Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Geology and mineralization of the Bellviksberg sandstone-hosted Pb(-Zn) deposit, Dorotea area, Sweden
2008 (English)Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
Abstract [en]

The Bellviksberg deposit in the Dorotea area is part of the sandstone-hosted lead-zinc deposits occurring all along the eastern front of the Scandinavian Caledonides in Precambrian to Lower Cambrian sandstone deposited uncomformably on the deeply eroded Precambrian basement (Laisvall, Vassbo, etc). The Bellviksberg deposit occurs in the Ström Quartzitic Nappe that shows décollement structure and thrusting directly over the Alum Shales formation of the Autochthon. The goal of this thesis is to give a reinterpretation of the Bellviksberg deposit on a geological and genetic point of view. It also aims to give guidelines for the exploration of the Bellviksberg deposit and the Dorotea area in general. Thus, most of the cores of the deposit have been logged. Thin and polished-sections were made to help the interpretation work. Within this nappe two lithologies have been identified which names are introduced here: the Varangerian Tillite and the Lower Cambrian Sandstone. The Varangerian Tillite is characterised by an overall greenish colour due to clay minerals coating quartz grains. It is composed of interbedded quartzitic sandstones and conglomerates with well-rounded quartz grains. Other minerals such as feldspar, epidotes and muscovite constitute only 1-2% of the mineralogical assemblage. This formation is interpreted as being of glacio-fluvial origin from a reworked sediment. The Lower Cambrian Sandstone overlaying the Varangerian Tillite hosts the mineralization. It is composed of interbedded fine and coarse grained quartzitic sandstone. The coarser grained units are poorly sorted, less compacted than the fine grained units and contain preferably organic matter with associated pyrite. Graphite- rich sandstone and siltstone members can be present within the Lower Cambrian Sandstone Formation. This formation is interpreted as being from deltaic origin dominated by fluvial action. The nappe hosting the Bellviksberg mineralization is composed of many thrust sheet stacked on each other with inverse faults striking -20°N to 0°N and small scale folds. A preliminary resource estimation results in 1.66 Mt of 5.35% Pb, 0.23% Zn and 21g/t Ag. The main part of the mineralization, galena-dominated, occurs in the less tectonically disturbed part of the Bellviksberg area and mostly in the coarser grained units that are usually richer in organic matter and less compacted. The host-rock is then thought to have been the main source of sulphurs that fixed metals carried by basinal brines transported during the Scandian Event of the Caledonian orogeny. Redox or pH controls for the precipitation of metals are suggested although a redox control is slightly favoured.

Place, publisher, year, edition, pages
2008.
Keyword [en]
Life Earth Science, Sandstone-hosted deposit, Dorotea area, Caledonian front, lead-zinc deposit, mineralization, lower Cambrian, sandstone, Varangerian Tillite
Keyword [sv]
Bio- och geovetenskaper
Identifiers
URN: urn:nbn:se:ltu:diva-43207ISRN: LTU-PB-EX--08/054--SELocal ID: 116a516c-3bc8-4fcf-a454-6cc014cb9a57OAI: oai:DiVA.org:ltu-43207DiVA: diva2:1016436
Subject / course
Student thesis, at least 30 credits
Educational program
Geosciences, master's level
Examiners
Note
Validerat; 20101217 (root)Available from: 2016-10-04 Created: 2016-10-04Bibliographically approved

Open Access in DiVA

fulltext(31330 kB)71 downloads
File information
File name FULLTEXT01.pdfFile size 31330 kBChecksum SHA-512
e9af8bef8ed68c2ae8accf829f75267c761289206a8919b8a4295687b1bf2c05f2e97a598b542a6e5d3574356a11db7cf5fdc3815188ce5d39d45a13cfb34142
Type fulltextMimetype application/pdf

Search outside of DiVA

GoogleGoogle Scholar
Total: 71 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

urn-nbn

Altmetric score

urn-nbn
Total: 46 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf