Kerkhof, Alfons M. van den

[["dc.bibliographiccitation.issue","13"],["dc.bibliographiccitation.journal","Geochimica et Cosmochimica Acta"],["dc.bibliographiccitation.volume","73"],["dc.contributor.author","Harlov, Daniel E."],["dc.contributor.author","van den Kerkhof, Alfons M."],["dc.contributor.author","Hansen, Edward"],["dc.contributor.author","Johansson, Leif"],["dc.date.accessioned","2018-11-07T08:29:12Z"],["dc.date.available","2018-11-07T08:29:12Z"],["dc.date.issued","2009"],["dc.format.extent","A495"],["dc.identifier.isi","000267229901221"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/16595"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Pergamon-elsevier Science Ltd"],["dc.publisher.place","Oxford"],["dc.relation.conference","19th Annual VM Goldschmidt Conference"],["dc.relation.eventlocation","Davos, SWITZERLAND"],["dc.relation.issn","0016-7037"],["dc.title","Magmatism and metamorphism in the middle-lower crust, SW Sweden"],["dc.type","conference_abstract"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","50"],["dc.bibliographiccitation.journal","Precambrian Research"],["dc.bibliographiccitation.lastpage","62"],["dc.bibliographiccitation.volume","253"],["dc.contributor.author","Harlov, Daniel E."],["dc.contributor.author","van den Kerkhof, Alfons M."],["dc.contributor.author","Johansson, Leif"],["dc.date.accessioned","2018-11-07T09:34:25Z"],["dc.date.available","2018-11-07T09:34:25Z"],["dc.date.issued","2014"],["dc.description.abstract","The mineralogy, petrology, and fluid inclusion chemistry of two charnockite patches within a distance of 4-5 km of the Varberg magmatic charnockite intrusion, SW Sweden, are investigated and described utilizing SEM, EMPA, and fluid inclusion microthermometry. Garnet-clinopyroxene (890-930 degrees C), garnet-amphibole (600-800 degrees C), and garnet-biotite (670-860 degrees C) Fe-Mg exchange thermometry indicates high temperatures for charnockite Patch I compared to relatively lower garnet-orthopyroxene, garnet-amphibole, and garnet-biotite temperatures of 500 to 600 degrees C for charnockite Patch II. Plagioclase in the charnockitic patches tends to be more anorthitic and less albitic (X-An = 0.20, X-Ab = 0.76) than in the surrounding regional granitic gneiss (X-An = 0.13, X-Ab = 0.84). Replacement antiperthite is commonly found in unrelated plagioclase grains from either patch compared to the regional granitic gneiss where it is relatively rare. In either patch, K-feldspar is considerably less albitic (X-Kfs = 0.90-0.92, X-Ab = 0.05-0.10) compared to K-feldspar from the regional granitic gneiss. It can also be found as micro-veins along quartz grain rims. Both patches are dominated by clinopyroxene as opposed to orthopyroxene. Garnet, biotite, and amphibole and in both charnockite patches tend to have lower Fe and correspondingly higher Mg values compared with garnet, biotite, and amphibole from the surrounding regional granitic gneiss. Fluorapatite tends to be relatively enriched in Cl and depleted in (Y+REE) compared with fluorapatite from the regional granitic gneiss. Fluid inclusions in charnockite Patches I and II are dominantly carbonic similar to what is seen for the Varberg charnockite. In addition to quartz, relatively high-density carbonic inclusions are also preserved in garnet and in fluorapatite. It is presumed that pure carbonic fluids must have once coexisted with relic magmatic H2O-CO2-NaCl fluids at peak metamorphic conditions. The most likely scenario suggests that charnockite Patches I and II were formed during the later stages of crystallization of the Varberg charnockite magmatic body during which copious amounts of CO2-rich fluids with a brine (CaCl2-dominated) component were expelled into the country rock via pegmatoid segregations both within and in the immediate surroundings of the charnockite body. Patch I appears to represent the extension of a pegmatoid segregation, whereas Patch II appears to represent fluid-induced lower temperature, solid-state dehydration. Transport was facilitated via a system of tectonic fissures and fractures generated in the regional migmatized granitic gneiss during its emplacement. Within the scope of what is known, these two charnockite patches fall into the generally observed parameters for localized dehydration zones in general. (C) 2014 Elsevier B.V. All rights reserved."],["dc.identifier.doi","10.1016/j.precamres.2014.04.019"],["dc.identifier.isi","000343380500006"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/32166"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Science