Note: This cache can be undertaken in most tidal conditions - however please take care if taking any children as there can be rouge waves.
Veins
A geology vein is a distinct sheet like body of crystalized minerals within a rock. Veins typically form when mineral constituents carried by water solutions within the rock mass are deposited in the cracks.
The mineral crystals within a vein are either blocky (also called sparry) or fibrous.
In blocky veins, the crystals in the vein fill roughly equant. The occurrence of blocky veins mans that the vein was an open cavity when the mineral formed and the rock strength was sufficient to permit a cavity to stay open.
In fibrous veins, the crystals are long relative to their width, so that the vein has the appearance of being spanned by a bunch of hairs. Geologists don't fully agree on the origin of fibrous veins, but some may form by the crack-seal process.
Crack-seal veins are thought to form quite quickly during deformation by precipitation of minerals within incipient fractures. This happens swiftly by geologic standards, because pressures and deformation mean that large open spaces cannot be maintained; generally the space is in the order of millimeters or micrometers. Veins grow in thickness by reopening of the vein fracture and progressive deposition of minerals on the growth surface, this process can takes tens of thousands of passes, where the existing grains act as nuclei on which the new mineral attaches.
Veins are of prime importance to mineral deposits, because they are the source of mineralisation either in or proximal to the veins. Typical examples include gold lodes, as well as skarn mineralisation.
To log this geocache, in a message send the answers to the following:
1. Looking at the veins would you say the crystals are either blocky or fibrous?
2. Pick a 1-meter section of rock - how many veins can you see? What is the range of thickness of the veins?
3. (Optional) take a photo -which would not allow someone to armchair this earthcache.
Please Note:
All team member names must be listed in the message if only one person is sending through the answers.
Please do not include this information in your log or photo, or you risk your log being deleted.
You may log the cache immediately, however answers sent within 30 days. If no message is received, you will be contacted and the log may be deleted.