Update search
- 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
Format
Article Type
Journal
Publisher
Section
GeoRef Subject
-
all geography including DSDP/ODP Sites and Legs
-
Africa
-
East Africa
-
Sudan (1)
-
-
North Africa
-
Algeria
-
Ahaggar (1)
-
-
Atlas Mountains
-
Moroccan Atlas Mountains (1)
-
-
Morocco
-
Moroccan Atlas Mountains (1)
-
-
-
Sahara (1)
-
Southern Africa
-
Karoo Basin (2)
-
South Africa
-
Bushveld Complex (1)
-
Free State South Africa
-
Vredefort Dome (1)
-
-
Limpopo South Africa (1)
-
-
-
West Africa
-
Guinea (1)
-
Mauritania
-
Richat Mountain (1)
-
-
Niger (1)
-
Nigeria (2)
-
-
-
Annapolis Valley (1)
-
Asia
-
Amur Basin (1)
-
Amur region (1)
-
Baikal region (1)
-
Chukotka Russian Federation
-
Anadyr Range (1)
-
Chukchi Peninsula (1)
-
-
Far East
-
Indonesia
-
Java (1)
-
-
Korea
-
South Korea (1)
-
-
-
Indian Peninsula
-
India
-
Karnataka India (1)
-
Madhya Pradesh India (1)
-
-
-
Kamchatka Russian Federation
-
Kamchatka Peninsula (1)
-
-
Khabarovsk Russian Federation (2)
-
Lake Baikal (1)
-
Magadan Russian Federation (1)
-
Middle East
-
Iran (2)
-
Zagros (1)
-
-
Russian Far East (1)
-
Siberia (1)
-
Siberian Platform
-
Anabar Shield (1)
-
-
Sikhote-Alin Range (2)
-
Tajikistan (1)
-
Yakutia Russian Federation
-
Anabar Shield (1)
-
-
-
Atlantic Ocean
-
Equatorial Atlantic (1)
-
North Atlantic
-
Gulf of Mexico (3)
-
North Sea (1)
-
-
-
Australasia
-
Australia
-
Queensland Australia (1)
-
-
New Zealand
-
Nelson New Zealand (3)
-
Westland New Zealand (3)
-
-
-
Canada
-
Carswell Structure (2)
-
Eastern Canada
-
Maritime Provinces
-
Nova Scotia
-
Annapolis County Nova Scotia (1)
-
-
-
Ontario
-
Sudbury igneous complex (1)
-
Sudbury Structure (1)
-
-
-
Western Canada
-
Athabasca Basin (1)
-
Saskatchewan (2)
-
-
-
Cascade Range (2)
-
Central America
-
Costa Rica (1)
-
-
Chicxulub Crater (6)
-
Commonwealth of Independent States
-
Azerbaijan (1)
-
Russian Federation
-
Amur region (1)
-
Baikal region (1)
-
Chukotka Russian Federation
-
Anadyr Range (1)
-
Chukchi Peninsula (1)
-
-
Kamchatka Russian Federation
-
Kamchatka Peninsula (1)
-
-
Khabarovsk Russian Federation (2)
-
Komsomolsk Russian Federation (1)
-
Lake Baikal (1)
-
Magadan Russian Federation (1)
-
Russian Far East (1)
-
Siberian Platform
-
Anabar Shield (1)
-
-
Sikhote-Alin Range (2)
-
Yakutia Russian Federation
-
Anabar Shield (1)
-
-
-
Tajikistan (1)
-
-
Europe
-
Azerbaijan (1)
-
Baltic region (2)
-
Central Europe
-
Germany
-
Bavaria Germany
-
Ries Crater (1)
-
-
-
-
Fennoscandian Shield (4)
-
Southern Europe
-
Iberian Peninsula
-
Spain (1)
-
-
-
Western Europe
-
France
-
Armorican Massif (1)
-
Corsica (1)
-
-
Ireland (2)
-
Scandinavia
-
Finland (1)
-
Sweden
-
Dalarna Sweden
-
Siljan Ring (2)
-
-
-
-
United Kingdom
-
Great Britain
-
Scotland
-
Argyllshire Scotland (1)
-
Highland region Scotland
-
Ardnamurchan (1)
-
-
-
-
Northern Ireland (1)
-
-
-
-
Indian Ocean
-
Arabian Sea
-
Persian Gulf (1)
-
-
-
International Ocean Discovery Program (2)
-
Mexico
-
Baja California Mexico (1)
-
Campeche Mexico (1)
-
Yucatan Mexico (3)
-
-
