A new model for the emplacement of Columbia River basalts as large, inflated Pahoehoe Lava Flow Fields

Self, Stephen; Thordarson, T.; Keszthelyi, L.; Walker, G. P. L.; Hon, Ken; Murphy, Mark T.; Long, Philip E.; Finnemore, S.H

doi:10.1029/96gl02450

Cited by 232 publications

(158 citation statements)

References 21 publications

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“…Although the vent sources for these lavas have yet to be identified. By other terranes, Allen and McPhie (2002) suggested that widespread outf low would be promoted by eruption from several vents along a fissure rather than from point-source vents, a relationship that is well demonstrated in flood basalt provinces (e.g., Self et al, 1996). From a chemical point of view, the Las Lozas rocks plot in diagrams in the subalkaline/tholeiitic (rhyolites), alkaline basalts (basalts) and alkaline (trachytes) fields.…”

Section: Disscusionmentioning

confidence: 99%

Extensional Carboniferous magmatism at the western margin of Gondwana: Las Lozas valley, Catamarca, Argentina

Coira

Cisterna

Ulbrich

et al. 2016

andgeo

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ABSTRACT. The Las Lozas volcanic sequence, which crops out at northwestern border of the Famatina belt-southeastern Puna, NW Argentina, is constituted mainly by rhyolites and a lesser volume of basalts and trachytes, and volcanoclastic deposits. These rocks, previously considered of Early Paleozoic age, are now assigned to the Lower Pennsylvanian (320 Ma U-Pb age). They represent a bimodal volcanic succession that plot in the subalkaline/tholeiitic (rhyolites), alkaline basalts (basalts) and alkaline (trachytes) fields on the total alkali-silica diagram. The basalts display features comparable to transitional MORB and within-plate tholeiites, with contributions from a mantle source affected by crustal contamination. The acid members also show geochemical affinities to within-plate magmas, and their composition suggest a derivation from continental crustal material with mantle source interaction or a juvenile essentially mantle derived crust. The 320 Ma age from the Las Lozas volcanic succession as well as the 342 and 348 Ma U-Pb ages, from rocks in the nearby Cazadero Grande section, to the south, and the U-Pb ages from Sierra Pampeanas granites (332-357 Ma) highlight the importance achieved by Carboniferous magmatic activity in that region, framed between 320 and 350 Ma. Low strontium initial ratios from the Las Lozas (0.70479-0.70164) indicate a predominant contribution by a juvenile component, while the ratios in the nearby Cazadero Grande (0.71433-0.71233) and Sierras Pampeanas granites (0.717 to 0.7124) point to an input by enriched sources with restricted contribution of a mantle component. Nd isotopes from a basalt from the Las Lozas section (ε Nd(320) with +3.11, T DM with 774.6 Ma) indicates a possible asthenospheric source, with evidence for some mixture between juvenile and reworked crustal material. In contrast Sr-Nd isotopes in a rhyolite from Cazadero Grande (εNd (t) of -2.91 and -0.3, T DM of 1.09 and 1

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Section: Disscusionmentioning

confidence: 99%

Extensional Carboniferous magmatism at the western margin of Gondwana: Las Lozas valley, Catamarca, Argentina

Coira

Cisterna

Ulbrich

et al. 2016

andgeo

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“…mechanism of these eruptions, which in turn has enhanced our understanding of larger-scale flood basalt eruptions on Earth and Mars (e.g. Larsen, 1979Larsen, , 2000Thordarson and Self, 1993, 1998Self et al, 1996Self et al, , 1997Thordarson et al, , 2003aKeszthelyi et al, 2000Keszthelyi et al, , 2004Guilbaud et al, 2005). It has also demonstrated that over the last 1130 years, these events are the most significant of Icelandic eruptions in terms of environmental and climatic effects because of the huge amount of sulphur (100-250 Mt of SO 2 ) they release into the atmosphere (Thorarinsson, 1979;Metrich et al, 1991;Stothers, 1996Stothers, , 1998Thordarson et al, , 2001Thordarson et al, , 2003bOman et al, 2006) The high-discharge flood lava events are prolonged fissure eruptions that last for months to years and feature numerous eruption episodes (Fig.…”

