This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1911 Excerpt: ...more readily occur in the older rocks than in the newer sediments. The latter have not been subjected to such violent or such long continued crystal movements and chemical action. In New South Wales the later sediments are unusually free from complex folding, while the western plains are composed of newer sediments ...
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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1911 Excerpt: ...more readily occur in the older rocks than in the newer sediments. The latter have not been subjected to such violent or such long continued crystal movements and chemical action. In New South Wales the later sediments are unusually free from complex folding, while the western plains are composed of newer sediments almost as level as when they were deposited in the old tertiary gulf or lake. It would be absurd to look for valuable gold, copper, or lead veins in these geologically recent rocks. Alluvial gold and tin occur in tertiary deposits, but are always associated with the palaeozoic rocks from which they have been derived. The third belt (the Western Plains) coincides approximately with the level tertiary and secondary deposits. In the north there is the Artesian Basin of New South Wales. The whole country is devoted to breeding sheep for wool, the numbers of sheep per acre increasing from west to east with the rainfall. The low-lying land near the rivers especially in the Riverina district, will soon be cut up into irrigation farms, for which there is a great future. The newer rocks, however, contain one valuable mineral, the precious opal. This is found sporadically but fairly abundantly in the north-west of the Artesian Basin. In this district is the Mount Brown goldfield, an island or inlier of older rock which does not happen to be covered by the later secondary strata. Lastly, on the western edge of the State is an area of very old rocks, possibly Cambrian in age, which contains the silver-lead of Broken Hill (see pp. 173-6). Here, in spite of a rainfall of little more than 5 inches per annum, and costly transport through another State, the third largest town of New South Wales has arisen. This is a striking example of an economic product proving...
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