North America
-
Canadian Shield (1)
-
Great Lakes (1)
-
Great Lakes region (1)
-
Western Interior
-
Western Interior Seaway (1)
-
-
-
Peninsular Ranges (1)
-
South America
-
Andes
-
Southern Andes (1)
-
-
Brazil
-
Goias Brazil (1)
-
Mato Grosso Brazil (1)
-
Rio Grande do Sul Brazil (1)
-
-
Chile (1)
-
Parana Basin (1)
-
Peru
-
Ancash Peru (1)
-
-
-
South Island (3)
-
Taoudenni (1)
-
United States
-
Arizona
-
Coconino County Arizona
-
Meteor Crater (1)
-
-
-
California
-
Central California (2)
-
Fresno County California (2)
-
Mono County California
-
Long Valley Caldera (1)
-
Mono Basin (1)
-
Mono Craters (1)
-
-
Siskiyou County California
-
Mount Shasta (1)
-
-
-
Columbia Plateau (1)
-
Idaho
-
Custer County Idaho (1)
-
Lemhi County Idaho (1)
-
Snake River plain (1)
-
Valley County Idaho (1)
-
-
Iowa
-
Manson impact structure (1)
-
-
Klamath Mountains (1)
-
Mississippi Valley
-
Lower Mississippi Valley (1)
-
-
Missouri
-
Saint Francois Mountains (2)
-
-
Nevada
-
Churchill County Nevada (1)
-
-
New Hampshire
-
Carroll County New Hampshire
-
Ossipee Mountains (1)
-
-
-
New York (1)
-
North Carolina (1)
-
Ohio
-
Ashtabula County Ohio (1)
-
Summit County Ohio
-
Akron Ohio (1)
-
-
-
Oregon (1)
-
Pennsylvania (1)
-
Texas
-
East Texas Basin (1)
-
-
Utah (1)
-
Washington
-
Lincoln County Washington
-
Odessa Washington (1)
-
-
Whatcom County Washington (1)
-
-
Wisconsin
-
Pierce County Wisconsin (1)
-
-
-
White Mountains (1)
-
Yucatan Peninsula (2)
-
-
commodities
-
energy sources (1)
-
gems (1)
-
geothermal energy (2)
-
metal ores
-
base metals (1)
-
copper ores (4)
-
gold ores (4)
-
iron ores (2)
-
lead ores (1)
-
lead-zinc deposits (1)
-
manganese ores (1)
-
mercury ores (1)
-
molybdenum ores (4)
-
polymetallic ores (1)
-
rare earth deposits (1)
-
silver ores (1)
-
uranium ores (1)
-
-
mineral deposits, genesis (9)
-
mineral exploration (7)
-
mineral resources (1)
-
petroleum
-
natural gas (1)
-
-
phosphate deposits (1)
-
-
elements, isotopes
-
carbon
-
C-13/C-12 (2)
-
-
hydrogen
-
D/H (2)
-
-
isotope ratios (3)
-
isotopes
-
stable isotopes
-
C-13/C-12 (2)
-
D/H (2)
-
O-18/O-16 (4)
-
Sr-87/Sr-86 (1)
-
-
-
metals
-
actinides
-
thorium (1)
-
uranium (1)
-
-
alkali metals
-
lithium (2)
-
potassium (1)
-
rubidium (1)
-
-
alkaline earth metals
-
barium (1)
-
beryllium (1)
-
strontium
-
Sr-87/Sr-86 (1)
-
-
-
niobium (1)
-
precious metals (1)
-
rare earths (4)
-
tantalum (1)
-
-
oxygen
-
O-18/O-16 (4)
-
-
-
fossils
-
microfossils (1)
-
Plantae
-
algae (1)
-
-
-
geochronology methods
-
Ar/Ar (2)
-
paleomagnetism (1)
-
Rb/Sr (1)
-
U/Pb (3)
-
-
geologic age
-
Cenozoic
-
Quaternary
-
Pleistocene
-
Bishop Tuff (1)
-
upper Pleistocene (1)
-
-
-
Tertiary
-
Challis Volcanics (1)
-
lower Tertiary (2)
-
middle Tertiary (1)
-
Neogene
-
Miocene
-
lower Miocene (1)
-
Yakima Basalt (1)
-
-
Pliocene (1)
-
-
Paleogene
-
Eocene (1)
-
Oligocene (1)
-
Paleocene
-
lower Paleocene
-
K-T boundary (2)
-
-
-
-
-
-
Mesozoic
-
Cretaceous
-
Graneros Shale (1)
-
Lower Cretaceous (3)
-
Upper Cretaceous
-
Carlile Shale (1)
-
Greenhorn Limestone (1)
-
