- Abstract
- Affiliation
- All
- Authors
- Book Series
- DOI
- EISBN
- EISSN
- Full Text
- GeoRef ID
- ISBN
- ISSN
- Issue
- Keyword (GeoRef Descriptor)
- Meeting Information
- Report #
- Title
- Volume
- Abstract
- Affiliation
- All
- Authors
- Book Series
- DOI
- EISBN
- EISSN
- Full Text
- GeoRef ID
- ISBN
- ISSN
- Issue
- Keyword (GeoRef Descriptor)
- Meeting Information
- Report #
- Title
- Volume
- Abstract
- Affiliation
- All
- Authors
- Book Series
- DOI
- EISBN
- EISSN
- Full Text
- GeoRef ID
- ISBN
- ISSN
- Issue
- Keyword (GeoRef Descriptor)
- Meeting Information
- Report #
- Title
- Volume
- Abstract
- Affiliation
- All
- Authors
- Book Series
- DOI
- EISBN
- EISSN
- Full Text
- GeoRef ID
- ISBN
- ISSN
- Issue
- Keyword (GeoRef Descriptor)
- Meeting Information
- Report #
- Title
- Volume
- Abstract
- Affiliation
- All
- Authors
- Book Series
- DOI
- EISBN
- EISSN
- Full Text
- GeoRef ID
- ISBN
- ISSN
- Issue
- Keyword (GeoRef Descriptor)
- Meeting Information
- Report #
- Title
- Volume
- Abstract
- Affiliation
- All
- Authors
- Book Series
- DOI
- EISBN
- EISSN
- Full Text
- GeoRef ID
- ISBN
- ISSN
- Issue
- Keyword (GeoRef Descriptor)
- Meeting Information
- Report #
- Title
- Volume
NARROW
GeoRef Subject
-
all geography including DSDP/ODP Sites and Legs
-
Africa
-
Central Africa
-
Congo (1)
-
-
East Africa
-
Zambia (1)
-
-
Southern Africa
-
South Africa (1)
-
-
West Africa
-
Mali (1)
-
-
-
Altiplano (1)
-
Asia
-
Buryat Russian Federation (1)
-
Far East
-
China
-
Guangxi China (1)
-
Guizhou China (2)
-
Sichuan China (1)
-
Yunnan China
-
Tengchong (1)
-
-
-
-
Indian Peninsula
-
India (1)
-
-
Kamchatka Russian Federation
-
Kamchatka Peninsula
-
Avacha (1)
-
Tolbachik (1)
-
-
-
Kemerovo Russian Federation (1)
-
Russian Pacific region (1)
-
Salair Ridge (1)
-
Siberia (1)
-
Siberian Platform (1)
-
Western Transbaikalia (1)
-
Yakutia Russian Federation (1)
-
-
Atlantic Ocean
-
North Atlantic
-
Gulf of Mexico (1)
-
-
-
Australasia
-
Australia (1)
-
New Zealand
-
Coromandel Peninsula (1)
-
Lake Taupo (1)
-
Northland New Zealand (1)
-
Otago New Zealand (1)
-
Otago Schist (1)
-
Rotorua New Zealand (1)
-
Taupo (1)
-
Taupo volcanic zone (19)
-
Waiotapu New Zealand (6)
-
Wairakei (1)
-
-
Papua New Guinea (1)
-
-
Canada
-
Eastern Canada
-
Ontario
-
Hemlo Deposit (5)
-
Prescott County Ontario (1)
-
Russell County Ontario (1)
-
-
-
Western Canada
-
Canadian Cordillera (1)
-
-
-
Commonwealth of Independent States
-
Russian Federation
-
Buryat Russian Federation (1)
-
Kamchatka Russian Federation
-
Kamchatka Peninsula
-
Avacha (1)
-
Tolbachik (1)
-
-
-
Kemerovo Russian Federation (1)
-
Russian Pacific region (1)
-
Salair Ridge (1)
