Forward modeling corona growth in a partially eclogitized leucogabbro, Bourbon Island, North-East Greenland
Abstract Coronitic textures are common in partially eclogitized igneous bodies, such as gabbros, leucogabbros, and anorthosites, east of the Germania Land Deformation Zone in North-East Greenland. Coronas formed by prograde metamorphic processes that transformed the gabbroic bodies to eclogite facie...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.1038.5136 2023-05-15T16:03:45+02:00 Forward modeling corona growth in a partially eclogitized leucogabbro, Bourbon Island, North-East Greenland C Sartini-Rideout J A Gilotti C T Foster Jr The Pennsylvania State University CiteSeerX Archives 2007 application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1038.5136 http://myweb.uiowa.edu/ctfoster/publications/Sartini_etalLithos%2095_279_295.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1038.5136 http://myweb.uiowa.edu/ctfoster/publications/Sartini_etalLithos%2095_279_295.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://myweb.uiowa.edu/ctfoster/publications/Sartini_etalLithos%2095_279_295.pdf text 2007 ftciteseerx 2020-03-08T01:19:07Z Abstract Coronitic textures are common in partially eclogitized igneous bodies, such as gabbros, leucogabbros, and anorthosites, east of the Germania Land Deformation Zone in North-East Greenland. Coronas formed by prograde metamorphic processes that transformed the gabbroic bodies to eclogite facies, and record frozen stages of the prograde metamorphic evolution of these rocks. A metaleucogabbro-norite body on Bourbon Island in Jøkelbugt is characterized by three concentric areas: a coronitic core, a mottled inner rim with areas of completely eclogitized material surrounded by a matrix of coronitic metaleucogabbro, and an outer rim of strongly foliated and completely retrogressed amphibolite. The Bourbon body preserves four stages of the prograde metamorphic history: Stage I, Stage II, Stage III, and Eclogite Stage. Stage I coronas are found only in the core of the body, which is the least reacted part of the leucogabbro-norite and the closest to the protolith, and is characterized by the corona sequence Pl rim / Grt + Kfs + Amp/Grt + Amp/Cpx rim . The typical corona sequence for Stage II is Pl rim /Grt + Pl + Zo/Cpx rim /Amp rim . Stage III samples show a Pl rim + Ky + Scp/Grt + Pl + Qtz/Qtz + Pl sequence, with the relict clinopyroxene being replaced in part by microcrystalline aggregates of Cpx + Amp + Pl. The Eclogite Stage shows relict Pl completely replaced by Grt, and the relict Cpx completely replaced by aggregates of Omp + Pl + Kfs + Amp. We tested open-system grain boundary diffusion (OSGBD) theories to model the prograde Stage I symplectitic coronas. The observed ratio of the thickness of the different layers is Pl rim :Grt + Kfs + Amp:Grt + Amp:Cpx rim equal to 3:1.3:0.95:0.5. These ratios are very close to the modeled ones of 2.7:1.1:1:0.5. Furthermore, subtle textural changes within the Grt + Kfs + Amp corona were also reproduced by the model. The model gave us insight into the conditions of the metamorphic system in which the coronas formed. The sequence Pl rim /Grt + Kfs + Amp/Grt + Amp/Cpx rim ... Text East Greenland Germania land Greenland Unknown Germania Land ENVELOPE(-20.042,-20.042,77.129,77.129) Greenland |
institution |
Open Polar |
collection |
Unknown |
op_collection_id |
ftciteseerx |
language |
English |
description |
Abstract Coronitic textures are common in partially eclogitized igneous bodies, such as gabbros, leucogabbros, and anorthosites, east of the Germania Land Deformation Zone in North-East Greenland. Coronas formed by prograde metamorphic processes that transformed the gabbroic bodies to eclogite facies, and record frozen stages of the prograde metamorphic evolution of these rocks. A metaleucogabbro-norite body on Bourbon Island in Jøkelbugt is characterized by three concentric areas: a coronitic core, a mottled inner rim with areas of completely eclogitized material surrounded by a matrix of coronitic metaleucogabbro, and an outer rim of strongly foliated and completely retrogressed amphibolite. The Bourbon body preserves four stages of the prograde metamorphic history: Stage I, Stage II, Stage III, and Eclogite Stage. Stage I coronas are found only in the core of the body, which is the least reacted part of the leucogabbro-norite and the closest to the protolith, and is characterized by the corona sequence Pl rim / Grt + Kfs + Amp/Grt + Amp/Cpx rim . The typical corona sequence for Stage II is Pl rim /Grt + Pl + Zo/Cpx rim /Amp rim . Stage III samples show a Pl rim + Ky + Scp/Grt + Pl + Qtz/Qtz + Pl sequence, with the relict clinopyroxene being replaced in part by microcrystalline aggregates of Cpx + Amp + Pl. The Eclogite Stage shows relict Pl completely replaced by Grt, and the relict Cpx completely replaced by aggregates of Omp + Pl + Kfs + Amp. We tested open-system grain boundary diffusion (OSGBD) theories to model the prograde Stage I symplectitic coronas. The observed ratio of the thickness of the different layers is Pl rim :Grt + Kfs + Amp:Grt + Amp:Cpx rim equal to 3:1.3:0.95:0.5. These ratios are very close to the modeled ones of 2.7:1.1:1:0.5. Furthermore, subtle textural changes within the Grt + Kfs + Amp corona were also reproduced by the model. The model gave us insight into the conditions of the metamorphic system in which the coronas formed. The sequence Pl rim /Grt + Kfs + Amp/Grt + Amp/Cpx rim ... |
author2 |
The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
C Sartini-Rideout J A Gilotti C T Foster Jr |
spellingShingle |
C Sartini-Rideout J A Gilotti C T Foster Jr Forward modeling corona growth in a partially eclogitized leucogabbro, Bourbon Island, North-East Greenland |
author_facet |
C Sartini-Rideout J A Gilotti C T Foster Jr |
author_sort |
C Sartini-Rideout |
title |
Forward modeling corona growth in a partially eclogitized leucogabbro, Bourbon Island, North-East Greenland |
title_short |
Forward modeling corona growth in a partially eclogitized leucogabbro, Bourbon Island, North-East Greenland |
title_full |
Forward modeling corona growth in a partially eclogitized leucogabbro, Bourbon Island, North-East Greenland |
title_fullStr |
Forward modeling corona growth in a partially eclogitized leucogabbro, Bourbon Island, North-East Greenland |
title_full_unstemmed |
Forward modeling corona growth in a partially eclogitized leucogabbro, Bourbon Island, North-East Greenland |
title_sort |
forward modeling corona growth in a partially eclogitized leucogabbro, bourbon island, north-east greenland |
publishDate |
2007 |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1038.5136 http://myweb.uiowa.edu/ctfoster/publications/Sartini_etalLithos%2095_279_295.pdf |
long_lat |
ENVELOPE(-20.042,-20.042,77.129,77.129) |
geographic |
Germania Land Greenland |
geographic_facet |
Germania Land Greenland |
genre |
East Greenland Germania land Greenland |
genre_facet |
East Greenland Germania land Greenland |
op_source |
http://myweb.uiowa.edu/ctfoster/publications/Sartini_etalLithos%2095_279_295.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1038.5136 http://myweb.uiowa.edu/ctfoster/publications/Sartini_etalLithos%2095_279_295.pdf |
op_rights |
Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
_version_ |
1766399440392814592 |