox, Lady Day), or Samhain (Hallowe'en, All
Hallow's Eve) are now held at Mount Franklin.
Mineralised Dyke
Follow the road out of the quarry, it will lead you back around
close to the stepping stone again.
Take care along this road as there is a wasp nest in one of the
trees to the left of the path. It's currently dormant (in winter),
however it may become active again in summer, so keep a sharp eye
out and give it a wide berth.
Climb back over the fence again and walk to the Mineralised
Dyke waypoint, which is located down the road, just past the
gate (but please don't climb through the gate).
Dykes result in the forcing apart by the magma of more or
less vertical fissures, so that the resultant intrusive igneous
rock has a wall-like form, and appears at the surface as a
straight band of rock often traceable over great distances.
The dyke found here is a mineralised dyke. Because it was
formed very close to the volcano it was very porous, and over time
minerals have come up through it. It has a high iron content, and
its texture almost makes it look man-made.
You'll need to walk behind the dyke to gauge its height, as the
West side has collected a bank of top soil washed down from the
mountain over the years.
Notice how part of this 3.5 million year old geological
formation has been callously chipped away to put up a wire
fence. That's progress, eh ?
If you look back along the dyke towards the stepping stone, you
can see where the top soil eventually covers the dyke. If you were
to dig in this area, I'm sure that you would find the dyke
continuing on for a much greater distance than is currently
visible.
Ford's Road Syncline
That's the end of this short geological tour, but if you feel
inclined, on the way out stop at the Syncline waypoint
(where the road passes under the Ranter's Gully water race pipe)
and examine the cutting, which contains a large symmetrical
syncline (where the rock layers fold downwards in the centre).
Extensive faulting can be seen in the cutting.