Petrology of the Western Reykjanes Peninsula, Iceland

Jakobsson, Sveinn P.; Jónsson, Jón Eínar; Shido, Fumiko

doi:10.1093/petrology/19.4.669

Cited by 217 publications

(166 citation statements)

References 0 publications

Supporting

Mentioning

144

Contrasting

Unclassified

Order By: Relevance

“…Later studies, independently, reached the same conclusions regarding the overall volcanotectonic architecture in Iceland (e.g. Walker, 1959Walker, , 1963Walker, , 1964Walker, , 1975Saemundsson, 1974Saemundsson, , 1978Saemundsson, , 1979Tryggvason, 1973;Jakobsson et al, 1978;Jakobsson, 1979a) and as such established the volcanic system as a fundamental structure in the volcanic successions (Jakobsson, 1979b;Gudmundsson, 1995bGudmundsson, , 2000.…”

Section: Volcanic Structures In Icelandmentioning

confidence: 78%

“…It is characterized by conspicuous volcanotectonic architecture that features a fissure (dyke) swarm or a central volcano or both and has a typical lifetime of 0.5-1.5 million years (e.g. Jakobsson et al, 1978;Jakobsson, 1979a;Saemundsson, 1978Saemundsson, , 1979. The fissure swarms of each system are elongate structures that normally are aligned sub-parallel to the axis of the hosting volcanic zone.…”

Section: Volcanic Structures In Icelandmentioning

confidence: 99%

“…of the 1963-1967 Surtsey eruption (Thordarson, 2000) and early Holocene picritic shields of the Reykjanes peninsula (e.g. Jónsson, 1978;Jakobsson et al, 1978). Magmatic linear-type volcanoes or volcanic fissures are the trademark of Icelandic volcanism.…”

Section: Bláfjallmentioning

confidence: 99%

See 2 more Smart Citations

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

Thordarson

Larsen

2007

Journal of Geodynamics

506

454

View full text Add to dashboard Cite

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...

show abstract

Section: Volcanic Structures In Icelandmentioning

confidence: 78%

Section: Volcanic Structures In Icelandmentioning

confidence: 99%

See 1 more Smart Citation

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

Thordarson

Larsen

2007

Journal of Geodynamics

506

454

View full text Add to dashboard Cite

show abstract

“…The high FeO content of the Southwest Iceland lavas, for example, has been known for decades [Jakobsson et al, 1978;Zindler et al, 1979;Langmuir and Hanson, 1980], but it has been attributed only to the melting process or previous depletion history, based on a correlation with La/Sm ratio.…”

Section: Discussionmentioning

confidence: 99%

Magmatism and dynamics of continental breakup in the presence of a mantle plume

Korenaga¹

2000

View full text Add to dashboard Cite

This thesis studies the dynamics of mantle melting during continental breakups by geophysical, geochemical, and numerical analyses. The first part focuses on the mantle melting and crustal accretion processes during the formation of the Southeast Greenland margin, on the basis of deep-crustal seismic data. A new seismic tomographic method is developed to jointly invert refraction and reflection travel times for a compressional velocity structure, and a long-wavelength structure with strong lateral heterogeneity is successfully recovered, including 30-to 15-km-thick igneous crust within a 150-km-wide continent-ocean transition zone. A nonlinear Monte Carlo analysis is also conducted to establish the absolute uncertainty of model parameters. The derived crustal structure is first used to resolve the origin of a margin gravity high, with new inversion schemes using both seismic and gravity constraints. Density anomalies producing the gravity high seem to be confined within the upper crust, not in the lower crust as suggested for other volcanic margins. A new robust framework is then developed for the petrological interpretation of the velocity structure of igneous crust, and the thick igneous crust formed at the continentocean transition zone is suggested to have resulted from vigorous active upwelling of mantle with only somewhat elevated potential temperature. In the second part, the nature of mantle melting during the formation of the North Atlantic igneous province is studied on the basis of the major element chemistry of erupted lavas. A new fractionation correction scheme based on the Ni concentrations of mantle olivine is used to estimate primary melt compositions, which suggest that this province is characterized by a large degree of major element source heterogeneity. In the third part, the nature of preexisting sublithospheric convection is investigated by a series of finite element analyses, because the strength of such convection is important to define the "normal" state of mantle, the understanding of which is essential to identify any anomalous behavior of mantle such as a mantle plume. The results suggest that small-scale convection is likely in normal asthenosphere, and that the upwelling velocity in such convection is on the order of 1-10 cm/yr. 271 Introductory NotesThis thesis is composed of three parts, all of which are related to the dynamics of mantle melting during continental breakups. In the first part, rifting magmatism associated with the opening of the North Atlantic (at -60 Ma) is investigated on the basis of deep-crustal seismic data collected across the Southeast Greenland continental margin. A new seismic tomographic method is developed to jointly invert refraction and reflection travel times for a two-dimensional velocity structure (Chapter 1). Several key issues in travel time tomography such as velocity-depth ambiguity and absolute parameter uncertainty are identified, and a practical strategy is presented to resolve them. The derived crustal velocity structure is the...

