Bushveld Complex EarthCache
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Location of cache is just outside Rustenburg amongs the shafts of RPM. Cache is close to the road in a open veld. its a good idea to do PMR aswell with this one
FTF goes to = GerhardoosMPsa
To log find - Please mail answers and log the find, you may snap a pic if you like aswell
The Bushveld Complex is a large igneous intrusion within the Earth's crust which has been tilted and eroded and now outcrops around what appears to be the edge of a great geological basin. Located in South Africa, the BIC contains some of the richest ore deposits on Earth. The reserves of platinum group metals (PGMs), platinum, palladium, osmium, iridium, rhodium, and ruthenium are the world's largest, and there are vast quantities of iron, tin, chromium, titanium and vanadium. Gabbro or norite is also quarried from parts of the Complex and rendered into dimension stone. Origin The Bushveld Igneous Complex is divided into an eastern and western lobe, with a further northern extension. All three sections of the system were formed around the same time - about 2 billion years ago - and are remarkably similar. Vast quantities of molten rock from the earth's mantle were brought to surface through long vertical cracks in the earth's crust - huge arcuate differentiated lopolithic intrusions - creating the geological intrusion known as the Bushveld Igneous Complex. The effects of these injections of molten rock over time, combined with the crystallisation of different minerals at different temperatures, resulted in the formation of a structure rather like a layered cake consisting of distinct rock strata, including three PGM-bearing layers, referred to as reefs. The Complex includes layered mafic intrusions (the Rustenburg Layered Suite) and a felsic phase. It has its geographic centre located north of Pretoria in South Africa at about 25° S and 29° E. It covers over 66,000 km², an area the size of Ireland. The complex varies in thickness, sometimes reaching 9,000 meters thick. Lithologies vary from largely ultramafic peridotite, chromitite, harzburgite, and bronzitite in the lower sections to mafic norite, anorthosite, and gabbro toward the top, and the mafic Rustenburg Layered Suite is followed by a felsic phase (the Lebowa Granite Suite). The orebodies within the complex include the UG2 reef containing up to 43.5% chromite, and the platinum-bearing horizons Merensky Reef and Plat Reef. The Merensky Reef varies from 30 to 90 cm in thickness. It is a norite with extensive chromitite and sulfide layers or zones containing the ore. The Reef contains an average of 10 ppm platinum group metals in pyrrhotite, pentlandite, and pyrite as well as in rare platinum group minerals and alloys. The Merensky and UG-2 reefs contain approximately 90% of the world's known PGE reserves. About 80% of the platinum and 20% of the palladium mined each year are produced from these horizons. The cache is located on the western lobe of the complex right next to Anglo Platinum Rustenburg Section (RPM) Waterval UG2 shaft, the only fully mechanized shaft at RPM with a LP (Low Profile) and XLP (Extra Low Profile) operations. RPM consists of 8 shafts of which 7 are conventional and 1 mechanized. What makes the cache unique is that it is situated 148.6 m above the entrance into the XLP in the East side of the shaft and LP operations on the West side of this shaft, and it’s the only fully mechanised XLP operation and the most successful of it’s kind in the Platinum industry thus far. Further expansions are under way at this stage to improve and expand the current operations and this section and of others in the industry. The XLP section is operated with 2 LHD’s (Load Haul Dumps), 1 Double Boom Drill Rig, 1 Roofbolter (Installs Support), 1 Dozer. Except for the LHD’s the machines do not exceed height of 1.1m and are operated with a remote control. Waterval UG2 mines only the UG2 reef band that outcrops close by, the mines first sections were only 40m below surface and the current deepest point is only 251m below surface and is in mining terms a shallow mine. The reef band here is at about average 70cm. the current grade of ore extracted here is 3.6 g/t (grams per ton). 10 000 tons of ore is blasted and tipped into the silo everyday, this is currently the most productive shaft in RPM, and contributes 33% of total production for RPM. Pile of large rocks close to road. On top of the rocks is a few smaller rocks,
Question 1 What is the colour of smaller pile of rocks?
Q2 Describe what you see when you reflect it on the Sun?
Q3 Describe the rock's texture.
Additional Hints
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