SwePub
Sök i LIBRIS databas

  Extended search

onr:"swepub:oai:DiVA.org:ltu-2637"
 

Search: onr:"swepub:oai:DiVA.org:ltu-2637" > Setting of Zn-Cu-Au...

  • 1 of 1
  • Previous record
  • Next record
  •    To hitlist
  • Allen, RodneyVolcanic Resources Ltd, Stavanger (author)

Setting of Zn-Cu-Au-Ag massive sulfide deposits in the evolution and facies architecture of a 1.9 Ga marine volcanic arc : Skellefte district, Sweden

  • Article/chapterEnglish1996

Publisher, publication year, extent ...

  • 1996-10-01
  • Society of Economic Geologists,1996
  • electronicrdacarrier

Numbers

  • LIBRIS-ID:oai:DiVA.org:ltu-2637
  • https://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-2637URI
  • https://doi.org/10.2113/gsecongeo.91.6.1022DOI
  • https://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-327735URI

Supplementary language notes

  • Language:English
  • Summary in:English

Part of subdatabase

Classification

  • Subject category:ref swepub-contenttype
  • Subject category:art swepub-publicationtype

Notes

  • Upprättat; 1996; 20070427 (bajo)
  • Skellefte mining district occurs in an Early Proterozoic, mainly 1.90-1.87 Ga (Svecofennian) magmatic province of low to medium metamorphic grade in the Baltic Shield in northern Sweden. The district contains over 85 pyritic Zn-Cu-Au-Ag massive sulfide deposits and a few vein Au deposits and subeconomic porphyry Cu-Au-Mo deposits, The massive sulfide deposits mainly occur within, and especially along the top of: a regional felsic-dominant volcanic unit attributed to a stage of intense, extensional, continental margin are volcanism. From facies analysis we interpret the paleogeography of this stage to have comprised many scattered islands and shallow-water areas. surrounded by deeper seas. All the major massive sulfide ores occur in below-wave base facies associations: however, some ores occur close to stratigraphic intervals of above-wave base facies associations, and the summits of some volcanoes that host massive sulfides emerged above sea level. Intense marine volcanism was superceded at different times in different parts of tile district by a stage of reduced volcanism, uplift resulting in subregional disconformities, and then differential uplift and subsidence resulting in a complex horst and graben paleogeography. Uplift of the are is attributed to the relaxation of crustal extension and the emplacement of granitoids to shallow crustal levels. A few massive sulfide ores formed within the basal strata of this second stage. The horst and graben system was filled by prograding fluvial-deltaic sediments and mainly mafic lavas, and during this stage the Skellefte district was a transitional area between renewed are volcanism of more continental character to the north, and subsidence and basinal mudstone-turbidite sedimentation to the south. This whole volcanotectonic cycle occurred within 10 to 15 m.y. We define 26 main volcanic, sedimentary, and intrusive facies in the Skellefte district. The most abundant facies are (1) normal-graded pumiceous breccias, which are interpreted as syneruptive subaqueous mass flow units of pyroclastic debris, (2) porphyritic intrusions, and (3) mudstone and sandstone turbidites. Facies associations define seven main volcano types, which range from basaltic shields to andesite cones and rhyolite calderas. Despite this diversity of volcano types, most massive sulfide ol es are associated with one volcano type: subaqueous rhyolite cryptodome-tuff volcanoes. These rhyolite volcanoes are 2 to 10 km in diameter, 250 to 1,200 m thick at the center, and are characterized by a small to moderate volume rhyolitic pyroclastic unit, intruded by rhyolite cryptodomes, sills, and dikes. Massive sulfide ores occur near the top of the proximal (near vent) facies association The remarkable coincidence in space and time between the ores and this volcano type indicates an intimate, genetic relationship between the ores and the magmatic evolution of the volcanoes.Many of the massive sulfide ores occur within rapidly emplaced volcaniclastic facies and are interpreted to have formed by infiltration and replacement of these facies. Some of the ore deposits have characteristics of both marine massive sulfides and subaerial epithelial deposits. We suggest that massive sulfides in the Skellefte district span a range in ore deposit style from deep-water sea floor ores, to subsea-floor replacements, to shallow-water and possible subaerial synvolcanic replacements. Facies models are provided for the mineralized rhyolite volcanoes and volcanological guides are provided for exploration for blind ores within these volcanoes.

Subject headings and genre

Added entries (persons, corporate bodies, meetings, titles ...)

  • Weihed, PärGeological Survey of Sweden(Swepub:uu)parwe420 (author)
  • Svensson, S. Å.Boliden AB (author)
  • Volcanic Resources Ltd, StavangerGeological Survey of Sweden (creator_code:org_t)

Related titles

  • In:Economic geology and the bulletin of the Society of Economic Geologists: Society of Economic Geologists91:6, s. 1022-10530361-01281554-0774

Internet link

Find in a library

To the university's database

  • 1 of 1
  • Previous record
  • Next record
  •    To hitlist

Find more in SwePub

By the author/editor
Allen, Rodney
Weihed, Pär
Svensson, S. Å.
About the subject
NATURAL SCIENCES
NATURAL SCIENCES
and Earth and Relate ...
and Geology
Articles in the publication
Economic geology ...
By the university
Luleå University of Technology
Uppsala University

Search outside SwePub

Wikipedia about the author:
Rodney_Allen
Allen, Rodney
en

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Close

Copy and save the link in order to return to this view