show abstract

“…The volcanic system is hosted in an oblique extensional tectonic setting, resulting in episodic fissure eruptions (Clifton and Kattenhorn, 2006). Tectonic extension-controlled structures and active volcanism have resulted in significant geothermal activity along the Reykjanes Peninsula, notably in the Reykjanes and Svartsengi geothermal systems (Jakobsson et al, 1978;Arnórsson, 1995). The Reykjanes geothermal system is located on the western tip of the Reykjanes Peninsula, approximately 50 km southwest of Reykjavík (Fig.…”

Section: Geological Settingmentioning

confidence: 99%

Evolution of fluid–rock interaction in the Reykjanes geothermal system, Iceland: Evidence from Iceland Deep Drilling Project core RN-17B

Fowler

Zierenberg

Schiffman

et al. 2015

Journal of Volcanology and Geothermal Research

View full text Add to dashboard Cite

We describe the lithology and present spatially resolved geochemical analyses of samples from the hydrothermally altered Iceland Deep Drilling Project (IDDP) drill core RN-17B. The 9.3 m long RN-17B core was collected from the seawater-dominated Reykjanes geothermal system, located on the Reykjanes Peninsula, Iceland. The nature of fluids and the location of the Reykjanes geothermal system make it a useful analog for seafloor hydrothermal processes, although there are important differences. The recovery of drill core from the Reykjanes geothermal system, as opposed to drill cuttings, has provided the opportunity to investigate evolving geothermal conditions by utilizing in-situ geochemical techniques in the context of observed paragenetic and spatial relationships of alteration minerals. The RN-17B core was returned from a vertical depth of~2560 m and an in-situ temperature of~345°C. The primary lithologies are basaltic in composition and include hyaloclastite breccia, fine-grained volcanic sandstone, lithic breccia, and crystalline basalt. Primary igneous phases have been entirely pseudomorphed by calcic plagioclase + magnesium hornblende + chlorite + titanite + albitized plagioclase + vein epidote and sulfides. Despite the extensive hydrothermal metasomatism, original textures including hyaloclastite glass shards, lithic clasts, chilled margins, and shell-fragment molds are superbly preserved. Multi-collector LA-ICP-MS strontium isotope ratio ( 87 Sr/ 86 Sr) measurements of vein epidote from the core are consistent with seawater as the dominant recharge fluid. Epidote-hosted fluid inclusion homogenization temperature and freezing point depression measurements suggest that the RN-17B core records cooling through the two-phase boundary for seawater over time to current in-situ measured temperatures. Electron microprobe analyses of hydrothermal hornblende and hydrothermal plagioclase confirm that while alteration is of amphibolite-grade, it is in disequilibrium and the extent of alteration is dependent upon protolith type and water/rock ratio. Alteration in the RN-17B core bares many similarities to that of Type II basalts observed in Mid-Atlantic Ridge samples.

show abstract

Petrology of the Western Reykjanes Peninsula, Iceland

Cited by 217 publications

References 0 publications

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

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

Magmatism and dynamics of continental breakup in the presence of a mantle plume

Evolution of fluid–rock interaction in the Reykjanes geothermal system, Iceland: Evidence from Iceland Deep Drilling Project core RN-17B

Contact Info

Product

Resources

About