Abstract
The Broken Hill Block consists of Upper Proterozoic amphibolite to granulite facies rocks, the protolith for which consisted of a sedimentary sequence which matured and fined upwards stratigraphically with intervals of bimodal volcanism and rare exhalative chemical sediments. This assemblage of rock types together with a high inferred geothermal gradient of 40 to 50 Co/km suggests a rift environment. Four folding episodes are recognized and described. The stratigraphic thickness of 7 km is insufficient to explain the peak pressure conditions of metamorphism; the history of metamorphism consists of an early high temperature, low pressure pulse with the pressure increasing through time presumably due to F1 formation. The area cooled isobarically with the development of widespread retrograde schist zones.-after Authors
Original language | English |
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Pages (from-to) | 353-368 |
Number of pages | 16 |
Journal | American Society of Mechanical Engineers (Paper) |
Publication status | Published - 1984 |
Externally published | Yes |