-
Siberian Platform (1)
-
Western Transbaikalia (1)
-
Yakutia Russian Federation (1)
-
-
-
Copperbelt (1)
-
Europe
-
Central Europe
-
Germany
-
Rhineland (1)
-
Schleswig-Holstein Germany (1)
-
-
-
Fennoscandian Shield (1)
-
Lower Rhine Basin (1)
-
Southern Europe
-
Italy
-
Apennines
-
Monte Amiata (1)
-
-
Tuscany Italy
-
Monte Amiata (1)
-
Siena Italy (1)
-
-
-
-
Western Europe
-
France (1)
-
Netherlands (1)
-
United Kingdom
-
Great Britain
-
England (1)
-
Scotland
-
Aberdeenshire Scotland
-
Aberdeen Scotland (1)
-
-
-
Wales (1)
-
-
-
-
-
North America
-
Canadian Shield
-
Superior Province
-
Wawa Belt (1)
-
-
-
North American Cordillera
-
Canadian Cordillera (1)
-
-
-
North German Basin (1)
-
North Island (29)
-
Pacific Ocean
-
South Pacific
-
Southwest Pacific
-
Bismarck Sea
-
Manus Basin
-
PACMANUS hydrothermal field (1)
-
-
-
-
-
West Pacific
-
Southwest Pacific
-
Bismarck Sea
-
Manus Basin
-
PACMANUS hydrothermal field (1)
-
-
-
-
-
-
South America
-
Andes (1)
-
Argentina
-
Catamarca Argentina (1)
-
-
Brazil
-
Brazilian Shield (1)
-
Rio de Janeiro Brazil (1)
-
-
Chile (3)
-
-
South Island (1)
-
United States
-
Michigan
-
Michigan Lower Peninsula
-
Midland County Michigan (1)
-
-
-
Nevada
-
Carlin Mine (1)
-
Carlin Trend (1)
-
Elko County Nevada (1)
-
-
Wyoming
-
Teton County Wyoming (1)
-
-
Yellowstone National Park (1)
-
-
-
commodities
-
bitumens (1)
-
diamond deposits (2)
-
energy sources (1)
-
gems (1)
-
geothermal energy (4)
-
heavy mineral deposits (1)
-
metal ores
-
antimony ores (1)
-
copper ores (1)
-
gold ores (17)
-
lithium ores (1)
-
molybdenum ores (2)
-
rare earth deposits (1)
-
silver ores (6)
-
-
mineral deposits, genesis (18)
-
mineral exploration (6)
-
oil and gas fields (1)
-
petroleum
-
natural gas (1)
-
-
placers (1)
-
water resources (1)
-
-
elements, isotopes
-
carbon
-
C-13/C-12 (8)
-
C-14 (2)
-
-
halogens
-
chlorine (1)
-
-
hydrogen
-
D/H (2)
-
deuterium (1)
-
-
isotope ratios (10)
-
isotopes
-
radioactive isotopes
-
C-14 (2)
-
Zn-65 (1)
-
-
stable isotopes
-
Ar-40/Ar-36 (1)
-
C-13/C-12 (8)
-
Cu-65 (1)
-
D/H (2)
-
deuterium (1)
-
Fe-54 (1)
-
Fe-56 (1)
-
Fe-57 (1)
-
N-15/N-14 (2)
-
Ne-22/Ne-20 (1)
-
O-17/O-16 (1)
-
O-18/O-16 (4)
-
S-34/S-32 (1)
-
Sr-87/Sr-86 (2)
-
Zn-66 (1)
-
-
-
metals
-
alkali metals
-
lithium (1)
-
-
alkaline earth metals
-
strontium
-
Sr-87/Sr-86 (2)
-
-
-
antimony (4)
-
arsenic (5)
-
bismuth (1)
-
cobalt (1)
-
copper
-
Cu-65 (1)
-
-
gold (1)
-
iron
-
Fe-54 (1)
-
Fe-56 (1)
-
Fe-57 (1)
-
-
manganese (1)
-
mercury (1)
-
precious metals (3)
-
rare earths (3)
-
silver (1)
-
thallium (2)
-
zinc
-
Zn-65 (1)
-
Zn-66 (1)
-
-
-
nitrogen
-
N-15/N-14 (2)
-
-
noble gases
-
argon