Section: Effusive Eruptionsmentioning

confidence: 99%

Volcanism in Iceland in historical time: Volcano types, eruption styles and eruptive history

Thordarson

Larsen

2007

Journal of Geodynamics

506

454

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The large-scale volcanic lineaments in Iceland are an axial zone, which is delineated by the Reykjanes, West and North Volcanic Zones (RVZ, WVZ, NVZ) and the East Volcanic Zone (EVZ), which is growing in length by propagation to the southwest through pre-existing crust. These zones are connected across central Iceland by the Mid-Iceland Belt (MIB). Other volcanically active areas are the two intraplate belts ofÖraefajökull (ÖVB) and Snaefellsnes (SVB). The principal structure of the volcanic zones are the 30 volcanic systems, where 12 are comprised of a fissure swarm and a central volcano, 7 of a central volcano, 9 of a fissure swarm and a central domain, and 2 are typified by a central domain alone.Volcanism in Iceland is unusually diverse for an oceanic island because of special geological and climatological circumstances. It features nearly all volcano types and eruption styles known on Earth. The first order grouping of volcanoes is in accordance with recurrence of eruptions on the same vent system and is divided into central volcanoes (polygenetic) and basalt volcanoes (monogenetic). The basalt volcanoes are categorized further in accordance with vent geometry (circular or linear), type of vent accumulation, characteristic style of eruption and volcanic environment (i.e. subaerial, subglacial, submarine).Eruptions are broadly grouped into effusive eruptions where >95% of the erupted magma is lava, explosive eruptions if >95% of the erupted magma is tephra (volume calculated as dense rock equivalent, DRE), and mixed eruptions if the ratio of lava to tephra occupy the range in between these two end-members. Although basaltic volcanism dominates, the activity in historical time (i.e. last 11 centuries) features expulsion of basalt, andesite, dacite and rhyolite magmas that have produced effusive eruptions of Hawaiian and flood lava magnitudes, mixed eruptions featuring phases of Strombolian to Plinian intensities, and explosive phreatomagmatic and magmatic eruptions spanning almost the entire intensity scale; from Surtseyan to Phreatoplinian in case of "wet" eruptions and Strombolian to Plinian in terms of "dry" eruptions. In historical time the magma volume extruded by individual eruptions ranges from ∼1 m 3 to ∼20 km 3 DRE, reflecting variable magma compositions, effusion rates and eruption durations.All together 205 eruptive events have been identified in historical time by detailed mapping and dating of events along with extensive research on documentation of eruptions in historical chronicles. Of these 205 events, 192 represent individual eruptions and 13 are classified as "Fires", which include two or more eruptions defining an episode of volcanic activity that lasts for months to years. Of the 159 eruptions verified by identification of their products 124 are explosive, effusive eruptions are 14 and mixed eruptions are 21. Eruptions listed as reported-only are 33. Eight of the Fires are predominantly effusive and the remaining five include explosive activity that produced extensive tephra layers...

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“…We assume that a surface crust forms quickly and the flow is completely covered. We assume eruption at a depth of-1 km below sea level and flow over a seafloor with a slope of 1 in 1000 (similar to that assumed for eraplacement of the Columbia River Basalt [Self et al, 1996; 1997]). For runs over massive substrates (e.g., basalt), it is assumed there was no intergranular water in the substrate (fw = 0).…”

Section: Assumptionsmentioning

confidence: 99%

Emplacement and erosion by Archean komatiite lava flows at Kambalda: Revisited

1998

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A new model for the emplacement of Columbia River basalts as large, inflated Pahoehoe Lava Flow Fields

Cited by 232 publications

References 21 publications

Extensional Carboniferous magmatism at the western margin of Gondwana: Las Lozas valley, Catamarca, Argentina

Extensional Carboniferous magmatism at the western margin of Gondwana: Las Lozas valley, Catamarca, Argentina

Volcanism in Iceland in historical time: Volcano types, eruption styles and eruptive history

Emplacement and erosion by Archean komatiite lava flows at Kambalda: Revisited

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