Bv"],["dc.relation.issn","1872-7433"],["dc.relation.issn","0301-9268"],["dc.title","Localized, solid-state dehydration associated with the Varberg charnockite intrusion, SW Sweden"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.issue","12"],["dc.bibliographiccitation.journal","Geochimica et Cosmochimica Acta"],["dc.bibliographiccitation.volume","72"],["dc.contributor.author","Harlov, Daniel E."],["dc.contributor.author","van den Kerkhof, Alfons M."],["dc.contributor.author","Johansson, L."],["dc.date.accessioned","2018-11-07T11:13:27Z"],["dc.date.available","2018-11-07T11:13:27Z"],["dc.date.issued","2008"],["dc.format.extent","A354"],["dc.identifier.isi","000257301600714"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/53895"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Pergamon-elsevier Science Ltd"],["dc.publisher.place","Oxford"],["dc.relation.conference","18th Annual V M Goldschmidt Conference"],["dc.relation.eventlocation","Vancouver, CANADA"],["dc.relation.issn","1872-9533"],["dc.relation.issn","0016-7037"],["dc.title","Localised fluid-induced, solid state dehydration in the lower crust: CO2-rich fluids vs. concentrated brines"],["dc.type","conference_abstract"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","3"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Journal of Petrology"],["dc.bibliographiccitation.lastpage","40"],["dc.bibliographiccitation.volume","54"],["dc.contributor.author","Harlov, Daniel E."],["dc.contributor.author","van Den Kerkhof, Alfons"],["dc.contributor.author","Johansson, Leif"],["dc.date.accessioned","2018-11-07T09:30:48Z"],["dc.date.available","2018-11-07T09:30:48Z"],["dc.date.issued","2013"],["dc.description.abstract","The Varberg-Torpa charnockite-granite association (Varberg, SW Sweden) consists of the magmatic Varberg charnockite (1399 +/- 6 Ma) and the Torpa granite (1380 +/- 12 Ma). The Torpa granite is both continuous and, based on its whole-rock geochemistry, synmagmatic with the Varberg charnockite. The granite body also contains a number of charnockite inliers. P-T estimation using garnet-clinopyroxene and orthopyroxene-clinopyroxene Fe-Mg exchange thermometry and garnet-orthopyroxene-plagioclase-quartz barometry gives temperatures and pressures (750-850 degrees C; 800-850 MPa) that most probably approximate the P-T conditions during emplacement of the charnockite compared with a lower crystallization temperature (650-700 degrees C) for the granite. The earliest recognized fluid inclusions in both the granite and charnockite consist of H2O-CO2 mixtures (H2O volume fraction 0 center dot 2-0 center dot 7). Fluid inclusions in the charnockite are characterized by high CO2 densities (up to 1 center dot 0 g cm(-3); 40-90% bulk CO2), of probable magmatic origin, and are best preserved in garnet, plagioclase, and fluorapatite (in order of decreasing CO2 densities), and sometimes also in clinopyroxene. Fluid inclusions with the highest CO2 densities (1 center dot 08-1 center dot 10 g cm(-3)) are found in quartz (T-h -31 to -36 degrees C) and may have originated under high P-T conditions during emplacement and cooling of the charnockite. Magmatic fluids in the granite correspond to aqueous-carbonic inclusions with an estimated bulk composition (mol %) of H2O 73%, CO2 25%, NaCl 2%. The salinity of the solutes in the granite (typically 14-20 wt % NaCl-eq.) is generally higher than for the charnockite (0-8 wt % NaCl-eq.). Field, petrographic, mineralogical, geochemical, and fluid inclusion evidence indicates that, compared with the H2O-rich granite, the magma responsible for the charnockite had a preponderance of CO2 over H2O, which lowered the H2O activity in the melt, stabilizing ortho- and clinopyroxene. This evidence also supports the idea that the granite and charnockite were derived from a common source magma (most probably a fluid-rich basalt at the base of the crust) as a result of fractional crystallization."],["dc.identifier.doi","10.1093/petrology/egs060"],["dc.identifier.isi","000312883000002"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/31394"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Oxford Univ Press"],["dc.relation.issn","0022-3530"],["dc.title","The Varberg-Torpa Charnockite-Granite Association, SW Sweden: Mineralogy, Petrology, and Fluid Inclusion Chemistry"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]