-
Ar-40/Ar-36 (1)
-
-
helium (1)
-
neon
-
Ne-22/Ne-20 (1)
-
-
xenon (1)
-
-
oxygen
-
O-17/O-16 (1)
-
O-18/O-16 (4)
-
-
sulfur
-
S-34/S-32 (1)
-
-
tellurium (1)
-
trace metals (1)
-
-
fossils
-
bacteria (5)
-
cyanobacteria (4)
-
eukaryotes (1)
-
fungi (1)
-
Invertebrata
-
Arthropoda
-
Mandibulata
-
Crustacea
-
Ostracoda (1)
-
-
-
-
Protista
-
Foraminifera (2)
-
Radiolaria (1)
-
-
-
microfossils
-
Conodonta (1)
-
-
palynomorphs
-
miospores
-
pollen (1)
-
-
-
Plantae
-
algae
-
diatoms (2)
-
nannofossils (2)
-
-
Pteridophyta (1)
-
Spermatophyta
-
Angiospermae
-
Dicotyledoneae
-
Rosidae (1)
-
-
-
-
-
prokaryotes (1)
-
thallophytes (1)
-
-
geochronology methods
-
radiation damage (1)
-
U/Pb (1)
-
-
geologic age
-
Cenozoic
-
Quaternary
-
Holocene (3)
-
Pleistocene
-
upper Pleistocene (1)
-
-
-
Tertiary
-
Neogene
-
Pliocene (1)
-
-
Paleogene
-
Paleocene
-
lower Paleocene
-
K-T boundary (1)
-
-
-
-
-
-
Mesozoic
-
Cretaceous
-
Lower Cretaceous (1)
-
Upper Cretaceous
-
Campanian (1)
-
K-T boundary (1)
-
Maestrichtian (1)
-
Senonian (1)
-
-
-
Jurassic
-
Upper Jurassic
-
Kimmeridgian (1)
-
-
-
-
Paleozoic (2)
-
Precambrian
-
Archean (2)
-
upper Precambrian
-
Proterozoic (1)
-
-
-
-
igneous rocks
-
igneous rocks
-
kimberlite (2)
-
plutonic rocks
-
diorites
-
tonalite (1)
-
-
lamproite (1)
-
lamprophyres (1)
-
ultramafics (1)
-
-
porphyry (1)
-
volcanic rocks
-
andesites (1)
-
basalts (1)
-
pyroclastics
-
ignimbrite (1)
-
-
-
-
-
metamorphic rocks
-
metamorphic rocks
-
metasedimentary rocks
-
metapelite (1)
-
-
quartzites (1)
-
schists
-
greenstone (1)
-
-
-
turbidite (1)
-
-
meteorites
-
meteorites
-
stony meteorites
-
chondrites (1)
-
-
-
-
minerals
-
arsenates (1)
-
arsenides
-
arsenopyrite (1)
-
-
arsenites (1)
-
carbonates
-
bastnaesite (1)
-
-
copper minerals (1)
-
halides
-
chlorides
-
halite (1)
-
-
fluorides
-
bastnaesite (1)
-
fluorite (1)
-
-
iodides (1)
-
-
native elements
-
diamond (1)
-
graphite (1)
-
-
onyx (1)
-
oxides
-
diaspore (1)
-
hydroxides (1)
-
-
phosphates
-
monazite (1)
-
-
silicates
-
aluminosilicates (1)
-
framework silicates
-
silica minerals
-
agate (1)
-
cristobalite (1)
-
moganite (1)
-
opal
-
opal-A (7)
-
-
quartz (4)
-
-
-
orthosilicates
-
nesosilicates
-
titanite group
-
titanite (1)
-
-
zircon group
-
zircon (1)
-
-
-
-
sheet silicates
-
clay minerals (1)
-
mica group
-
muscovite (1)
-
-
-
-
sulfates
-
alum (1)
-
alunite (1)
-
anhydrite (1)
-
barite (1)
-
gypsum (1)
-
voltaite (1)
-
-
sulfides
-
arsenopyrite (1)
-
carrollite (1)
-
cinnabar (1)
-
galena (1)
-
linnaeite (1)
-
marcasite (1)
-
polydymite (1)
-
pyrite (1)
-
siegenite (1)
-
sphalerite (1)
-
stibnite (2)
-
ullmannite (1)
-
-
sulfosalts (3)
