Available on ORBi since
15 July 2008
Collective work published as editor or director (Books)
Ilmenite deposits and their geological environment (with special reference to the Rogaland Anorthosite province, including a geological map at scale 1:75,000)
Duchesne, Jean-Clair  ; Korneliussen, Are
2003 • NGU, Trondheim, Norway
 

Files


Full Text
Rogaland anorthosite guide-book.pdf
Publisher postprint (10.17 MB)

the book also includes a CD with the text of a geological guide to the province


All documents in ORBi are protected by a user license.

Send to



Details



Keywords :
magnetite; nelsonite; AMCG; Bjerkreim-Sokndal intrusion; jotunite; charnockite
Abstract :
[en] The Rogaland Anorthosite Province comprises three major massif-type anorthosites, two smaller-sized anorthositic-leuconoritic bodies, as well as a large layered, dominantly noritic intrusion. A mangero-noritic intrusion is found in the northeastern part of the province and major acidic intrusions are located to the far southeast. The Rogaland Anorthosite Province was emplaced into the Sveconorwegian orogenic belt of southwest Scandinavia at 931±3 Ma. Emplacement took place at around 5.5 kbar producing a thermal aureole with osumilite and pigeonite isograds and evidence for dehydration melting. The early history of the hosting terrane most likely dates back to Gothian or late Pre-Gothian times and contain evidence for numerous episodes of folding and deformation. Contact metamorphism was superimposed on a crustal volume, which had been exposed to Sveconorwegian granulite facies metamorphism between 1024 and 970 Ma. Deformation patterns, mineral compositional considerations and geothermobarometry imply that the Rogaland anorthosites crystallized along a P-T trajectory starting at 10-13 kbar, and were emplaced in a mushy state. The possibility that primitive jotunites may be parental to the andesine anorthosites have recently been substantiated, and experimental data show that these jotunites most likely formed by melting of gabbronoritic sources in the lower crust. The 230 km2 Bjerkreim-Sokndal Layered Intrusion also derive from jotunitic parents, and jotunites form a continuous liquid line of descent filling the gap between basic and acidic rocks in Rogaland. This intrusion contains a >7000 m thick layered cumulate sequence, consisting of virtually all the rock types belonging to the anorthosite kindred. The intrusion morphology, layering and compositional variation result from a variety of magma chamber processes, which are discussed in detail. The Rogaland Anorthosite Province also hosts numerous Fe-Ti oxide deposits of variable size, grade and composition. The oxide deposits have been divided into three basic types based on their oxide-phosphate association; type 1: ilmenite-only, type 2: ilmenite + magnetite and type 3: ilmenite + magnetite + apatite. This excursion guide provides detailed itineraries to most parts of the Rogaland Anorthosite Province, with in-depth descriptions of more than 40 key localities, The itineraries cover the various anorthosites, the Bjerkreim-Sokndal Layered Intrusion, jotunitic and acidic intrusions, the hosting metamorphic complex, as well as Fe-Ti oxide and sulfide deposits.
Disciplines :
Earth sciences & physical geography
Language :
English
Title :
Ilmenite deposits and their geological environment (with special reference to the Rogaland Anorthosite province, including a geological map at scale 1:75,000)
Publication date :
2003
Publisher :
NGU, Trondheim, Norway
Number of pages :
138
Collection name :
Norges geologiske undersokelse, Special publication n°9

Statistics


Number of views
269 (3 by ULiège)
Number of downloads
120 (0 by ULiège)

Bibliography


Similar publications



Contact ORBi