- 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
-
Southern Africa
-
Kaapvaal Craton (1)
-
Namaqualand (3)
-
South Africa
-
Transvaal region (1)
-
-
-
West Africa
-
Liberia (1)
-
-
West African Shield (1)
-
-
Atlantic region (1)
-
Coast Mountains (1)
-
Europe
-
Western Europe
-
Scandinavia
-
Norway
-
Northern Norway (1)
-
-
-
-
-
South America
-
Guiana Shield (1)
-
Venezuela
-
Eastern Venezuela (1)
-
-
-
United States
-
Alaska (1)
-
Virginia (1)
-
-
-
commodities
-
petroleum (1)
-
-
elements, isotopes
-
isotope ratios (1)
-
isotopes
-
radioactive isotopes
-
Ar-40/Ar-39 (1)
-
-
stable isotopes
-
Ar-40/Ar-39 (1)
-
-
-
noble gases
-
argon
-
Ar-40/Ar-39 (1)
-
-
-
-
geochronology methods
-
Ar/Ar (7)
-
fission-track dating (1)
-
paleomagnetism (5)
-
Rb/Sr (1)
-
-
geologic age
-
Cenozoic
-
Tertiary
-
Paleogene (1)
-
-
-
Mesozoic
-
Newark Supergroup (1)
-
Triassic (1)
-
-
Paleozoic
-
Devonian (1)
-
Silurian (1)
-
-
Precambrian
-
upper Precambrian
-
Proterozoic
-
Mesoproterozoic (1)
-
-
-
-
-
igneous rocks
-
igneous rocks
-
kimberlite (1)
-
plutonic rocks
-
gabbros (1)
-
granites (1)
-
ultramafics
-
peridotites
-
garnet lherzolite (1)
-
-
-
-
-
-
metamorphic rocks
-
metamorphic rocks
-
amphibolites (2)
-
mylonites (1)
-
-
-
minerals
-
phosphates
-
apatite (1)
-
-
silicates
-
chain silicates
-
amphibole group
-
clinoamphibole
-
hornblende (2)
-
-
-
-
framework silicates
-
feldspar group
-
plagioclase (1)
-
-
-
sheet silicates
-
mica group
-
biotite (1)
-
phlogopite (1)
-
-
-
-
-
Primary terms
-
absolute age (8)
-
Africa
-
Southern Africa
-
Kaapvaal Craton (1)
-
Namaqualand (3)
-
South Africa
-
Transvaal region (1)
-
-
-
West Africa
-
Liberia (1)
-
-
West African Shield (1)
-
-
Atlantic region (1)
-
Cenozoic
-
Tertiary
-
Paleogene (1)
-
-
-
continental drift (1)
-
Europe
-
Western Europe
-
Scandinavia
-
Norway
-
Northern Norway (1)
-
-
-
-
-
faults (1)
-
geochemistry (1)
-
geochronology (3)
-
igneous rocks
-
kimberlite (1)
-
plutonic rocks
-
gabbros (1)
-
granites (1)
-
ultramafics
-
peridotites
-
garnet lherzolite (1)
-
-
-
-
-
inclusions
-
fluid inclusions (2)
-
-
intrusions (2)
-
isotopes
-
radioactive isotopes
-
Ar-40/Ar-39 (1)
-
-
stable isotopes
-
Ar-40/Ar-39 (1)
-
-
-
mantle (1)
-
Mesozoic
-
Newark Supergroup (1)
-
Triassic (1)
-
-
metamorphic rocks
-
amphibolites (2)
-
mylonites (1)
-
-
metamorphism (1)
-
noble gases
-
argon
-
Ar-40/Ar-39 (1)
-
-
-
orogeny (1)
-
paleogeography (1)
-
paleomagnetism (5)
-
Paleozoic
-
Devonian (1)
-
Silurian (1)
-
-
petroleum (1)
-
plate tectonics (1)
-
Precambrian
-
upper Precambrian
-
Proterozoic
-
Mesoproterozoic (1)
-
-
-
-
sedimentary rocks
-
clastic rocks (1)
-
-
South America
-
Guiana Shield (1)
-
Venezuela
-
Eastern Venezuela (1)
-
-
-
stratigraphy (2)
-
structural geology (3)
-
tectonics (4)
-
tectonophysics (1)
-
United States
-
Alaska (1)
-
Virginia (1)
-
-
-
sedimentary rocks
-
sedimentary rocks
-
clastic rocks (1)
-
-
Paleofluid-flow circulation within a Triassic rift basin: Evidence from oil inclusions and thermal histories
Argon composition of metamorphic fluids: Implications for 40 Ar/ 39 Ar geochronology
Palaeomagnetic results from the Timbavati Gabbros in the Kruger National Park, South Africa
Dikes and pods of pseudotachylite up to one meter thick have been found over an area >50 km 2 in the same area as shatter cones and other possible features of shock metamorphism in the Beaverhead and Tendoy Mountains in southwestern Montana, defining the allochthonous remains of the Beaverhead impact structure (see also Hargraves et al., Chapter 19, this volume). They are not associated with any tectonic feature in the area and have several features uncommon in pseudotachylites formed by tectonic processes (large size, vesicles, pseudotachylite clasts within pseudotachylite), but which have been documented in pseudotachylites from other impact structures. Rare single sets of planar deformation features (PDFs) are found in quartz grains in the pseudotachylites with crystallographic orientations similar to those found in shocked quartz from other impact structures. The major and trace element chemistry of the pseudotachylites is similar to their host rocks, but with some enrichments (Al, Mg, Fe, K, volatiles) and depletions (Si, Na) indicating low-grade metasomatic alteration. 40 Ar/ 39 Ar laser microprobe analyses of pseudotachylites from three localities show a wide spectrum of ages, from Precambrian to Tertiary. The distribution of ages suggests two isotopic signatures, one of Precambrian age (although younger than the age of the protoliths), and the other of Cretaceous age. 29 Si Magic angle spinning (MAS) nuclear magnetic resonance (NMR) studies of the pseudotachylite failed to detect the presence of high-pressure polymorphs of quartz. The evidence suggests that these pseudotachylites were formed by the same event that formed the shatter cones. Related work (see Hargraves et al., Chapter 19, this volume) suggests that the original crater was at least 75 km in diameter and was formed in the late Proterozoic to Cambrian, 20 to 150 km to the west of the present location.