-
-
Primary terms
-
absolute age (3)
-
Africa
-
Central Africa
-
Congo (1)
-
-
East Africa
-
Zambia (1)
-
-
Southern Africa
-
South Africa (1)
-
-
West Africa
-
Mali (1)
-
-
-
Asia
-
Buryat Russian Federation (1)
-
Far East
-
China
-
Guangxi China (1)
-
Guizhou China (2)
-
Sichuan China (1)
-
Yunnan China
-
Tengchong (1)
-
-
-
-
Indian Peninsula
-
India (1)
-
-
Kamchatka Russian Federation
-
Kamchatka Peninsula
-
Avacha (1)
-
Tolbachik (1)
-
-
-
Kemerovo Russian Federation (1)
-
Russian Pacific region (1)
-
Salair Ridge (1)
-
Siberia (1)
-
Siberian Platform (1)
-
Western Transbaikalia (1)
-
Yakutia Russian Federation (1)
-
-
Atlantic Ocean
-
North Atlantic
-
Gulf of Mexico (1)
-
-
-
atmosphere (2)
-
Australasia
-
Australia (1)
-
New Zealand
-
Coromandel Peninsula (1)
-
Lake Taupo (1)
-
Northland New Zealand (1)
-
Otago New Zealand (1)
-
Otago Schist (1)
-
Rotorua New Zealand (1)
-
Taupo (1)
-
Taupo volcanic zone (19)
-
Waiotapu New Zealand (6)
-
Wairakei (1)
-
-
Papua New Guinea (1)
-
-
bacteria (5)
-
bibliography (2)
-
biogeography (1)
-
biography (1)
-
bitumens (1)
-
Canada
-
Eastern Canada
-
Ontario
-
Hemlo Deposit (5)
-
Prescott County Ontario (1)
-
Russell County Ontario (1)
-
-
-
Western Canada
-
Canadian Cordillera (1)
-
-
-
carbon
-
C-13/C-12 (8)
-
C-14 (2)
-
-
Cenozoic
-
Quaternary
-
Holocene (3)
-
Pleistocene
-
upper Pleistocene (1)
-
-
-
Tertiary
-
Neogene
-
Pliocene (1)
-
-
Paleogene
-
Paleocene
-
lower Paleocene
-
K-T boundary (1)
-
-
-
-
-
-
climate change (1)
-
core (1)
-
crystal chemistry (1)
-
crystal growth (1)
-
crystal structure (1)
-
dams (1)
-
deformation (7)
-
diagenesis (6)
-
diamond deposits (2)
-
Earth (2)
-
earthquakes (2)
-
ecology (1)
-
economic geology (2)
-
energy sources (1)
-
Europe
-
Central Europe
-
Germany
-
Rhineland (1)
-
Schleswig-Holstein Germany (1)
-
-
-
Fennoscandian Shield (1)
-
Lower Rhine Basin (1)
-
Southern Europe
-
Italy
-
Apennines
-
Monte Amiata (1)
-
-
Tuscany Italy
-
Monte Amiata (1)
-
Siena Italy (1)
-
-
-
-
Western Europe
-
France (1)
-
Netherlands (1)
-
United Kingdom
-
Great Britain
-
England (1)
-
Scotland
-
Aberdeenshire Scotland
-
Aberdeen Scotland (1)
-
-
-
Wales (1)
-
-
-
-
-
explosions (1)
-
faults (5)
-
folds (1)
-
foliation (1)
-
fractures (1)
-
fungi (1)
-
gems (1)
-
geochemistry (13)
-
geophysical methods (1)
-
geothermal energy (4)
-
ground water (24)
-
heavy mineral deposits (1)
-
hydrogen
-
D/H (2)
-
deuterium (1)
-
-
hydrology (2)
-
igneous rocks
-
kimberlite (2)
-
plutonic rocks
-
diorites
-
tonalite (1)
-
-
lamproite (1)
-
lamprophyres (1)
-
ultramafics (1)
-
-
porphyry (1)
-
volcanic rocks
-
andesites (1)
-
basalts (1)
-
pyroclastics
-
ignimbrite (1)
