Change search
Refine search result
1 - 8 of 8
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • 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
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Allen, Rodney
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Montelius, Cecilia
    Schlatter, Denis
    Imana, Marcello
    Barrett, T.
    Svenson, Sven-Åke
    Boliden Mineral AB.
    Application of volcanology to understanding massive sulphide deposits in the 1.9 Ga Skell2004In: The 26th Nordic Geological Winter Meeting: abstract volume / [ed] Joakim Mansfeld, Uppsala: Geological Society of Sweden , 2004, p. 45-Conference paper (Refereed)
  • 2.
    Schlatter, Denis
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Volcanic stratigraphy and hydrothermal alteration of the Petiknäs south Zn-Pb-Cu-Au-Ag volcanic-hosted massive sulfide deposit, Sweden2007Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The Skellefte district is one of the most important mining regions in Sweden and Europe. The district contains more than 85 pyritic Zn-Cu-Au-Ag massive sulfide deposits. The discovery of new ores, which likely are located >200 m below surface is a challenge and requires improved exploration methods, which in turn require a better understanding of the geology and alteration patterns of known volcanic-hosted massive sulfide (VMS) deposits in the district. The Petiknäs South ore deposit lies in the eastern part of the Skellefte district. Between 1992 and 2006, 5.3 Mt of ore grading 4.9% Zn, 0.9% Cu, 0.9% Pb, 31% S, 2.4 g/t Au and 102 g/t Ag were mined in an underground operation by Boliden Mineral AB. The ores are pyritic massive sulfides, hosted within altered, deformed and metamorphosed volcanic rocks of the Paleoproterozoic Skellefte Group. The deposit contained several ore lenses at three stratigraphic levels. This study indicates that the Petiknäs South ore deposit occurs on the southern limb of a steeply plunging, tight, upright, F2-anticline. The mine stratigraphy dips subvertically and youngs consistently southwards. A major thrust fault truncates the down-dip portion of the deposit at the 700 m level. The rocks generally show one penetrative tectonic foliation and have been metamorphosed to greenschist facies. The following six mine-scale units occur from north to south (footwall to hanging-wall): diffusely stratified andesite breccias (Unit 1a), thick dacitic pumice breccia (Unit 1b) overlain by feldspar-porphyritic rhyolitic domes and sills with hyaloclastitic and peperitic contacts (top of Unit 1b and Unit 1d), the B-C ore lens enveloped by a thin screen of reworked rhyolitic volcaniclastic rocks (Unit 2), thick andesitic and basaltic andesitic pumiceous mass-flow deposits (Unit 3), volcanic sandstones and siltstones containing large quartz-phyric pumice clasts, and strongly altered volcanic rocks enveloping the D-, and A-ore lenses (Unit 4), and finally the hanging-wall complex comprising feldspar-quartz porphyritic rhyolite sills (Unit 5). The andesite breccias, dacite pumice breccia and high-Ti rhyolites (Units 1a and 1b) represent an andesite-dacite-rhyolite shield volcano whereas the feldspar-porphyritic rhyolite (Unit 1d) corresponds to a cryptodome-sill-tuff volcano with peperitic margins. The rhyolitic sandstones (Unit 2) were emplaced via turbidity currents under subaqueous conditions below wave base and the main B-C ore lens formed at the sea-floor within this facies. The intermediate mass-flow breccias (Unit 3) were rapidly emplaced in subaqueous conditions following a pyroclastic eruption and the host unit of the D-, and A-ore lenses (Unit 4) was deposited by turbidity currents below wave base. The hanging-wall fault causes repetition of Units 3 and 4. The rhyolitic sills of the hanging-wall complex (Unit 5) were intruded into wet volcaniclastic sediments. Post-ore and post-alteration andesite and felsic sills