K-T boundary (2)
-
Niobrara Formation (1)
-
Pierre Shale (1)
-
-
-
Jurassic (4)
-
Serra Geral Formation (1)
-
-
Paleozoic
-
Cambrian (2)
-
Carboniferous (1)
-
Devonian
-
Upper Devonian (1)
-
-
lower Paleozoic (1)
-
Ordovician
-
Middle Ordovician (1)
-
-
Permian
-
Ecca Group (1)
-
-
-
Precambrian
-
Archean
-
Neoarchean (1)
-
-
upper Precambrian
-
Proterozoic
-
Athabasca Formation (2)
-
Huronian
-
Onaping Formation (1)
-
-
Malmani Subgroup (1)
-
Mesoproterozoic
-
Helikian (1)
-
-
Neoproterozoic
-
Moine Supergroup (1)
-
Riphean (1)
-
Vendian (1)
-
-
Paleoproterozoic (3)
-
-
-
-
-
igneous rocks
-
extrusive rocks (1)
-
igneous rocks
-
carbonatites (1)
-
granophyre (2)
-
phoscorites (1)
-
plutonic rocks
-
diabase (2)
-
diorites
-
quartz diorites (3)
-
tonalite (2)
-
-
gabbros (3)
-
granites
-
granite porphyry (1)
-
microgranite (2)
-
-
granodiorites (2)
-
pegmatite (3)
-
syenites
-
nepheline syenite
-
agpaite (1)
-
foyaite (1)
-
miaskite (1)
-
-
-
ultramafics
-
pyroxenite
-
clinopyroxenite (1)
-
-
-
-
volcanic rocks
-
andesites (2)
-
basalts
-
tholeiite (1)
-
-
dacites (2)
-
glasses
-
palagonite (1)
-
-
pyroclastics
-
ash-flow tuff (1)
-
ignimbrite (4)
-
rhyolite tuff (1)
-
tuff (1)
-
-
rhyolites (4)
-
trachytes (1)
-
-
-
-
metamorphic rocks
-
metamorphic rocks
-
gneisses (1)
-
impactites
-
impact breccia (2)
-
-
metaigneous rocks (1)
-
metasedimentary rocks (1)
-
mylonites
-
pseudotachylite (3)
-
-
-
-
minerals
-
carbonates
-
dolomite (1)
-
witherite (1)
-
-
halides
-
chlorides
-
halite (1)
-
-
fluorides
-
topaz (1)
-
-
-
oxides
-
brucite (1)
-
ilmenite (1)
-
magnetite (2)
-
-
phosphates
-
apatite (1)
-
-
silicates
-
chain silicates
-
pyroxene group
-
clinopyroxene
-
hedenbergite (1)
-
-
-
-
framework silicates
-
feldspar group
-
alkali feldspar
-
K-feldspar (2)
-
-
-
silica minerals
-
quartz (3)
-
-
-
orthosilicates
-
nesosilicates
-
olivine group
-
fayalite (1)
-
-
topaz (1)
-
zircon group
-
zircon (3)
-
-
-
-
ring silicates
-
milarite group
-
milarite (1)
-
-
-
sheet silicates
-
mica group
-
biotite (1)
-
phlogopite (1)
-
-
-
-
sulfides
-
molybdenite (1)
-
-
-
Primary terms
-
absolute age (5)
-
Africa
-
East Africa
-
Sudan (1)
-
-
North Africa
-
Algeria
-
Ahaggar (1)
-
-
Atlas Mountains
-
Moroccan Atlas Mountains (1)
-
-
Morocco
-
Moroccan Atlas Mountains (1)
-
-
-
Sahara (1)
-
Southern Africa
-
Karoo Basin (2)
-
South Africa
-
Bushveld Complex (1)
-
Free State South Africa
-
Vredefort Dome (1)
-
-
Limpopo South Africa (1)
-
-
-
West Africa
-
Guinea (1)
-
Mauritania
-
Richat Mountain (1)
-
-
Niger (1)
-
Nigeria (2)
-
-
-
Asia
-
Amur Basin (1)
-
Amur region (1)
-
Baikal region (1)
-
Chukotka Russian Federation
-
Anadyr Range (1)
-
Chukchi Peninsula (1)
-
-
Far East
-
Indonesia
-
Java (1)
-
-
Korea
-
South Korea (1)
-
-
-
Indian Peninsula
-
India
-
Karnataka India (1)
-
Madhya Pradesh India (1)
-
-
-
Kamchatka Russian Federation
-
Kamchatka Peninsula (1)
-
-
Khabarovsk Russian Federation (2)
-
Lake Baikal (1)
-
Magadan Russian Federation (1)
-
Middle East
-
Iran (2)
-
Zagros (1)
-
-
Russian Far East (1)
-
Siberia (1)
