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Improbable Fossil Stones v2

A cache by LouiseAnn Send Message to Owner Message this owner
Hidden : 01/07/2012
1 out of 5
1 out of 5

Size: Size:   other (other)

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Geocache Description:

Introduction. This street exhibition is a most unlikely geological occurrence created for the sake of art.

Fossil Stones
This exhibition is called Fossil Stones.
Bluestone is a common building material in the city of Melbourne but here you will find twelve large 'bluestone' boulders sitting on the pavement. Upon closer inspection you will also find ten other allegedly, but very improbable, geological features= the fossils.

Bluestone Australian bluestone is a volcanic basalt or olivine basalt.

In Victoria, Australia, bluestone was one of the favoured building materials of the 1850s during the Victorian Gold Rush.

In Melbourne it was extracted from a quarry in the Clifton Hill area and used extensively in the 19th century. Because the material was difficult to carve, it was predominantly used for warehouses and the foundations of public buildings. Significant bluestone buildings include the Melbourne Gaol, HM Prison Pentridge, St Patrick's Cathedral, Victoria Barracks, Melbourne Grammar School, Deaf Children Australia and Victorian College for the Deaf, Royal Victorian College for the Blind, the Goldsborough Mort warehouses (Bourke Street) and Timeball Tower. It was also used extensively for cobblestone roads, many which still exist in some of Melbourne's smaller lanes as well as walls, bridges, curbs and gutters in many of the inner suburbs. Some examples of structures that use the material include Princes Bridge and Federation Wharf and Hawthorn Bridge. Because of its distinctive qualities, post-modern Melbourne buildings have also made use of nostalgic bluestone, including the Southgate complex and promenade in Southbank, Victoria and apartments such as the Melburnian.

Bluestone was also sourced in many other regions of the Victorian volcanic plains and used in towns and cities of central and western regions including Ballarat, Geelong, Kyneton, Port Fairy and Portland.

When ships arrived at Melbourne laden with passengers and/or cargo, they would normally depart with less in weight that what they arrived. This would lead to instability of the vessel if they should continue their outward voyages, so they were loaded with ‘ballast', small bluestone pieces called ‘spalls'. With limited dock and wharf space available, a vessel could not simply lie at wharf till the ballast was loaded hence the ballast craft were required to ferry the stones to the ships at anchor. It would be stretching the imagination to suggest that they had a romance of their own, but there was a culture, a bond, sometimes tenuous, between the ballast men.

Williamstown was the original site for Melbourne's first settlers. Many of the first ships arriving from the UK laden with settlers, stock, building materials etc. returned to England with Williamstown mined bluestone as ballast.

EarthCache Twelve basalt boulders are sitting on the street pavement here ( which is also made of Bluestone slabs). Compare the pitted texture of the pavement slabs with the fresh faces of the boulders. These pits are known as vesicles which were gas filled cavities in the molten lava prior to cooling and crystallization

To log this Earthcache you are required to email LouiseAnn with the answers to the following. Do not post the answers online and do not log your find until you have received confirmation. Unconfirmed logs will be deleted. If you want to keep your logs in order, log the find as a note and edit it later to make it a find
A Explain why the ten 'fossils' are geologically improbable,
B Identify / Name one fossil that can fly and one that is sleeping
C Provide the year when these boulders were placed here the plaque is currently missing, so in between times, please provide the shape of the plaque that is missing from the ground near the boulders.

This cache has been created to replace the original version of it by Geodirect.

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