- 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
-
East Africa
-
Kenya (1)
-
Lake Turkana (1)
-
-
East African Lakes
-
Lake Turkana (1)
-
-
Southern Africa
-
Namibia (1)
-
South Africa (1)
-
-
West Africa
-
Cameroon
-
Mount Cameroon (1)
-
-
-
-
Antarctica
-
East Antarctica (1)
-
Queen Maud Land (1)
-
Transantarctic Mountains (1)
-
-
Asia
-
Far East
-
Indonesia
-
Sumatra
-
Toba Lake (1)
-
-
-
-
Indian Peninsula
-
India
-
Gujarat India
-
Saurashtra (1)
-
-
Maharashtra India
-
Lonar Crater (1)
-
-
-
-
Middle East
-
Iran (1)
-
-
-
Atlantic Ocean
-
North Atlantic
-
Bay of Fundy (1)
-
-
-
Atlantic Ocean Islands
-
Canary Islands
-
Grand Canary (1)
-
-
-
Canada
-
Eastern Canada
-
Maritime Provinces
-
Nova Scotia (1)
-
-
-
Western Canada
-
British Columbia (1)
-
-
-
Central America
-
Guatemala
-
Pacaya (1)
-
-
-
Craters of the Moon (1)
-
East Pacific Ocean Islands
-
Hawaii
-
Hawaii County Hawaii
-
Hawaii Island
-
Kilauea (8)
-
Kohala (1)
-
Mauna Kea (1)
-
Mauna Ulu (1)
-
Puu Oo (1)
-
-
-
Honolulu County Hawaii
-
Oahu (1)
-
-
Kauai County Hawaii (1)
-
Mauna Loa (4)
-
-
-
Europe
-
Southern Europe
-
Italy
-
Sicily Italy
-
Mount Etna (1)
-
-
-
-
Western Europe
-
Iceland (1)
-
United Kingdom
-
Great Britain
-
Scotland
-
Argyllshire Scotland
-
Mull Island (2)
-
-
Hebrides
-
Inner Hebrides
-
Mull Island (2)
-
-
-
-
-
-
-
-
Indian Ocean Islands
-
Mascarene Islands
-
Reunion
-
Piton de la Fournaise (1)
-
-
-
-
Kerguelen Plateau (1)
-
Mexico
-
Sonora Mexico (1)
-
-
North America
-
Great Lakes region (1)
-
-
Oceania
-
Polynesia
-
Hawaii
-
Hawaii County Hawaii
-
Hawaii Island
-
Kilauea (8)
-
Kohala (1)
-
Mauna Kea (1)
-
Mauna Ulu (1)
-
Puu Oo (1)
-
-
-
Honolulu County Hawaii
-
Oahu (1)
-
-
Kauai County Hawaii (1)
-
Mauna Loa (4)
-
-
-
-
Pacific Ocean
-
East Pacific
-
Galapagos Rift (1)
-
Northeast Pacific
-
Loihi Seamount (1)
-
-
Panama Basin (1)
-
-
North Pacific
-
Northeast Pacific
-
Loihi Seamount (1)
-
-
-
-
United States
-
Arizona
-
Coconino County Arizona (1)
-
Mogollon Rim (1)
-
Yavapai County Arizona (1)
-
-
Colorado Plateau (1)
-
Hawaii
-
Hawaii County Hawaii
-
Hawaii Island
-
Kilauea (8)
-
Kohala (1)
-
Mauna Kea (1)
-
Mauna Ulu (1)
-
Puu Oo (1)
-
-
-
Honolulu County Hawaii
-
Oahu (1)
-
-
Kauai County Hawaii (1)
-
Mauna Loa (4)
-
-
Idaho
-
Blaine County Idaho (1)
-
Butte County Idaho (1)
-
Gooding County Idaho (1)
-
Snake River plain (2)
-
-
Minnesota
-
Cook County Minnesota (1)
-
Lake County Minnesota (1)
-
Saint Louis County Minnesota (1)
-
-
New Jersey (1)
-
Oregon (1)
-
Washington (1)
-
-
-
elements, isotopes
-
Lu/Hf (1)
-
sulfur (1)
-
-
fossils
-
lichens (1)
-
-
geochronology methods
-
K/Ar (2)
-
Lu/Hf (1)
-
paleomagnetism (1)
-
U/Pb (1)
-
-
geologic age
-
Cenozoic
-
Quaternary
-
Holocene (1)
-
Pleistocene (2)
-
upper Quaternary (1)
-
-
Tertiary
-
Neogene
-
Miocene
-
Columbia River Basalt Group (4)
-
Grande Ronde Basalt (1)
-
lower Miocene (1)
-
-
Pliocene (1)
-
-
Paleogene
-
Eocene
-
upper Eocene (1)
-
-
Oligocene
-
upper Oligocene (1)
-
-
Paleocene
-
lower Paleocene
-
K-T boundary (1)
-
-
-
-
-
-
Mesozoic
-
Cretaceous
-
Upper Cretaceous
-
K-T boundary (1)
-
-
-
Jurassic
-
Lower Jurassic (1)
-
-
-
Paleozoic
-
Devonian
-
Old Red Sandstone (2)
-
-
-
Precambrian
-
Archean
-
Mesoarchean (1)
-
-
North Shore Volcanics (1)
-
Pongola Supergroup (1)
-
upper Precambrian
-
Proterozoic
-
Keweenawan (1)
-
-
-
-
-
igneous rocks
-
igneous rocks
-
peperite (2)
-
plutonic rocks
-
diabase (1)
-
gabbros (1)
-
granites (1)
-
lamprophyres
-
minette (1)
-
-
pegmatite (1)
-
ultramafics
-
pyroxenite (1)
-
-
-
volcanic rocks
-
andesites (1)
-
basalts
-
alkali basalts (2)
-
flood basalts (10)
-
olivine basalt (1)
-
tholeiite (2)
-
tholeiitic basalt (1)
-
-
basanite (1)
-
pyroclastics
-
hyaloclastite (1)
-
tuff (1)
-
-
rhyolites (1)
-
-
-
volcanic ash (2)
-
-
metamorphic rocks
-
metamorphic rocks
-
metavolcanic rocks (1)
-
-
-
minerals
-
silicates
-
framework silicates
-
feldspar group
-
plagioclase (1)
-
-
-
orthosilicates
-
nesosilicates
-
zircon group
-
zircon (1)
-
-
-
-
-
-
Primary terms
-
absolute age (3)
-
Africa
-
East Africa
-
Kenya (1)
-
Lake Turkana (1)
-
-
East African Lakes
-
Lake Turkana (1)
-
-
Southern Africa
-
Namibia (1)
-
South Africa (1)
-
-
West Africa
-
Cameroon
-
Mount Cameroon (1)
-
-
-
-
Antarctica
-
East Antarctica (1)
-
Queen Maud Land (1)
-
Transantarctic Mountains (1)
-
-
Asia
-
Far East
-
Indonesia
-
Sumatra
-
Toba Lake (1)
-
-
-
-
Indian Peninsula
-
India
-
Gujarat India
-
Saurashtra (1)
-
-
Maharashtra India
-
Lonar Crater (1)
-
-
-
-
Middle East
-
Iran (1)
-
-
-
Atlantic Ocean
-
North Atlantic
-
Bay of Fundy (1)
-
-
-
Atlantic Ocean Islands
-
Canary Islands
-
Grand Canary (1)
-
-
-
atmosphere (1)
-
Canada
-
Eastern Canada
-
Maritime Provinces
-
Nova Scotia (1)
-
-
-
Western Canada
-
British Columbia (1)
-
-
-
Cenozoic
-
Quaternary
-
Holocene (1)
-
Pleistocene (2)
-
upper Quaternary (1)
-
-
Tertiary
-
Neogene
-
Miocene
-
Columbia River Basalt Group (4)
-
Grande Ronde Basalt (1)
-
lower Miocene (1)
-
-
Pliocene (1)
-
-
Paleogene
-
Eocene
-
upper Eocene (1)
-
-
Oligocene
-
upper Oligocene (1)
-
-
Paleocene
-
lower Paleocene
-
K-T boundary (1)
-
-
-
-
-
-
Central America
-
Guatemala
-
Pacaya (1)
-
-
-
climate change (1)
-
deformation (2)
-
Earth (2)
-
East Pacific Ocean Islands
-
Hawaii
-
Hawaii County Hawaii
-
Hawaii Island
-
Kilauea (8)
-
Kohala (1)
-
Mauna Kea (1)
-
Mauna Ulu (1)
-
Puu Oo (1)
-
-
-
Honolulu County Hawaii
-
Oahu (1)
-
-
Kauai County Hawaii (1)
-
Mauna Loa (4)
-
-
-
education (1)
-
Europe
-
Southern Europe
-
Italy
-
Sicily Italy
-
Mount Etna (1)
-
-
-
-
Western Europe
-
Iceland (1)
-
United Kingdom
-
Great Britain
-
Scotland
-
Argyllshire Scotland
-
Mull Island (2)
-
-
Hebrides
-
Inner Hebrides
-
Mull Island (2)
-
-
-
-
-
-
-
-
faults (2)
-
folds (1)
-
fractures (4)
-
geochemistry (3)
-
geomorphology (3)
-
geophysical methods (1)
-
igneous rocks
-
peperite (2)
-
plutonic rocks
-
diabase (1)
-
gabbros (1)
-
granites (1)
-
lamprophyres
-
minette (1)
-
-
pegmatite (1)
-
ultramafics
-
pyroxenite (1)
-
-
-
volcanic rocks
-
andesites (1)
-
basalts
-
alkali basalts (2)
-
flood basalts (10)
-
olivine basalt (1)
-
tholeiite (2)
-
tholeiitic basalt (1)
-
-
basanite (1)
-
pyroclastics
-
hyaloclastite (1)
-
tuff (1)
-
-
rhyolites (1)
-
-
-
inclusions (1)
-
Indian Ocean Islands
-
Mascarene Islands
-
Reunion
-
Piton de la Fournaise (1)
-
-
-
-
intrusions (3)
-
lava (42)
-
lichens (1)
-
magmas (6)
-
mantle (2)
-
Mesozoic
-
Cretaceous
-
Upper Cretaceous
-
K-T boundary (1)
-
-
-
Jurassic
-
Lower Jurassic (1)
-
-
-
metamorphic rocks