-
Siberian Platform
-
Anabar Shield (1)
-
-
Sikhote-Alin Range (2)
-
Tajikistan (1)
-
Yakutia Russian Federation
-
Anabar Shield (1)
-
-
-
Atlantic Ocean
-
Equatorial Atlantic (1)
-
North Atlantic
-
Gulf of Mexico (3)
-
North Sea (1)
-
-
-
Australasia
-
Australia
-
Queensland Australia (1)
-
-
New Zealand
-
Nelson New Zealand (3)
-
Westland New Zealand (3)
-
-
-
Canada
-
Carswell Structure (2)
-
Eastern Canada
-
Maritime Provinces
-
Nova Scotia
-
Annapolis County Nova Scotia (1)
-
-
-
Ontario
-
Sudbury igneous complex (1)
-
Sudbury Structure (1)
-
-
-
Western Canada
-
Athabasca Basin (1)
-
Saskatchewan (2)
-
-
-
carbon
-
C-13/C-12 (2)
-
-
Cenozoic
-
Quaternary
-
Pleistocene
-
Bishop Tuff (1)
-
upper Pleistocene (1)
-
-
-
Tertiary
-
Challis Volcanics (1)
-
lower Tertiary (2)
-
middle Tertiary (1)
-
Neogene
-
Miocene
-
lower Miocene (1)
-
Yakima Basalt (1)
-
-
Pliocene (1)
-
-
Paleogene
-
Eocene (1)
-
Oligocene (1)
-
Paleocene
-
lower Paleocene
-
K-T boundary (2)
-
-
-
-
-
-
Central America
-
Costa Rica (1)
-
-
crust (4)
-
crystal chemistry (1)
-
crystal structure (1)
-
data processing (2)
-
deformation (5)
-
diagenesis (1)
-
Earth (1)
-
economic geology (9)
-
energy sources (1)
-
Europe
-
Azerbaijan (1)
-
Baltic region (2)
-
Central Europe
-
Germany
-
Bavaria Germany
-
Ries Crater (1)
-
-
-
-
Fennoscandian Shield (4)
-
Southern Europe
-
Iberian Peninsula
-
Spain (1)
-
-
-
Western Europe
-
France
-
Armorican Massif (1)
-
Corsica (1)
-
-
Ireland (2)
-
Scandinavia
-
Finland (1)
-
Sweden
-
Dalarna Sweden
-
Siljan Ring (2)
-
-
-
-
United Kingdom
-
Great Britain
-
Scotland
-
Argyllshire Scotland (1)
-
Highland region Scotland
-
Ardnamurchan (1)
-
-
-
-
Northern Ireland (1)
-
-
-
-
faults (25)
-
folds (5)
-
foliation (1)
-
fractures (4)
-
gems (1)
-
geochemistry (5)
-
geomorphology (12)
-
geophysical methods (14)
-
geothermal energy (2)
-
ground water (2)
-
hydrogen
-
D/H (2)
-
-
igneous rocks
-
carbonatites (1)
-
granophyre (2)
-
phoscorites (1)
-
plutonic rocks
-
diabase (2)
-
diorites
-
quartz diorites (3)
-
tonalite (2)
-
-
gabbros (3)
-
granites
-
granite porphyry (1)
-
microgranite (2)
-
-
granodiorites (2)
-
pegmatite (3)
-
syenites
-
nepheline syenite
-
agpaite (1)
-
foyaite (1)
-
miaskite (1)
-
-
-
ultramafics
-
pyroxenite
-
clinopyroxenite (1)
-
-
-
-
volcanic rocks
-
andesites (2)
-
basalts
-
tholeiite (1)
-
-
dacites (2)
-
glasses
-
palagonite (1)
-
-
pyroclastics
-
ash-flow tuff (1)
-
ignimbrite (4)
-
rhyolite tuff (1)
-
tuff (1)
-
-
rhyolites (4)
-
trachytes (1)
-
-
-
inclusions
-
fluid inclusions (2)
-
-
Indian Ocean
-
Arabian Sea
-
Persian Gulf (1)
-
-
-
intrusions (36)
-
isostasy (1)
-
isotopes
-
stable isotopes
-
C-13/C-12 (2)
-
D/H (2)
-
O-18/O-16 (4)
-
Sr-87/Sr-86 (1)
-
-
-
lava (3)
-
magmas (13)
-
mantle (2)
-
maps (1)
-
Mesozoic
-
Cretaceous
-
Graneros Shale (1)
-
Lower Cretaceous (3)
-
Upper Cretaceous
-
Carlile Shale (1)
-
Greenhorn Limestone (1)
-
K-T boundary (2)
-
Niobrara Formation (1)
-
Pierre Shale (1)
-
-
-
Jurassic (4)
-
Serra Geral Formation (1)
-
-
metal ores
-
base metals (1)
-
copper ores (4)
-
gold ores (4)
-
iron ores (2)
-
lead ores (1)
-
lead-zinc deposits (1)
-
manganese ores (1)
-
mercury ores (1)
-
molybdenum ores (4)
-
polymetallic ores (1)
-
rare earth deposits (1)
-
silver ores (1)
-
uranium ores (1)
-
-
metals
-
actinides
-
thorium (1)
-
uranium (1)
-
-
alkali metals
-
lithium (2)
-
potassium (1)
-
rubidium (1)
-
-
alkaline earth metals
-
barium (1)
-
beryllium (1)
-
strontium
-
Sr-87/Sr-86 (1)
-
-
-
niobium (1)
-
precious metals (1)
-
rare earths (4)
-
tantalum (1)
-
-
metamorphic rocks
-
gneisses (1)
-
impactites
-
impact breccia (2)
-
-
metaigneous rocks (1)
-
metasedimentary rocks (1)
-
mylonites
-
pseudotachylite (3)
-
-
-
metamorphism (7)
-
metasomatism (7)
-
Mexico
-
Baja California Mexico (1)
-
Campeche Mexico (1)
-
Yucatan Mexico (3)
-
-
mineral deposits, genesis (9)
-
mineral exploration (7)
-
mineral resources (1)
-
Moon (1)
-
mud volcanoes (1)
-
North America
-
Canadian Shield (1)
-
Great Lakes (1)
-
Great Lakes region (1)
-
Western Interior
-
Western Interior Seaway (1)
-
-
-
oxygen
-
O-18/O-16 (4)
-
-
paleogeography (1)
-
paleomagnetism (1)
-
Paleozoic
-
Cambrian (2)
-
Carboniferous (1)
-
Devonian
-
Upper Devonian (1)
-
-
lower Paleozoic (1)
-
Ordovician
-
Middle Ordovician (1)
-
-
Permian
-
Ecca Group (1)
-
-
-
paragenesis (3)
-
petroleum
-
natural gas (1)
-
-
petrology (15)
-
phase equilibria (1)
-
phosphate deposits (1)
-
Plantae
-
algae (1)
-
-
plate tectonics (3)
-
pollution (2)
-
Precambrian
-
Archean
-
Neoarchean (1)
-
-
upper Precambrian
-
Proterozoic
-
Athabasca Formation (2)
-
Huronian
-
Onaping Formation (1)
-
-
Malmani Subgroup (1)
-
Mesoproterozoic
-
Helikian (1)
-
-
Neoproterozoic
-
Moine Supergroup (1)
-
Riphean (1)
-
Vendian (1)
-
-
Paleoproterozoic (3)
-
-
-
-
remote sensing (13)
-
rock mechanics (1)
-
sedimentary rocks
-
carbonate rocks
-
dolostone (1)
-
-
chemically precipitated rocks
-
evaporites
-
salt (1)
-
-
-
clastic rocks
-
sandstone (1)
-
-
-
sedimentary structures
-
biogenic structures
-
stromatolites (1)
-
-
seismites (1)
-
-
sedimentation (1)
-
sediments
-
clastic sediments
-
till (1)
-
-
-
South America
-
Andes
-
Southern Andes (1)
-
-
Brazil
-
Goias Brazil (1)
-
Mato Grosso Brazil (1)
-
Rio Grande do Sul Brazil (1)
-
-
Chile (1)
-
Parana Basin (1)
-
Peru
-
Ancash Peru (1)
-
-
-
springs (1)
-
stratigraphy (1)
-
structural analysis (8)
-
structural geology (3)
-
tectonics
-
salt tectonics (3)
-
-
tectonophysics (1)
-
United States
-
Arizona
-
Coconino County Arizona
-
Meteor Crater (1)
-
-
-
California
-
Central California (2)
-
Fresno County California (2)
-
Mono County California
-
Long Valley Caldera (1)
-
Mono Basin (1)
-
Mono Craters (1)
-
-
Siskiyou County California
-
Mount Shasta (1)
-
-
-
Columbia Plateau (1)
-
Idaho
-
Custer County Idaho (1)
-
Lemhi County Idaho (1)
-
Snake River plain (1)
-
Valley County Idaho (1)
-
-
Iowa
-
Manson impact structure (1)
-
-
Klamath Mountains (1)
-
Mississippi Valley
-
Lower Mississippi Valley (1)
-
-
Missouri
-
Saint Francois Mountains (2)
-
-
Nevada
-
Churchill County Nevada (1)
