Matches in SemOpenAlex for { <https://semopenalex.org/work/W3147969384> ?p ?o ?g. }
- W3147969384 abstract "Lava shields in Iceland are monogenic shield volcanoes mostly composed of primitive basalts, picrite and olivine tholeiite. The Holocene shields are restricted in space and time: in space they are essentially confined to the North and West Volcanic Zones; in time they are essentially confined to the early part of the Holocene. The volcanic zones are characterised by volcanic systems, that is, 5-20 km wide and 40-150 km long swarms of tectonic fractures and volcanic fissures where most of the Holocene volcanotectonic activity takes place. However, most lava shields are not located inside the volcanic systems but rather at their margins or in between systems. In addition to the lavas of the shields being more primitive those issued from nearby volcanic fissures, the average volume of a shield is an order of a magnitude larger than that of the lava from a fissure. Here we present the results of new field observations of Holocene shields and provide numerical models to explain their location, time of formation, primitive composition, and large volumes. We made models with varying ice-sheet size and thickness (glacial load), the ice resting on a mechanically layered crust, and studied the stress effects that the load would have on a double magma chamber, that is, a small, shallow crustal chamber at 3 km depth and a deep-seated reservoir at 20 km depth (the base of the crust). Such a pair of chambers is typical for volcanic systems and associated central volcanoes (composite volcanoes) in Iceland. For an ice sheet covering an entire volcanic zone or more, that is, 100 km or wider, the ice-induced compressive stress extends to the deep-seated reservoir and into the upper mantle. Consequently, such a loading suppresses magma accumulation in the reservoir and associated volcanism. During the late-glacial period, when the ice sheet is only 20 km wide, the glacial load generates tensile stresses around the deep-seated reservoir, increases its fracture porosity and magma content, and extends the reservoir laterally and vertically into the upper mantle. Consequently, when the lava shields (and, somewhat earlier, the tablemountains) were erupted, much more melt or magma was available to feed a single eruption than during the later part of the Holocene. And because of the greater vertical extent of the reservoir, this magma tended to be hotter and more primitive than that issued in later-formed fissure eruptions. Also, the stress field generated at the end of the glacial and in the early Holocene favoured dyke injections at the marginal parts of, or in between, the volcanic systems, thereby explaining the location of the lava shields." @default.
- W3147969384 created "2021-04-13" @default.
- W3147969384 creator A5004841571 @default.
- W3147969384 creator A5028577991 @default.
- W3147969384 date "2008-01-01" @default.
- W3147969384 modified "2023-09-24" @default.
- W3147969384 title "Volcanotectonic Evolution and Characteristic Volcanism of the Neovolcanic Zone of Iceland" @default.
- W3147969384 cites W1590705769 @default.
- W3147969384 cites W1596129456 @default.
- W3147969384 cites W1623582059 @default.
- W3147969384 cites W1965038520 @default.
- W3147969384 cites W1967143210 @default.
- W3147969384 cites W1978230000 @default.
- W3147969384 cites W1988518537 @default.
- W3147969384 cites W1990509154 @default.
- W3147969384 cites W1996053221 @default.
- W3147969384 cites W1997682393 @default.
- W3147969384 cites W2002783931 @default.
- W3147969384 cites W2003623213 @default.
- W3147969384 cites W2004487553 @default.
- W3147969384 cites W2006745337 @default.
- W3147969384 cites W2009420010 @default.
- W3147969384 cites W2012892094 @default.
- W3147969384 cites W2013074586 @default.
- W3147969384 cites W2020976223 @default.
- W3147969384 cites W2022424435 @default.
- W3147969384 cites W2022787535 @default.
- W3147969384 cites W2027525152 @default.
- W3147969384 cites W2028064909 @default.
- W3147969384 cites W2029786990 @default.
- W3147969384 cites W2043861894 @default.
- W3147969384 cites W2045437992 @default.
- W3147969384 cites W2046867384 @default.
- W3147969384 cites W2048878937 @default.
- W3147969384 cites W2050269648 @default.
- W3147969384 cites W2051387741 @default.
- W3147969384 cites W2056630263 @default.
- W3147969384 cites W2061558709 @default.
- W3147969384 cites W2062854986 @default.
- W3147969384 cites W2067703344 @default.
- W3147969384 cites W2068641796 @default.
- W3147969384 cites W2073774075 @default.
- W3147969384 cites W2073908251 @default.
- W3147969384 cites W2081285853 @default.
- W3147969384 cites W2087508280 @default.
- W3147969384 cites W2090668756 @default.
- W3147969384 cites W2093702694 @default.
- W3147969384 cites W2100719803 @default.
- W3147969384 cites W2101318489 @default.
- W3147969384 cites W2115949964 @default.
- W3147969384 cites W2131930395 @default.
- W3147969384 cites W2139854519 @default.
- W3147969384 cites W2145496138 @default.
- W3147969384 cites W2145856055 @default.
- W3147969384 cites W2154392372 @default.
- W3147969384 cites W2326716949 @default.
- W3147969384 cites W2483284175 @default.
- W3147969384 cites W2767466213 @default.
- W3147969384 cites W2910693340 @default.
- W3147969384 cites W56590412 @default.
- W3147969384 cites W580156106 @default.
- W3147969384 cites W642949392 @default.
- W3147969384 hasPublicationYear "2008" @default.
- W3147969384 type Work @default.
- W3147969384 sameAs 3147969384 @default.
- W3147969384 citedByCount "0" @default.
- W3147969384 crossrefType "journal-article" @default.
- W3147969384 hasAuthorship W3147969384A5004841571 @default.
- W3147969384 hasAuthorship W3147969384A5028577991 @default.
- W3147969384 hasConcept C113754120 @default.
- W3147969384 hasConcept C114793014 @default.
- W3147969384 hasConcept C120806208 @default.
- W3147969384 hasConcept C127313418 @default.
- W3147969384 hasConcept C140345934 @default.
- W3147969384 hasConcept C151730666 @default.
- W3147969384 hasConcept C158959774 @default.
- W3147969384 hasConcept C161509811 @default.
- W3147969384 hasConcept C17409809 @default.
- W3147969384 hasConcept C183222429 @default.
- W3147969384 hasConcept C187779500 @default.
- W3147969384 hasConcept C2776698055 @default.
- W3147969384 hasConcept C5900021 @default.
- W3147969384 hasConcept C6363049 @default.
- W3147969384 hasConcept C77928131 @default.
- W3147969384 hasConcept C9566828 @default.
- W3147969384 hasConceptScore W3147969384C113754120 @default.
- W3147969384 hasConceptScore W3147969384C114793014 @default.
- W3147969384 hasConceptScore W3147969384C120806208 @default.
- W3147969384 hasConceptScore W3147969384C127313418 @default.
- W3147969384 hasConceptScore W3147969384C140345934 @default.
- W3147969384 hasConceptScore W3147969384C151730666 @default.
- W3147969384 hasConceptScore W3147969384C158959774 @default.
- W3147969384 hasConceptScore W3147969384C161509811 @default.
- W3147969384 hasConceptScore W3147969384C17409809 @default.
- W3147969384 hasConceptScore W3147969384C183222429 @default.
- W3147969384 hasConceptScore W3147969384C187779500 @default.
- W3147969384 hasConceptScore W3147969384C2776698055 @default.
- W3147969384 hasConceptScore W3147969384C5900021 @default.
- W3147969384 hasConceptScore W3147969384C6363049 @default.
- W3147969384 hasConceptScore W3147969384C77928131 @default.