-
metavolcanic rocks (1)
-
-
metasomatism (1)
-
Mexico
-
Sonora Mexico (1)
-
-
North America
-
Great Lakes region (1)
-
-
ocean floors (2)
-
Oceania
-
Polynesia
-
Hawaii
-
Hawaii County Hawaii
-
Hawaii Island
-
Kilauea (8)
-
Kohala (1)
-
Mauna Kea (1)
-
Mauna Ulu (1)
-
Puu Oo (1)
-
-
-
Honolulu County Hawaii
-
Oahu (1)
-
-
Kauai County Hawaii (1)
-
Mauna Loa (4)
-
-
-
-
Pacific Ocean
-
East Pacific
-
Galapagos Rift (1)
-
Northeast Pacific
-
Loihi Seamount (1)
-
-
Panama Basin (1)
-
-
North Pacific
-
Northeast Pacific
-
Loihi Seamount (1)
-
-
-
-
paleoclimatology (2)
-
paleogeography (3)
-
paleomagnetism (1)
-
Paleozoic
-
Devonian
-
Old Red Sandstone (2)
-
-
-
petrology (7)
-
plate tectonics (3)
-
Precambrian
-
Archean
-
Mesoarchean (1)
-
-
North Shore Volcanics (1)
-
Pongola Supergroup (1)
-
upper Precambrian
-
Proterozoic
-
Keweenawan (1)
-
-
-
-
remote sensing (2)
-
sedimentary rocks
-
clastic rocks
-
conglomerate (2)
-
sandstone (2)
-
-
-
sedimentary structures
-
soft sediment deformation (1)
-
-
sedimentation (2)
-
sediments
-
clastic sediments
-
gravel (1)
-
-
-
springs (1)
-
stratigraphy (2)
-
sulfur (1)
-
tectonics (3)
-
tectonophysics (1)
-
United States
-
Arizona
-
Coconino County Arizona (1)
-
Mogollon Rim (1)
-
Yavapai County Arizona (1)
-
-
Colorado Plateau (1)
-
Hawaii
-
Hawaii County Hawaii
-
Hawaii Island
-
Kilauea (8)
-
Kohala (1)
-
Mauna Kea (1)
-
Mauna Ulu (1)
-
Puu Oo (1)
-
-
-
Honolulu County Hawaii
-
Oahu (1)
-
-
Kauai County Hawaii (1)
-
Mauna Loa (4)
-
-
Idaho
-
Blaine County Idaho (1)
-
Butte County Idaho (1)
-
Gooding County Idaho (1)
-
Snake River plain (2)
-
-
Minnesota
-
Cook County Minnesota (1)
-
Lake County Minnesota (1)
-
Saint Louis County Minnesota (1)
-
-
New Jersey (1)
-
Oregon (1)
-
Washington (1)
-
-
volcanology (4)
-
weathering (3)
-
-
rock formations
-
Deccan Traps (5)
-
Karoo Supergroup (1)
-
-
sedimentary rocks
-
molasse (1)
-
sedimentary rocks
-
clastic rocks
-
conglomerate (2)
-
sandstone (2)
-
-
-
volcaniclastics (3)
-
-
sedimentary structures
-
channels (1)
-
sedimentary structures
-
soft sediment deformation (1)
-
-
-
sediments
-
sediments
-
clastic sediments
-
gravel (1)
-
-
-
volcaniclastics (3)
-
pahoehoe
Pāhoehoe lava emplacement in Lon Reudle, Mull
When knickzones limit upstream transmission of base-level fall: An example from Kaua‘i, Hawai‘i
Multiple volcanic episodes of the Kermanshah forearc basin, SW Iran: a record of the deactivation and re-initiation of Neotethyan subduction involving a mid-ocean ridge
Flood basalt structures and textures as guides to cooling histories and palaeoclimates: the Deccan Traps of Saurashtra, western India
Chapter 2.3 Dronning Maud Land Jurassic volcanism: volcanology and petrology
Abstract The Jurassic igneous rocks of Dronning Maud Land represent Karoo flood basalt magmatism in Antarctica. Fifty years of research has documented systematic differences between magmas associated with the Karoo rift-zone (Vestfjella and Ahlmannryggen) and the rift-shoulder (Sembberget, Kirwanveggen) settings. The 189–182 Ma rift-zone tholeiites were chemically diverse and mainly formed compound-braided flow fields which record several magnetic polarity reversals. In contrast, the c. 181 Ma rift-shoulder tholeiites were chemically uniform and formed thick