Tektites

Plate I. -Surface structures of billitonites and australite cores Plate II.-Surface structures of indochinites Plate III.-Surface structures of moldavites Plate IV. -Surface structures of moldavites Plate V. -Surface structures of australites Plate VI. -Surface structures of indochinites beneath which the substratum varies from gneiss, mica schist, granite!Palaeozoic metamorphic schist, andesite and Permo-Triassic sandstone, to ancient 2392/58-2 to South Australia and Western Australia south of the South Tropic, the west- ward trend being governed by the direction of high altitude air currents, but there is no support for this postulate.As Selga (1930, p. 25) commented, no one who has seen the size and markings of tektites, could seriously consider the hypothesis of dispersal from volcanoes to non-volcanic areas by such transportation as amulets by primitive man, gizzard stones by birds, glacial deposits by ice sheets, pebbles by water, or as small volcanic bullets shot out by volcanoes. Since the Nullarbor Plain stretching from South Australia into WesternAustralia, where many australites are found, is an uninhabited, monotonous limestone plain without watercourses, the suggestion that australite distribution was carried out by running water or by aborigines, receives no support (Fenner, 1934, p. 64).The facts of australite distribution strongly support the belief held in Australia, that most australites are generally found approximately where they originally fell.Some certainly have been carried around by aborigines and as gizzard stones by large native birds, and some have been concentrated into placer deposits by running water, but these are largely of local importance only, and scarcely affect the overall distribution across 2,000 miles of the continent.It is thus apparent that neither aborigines, glaciers, icebergs, streams, birds, winds nor volcanoes adequately account for tektite spreading over the vast areas where they are known.Moreover, no primary sources for such distribution have been located on any part of the earth's surface.In Australia (fig.4), tektites are spread over 2,000,000 square miles of the continent as a conservative estimate.They are found on mountain tops, on the surfaces of vast plains (both volcanic and sedimentary), in desert sand dunes, in clay pans and creek beds, buried deep (20 to 30 feet) in alluvial deposits* and less in shallow surface soils.In the Australian tektite zone, it is thus necessary to invoke an extra-terrestrial method to account for such an extensive vertical and lateral distribution.Certain centres of concentration within the vast strewnfield in Australia occur in auriferous and other gravels, as in various parts of New South Wales, Victoria and Tasmania, and some occur at various depths in the clay pans of the more arid regions.Such concentrations are best explained in terms of local stream action.Other centres of relatively abundant concentration occur at Mulka, Oodnadatta and William Creek in South Australia, at Port Campbell and Nirranda in Victoria, at Charlotte Waters in Central Australia, at Kalgoorlie in Western Australia and on the Nullarbor Plain.The occurrences at all of these places are not satisfactorily explained by stream action, and at all events, there has to be a primary source from whence streams Pavilion of the Mineral Gallery, British Mm um If 7 °" loan in llu ' 1927), and later presented to fhe British MuLum by the",' i TS* (fttor ' specimens of australites collected by Dr C TWr, me .I ?lsses Dunn.280 Australia are also housed in the British Museum MosTau L ^?V ' Wtern «t ^usiiaimn Museums * u *jj» Seated from the ™rc J^£W££Z«£* * Albedothe brightness of a reflecting surface as measured by the proportion of incident light that it reflects.