Access
Either travel to GZ via Skyline Gondola (terrain 1.5) or via one of the many Queenstown Walking Tracks (terrain 3.5)(click the links for details).
Background
Rocks, where they protrude through the lithosphere* surface provide a window back in time. This is a chance for us to study and learn more about the geological history of the Earth.
The co-ordinates for GZ take you to one such window which is in the form of an outcrop of schist. Schist covers much of Otago as a vast peneplain** that formed 200-160 million years ago. There are two interpretative panels which will educate you as to the formation and subsequent changes to the schist.
* outer-most shell of a rocky planet. On Earth, it comprises the crust and the portion of the upper mantle that behaves elastically on time scales of thousands of years or greater.
** a low-relief plain representing the final stage of fluvial erosion (occurs during times of extended tectonic stability). In time the land would be reduced to almost sea level leaving so little gradient that essentially no more erosion could occur.
Schist
Source: www.wikipedia.com
Logging Requirements
0. Preface any email with GC3QDMV Window Back in Time in the subject line and title and clearly note the question number and answer. Do not wait for a confirmation email to log but be prepared to be asked for additional information if your answers are slim.
1. Describe the events that led to the formation of schist in Otago.
2. At what point in time did NZ separate from Gondwana?
3. What caused the schist at GZ to become exposed?
4a. What minerals are the dark layers made up of?
4b. Count the approximate number of light layers across one hand breadth.
5. What geological phenomenon has caused the steep sides of the gorge in front of GZ?
Email answers to gcstegan"at"gmail.com
No photo is necessary but please make sure your answers are correct or your log will not be valid.
2012 Stegan’s EarthCache Masters Programme
It is not very feasible for many New Zealanders to get past the Bronze level on the earthcache.org programme becase you need three states for Silver which means leaving the country! So, as in 2010 I've decided to run a little sideshow on my new earthcaches this year... with the following points system:
5 points: First to find
3 points: 2nd to find
1 point: Logging a find
1-5 points: Special bonus questions.
At the end of 2012, I’ll issue certificates for 1st, 2nd and 3rd.
Updated information and Leaderboard at: Stegan’s Earthcache Programme