-
-
-
-
inclusions
-
fluid inclusions (2)
-
-
intrusions (5)
-
Invertebrata
-
Arthropoda
-
Mandibulata
-
Crustacea
-
Ostracoda (1)
-
-
-
-
Protista
-
Foraminifera (2)
-
Radiolaria (1)
-
-
-
isotopes
-
radioactive isotopes
-
C-14 (2)
-
Zn-65 (1)
-
-
stable isotopes
-
Ar-40/Ar-36 (1)
-
C-13/C-12 (8)
-
Cu-65 (1)
-
D/H (2)
-
deuterium (1)
-
Fe-54 (1)
-
Fe-56 (1)
-
Fe-57 (1)
-
N-15/N-14 (2)
-
Ne-22/Ne-20 (1)
-
O-17/O-16 (1)
-
O-18/O-16 (4)
-
S-34/S-32 (1)
-
Sr-87/Sr-86 (2)
-
Zn-66 (1)
-
-
-
land subsidence (1)
-
land use (1)
-
magmas (4)
-
mantle (1)
-
Mesozoic
-
Cretaceous
-
Lower Cretaceous (1)
-
Upper Cretaceous
-
Campanian (1)
-
K-T boundary (1)
-
Maestrichtian (1)
-
Senonian (1)
-
-
-
Jurassic
-
Upper Jurassic
-
Kimmeridgian (1)
-
-
-
-
metal ores
-
antimony ores (1)
-
copper ores (1)
-
gold ores (17)
-
lithium ores (1)
-
molybdenum ores (2)
-
rare earth deposits (1)
-
silver ores (6)
-
-
metals
-
alkali metals
-
lithium (1)
-
-
alkaline earth metals
-
strontium
-
Sr-87/Sr-86 (2)
-
-
-
antimony (4)
-
arsenic (5)
-
bismuth (1)
-
cobalt (1)
-
copper
-
Cu-65 (1)
-
-
gold (1)
-
iron
-
Fe-54 (1)
-
Fe-56 (1)
-
Fe-57 (1)
-
-
manganese (1)
-
mercury (1)
-
precious metals (3)
-
rare earths (3)
-
silver (1)
-
thallium (2)
-
zinc
-
Zn-65 (1)
-
Zn-66 (1)
-
-
-
metamorphic rocks
-
metasedimentary rocks
-
metapelite (1)
-
-
quartzites (1)
-
schists
-
greenstone (1)
-
-
-
metamorphism (4)
-
metasomatism (9)
-
meteorites
-
stony meteorites
-
chondrites (1)
-
-
-
micropaleontology (1)
-
mineral deposits, genesis (18)
-
mineral exploration (6)
-
Moon (2)
-
nitrogen
-
N-15/N-14 (2)
-
-
noble gases
-
argon
-
Ar-40/Ar-36 (1)
-
-
helium (1)
-
neon
-
Ne-22/Ne-20 (1)
-
-
xenon (1)
-
-
nodules (1)
-
North America
-
Canadian Shield
-
Superior Province
-
Wawa Belt (1)
-
-
-
North American Cordillera
-
Canadian Cordillera (1)
-
-
-
oil and gas fields (1)
-
oxygen
-
O-17/O-16 (1)
-
O-18/O-16 (4)
-
-
Pacific Ocean
-
South Pacific
-
Southwest Pacific
-
Bismarck Sea
-
Manus Basin
-
PACMANUS hydrothermal field (1)
-
-
-
-
-
West Pacific
-
Southwest Pacific
-
Bismarck Sea
-
Manus Basin
-
PACMANUS hydrothermal field (1)
-
-
-
-
-
-
paleoclimatology (1)
-
paleoecology (1)
-
Paleozoic (2)
-
palynomorphs
-
miospores
-
pollen (1)
-
-
-
petroleum
-
natural gas (1)
-
-
phase equilibria (2)
-
placers (1)
-
Plantae
-
algae
-
diatoms (2)
-
nannofossils (2)
-
-
Pteridophyta (1)
-
Spermatophyta
-
Angiospermae
-
Dicotyledoneae
-
Rosidae (1)
-
-
-
-
-
pollution (4)
-
Precambrian
-
Archean (2)
-
upper Precambrian
-
Proterozoic (1)
-
-
-
remote sensing (2)
-
sea water (1)
-
sedimentary rocks
-
carbonate rocks
-
limestone
-
micrite (1)
-
microbialite (3)
-
-
