Cache in, Trash out #63 EarthCache
Hidden : 6/17/2013
Difficulty:
3 out of 5
Terrain:
2.5 out of 5

Size: Size: other (other)

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Geocache Description:


Non-official obligation is to collect any trash on your way. Yes you will have to scour the area, but find a piece of litter no matter how small.
DO Not Climb GZ

Feel free to submit "find" before CO approval if you are supremely confident of your earth-caching prowess, but know that it will be deleted if answers are not forthcoming or insufficient..
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These Mudstone quarries were mined in the 1850s for housing, and for road-base
It took about the next 20yrs before quality control realised the stone was too soft and the quarry was abandoned.
The last time it was used commercially was to provide rock to rebuild part of the Holy Trinity Church on the corner of Doncaster Rd and Church St.
There are three distinct quarries along this track, the amphitheater in front of you at GZ is picturesque but unstable; especially as it attracts the inexperienced or opportunistic climber.


The lack of fissility or layering in mudstone may be due either to the original texture or to the disruption of layering by burrowing organisms in the sediment before lithification. Mud rocks, such as mudstone and shale comprise some 65% of all sedimentary rocks.
Mudstone looks like hardened clay and, depending upon the circumstances under which it was formed, it may show cracks or fissures, like a sun-baked clay deposit.
Our local Mud or Siltstone is Silurian aged, laid deep under the ocean 420 million years ago, and underlies much of the Municipal Gardens (Ruffey Lake Park).
Mudstone is mostly composed of clay and silt particles; it is formed in a water-driven depositional environment characterized by a fast-moving narrow flow that suddenly opens up into a very wide, slow-moving flow, such as a river delta. The fast-moving water carries a sediment load along with a makeup determined a great deal by the speed of the flow. The greater the speed of the flow, the heavier and larger the objects it can carry downstream.

So when the fast and narrow flow suddenly opens up and gets very broad and very shallow the heavier particles drop out almost immediately, leaving the smaller, lighter particles to carry a little further, settling to the bottom in smooth, even layers. These lighter particles are composed of very small and very fine sand, silt, and the greatest component of the load is clay; with some minor organic material mixed for good measure.

These layers are laid down continuously, building up with each successive heavy flow coming down the river (or stream), new layers building on top of each previous layer, pushing them down, down, down, squeezing the water out from between the grains and platelets.

When these layers have been compressed with the high pressure of overburden long enough, some minor "silicification" takes place between the particles from the sand grains' contribution of silica in the solution. This weakly 'binds' the mudstone together in thin plates. If the mudstone undergoes high heat as well as high pressure, it may metamorphose into shale.

Over time these beds buckled and fractured to form the rolling Northeastern landscape that characterises the Manningham area.

Rocks of similar origin to those of the Melbourne Zone appear as outcrops across Victoria forming the basis of the Victorian mountain areas. In the Melbourne Zone, the sediments are up to 10,000 meters thick.
These rocks were deposited in a deep ocean basin as layers of mud (silt and clay) and sand, or low turbulence tidal flats.


After compression and cementation, the sedimentary rocks were uplifted and folds were formed, with the thick competent sandstone beds deforming often by brittle fracture, bending around and deforming the less competent mudstones.

References: Manningham Council Heritage Trail Merri Creek Management Committee (http://www.mcmc.org.au/index.php?option=com_content&view=article&id=148&Itemid=245)
Wikipedia



Please email the answers to Questions Promptly or censorship will bite
Include your caching name, and any other parties caching names who will be using your answers to prove their claim to find.

1/ Why is it that mudstone is not ideally structurally stable as a building material?

2/ Sedimentary rocks are formed from sediment grains deposited by water, wind or ice. They are always formed in layers, called “beds or strata”, and quite often contain fossils. Name 3 other sedimentary rocks

3/ What is the term used to describe the cementing together of particles?
(for Pete's sake, don't say cementation!)
4/ Which historical local family used the quarry to provide foundations for their home?

PROOF OF SITE VISIT:
5/ Would you say there is any evidence of Metamorphic shale formation at this site? Where did you spot it?

6/ How many large living pine trees encircle the amphitheater, up on the ridge line, between the Fence and the dropoff?? Please be careful.
This is the one that tricks most respondents.


7/ a) What is the altitude at GZ, and b) how high is the step up to the platform?

8/ Which side of the amphitheater has the tortuous roots of a Monterey Radiata climbing down the exposed cliff face?

BONUS CACHING Karma option: Post a photo of you practicing CITO at this lovely site on your found log (when approved)

Feel free to submit find log before CO approval, but it will be deleted if inadequate.

Additional Hints (Decrypt)

QeYhxr@zr.pbz Cyf vapyhqr lbhe erghea rznvy jvgu nafjref

Decryption Key

A|B|C|D|E|F|G|H|I|J|K|L|M
-------------------------
N|O|P|Q|R|S|T|U|V|W|X|Y|Z

(letter above equals below, and vice versa)


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