and mafic dykes (Unit 6) intruded most of the mine sequence. Lithogeochemical studies show that the thick andesite and dacite breccias, and rhyolites of the lower footwall (Units 1a, 1b) belong to a high-TiO2 fractionation trend, whereas rocks of the upper footwall (Unit 1d), the host unit to the B-C ore lenses (Unit 2) and most of the felsic rocks higher in the stratigraphy belong to a low-TiO2 trend. This change from a high-TiO2 to a low TiO2 series corresponds closely to the change from an early andesite-dacite-rhyolite shield volcano to a later rhyolitic cryptodome-sill-tuff volcano. The B-C ore horizon is considered the most favorable stratigraphic horizon for mineral exploration and lies between calc-alkaline to transitional, felsic volcanic rocks (Unit 2) and tholeiitic, basaltic-andesitic and andesitic juvenile mass-flow deposits (Unit 3) that were derived from a different and relatively distal volcanic center. This ore horizon can be traced along strike for several hundred meters and its position has also been located on the northern limb of the regional anticline, 700 m north of Petiknäs South. Furthermore, the Petiknäs South ore horizon can be correlated with the ore horizon of the Renström mine which is located 2 km to the east. These extensions of the Petiknäs South ore horizon provide potential drill targets for new VMS ore lenses. Application of immobile-element lithogeochemical methods has allowed definition of a series of chemostratigraphic units, which can be correlated throughout and beyond the mine, even where the rocks are strongly altered. At the Kristineberg and Rävliden mines in the western part of the Skellefte district it has been shown that lithogeochemical techniques can also be applied to intensely altered rocks that have been metamorphosed to amphibolite facies. The chemostratigraphic correlations at Petiknäs South support and verify the volcanic-stratigraphic correlations based on lithology and facies. The results show that the ore lenses occur at different stratigraphic positions within clastic stratigraphic intervals of dominantly rhyolitic composition. Six alteration types have been distinguished based on mineral assemblage. Intense chlorite-sericite-quartz-garnet±feldspar alteration is found immediately below the ore lenses and locally in the distal footwall and represents the strongest alteration. These zones are interpreted to represent the upflow zones of hot hydrothermal fluids. Haloes of sericite alteration occur around the ore lenses and are wider than the zones of chlorite-sericite-garnet. Mass change calculations show that alteration zones below the ore lenses are characterized by large mass gains of FeO, MnO, MgO and K2O together with large mass gains or losses in silica. The latter alteration zones are about three times larger than the actual ore lenses, and consequently could provide a good exploration guide to ore. Other alteration zones with Na2O and CaO depletions occur on a semi-regional scale, but are most intense close to the ores. Surprisingly, the proximal part of the footwall complex, which is dominated by syn-volcanic felsic intrusions, is only weakly altered, which suggests that these intrusions were emplaced slightly after formation of the massive sulfide lenses at the waning stage of hydrothermal alteration. The Manus basin in Papua New Guinea is a back-arc basin where VMS ores are presently forming and represents a good modern analogue to the Petiknäs South ores. The rocks from the Manus basin are basalt, basaltic-andesite, andesite and rhyodacite, similar to rocks from the Petiknäs South mine sequence, and the ores are located just above a felsic proximal facies association. The results of this study can be used to help identify (1) felsic proximal facies associations, (2) ore horizons and (3) favorable hydrothermal alteration zones, in other parts of the Skellefte district and elsewhere.