travertine (2)
-
-
chemically precipitated rocks
-
siliceous sinter (18)
-
tufa (1)
-
-
clastic rocks (2)
-
-
sedimentary structures
-
biogenic structures
-
algal structures
-
algal mats (1)
-
-
microbial mats (2)
-
stromatolites (6)
-
-
planar bedding structures
-
cross-stratification (1)
-
laminations (5)
-
-
-
sedimentation (6)
-
sediments
-
clastic sediments
-
clay (1)
-
loess (1)
-
pebbles (1)
-
-
-
soils (5)
-
South America
-
Andes (1)
-
Argentina
-
Catamarca Argentina (1)
-
-
Brazil
-
Brazilian Shield (1)
-
Rio de Janeiro Brazil (1)
-
-
Chile (3)
-
-
springs (21)
-
sulfur
-
S-34/S-32 (1)
-
-
tectonics
-
neotectonics (1)
-
-
tellurium (1)
-
thallophytes (1)
-
thermal analysis (1)
-
thermal waters (20)
-
United States
-
Michigan
-
Michigan Lower Peninsula
-
Midland County Michigan (1)
-
-
-
Nevada
-
Carlin Mine (1)
-
Carlin Trend (1)
-
Elko County Nevada (1)
-
-
Wyoming
-
Teton County Wyoming (1)
-
-
Yellowstone National Park (1)
-
-
volcanology (1)
-
water resources (1)
-
weathering (2)
-
-
sedimentary rocks
-
sedimentary rocks
-
carbonate rocks
-
limestone
-
micrite (1)
-
microbialite (3)
-
-
travertine (2)
-
-
chemically precipitated rocks
-
siliceous sinter (18)
-
tufa (1)
-
-
clastic rocks (2)
-
-
turbidite (1)
-
-
sedimentary structures
-
boudinage (1)
-
mounds (1)
-
sedimentary structures
-
biogenic structures
-
algal structures
-
algal mats (1)
-
-
microbial mats (2)
-
stromatolites (6)
-
-
planar bedding structures
-
cross-stratification (1)
-
laminations (5)
-
-
-
-
sediments
-
sediments
-
clastic sediments
-
clay (1)
-
loess (1)
-
pebbles (1)
-
-
-
turbidite (1)
-
-
soils
-
soils (5)
-
Champagne Pool
Bacterial S-layer preservation and rare arsenic–antimony–sulphide bioimmobilization in siliceous sediments from Champagne Pool hot spring, Waiotapu, New Zealand
Biogenicity of gold- and silver-bearing siliceous sinters forming in hot (75°C) anaerobic spring-waters of Champagne Pool, Waiotapu, North Island, New Zealand
Macroscopic features of Champagne Pool, Waiotapu. (A) Western pool margin s...
Oblique aerial view to the south-southeast over the Champagne Pool area of ...
( A ) Champagne Pool and Artist’s Palette, Waiotapu geothermal system (New ...
Photograph of Waiotapu, looking SE. Champagne Pool, a hydrothermal eruption...
Champagne Pool, New Zealand. The colourful colloids of S, As and Sb serve t...
Location and setting of Champagne Pool. ( a ) Location of Taupo Volcanic Zo...
Sinter shelf around Champagne Pool. ( a ) Shallow, orange, subaqueous sinte...
( a ) Speciation plot of dissolved arsenic species in Champagne Pool genera...
Experimental sinter growths on glass slides from Champagne Pool. (A) After ...