-
-
New Hampshire
-
Carroll County New Hampshire
-
Ossipee Mountains (1)
-
-
-
New York (1)
-
North Carolina (1)
-
Ohio
-
Ashtabula County Ohio (1)
-
Summit County Ohio
-
Akron Ohio (1)
-
-
-
Oregon (1)
-
Pennsylvania (1)
-
Texas
-
East Texas Basin (1)
-
-
Utah (1)
-
Washington
-
Lincoln County Washington
-
Odessa Washington (1)
-
-
Whatcom County Washington (1)
-
-
Wisconsin
-
Pierce County Wisconsin (1)
-
-
-
volcanology (3)
-
-
rock formations
-
Botucatu Formation (1)
-
Louann Salt (1)
-
-
sedimentary rocks
-
sedimentary rocks
-
carbonate rocks
-
dolostone (1)
-
-
chemically precipitated rocks
-
evaporites
-
salt (1)
-
-
-
clastic rocks
-
sandstone (1)
-
-
-
-
sedimentary structures
-
mounds (2)
-
sedimentary structures
-
biogenic structures
-
stromatolites (1)
-
-
seismites (1)
-
-
-
sediments
-
sediments
-
clastic sediments
-
till (1)
-
-
-
GeoRef Categories
Era and Period
Epoch and Age
Book Series
Date
Availability
ring structures
Use of Digital Elevation Models in Metallogenic Investigations on the Example of the Central Part of the Lower Amur Province Available to Purchase
Further Insights into Deep Structure of Malmyzh, Pony-Muli, and Anadzhakan Ore Clusters in the Middle Amur Sedimentary Basin (Northern Sikhote-Alin Orogenic Belt) Available to Purchase
Anisotropy of magnetic susceptibility (AMS) of impact melt breccia and target rocks from the Dhala impact structure, India Available to Purchase
ABSTRACT The ~11-km-wide, Paleoproterozoic Dhala impact structure in north-central India comprises voluminous exposures of impact melt breccia. These outcrops are discontinuously spread over a length of ~6 km in a semicircular pattern along the northern, inner limit of the monomict breccia ring around the central elevated area. This study of the magnetic fabrics of impact breccias and target rocks from the Dhala impact structure identified a weak preferred magnetic orientation for pre-impact crystalline target rocks. The pre- and synimpact rocks from Dhala have magnetite and ilmenite as common magnetic phases. The distributions of magnetic vectors are random for most impact melt breccia samples, but some do indicate a preferred orientation. Our anisotropy of magnetic susceptibility (AMS) data demonstrate that the shape of susceptibility ellipsoids for the target rocks varies from prolate to oblate, and most impact melt breccia samples display both shapes, with a slight bias toward the oblate geometry. The average value for the corrected degree of anisotropy of impact melt rock (P′ = 1.009) is lower than that for the target rocks (P′ = 1.091). The present study also shows that both impact melt breccia and target rock samples of the Dhala structure have undergone minor postimpact alteration, and have similar compositions in terms of magnetic phases and high viscosity. Fine-grained iron oxide or hydroxide is the main alteration phase in impact melt rocks. Impact melt rocks gave a narrow range of mean magnetic susceptibility (K m ) and P′ values, in contrast to the target rock samples, which gave K m = 0.05–12.9 × 10 −3 standard international units (SI) and P′ = 1.036–1.283. This suggests similar viscosity of the source magma, and limited difference in the degrees of recorded deformation. Between Pagra and Maniar villages, the K m value of impact melt breccias gradually decreases in a clockwise direction, with a maximum value observed near Pagra (K m = 1.67 × 10 −3 SI). The poor grouping of magnetic fabrics for most impact melt rock samples implies local turbulence in rapidly cooled impact melt at the front of the melt flow immediately after the impact. The mean K 1 for most impact melt samples suggests subhorizontal (<5°) flow in various directions. The average value of K m for the target rocks (4.41 × 10 −3 SI) is much higher compared to the value for melt breccias (1.09 × 10 −3 SI). The results of this study suggest that the melt breccias were likely part of a sheet-like body of sizeable extent. Our magnetic fabric data are also supported by earlier core drilling information from ~70 locations, with coring depths reaching to −500 m. Our extensive field observations combined with available widespread subsurface data imply that the impact melt sheet could have covered as much as 12 km 2 in the Dhala structure, with an estimated minimum melt volume of ~2.4 km 3 .
Comparison of stress orientation indicators in Chicxulub’s peak ring: Kinked biotites, basal PDFs, and feather features Available to Purchase
ABSTRACT During hypervelocity impacts, target rocks are subjected to shock wave compression with high pressures and differential stresses. These differential stresses cause microscopic shear-induced deformation, which can be observed in the form of kinking, twinning, fracturing, and shear faulting in a range of minerals. The orientation of these shear-induced deformation features can be used to constrain the maximum shortening axis. Under the assumption of pure shear deformation, the maximum shortening axis is parallel to the maximum principal axis of stress, σ 1 , which gives the propagation direction of the shock wave that passed through a rock sample. In this study, shocked granitoids cored from the uppermost peak ring of the Chicxulub crater (International Ocean Discovery Program [IODP]/International Continental Drilling Project [ICDP] Expedition 364) were examined for structures formed by shearing. Orientations of kink planes in biotite and basal planar deformation features (PDFs) in quartz were measured with a U-stage and compared to a previous study of feather feature orientations in quartz from the same samples. In all three cases, the orientations of the shortening axis derived from these measurements were in good agreement with each other, indicating that the shear deformation features all formed in an environment with similar orientations of the maximum principal axis of stress. These structures formed by shearing are useful tools that can aid in understanding the deformational effects of the shock wave, as well as constraining shock wave propagation and postshock deformation during the cratering process.