tabular sheet lavas within a single normal polarity period. The volcanic architecture records a long initial phase of slow eruptions from shield volcanoes in the initial rift and a brief phase of voluminous fissure eruptions flooding the rift shoulder. All of the major magma types in the rift-zone and rift-shoulder settings belong to a Nb-depleted category of Karoo flood basalts and were mainly derived from depleted convective upper mantle by magmatic differentiation. Pyroxenite-rich mantle components may have been significant sources for the most enriched magma types. Geochemical fingerprints of recycled crustal material imply that the Nb-depleted Karoo tholeiites may have been derived from mildly subduction-modified parts of the same overall upper-mantle reservoir which has been associated with the Ferrar tholeiites.
Revealing emplacement dynamics of a simple flood basalt eruption unit using systematic compositional heterogeneities
ABSTRACT Intralava geochemical variations resulting from subtle changes in magma composition are used here to provide insights into the spatial-temporal development of large basalt lava flow fields. Recognition that flood basalt lavas are emplaced by inflation processes, akin to modern pāhoehoe lava, provides a spatial and temporal frame-work, both vertically at single locations and laterally between locations, in which to examine lava flow emplacement and lava flow field development. Assuming the lava inflation model, we combined detailed field mapping with analysis of compositional profiles across a single flow field to determine the internal spatio-temporal development of the Palouse Falls flow field, a lava produced by an individual Columbia River flood basalt eruption. Geochemical analyses of samples from constituent lobes of the Palouse Falls lava field demonstrate that systematic compositional whole-rock variations can be traced throughout the flow field from the area of the vent to the distal limits. Chemical heterogeneity within individual lava lobes (and outcrops) shows an increase from lava crusts to cores, e.g., MgO = 3.24–4.23 wt%, Fe 2 O 3 = 14.71–16.05 wt%, Cr = 29–52 ppm, and TiO 2 = 2.83–3.14 wt%. This is accompanied by a decrease in incompatible elements, e.g., Y = 46.1–43.4 ppm, Zr = 207–172 ppm, and V = 397–367 ppm. Systematic compositional variations from the source to distal areas are observed through constituent lobes of the Palouse Falls flow field. However, compositional heterogeneity in any one lobe appears less variable in the middle of the flow field as compared to more proximal and distal margins. Excursions from the general progressive trend from vent to distal limits are also observed and may reflect lateral spread of the flow field during emplacement, resulting in the juxtaposition of lobes of different composition. Transport of magma through connected sheet lobe cores, acting as internal flow pathways to reach the flow front, is interpreted as the method of lava transport. Additionally, this can explain the general paucity of lava tubes within flood basalt provinces. In general, flow field development by a network of lava lobes may account for the occurrence of compositionally similar glasses noted at the proximal and distal ends of some flood basalt lavas.
