DOI: 10.1038/ngeo1759
论文题名: Flash vaporization during earthquakes evidenced by gold deposits
作者: Weatherley D.K. ; Henley R.W.
刊名: Nature Geoscience
ISSN: 17520894
出版年: 2013
卷: 6, 期: 4 起始页码: 294
结束页码: 298
语种: 英语
Scopus关键词: active fault
; deposition
; fluid pressure
; gold
; mineral deposit
; numerical model
; ore grade
; pressure drop
; pressure gradient
; quartz vein
; vaporization
; Australia
; Western Australia
英文摘要: Much of the world's known gold has been derived from arrays of quartz veins. The veins formed during periods of mountain building that occurred as long as 3 billion years ago, and were deposited by very large volumes of water that flowed along deep, seismically active faults. The veins formed under fluctuating pressures during earthquakes, but the magnitude of the pressure fluctuations and their influence on mineral deposition is not known. Here we use a simple thermo-mechanical piston model to calculate the drop in fluid pressure experienced by a fluid-filled fault cavity during an earthquake. The geometry of the model is constrained using measurements of typical fault jogs, such as those preserved in the Revenge gold deposit in Western Australia, and other gold deposits around the world. We find that cavity expansion generates extreme reductions in pressure that cause the fluid that is trapped in the jog to expand to a very low-density vapour. Such flash vaporization of the fluid results in the rapid co-deposition of silica with a range of trace elements to form gold-enriched quartz veins. Flash vaporization continues as more fluid flows towards the newly expanded cavity, until the pressure in the cavity eventually recovers to ambient conditions. Multiple earthquakes progressively build economic-grade gold deposits. © 2013 Macmillan Publishers Limited. All rights reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/106814
Appears in Collections: 气候减缓与适应 科学计划与规划
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作者单位: WH Bryan Mining and Geology Research Centre, Sustainable Minerals Institute, University of Queensland, Brisbane, QLD 4072, Australia; Research School of Earth Sciences, Australian National University, Canberra, ACT 0200, Australia
Recommended Citation:
Weatherley D.K.,Henley R.W.. Flash vaporization during earthquakes evidenced by gold deposits[J]. Nature Geoscience,2013-01-01,6(4)