( a ) General view of Champagne Pool (CP) and Artist’s Palette (AP) looking...
Stromatolitic sinters from shelf around Champagne Pool. Lightest laminae ha...
Microbes from stromatolites on subaqueous shelf around Champagne Pool. ( a ...
Gold Concentrations in Springs at Waiotapu, New Zealand: Implications for Precious Metal Deposition in Geothermal Systems
Vertical zonation of biota in microstromatolites associated with hot springs, North Island, New Zealand
Hydrothermal eruptions in the Waiotapu geothermal system, New Zealand; their origin, associated breccias, and relation to precious metal mineralization
Actively growing siliceous oncoids in the Waiotapu geothermal area, North Island, New Zealand
Abstract Epithermal, Carlin, and orogenic Au deposits form in diverse geologic settings and over a wide range of depths, where Au precipitates from hydrothermal fluids in response to various physical and chemical processes. The compositions of Au-bearing sulfidic hydrothermal solutions across all three deposit types, however, are broadly similar. In most cases, they comprise low-salinity waters, which are reduced, have a near-neutral pH, and CO 2 concentrations that range from <4 to >10 wt %. Experimental studies show that the main factor controlling the concentration of Au in hydrothermal solutions is the concentration of reduced S, and in the absence of Fe-bearing minerals, Au solubility is insensitive to temperature. In a solution containing ~300 ppm H 2 S, the maximum concentration of Au is ~1 ppm, representing a reasonable upper limit for many ore-forming solutions. Where Fe-bearing minerals are being converted to pyrite, Au solubility decreases as temperature cools due to the decreasing concentration of reduced S. High Au concentrations (~500 ppb) can also be achieved in strongly oxidizing and strongly acidic chloride solutions, reflecting chemical conditions that only develop during intense hydrolytic leaching in magmatic-hydrothermal high-sulfidation epithermal environments. Gold is also soluble at low to moderate levels (10–100 ppb) over a relatively wide range of pH values and redox states. The chemical mechanisms which induce Au deposition are divided into two broad groups. One involves achieving states of Au supersaturation through perturbations in solution equilibria caused by physical and chemical processes, involving phase separation (boiling), fluid mixing, and pyrite deposition via sulfidation of Fe-bearing minerals. The second involves the sorption of ionic Au on to the surfaces of growing sulfide crystals, mainly arsenian pyrite. Both groups of mechanisms have capability to produce ore, with distinct mineralogical and geochemical characteristics. Gold transport and deposition processes in the Taupo Volcanic Zone, New Zealand, show how ore-grade concentrations of Au can accumulate by two different mechanisms of precipitation, phase separation and sorption, in three separate hydrothermal environments. Phase separation caused by flashing, induced by depressurization and associated with energetic fluid flow in geothermal wells, produces sulfide precipitates containing up to 6 wt.% Au from a hydrothermal solution containing a few ppb Au. Sorption on to As-Sb-S colloids produces precipitates containing tens to hundreds of ppm Au in the Champagne Pool hot spring. Sorption on to As-rich pyrite also leads to anomalous endowments of Au of up to 1 ppm in hydrothermally altered volcanic rocks occurring in the subsurface. In all of these environments, Au-undersaturated solutions produce anomalous concentrations of Au that match and surpass typical ore-grade concentrations, indicating that near-saturated concentrations of dissolved metal are not a prerequisite for generating economic deposits of Au. The causes of Au deposition in epithermal deposits are related to sharp temperature-pressure gradients that induce phase separation (boiling) and mixing. In Carlin deposits, Au deposition is controlled by surface chemistry and sorption processes on to rims of As-rich pyrite. In orogenic deposits, at least two Au-depositing mechanisms appear to produce ore; one involves phase separation and the other involves sulfidation reactions during water-rock interaction that produces pyrite; a third mechanism involving codeposition of Au-As in sulfides might also be important. Differences in the regimes of hydrothermal fluid flow combined with mechanisms of Au precipitation play an important role in shaping the dimensions and geometries of ore zones. There is also a strong link between Au-depositing mechanisms and metallurgical characteristics of ores.