Immiscible iron- and silica-rich melts in basalt petrogenesis documented in the Skaergaard intrusion

Abstract

Research Article| November 01, 2005 Immiscible iron- and silica-rich melts in basalt petrogenesis documented in the Skaergaard intrusion J.K. Jakobsen; J.K. Jakobsen 1Department of Earth Sciences, University of Aarhus, C.F. Møllers Allé 110, DK-8000 Aarhus C, Denmark Search for other works by this author on: GSW Google Scholar I.V. Veksler; I.V. Veksler 2GeoForschungsZentrum Potsdam, Telegrafenberg B-120, D-14473 Potsdam, Germany Search for other works by this author on: GSW Google Scholar C. Tegner; C. Tegner 3Department of Earth Sciences, University of Aarhus, C.F. Møllers Allé 110, DK-8000 Aarhus C, Denmark Search for other works by this author on: GSW Google Scholar C.K. Brooks C.K. Brooks 4Geological Institute, University of Copenhagen, Øster Voldgade 10, DK-1350 Copenhagen K, Denmark Search for other works by this author on: GSW Google Scholar Author and Article Information J.K. Jakobsen 1Department of Earth Sciences, University of Aarhus, C.F. Møllers Allé 110, DK-8000 Aarhus C, Denmark I.V. Veksler 2GeoForschungsZentrum Potsdam, Telegrafenberg B-120, D-14473 Potsdam, Germany C. Tegner 3Department of Earth Sciences, University of Aarhus, C.F. Møllers Allé 110, DK-8000 Aarhus C, Denmark C.K. Brooks 4Geological Institute, University of Copenhagen, Øster Voldgade 10, DK-1350 Copenhagen K, Denmark Publisher: Geological Society of America Received: 17 Mar 2005 Revision Received: 06 Jul 2005 Accepted: 11 Jul 2005 First Online: 02 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (2005) 33 (11): 885–888. https://doi.org/10.1130/G21724.1 Article history Received: 17 Mar 2005 Revision Received: 06 Jul 2005 Accepted: 11 Jul 2005 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Tools Icon Tools Get Permissions Search Site Citation J.K. Jakobsen, I.V. Veksler, C. Tegner, C.K. Brooks; Immiscible iron- and silica-rich melts in basalt petrogenesis documented in the Skaergaard intrusion. Geology 2005;; 33 (11): 885–888. doi: https://doi.org/10.1130/G21724.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Silicate liquid immiscibility in basalt petrogenesis is a contentious issue. Immiscible iron- and silica-rich liquids were reported in melt inclusions of lunar basalt and in groundmass glasses of terrestrial volcanics. In fully crystallized plutonic rocks, however, silicate liquid immiscibility has yet to be proven. Here we report the first finding of natural, immiscible iron- and silica-rich melts in a plutonic environment documented in the Skaergaard intrusion, East Greenland. Primary melt inclusions (now finely crystallized) in apatite are either dark or light colored. The predominant dark colored type contains 30.9 ± 4.2 wt% FeOt and 40.7 ± 3.6 wt% SiO2, whereas the light colored type contains 8.6 ± 5.9 wt% FeOt and 65.6 ± 7.3 wt% SiO2. Similar light colored melt inclusions in olivine and fine-grained dark and light colored interstitial pockets also give evidence of crystallization from emulsion of silica and iron-rich liquids. On the outcrop scale, silica-rich (melanogranophyre) pods and layers in iron-rich ferrodiorite of the Upper Zone of the Skaergaard intrusion witness segregation of the two liquids. These findings demand that silicate immiscibility is considered in basalt petrogenesis. Some granitic rocks may represent unmixed silica-rich melt, whereas the dense, iron-rich melt is likely to sink in the crust and could mix with hot mantle-derived magma to form unusual rocks, like ferropicrites, otherwise interpreted as products of heterogeneous mantle sources. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.