Hoba meteorite (Hoba West iron meteorite)
It is inferred that the Earth’s atmosphere slowed the object down to the point that it fell to the surface at terminal velocity, thereby remaining intact and causing little excavation. The meteorite is unusual in that it is flat on both major surfaces, possibly causing it to have skipped across the top of the atmosphere in the way a flat stone skips on water. – Hoba meteorite (Hoba West) – Wiki
The Hoba West meteorite was discovered just below the surface.
The old report “Radioactive Isotopes in Hoba West and Other Iron Meteorites” carried out by the Smithsonian Astrophysical Observatory has many interesting parts and a detailed chemical analysis. A few of these are shown below.
In both hoba and sikhote-alin the Ni59, which is a neutron-produced isotope, is higher than would be expected from the Cl36 content. This indicates that solar flares contributed to the neutron-produced isotopes in these iron meteorites.
…A 30 cm thick layer of “iron shale”, a weathering product, surrounds the sides and bottom of the meteorite and probably once covered the top.
The terrestrial age of Hoba is a useful tool in the interpretation of the geologic and climatic history of the region. Postdating the fall of Hoba is a limestone deposit that has been laid over the surrounding granite. The 30cm thick layer of unusual iron shale on the sides and bottom of Hoba is of a related interest.
The preterrestrial size of Hoba is important because Hoba is the largest known meteorite and probably did not fragment in its atmospheric passage. Hoba contains no cracks nor planes of weakness, and, since it is a high-nickel ataxite, it is exceedingly uniform and does not easily fragment nor erode.
…Geological and climatic changes in the region in which Hoba is found can be deduced from the geological conditions in which the meteorite lies. The terrestrial age of Hoba requires these geological and climatic changes to be of recent origin. Hoba does not lie in a crater, and there is no geological evidence of impact. Since its fall, it has been covered by a layer of calcareous tuffa or surface limestone that overlies granite (Spencer 1932). This probably formed by the evapouration of stagnant surface water bearing calcium carbonate from the nearby Otavi dolomite. The region today is arid, with an annual rainfall of only 20 to 30 inches and little runoff. Thus, it seems probable that a period of moister climate occurred in the region during the last 80,000 years, probably at the time of the last pluvial and glacial period in the Northern Hemisphere.
The oxidation crust or “iron shale” that covers the bottom and sides of Hoba contains Fe, Ni and Co in the same proportions as does the metal (Spencer 1932), indicating that the oxidation occurred with no leaching. The oxidation probably took place rapidly during the moist period in which the surface limestone formed.
FE60 in Hoba
Because Co60 has a half-life of only 5.27 years, its presence would not be expected in a meteorite such as Hoba West, except as the daughter of FE60 or as the product of the capture of cosmic-ray neutrons by Co59 in the meteorite at the earth’s surface. The Co60 from meteorite Fe60 has been measured only once, by Goel and Honda (1965); compared with their value, the Co60 activity in Hoba is high. Calculation using the methods and data of Montgomery and Tobey (1949), with consideration of resonance neutron capture, indicate that most or perhaps all the Co60 found in Hoba arises from the capture of cosmic-ray neutrons in meteoritic cobalt at the earth’s surface. Radioactive Isotopes in Hoba West and Other Iron Meteorites (pdf)
The iron shale with no signs of leaching, no cracks in the Hoba West meteorite, the calcareous tuffa (surface limestone), half lifes of chemicals, no evidence of impact and the fact that it and other iron meteorites are found on or just below the surface seem to indicate that they are found where they are formed.
The fact that the iron shale and the meteorite contain the same proportions of Fe, Ni and Co could mean they were formed at the same time by the same process.
Some aspects of the nature of the Hoba meteorite are truely puzzling. On the one hand, the meteorite belongs, despite its huge size, to a very rare class of meteorites and is defined as nickel – rich ataxite. Ataxites consists almost entirely out a dense packing of the meteorite mineral taenite and do not display the otherwise typical ‘Widmannstaettensche Figuren’ on acid edging. Another enigma is the absence of any crater like structure. The meteorite was covered by a thin crust of calcrete at the time of discovery, but upon excavation no signs of the otherwise very typical temperature & pressure induced shock phenomenae, nor any buried remains of a crater structure were reported.
During excavation an odd “Iron shale” = an odd magnetic (!) and limonite rich laminated sediment was observed in close proximity to the meteorite mass, which most probably results from long time weathering.
All this support the theory, that the meteorite with its unusual form hit the earth – estimated 80.000 B.C. ago – at an very low angle, jumping like a stone on water from place to place until it reached its present position. – Africa : Namibia : Largest known iron meteorite on Farm Hoba West
The gEUlogy of the area shows some interesting possible Electric Universe geology. Two very deep sunken lakes that may be related to the Martian Skylights are found close by, Lake Otjikoto and Lake Guinas.
There was also a large natural hill of copper and the famous and mysterious Tsumeb mineralised pipe. The Tsumeb pipe goes vertically through the Precambrian Otavi and it has many minerals including gold, arsenic, lead, silver, zinc etc. It has over 200 minerals and some are only found here. Was the Tsumeb mineral pipe created at the same time as the Hoba West meteorite or does it show that the area is an attractive area to the Electric Universe?