争吵加
发表于 2025-3-25 06:35:49
https://doi.org/10.1007/978-3-642-01774-2tions, mixed chemical and clastic sediments, tuffaceous exhalites, and disseminated or massive sulphides in both volcanic-and sediment-dominated sequences. Gold-bearing iron formations and interflow metalliferous sediments associated with seafloor hydrothermal activity also have been implicated as p
代理人
发表于 2025-3-25 10:36:27
Long-term effects of Learning English, they present economically attractive exploration targets. Individual ancient placer deposits like the Steyn/Basal placer in the Welkom goldfield of South Africa have produced in excess of 4500 t (metric tons) of gold from heavy mineral concentrates distributed over a palaeosurface area of 170 km.
labyrinth
发表于 2025-3-25 14:57:48
https://doi.org/10.1007/978-90-313-9253-7atures of which must be identified in the various sampling media (rock, soil, etc.) used for exploration. The geochemical signature of gold mineralization depends upon several parameters, particularly the style of mineralization in question and the physico-chemical characteristics of the supergene e
averse
发表于 2025-3-25 17:11:03
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irritation
发表于 2025-3-25 21:51:50
Inflammation: The Fire of Frailty?,l prospecting. In the 1950s and 1960s, direct detection methods (chiefly airborne and ground electromagnetics (EM)) were applied widely in the search for massive sulphide-hosted base-metal deposits (Paterson, 1967). At the same time, induced-polarization (IP) methods were developed for the direct de
名字的误用
发表于 2025-3-26 00:43:15
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攀登
发表于 2025-3-26 07:45:37
,Distribution of gold in the Earth’s crust,arge masses of rock through fluid—rock reactions in the deep crust (Kerrich, 1983; Groves and Phillips, 1987; Colvine ., 1988) while others stress the importance of relatively restricted petrogenetic groups of rocks termed source rocks that concentrate gold above the norm (Viljoen ., 1970; Keays, 19
轻信
发表于 2025-3-26 11:53:20
The hydrothermal geochemistry of gold,e Earth’s crust. Deposition of elemental gold and gold-containing minerals occurs in response to changes in the chemical and physical environment through which the hydrothermal ore fluid is migrating. For example, a buoyantly ascending hydrothermal fluid may encounter a permeable zone which induces
FIS
发表于 2025-3-26 12:49:48
Archaean lode gold deposits,situated in most major cratonic areas (e.g. Australia, Brazil, Canada, India, South Africa, Zimbabwe: Foster, 1984; Macdonald, 1986; Ho and Groves, 1987). Even relatively small cratons typically contain some Archaean gold deposits (e.g. Tanzania; van Straaten, 1984), and the Archaean belts of China
Rotator-Cuff
发表于 2025-3-26 20:09:33
Phanerozoic gold deposits in tectonically active continental margins,the deposits of the Witwatersrand are excluded (data from Woodall, 1988). With the anticipated increase in production from newly discovered gold deposits of the southern Pacific and western US, this percentage should increase substantially in the coming years. Consequently, the understanding of and