ISSN:
1432-1866
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Geologie und Paläontologie
Notizen:
Abstract Several major shear zones trending WNW through the southern Tennant Creek goldfield show evidence for south up over north (reverse) movement during low temperature brittle-ductile shear. Total vertical displacements across two of these shears are around 1 km based on the apparent offset of a concordant porphyry. A thin-skinned linked fold-thrust model for the early deformation of the Tennant Creek goldfield is supported by the disharmonie fold profile shapes, the subhorizontal enveloping surface of folding and a shallow and relatively planar basement topography inferred from two-dimensional gravity modelling. Massive iron oxide deposits within the Warramunga Group, which host gold, copper and bismuth ore, formed during folding and reverse faulting, but the shear zones are neither unusually altered nor mineralised compared to the surrounding rocks emphasising the importance of chemical controls on ironstone formation, such as hematite-rich layers in the stratigraphy, rather than direct structural controls.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF00206873
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