ABSTRACT Near Moku‘āweoweo, Mauna Loa’s summit caldera, there are three fans of explosive deposits. The fans, located to the west, northwest, and east, are strongly arcuate in map view. Along ‘Āinapō Trail, 2.8–3.5 km southeast of the caldera, there are several small kīpuka that expose a fourth explosive deposit. Although these explosive deposits have been known for some time, no study bearing on the nature of the explosive activity that formed them has been done. By analyzing cosmogenic exposure age data and the physical properties of the debris fans—lithology, size distributions, and clast dispersal—we conclude that the lithic deposits are the result of five separate phreatic events. The lithic ejecta consist of fragments of ponded lavas, pāhoehoe, gabbroic xenoliths, and “bread-crust” fragments. The exposure ages indicate that the explosive deposit on the west caldera rim was erupted 868 ± 57 yr B.P.; for the northwest fan, the age determination is 829 ± 51 yr B.P.; and on the east rim, ejecta deposits are younger, with ages of 150 ± 20 and 220 ± 20 yr B.P. Lavas underlying these deposits have exposure ages of 960–1020 yr B.P., consistent with the stratigraphy. Near ‘Āinapō Trail, the explosive deposit is much older, overlain by flows dated with a pooled mean age of 1507 ± 19 yr B.P. From the cosmogenic dating, we have three reliable and unambiguous dates. At a much earlier time, a fourth explosive eruption created the ‘Āinapō Trail deposit. We conclude there were at least five explosive episodes around the summit caldera. These deposits, along with recent work done on Kīlauea’s explosive activity, further discredit the notion that Hawaiian volcanoes are strictly effusive in nature. The evidence from the summit of Mauna Loa indicates that it, too, has erupted explosively in recent history.
Anisotropy of Magnetic Susceptibility and Rock Magnetic Applications in the Deccan Volcanic Province based on some Case Studies
Lava Flow Transition in Pāhoehoe-Dominated Lower Pile of Deccan Traps from Manmad-Chandwad Area, Western Maharashtra
Polygonal feeder tubes filled with hydroclasts: a new volcanic lithofacies marking shoreline subaerial–submarine transition
Continental flood basalt provinces are the subaerial expression of large igneous province volcanism. The emplacement of a continental flood basalt is an exceptional volcanic event in the geological history of our planet with the potential to directly impact Earth's atmosphere and environment. Large igneous province volcanism appears to have occurred episodically every 10–30 m.y. through most of Earth history. Most continental flood basalt provinces appear to have formed within 1–3 m.y., and within this period, one or more pulses of great magma production and lava eruption took place. These pulses may have lasted from 1 m.y. to as little as a few hundred thousand years. Within these pulses, tens to hundreds of volumetrically large eruptions took place, each producing 10 3 –10 4 km 3 of predominantly p3hoehoe lava and releasing unprecedented amounts of volcanic gases and ash into the atmosphere. The majority of magmatic gas species released had the potential to alter climate and/or atmospheric composition, in particular during violent explosive phases at the eruptive vents when volcanic gases were lofted into the stratosphere. Aside from the direct release of magmatic gases, magma-sediment interactions featured in some continental flood basalt provinces could have released additional carbon, sulfur, and halogen-bearing species into the atmosphere. Despite their potential importance, given the different nature of the country rock associated with each continental flood basalt province, it is difficult to make generalizations about these emissions from one province to another. The coincidence of continental flood basalt volcanism with periods of major biotic change is well substantiated, but the actual mechanisms by which the volcanic gases might have perturbed the environment to this extent are currently not well understood, and have been little studied by means of atmospheric modeling. We summarize current, albeit rudimentary, knowledge of continental flood basalt eruption source and emplacement characteristics to define a set of eruption source parameters in terms of magmatic gases that could be used as inputs for Earth system modeling studies. We identify our limited knowledge of the number and length of non-eruptive phases (hiatuses) during continental flood basalt volcanism as a key unknown parameter critical for better constraining the severity and duration of any potential environmental effects caused by continental flood basalt eruptions.