  • 3. Schlatter, Denis
    Volcanic stratigraphy, chemical stratigraphy, and hydrothermal alteration of the Petiknäs South Volcanic-hosted massive sulfide deposit, Sweden2005Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    The main exploration methods which have been used in the Skellefte district are prospecting for ore boulders in young glacial deposits and electrical geophysical methods. The discovery of new ores which likely are located at deep levels (>200 m), requires improved exploration methods, which in turn require a better understanding of the geology and alteration patterns of the known VMS deposits. This thesis seeks to improve the understanding of the geology and alteration patterns of VMS deposits in the Skellefte district by providing new data and new interpretation of the geology and alteration system of the Petiknäs South VMS deposit. The Skellefte district is an important ore province, containing more than 80 pyritic Zn-Cu-Au-Ag massive sulfide deposits within volcanic rocks of the Paleoproterozoic Skellefte Group. The Petiknäs South volcanic-hosted massive sulfide deposit is a producing underground mine in the eastern part of the Paleoproterozoic Skellefte district. The deposit consists of several ore lenses (A, B, C and D) and prior to mining contained 6 Mt of ore grading 5 % Zn, 1 % Cu, 1 % Pb, 2.5 g/t Au and 105 g/t Ag. The deposit occurs on the southern limb of a tight, steeply plunging, upright, anticline. The mine stratigraphy dips subvertically and youngs consistently southwards. A major thrust fault truncates the downdip portion of the deposit at the 700 m level of the mine. The volcanic rocks of the mine sequence generally have one penetrative tectonic foliation and have been metamorphosed to greenschist facies, although garnet-biotite bearing rocks are present locally. Application of immobile-element lithogeochemical methods to 469 samples has allowed classification of the mine sequence into a series of chemostratigraphic units, while the degree of hydrothermal alteration of these units has been quantified using mass change methods. From oldest to youngest, the main units are: The footwall complex (Unit 1) consists of rhyolite B and minor rhyolite C, B/C, and dacite feldspar-porphyritic rhyolitic cryptodomes, sills and volcaniclastic rocks, and is overlain by rhyolitic sandstone-siltstone beds, an up to 20 m thick unit hosting the B/C ore lens (Unit 2). The B/C ore lenses formed a single lens prior to intrusion of the late andesite sills. Unit 2 is overlain by unmineralized basaltic andesite volcaniclastic rocks (Unit 3). Above this, Unit 4 is host to the D and A ore lenses. This unit comprises mainly rhyolitic volcaniclastics with several thin andesitic intercalations. A WNW-ESE trending fault separates Unit 4 from Unit 5, which comprises feldspar-quartz porphyritic rhyolite sills and sandstone- siltstone volcaniclastic rocks. The lower part of Unit 5 is a mass flow deposit of distinctive low-Ti mafic composition that can be traced for 700 m eastwards from the proximal part of the mine. Unit 6 comprises the post- ore andesite sills and mafic dykes. A portion of the chemostratigraphic sequence (Units 1 and 2) has also been recognized on the northern limb of the Petiknäs South anticline. In summary, 6 chemostratigraphic units can be identified at the Petiknäs South mine and these can be correlated throughout and beyond the mine, even where they are strongly altered. Two good chemostratigraphic marker horizons were identified: one is of basaltic andesite and andesite composition (unit 3) and one is of low-Ti mafic composition (unit 5a) and both markers can be correlated on the mine-scale and semi-regional scale. The chemostratigraphic results show that ore lenses (B/C, D and A) occur at different stratigraphic positions within clastic stratigraphic intervals of dominantly rhyolitic composition. The most favorable exploration horizon (the B/C ore horizon) is located at the contact between a felsic clastic and a basaltic-andesitic clastic unit. Based on identification of magmatic affinity, chemostratigraphy revealed that the volcanic succession at Petiknäs South comprises calc-alkaline to transitional footwall rocks representing a proximal facies association and this succession is overlain by tholeiitc juvenile volcaniclastic rocks which were derived from a different and relatively distal volcanic center. In terms of ore location chemostratigraphy revealed that the main ore body at Petiknäs South is located at the contact between rhyolitic calc-alkaline to transitional and basaltic-andesitic tholeiitic rocks. This ore horizon can be traced along strike for several hundred meters and its position has also been located on the northern limb of the regional anticline, 700 m north of Petiknäs South. These extensions of the Petiknäs South ore horizon are potential drill targets for new VMS ore lenses. The main alteration minerals are sericite, quartz, chlorite, garnet, and locally carbonate. Intense chlorite-garnet alteration occurs immediately below the A and D ore lenses, and in the distal footwall of the B and C ore lenses. These zones are interpreted as hydrothermal upflow or feeder zones. Haloes of serizitization occur around the ore lenses and are wider than the zones of chlorite-garnet alteration. Carbonatization occurs in narrow zones throughout the mine sequence. Sericitic alteration in felsic footwall rocks that show only small mass changes in K and Si is explained by hydration at low water/rock ratios. By contrast sericitic altered felsic rocks immediately below the B/C ore lens show large gains in K and Si and are attributed to alteration by hot fluids. Restoration of the Petiknäs South stratigraphy and alteration system prior to deformation indicates that the Petiknäs South deposit originally contained three stacked ore lenses: from oldest to youngest, the B/C, D and A lenses. The B/C and the A ore lens were formed at the seafloor above a zone of hydrothermal upflow and the D ore lens is interpreted to have formed in the footwall of the A ore lens via replacement. Alteration zones below the B/C and the A ore lens and around the D ore lens are characterized by large mass gains of FeO, MnO, MgO and K2O together with large mass gains or losses in silica. The latter alteration zones are around three times larger than the actual ore lenses, and consequently could provide a good exploration guide to ore. Other alteration zones with Na2O and CaO depletions occur on a semi-regional scale, but are most intense close to the ores. The proximal part of the footwall complex, which is dominated by synvolcanic felsic intrusions, is only weakly altered, which suggests that the intrusions were emplaced slightly after formation of the massive sulfide lenses. The results of this study can be used to help identify ore horizon and favorable alteration zones in other parts of the Skellefte district and elsewhere.

  • 4. Schlatter, Denis
    et al.
    Allen, Rodney
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Barrett, Tim
    Volcanic setting of the 1.89 Ga Petiknäs South massive sulfide deposit, Skellefte district, Sweden2006In: Understanding the genesis of ore deposits to meet the demands of the 21st century: 12th Quadrennial IAGOD Symposium, Taylor and Francis Group , 2006Conference paper (Other academic)
    Abstract [en]

    Petiknäs South is a producing underground mine in the eastern part of the Skellefte district. The massive sulfide deposit, which consists of several stacked ore lenses, is hosted by altered, deformed and metamorphosed volcanic rocks belonging to the Paleoproterozoic Skellefte Group. The mine sequence ranges in composition from rhyolite to basaltic andesite and includes abundant volcaniclastic and lesser coherent rocks. This sequence is interpreted to have been deposited in a deep marine environment. The volcaniclastic rocks include rhyolite hyaloclastites, subaqueous mass flow units of juvenile felsic pyroclastic debris and mass flow units of mafic fire fountain debris. The main ore lens is located at the contact of felsic and basaltic andesitic volcaniclastic rocks. This "ore horizon" can be traced laterally through the mine area and is a major exploration guide to ore. A synvolcanic felsic sill, comagmatic with some of the felsic footwall volcaniclastic rocks, was emplaced in the proximal footwall slightly after formation of the massive sulfide lenses. The mine sequence was then intruded by andesite and rhyolite sills and mafic dykes after ore formation and alteration. The ores are interpreted to have formed at or slightly below the sea floor, above the proximal part of the footwall rhyolite volcano. The ore-host rhyolite volcano overlies a shallow marine andesite-dacite shield volcano, and the proximal facies of the rhyolite volcano interfingers with medial facies of an adjacent andesite volcano.

  • 5. Schlatter, Denis
    et al.
    Allen, Rodney
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Jonsson, Rolf
    Barrett, T.
    Volcanic and chemical stratigraphy of the Petiknäs South Zn-Cu-Au-Ag-Pb VMS deposit, Skellefte district, Sweden2004In: The 26th Nordic Geological Winter Meeting: abstract volume / [ed] Joakim Mansfeld, Uppsala: Geological Society of Sweden , 2004, p. 151-Conference paper (Refereed)
  • 6. Schlatter, Denis
    et al.
    Allen, Rodney
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Jonsson, Rolf
    Boliden Mineral AB.
    Barrett, T. J.
    Stratigraphy of the Petiknäs South volcanic-hosted massive sulphide deposit, Skellefte district, Sweden2004Conference paper (Refereed)
    Abstract [en]

    The Petiknäs South VMS deposit in the eastern part of the early Proterozoic Skellefte mining district contained 6 Mt of Zn-Cu-Pb-Au-Ag ore prior to mining. The deposit occurs on the southern limb of a major anticline, dips subvertically, and youngs southwards. The main alteration minerals are sericite, chlorite, quartz, carbonate, talc and carbonate. Two cross sections and one plan section have been constructed on the basis of detailed logging of 35 drill cores, 400 whole-rock analyses and 100 thin sections. Chemostratigraphic units were identified using lithogeochemical techniques. Excluding post-ore andesite sills, the north to south sequence is: feldspar-porphyritic rhyolitic sill; C and B ore lenses hosted by rhyolitic tuffaceous sandstone; andesitic pumiceous mass flows; felsic and intermediate tuffaceous sandstones and siltstones hosting the D and A ore lenses; and a fault followed by rhyodacitic feldspar-quartz porphyry. Prior to andesite sill injection, the C and B ores formed a single massive sulphide lens within a thin interval of rhyolitic volcaniclastic rocks. The D and A ores formed at a stratigraphically higher level, in an interval of alternating rhyolitic and andesitic gravity flow deposits. Weakly altered feldspar-porphyritic rhyolite sills with peperitic margins were then intruded into the felsic volcaniclastic rocks directly below the C+B ore lens. In summary, the two main horizons of ore formation at Petiknäs South are associated with felsic volcaniclastic intervals; coherent felsic rocks occur only as slightly post-ore intrusions. Similar volcanic successions have been recognized elsewhere in the Skellefte district, e.g. at the Renström mine 3 kilometers to the east.

  • 7. Schlatter, Denis
    et al.
    Barrett, T.J.
    Abrahamsson, S
    Chemostratigraphy of metamorphosed and altered Paleoproterozoic volcanic rocks associated with massive sulfide deposits at Rävliden and Kristineberg West, Skellefte district, Sweden2003In: Mineral exploration and sustainable development: proceedings of the Seventh Biennial SGA Meeting, Athens, Greece, 24-28 August 2003 / [ed] D.G. Eliopoulos, Rotterdam: Millpress , 2003, p. 1103-1106Conference paper (Other academic)
    Abstract [en]

    The Rävliden and Kristineberg massive sulfide deposits in northern Sweden are hosted by Paleoproterozoic volcanic rocks of the Skellefte group. At Kristineberg West, exploration drilling on the 1000 m level, 1 km west of the operating mine, has encountered various types of sulfide mineralization hosted by volcanic rocks. At Rävliden, a further 2.5 km to the west, massive sulfides occur near the top of the volcanic sequence, which is overlain by graphitic sedimentary rocks of the Vargfors group. In both areas, the original rock types generally cannot be identified visually, as the rocks are altered and metamorphosed to schistose assemblages including muscovite, chlorite, phlogopite, talc, quartz, cordierite, and andalusite. However, application of immobile-element methods to 165 new whole-rock analyses, together with relogging and petrographic observations, has allowed 6 main chemical rock types to be identified. These have been used to establish the chemostratigraphic sequence in each area. Mineralization is hosted mainly by rhyolites, of which there are at least three subtypes; intervals of dacite and andesite are also present. The sedimentary rocks that overlie the Rävliden ores have a distinctive composition that has not been found in the area of the Kristineberg West ores, which supports the idea that the latter ores lie lower in the Skellefte group than the Rävliden ores.

  • 8. Schlatter, Denis
    et al.
    Barrett, T.J.
    Allen, Rodney
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Mass changes in alteration zones of the Petiknäs South volcanic-hosted massive sulfide deposit, Skellefte district, Sweden2006In: The 27th Nordic Geological Winter Meeting, January 9-12, 2006, Oulu, Finland: abstract volume / [ed] Petri Peltonen ; Antti Pasanen, Helsinki: Geological Society of Finland , 2006, p. 142-Conference paper (Other academic)
    Abstract [en]

    Petiknäs South is a producing underground mine in the eastern part of the Skellefte district and contained 6 Mt of pyritic massive sulfide ore grading 5 % Zn, 1 % Cu, 1 % Pb, 2.5 g/t Au and 105 g/t Ag prior to mining. The deposit is hosted within volcanic rocks of the Paleoproterozoic Skellefte Group and consists of several stacked ore lenses (from oldest to youngest: C, B, D and A). The mine sequence comprises coherent and volcaniclastic units of rhyolitic to basaltic andesitic composition, and post-ore andesite sills and mafic dykes. The mine stratigraphy dips subvertically and youngs consistently southwards and the volcanic rocks have been metamorphosed to greenschist facies. Application of immobile-element lithogeochemical methods to 469 samples has allowed classification of the mine sequence into a series of chemostratigraphic units, while the degree of hydrothermal alteration of these units has been quantified using mass change methods. The main alteration minerals are sericite, chlorite, garnet, quartz and locally carbonate. Intense chlorite-garnet alteration occurs immediately below the A and D ore lenses, and in the distal footwall of the C and B ore lenses. A synvolcanic felsic sill was emplaced in the proximal footwall slightly after formation of the massive sulfide lenses. Consequently, a major part of the proximal footwall is only weakly altered and zones of strong alteration are truncated by the sill. The alteration zones are interpreted as hydrothermal upflow or feeder zones. Haloes of serizitization occur around the ore lenses and are wider than the zones of chlorite-garnet alteration and alteration zones with Na2O and CaO depletions occur on a semi-regional scale, but are most intense close to the ores. Alteration zones below and around the ore lenses are characterized by large mass gains of FeO, MnO, MgO and K2O together with large mass gains or losses in silica. The latter alteration zones are approximately three times larger than the actual ore lenses, and consequently could provide a good exploration guide to ore.

1 - 8 of 8
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • 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