Experimental petrology of alkalic lavas: constraints on cotectics of multiple saturation in natural basic liquids

  title={Experimental petrology of alkalic lavas: constraints on cotectics of multiple saturation in natural basic liquids},
  author={Richard O. Sack and David Walker and Ian Carmichael},
  journal={Contributions to Mineralogy and Petrology},
Experimental study of natural alkalic lava compositions at low pressures (pO2∼QFM) reveals that crystallization of primitive lavas often occurs in the sequence olivine, plagioclase, clinopyroxene, nepheline without “obvious” reaction relation. Pseudoternary liquidus projections of multiply saturated liquids coexisting with plagioclase (±olivine±clinopyroxene±nepheline) have been prepared to facilitate graphical analysis of the evolution of lava compositions during hypabyssal cooling. Use of… 
Experimental and major element constraints on the evolution of lavas from Lihir Island, Papua New Guinea
The major element chemistry of SiO2-undersaturated arc lavas from Lihir Island, Papua New Guinea, and 1 atmosphere experiments on an alkali basalt from this island show complex polybaric
Clinopyroxene geobarometry of magmatic rocks. Part 2. Structural geobarometers for basic to acid, tholeiitic and mildly alkaline magmatic systems
Abstract The crystal structures of 212 experimentally synthesized, igneous clinopyroxenes were modeled from electronprobe chemical data. The coexisting melts span a wide range of petrologically
Nature and cause of compositional variation among the alkalic cap lavas of Mauna Kea Volcano, Hawaii
Most Hawaiian basaltic shield volcanoes are capped by moderately to strongly evolved alkalic lavas (MgO<4.5 wt.%). On Mauna Kea Volcano the cap is dominantly composed of hawaiite with minor
An enriched mantle source for potassic basanites: evidence from Karisimbi volcano, Virunga volcanic province, Rwanda
Lavas from Karisimbi, the largest volcano in the Virunga province in the Western Branch of the African rift on the Zaire-Rwandan border, constitute a suite of mafic potassic basanites and more
Geochemical characteristics of Cocos Plate seamount lavas
A wide compositional continuum of basalts has been erupted from near-ridge seamounts constructed on the Cocos Plate between the Clipperton and Orozco Francture Zones. They range from highly evolved
Melting phase relations of a mica–clinopyroxenite from the Milk River area, southern Alberta, Canada
AbstractMelting experiments were conducted on a mica–clinopyroxenite xenolith brought up in a minette dyke in southern Alberta, Canada, near Milk River. Both the minettes and mica–clinopyroxenite
Source of the Quaternary alkalic basalts, picrites and basanites of the Potrillo Volcanic Field, New Mexico, USA: lithosphere or convecting mantle?
The <80 ka basalts–basanites of the Potrillo Volcanic Field (PVF) form scattered scoria cones, lava flows and maars adjacent to the New Mexico–Mexico border. MgO ranges up to 12·5%; lavas with MgO <


Composition of liquids coexisting with spinel lherzolite at 10 kbar and the genesis of MORBs
Because of the controversy over the nature of the parental magma for MORBs, experiments have been performed at 10 kbar in order to assess the effect of modal variations in the source peridotite and
Fractionation of pyroxene-phyric MORB at low pressure: An experimental study
One-atmosphere melting experiments are used to assess the role of clinopyroxene in producing the compositional variations observed in mid-ocean-ridge basalts (MORBs) from the North Atlantic. Analog
Petrology of the leucite‐bearing lavas in New South Wales∗
Abstract Several isolated outcrops of melanocratic leucitite lava in central New South Wales are interpreted as remnants of flows erupted in late Cainozoic time by small lava‐volcanoes. The general
Abyssal tholeiites from the Oceanographer Fracture Zone
Fresh basalts from the Oceanographer Fracture Zone are petrographically and chemically similar to typical abyssal tholeiites, but are somewhat enriched in large ion lithophile elements, with
Mantle‐derived amphibole within inclusions in alkalic‐basaltic lavas
Amphibole in mantle-derived inclusions in alkalic-basaltic rocks occurs in four textural modes: veins and interstitial grains in chromian-spinel peridotite, poikilitic grains in igneous textured
Quaternary lavas from the southern Cascades, western U.S.A.
A series of basaltic and andesitic lavas from three centers in the Cascades (Lassen, Medicine Lake, Mt. Shasta) have been investigated. The lavas are weakly porphyritic, containing phenocrysts of
Stages in the P-T path of ascending basalt magma: An example from San Quintin, Baja California
AbstractLate Pleistocene or Recent lavas from San Quintin, Baja California are basanitoids and alkali basalts. The surface quench temperatures of the lavas average 1 005° C with log
Experimental Studies Bearing on the Origin of Pseudoleucite and Associated Problems of Alkalic Rock Systems
Selected parts of the system nepheline-kalsilite-silica-water were studied at elevated temperatures and, for the most part, at a constant P H 2 o of 1000 bars. Concomitantly, experimental work was