Lithofacies architecture of basaltic andesite lavas and their interaction with wet-sediment: Port a’ Chroinn, Kerrera, NW Scotland
After 200 yr of repose, Pacaya Volcano resumed Strombolian activity in 1961 and has remained active until the time of this writing (2013). A three-dimensional map of 50 yr of nearly continuous activity of Pacaya depicts an accumulation of homogeneous, crystal-rich high-Al basalt on the west side of a preexisting cone. The material erupted is loose and welded spatter, volcanic ash, and 249 pahoehoe and a‘a lava flows, most of which were extruded in a few days, and most have extended less than 2 km in length from vents near the 2500-m-high summit down slopes of 20°–33°. The configuration of lava flows makes up a rigid, web-like network that welds the asymmetrical, steep western slope of an expanded Pacaya cone. The vents have fed the lava flows, forming a sieve-like pattern where lava leaks out. The cone contains a complex network of intrusive feeders, which fill and empty with lava, degas, and drain back. The volcano has shown explosive lava fountaining and effusive periods of activity and often exhibits both, as summit eruptions occur while lava drains from the cone. Lava flows and pyroclastic units from collapse-related avalanches and tephra fall tend to alternate. The overall length of lavas is limited, so that inhabited areas below the cone on most flanks are unlikely to be reached by flows, although topographic barriers, which blocked the flow of lava to the closest villages north of Pacaya, are now filled, so that lavas of moderate length (~2 km) could reach towns to the north under some conditions. The volcano is known to have experienced catastrophic explosive collapse in the last few thousand years. The current cone itself may be unstable because the new material has mostly asymmetrically loaded the west side of an old cone, and collapse to the west may be more likely because of mass imbalance and because of persistent activity that opens paths and accumulates on that side. Collapse to the west would threaten significant populations. Pacaya's past eruptions lasted centuries, with repose intervals of similar length, so the current activity may continue for another century or more. Overall, Pacaya is a complex of overlapping basaltic cones, and its pattern of activity provides insight into the early stages of composite cones such as nearby Agua, Fuego, Atitlán, and Santa María, all larger and older cones on the volcanic front of Guatemala with Pacaya.
Lava–sediment interactions in an Old Red Sandstone basin, NE Scotland
Inflation rates, rifts, and bands in a pāhoehoe sheet flow
Field exercises in the Pinacate volcanic field, Mexico: An analog for planetary volcanism
The Pinacate volcanic field is ~330 km SSW of Phoenix, and it is a popular destination for volcanology and planetary geology field trips. The volcanic field, located on the Pinacate Biosphere Reserve in Sonora, Mexico, is a 1500 km 2 basaltic field including a shield volcano, lava tubes, maars, a tuff cone, cinder cones, pāhoehoe and ‘a‘ā lava flows as young as 12 ka, and phreatomagmatic constructs as young as 32 ka. We developed an image-based set of exercises for a 2 day field trip focusing on (1) Crater Elegante, a maar crater, (2) pāhoehoe and ‘a‘ā flows near Tecolote Cone campground, (3) the complex eruptive history of Mayo (cinder) Cone, and (4) Cerro Colorado tuff cone. This paper discusses exercises to teach concepts in visible and radar image interpretation and planetary volcanology, and provides an overview of the field trip.
THE LATE-STAGE CRYSTALLIZATION HISTORY OF THE JURASSIC NORTH MOUNTAIN BASALT, NOVA SCOTIA, CANADA. II. NATURE AND ORIGIN OF SEGREGATION PIPES
Morphology and structure of the 1999 lava flows at Mount Cameroon Volcano (West Africa) and their bearing on the emplacement dynamics of volume-limited flows
Effects of megascale eruptions on Earth and Mars
Volcanic features are common on geologically active earthlike planets. Megascale or “super” eruptions involving >1000 Gt of magma have occurred on both Earth and Mars in the geologically recent past, introducing prodigious volumes of ash and volcanic gases into the atmosphere. Here we discuss felsic (explosive) and mafic (flood lava) supereruptions and their potential atmospheric and environmental effects on both planets. On Earth, felsic supereruptions recur on average about every 100–200,000 years and our present knowledge of the 73.5 ka Toba eruption implies that such events can have the potential to be catastrophic to human civilization. A future eruption of this type may require an unprecedented response from humankind to assure the continuation of civilization as we know it. Mafic supereruptions have resulted in atmospheric injection of volcanic gases (especially SO 2 ) and may have played a part in punctuating the history of life on Earth. The contrast between the more sustained effects of flood basalt eruptions (decades to centuries) and the near-instantaneous effects of large impacts (months to years) is worthy of more detailed study than has been completed to date. Products of mafic supereruptions, significantly larger than known from the geologic record on Earth, are well preserved on Mars. The volatile emissions from these eruptions most likely had global dispersal, but the effects may not have been outside what Mars endures even in the absence of volcanic eruptions. This is testament to the extreme variability of the current Martian atmosphere: situations that would be considered catastrophic on Earth are the norm on Mars.