There is a number of significant granite outcrops in the Western Australian wheatbelt. Sandford Rocks Nature Reserve is one of these. Named after a prominent mining surveyor, Henry Sandford King, it contains a complex mosaic of exposed granite rock with surrounding herb fields, heath, and long unburnt woodlands. The granite has been shaped and eroded by wind, rain, lichen and mosses to form the surrounding soils and distinct vegetation assemblages.
The 806 hectare reserve protects an ancient granite outcop as well as ephemeral rock pools “gnammas” and a diverse array of flora and fauna, some found only on granite outcrops in this region.
Look closely at these miniature meadows and the surrounding granite rock. The multi-coloured patterns on the rock which look like pain blotches are actually lichens, mosses and algae. Some mosses are more pronounced in the Winter months. The lichens play a part in the breakdown of granite rocks. They secrete very weak acids that slowly loosen the tiny sand grains in the rock surface. The root like rhizoids of mosses also help loosen sand grains. Both mosses and lichens trap dust, sand and other materials. When they die, this matter adds to a seed bed for larger plants. As the surface changes, different type of plants can grow on the rock. This progressive change of plant communities is called “succession”. There are good examples of this cycle at the stated co-ordinates.
Granite outcrops of Western Australia are inselbergs and monoliths made from granite and are found across much of Western Australia. Granite is a light-coloured igneous rock with grains large enough to be visible with the unaided eye. It forms from the slow crystallization of magma below Earth's surface. Granite is composed mainly of quartz and feldspar with minor amounts of mica, amphiboles and other minerals.
To log this cache, go to the listed coordinates and then email me the answers to these questions. You can immediately log the find and if there are any problems I will contact you.
1.What form of geological phenomenon do you think may have caused the formation of Sandford Rock?
2. How extensive are the lichens on the rock at the time of your visit.
3. Is there any sign of the mosses or lichens breaking down the rock formation in a process of succession ?