The 12 Days of Cachemas (TDOC24) is a series of caches placed across Victoria to celebrate Cachemas in July in 2024. The series is a joint initiative of Geocaching Victoria and the local community to release caches in a different category each day across the state. We hope you have as much fun finding this series, as we all had placing them. A geocaching list of the full series is available at https://coord.info/BMDGW0P
On the second day of Cachemas, Signal gave to me,
two earthcaches,
and a wherigo up in a tree.
Note: This is an Earthcache. There is no physical cache to find. Logging this Earthcache requires that you undertake an educational task relating to the specific Earth Science at the site. You can log the find immediately, but such logs which are not followed up with answers will be deleted after a reasonable period of time, say two weeks, has elapsed.
Logging Tasks
Click on ‘Message this owner’, or send an email here with answers to the following logging tasks:
Q1. At GZ, describe the rock layers as you observe them. Things that may be included are colour, grain size, layer orientation etc.
Q2. Based on your answer to Q1, do the layers here comply with the principle of original horizontality?
Q3. Who is considered the father of stratigraphy?
Please include a photo with a personal/identifying item in your log.
Geocache Description
The White Hills Sediments Geological Reserve is a 15.5-hectare area that over the years has been regenerated and turned into a community space. There are approximately 2.5 kilometres of walking tracks for visitors to enjoy.
A leisurely stroll through this Geological Reserve will reveal interesting geology, a variety of plants and wildlife, two sediment ponds and the remnants of many Chinese mines.
This area was worked from the 1850s up to the 1930s, and contains many well preserved round and rectangular mine shafts. This reserve consists of dense scrub, uneven ground and many open mine shafts. Always watch where you are walking in this area and supervise children at all times.
As you stroll towards the posted coordinates, listen out for the chorus of frogs as you approach the dams, and keep to the track because the water’s edge is hidden beneath the reeds.
Being a Sediments Geological Reserve, it reminds me of Nicolas Steno, a Danish physician, who in the mid-seventeenth century made significant contributions to geology and in particular to palaeontology: the study of fossil life. Through his studies, Steno advanced many ideas through observations and the study of rocks.
Steno went on to be considered the father of modern stratigraphy, the study of rock layers. He proposed four principles of stratigraphy that still hold true today.
- Principle of superposition: In an uninterrupted sequence of sedimentary rocks, the rock layers below are older than the rock layers above.
- Principle of original horizontality: Sediments forming sedimentary rocks are usually laid down in a horizontal position (due to gravity). Rock layers that appear vertical have been moved from their original, horizontal position by some natural force. The two most common deformation forces are folding and faulting.
- Principle of lateral continuity: When sediments are laid down, creating sedimentary rocks, they spread out until they reach some other object that confines them. Sedimentary rocks continue laterally until they are stopped by some other object.
- Principle of cross-cutting relationships: Where one type of rock cuts across or through another type of rock, the rock being cut is older and the rock cutting through is younger.