scholarly journals Epithermal gold and massive sulphide mineralisation in oil impregnated Palaeogene volcanic rocks of Ubekendt Ejland,West Greenland

2004 ◽  
Vol 4 ◽  
pp. 77-80 ◽  
Author(s):  
Stefan Bernstein ◽  
Christian Knudsen
Keyword(s):  
East Coast ◽  
Volcanic Rocks ◽  
Field Work ◽  
Hydrothermal Activity ◽  
Massive Sulphide ◽  
Sulphide Mineral ◽  
The South ◽  
West Greenland ◽  
Sulphide Mineralisation ◽  
Volcaniclastic Rocks

The discovery in 2002 of a gold mineralised quartz-carbonate vein at Ubekendt Ejland, central West Greenland, yielding 0.6 ppm Au over 0.7 m, led to a reconnaissance sampling project in summer 2003. Most of the accessible quartz-carbonate veins on the south-east coast of the island (Figs 1, 2) were sampled during boat-supported field work. Massive sulphide mineral deposits (Fe-Zn-Pb) were located in the centre of brecciated quartz-carbonate vein systems at several places along the south and south-east coast of the island, and gold anomalies mainly associated with the occurrence of the massive sulphides were identified. Pervasive hydrothermal alteration of the volcanic wall rocks surrounds the quartz-carbonate vein systems, which comprise low-temperature mineral assemblages dominated by dolomite and veined by chalcedony and fibrous silica. Evidence of oil migration into volcaniclastic rocks prior to the intense hydrothermal activity was found in several places in the form of organic carbon, interpreted to be pyrobitumen, that infills pores and cavities in hyaloclastites.

Mafic igneous rocks and mineralisation in the Palaeoproterozoic Ketilidian orogen, South-East Greenland: project SUPRASYD 1996

1997 ◽  
pp. 66-74
Author(s):  
Henrik Stendal ◽  
Wulf Mueller ◽  
Nicolai Birkedal ◽  
Esben I. Hansen ◽  
Claus Østergaard
Keyword(s):  
Mineral Exploration ◽  
Volcanic Rocks ◽  
Shear Zones ◽  
Field Work ◽  
Igneous Rocks ◽  
Border Zone ◽  
The South ◽  
East Greenland ◽  
North West ◽  
Arc Setting

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Stendal, H., Mueller, W., Birkedal, N., Hansen, E. I., & Østergaard, C. (1997). Mafic igneous rocks and mineralisation in the Palaeoproterozoic Ketilidian orogen, South-East Greenland: project SUPRASYD 1996. Geology of Greenland Survey Bulletin, 176, 66-74. https://doi.org/10.34194/ggub.v176.5064 _______________ The multidisciplinary SUPRASYD project (1992–96) focused on a regional investigation of the Palaeoproterozoic Ketilidian orogenic belt which crosses the southern tip of Greenland. Apart from a broad range of geological and structural studies (Nielsen et al., 1993; Garde & Schønwandt, 1994, 1995; Garde et al., 1997), the project included a mineral resource evaluation of the supracrustal sequences associated with the Ketilidian orogen (e.g. Mosher, 1995). The Ketilidian orogen of southern Greenland can be divided from north-west to south-east into: (1) a border zone in which the crystalline rocks of the Archaean craton are unconformably overlain by Ketilidian supracrustal rocks; (2) a major polyphase pluton, referred to as the Julianehåb batholith; and (3) extensive areas of Ketilidian supracrustal rocks, divided into psammitic and pelitic rocks with subordinate interstratified mafic volcanic rocks (Fig. 1). The Julianehåb batholith is viewed as emplaced in a magmatic arc setting; the supracrustal sequences south of the batholith have been interpreted as either (1) deposited in an intra-arc and fore-arc basin (Chadwick & Garde, 1996), or (2) deposited in a back-arc or intra-arc setting (Stendal & Swager, 1995; Swager, 1995). Both possibilities are plausible and infer subduction-related processes. Regional compilations of geological, geochemical and geophysical data for southern Greenland have been presented by Thorning et al. (1994). Mosher (1995) has recently reviewed the mineral exploration potential of the region. The commercial company Nunaoil A/S has been engaged in gold prospecting in South Greenland since 1990 (e.g. Gowen et al., 1993). A principal goal of the SUPRASYD project was to test the mineral potential of the Ketilidian supracrustal sequences and define the gold potential in the shear zones in the Julianehåb batholith. Previous work has substantiated a gold potential in amphibolitic rocks in the south-west coastal areas (Gowen et al., 1993.), and in the amphibolitic rocks of the Kutseq area (Swager et al., 1995). Field work in 1996 was focused on prospective gold-bearing sites in mafic rocks in South-East Greenland. Three M.Sc. students mapped showings under the supervision of the H. S., while an area on the south side of Kangerluluk fjord was mapped by H. S. and W. M. (Fig. 4).

scholarly journals The South Greenland regional uranium exploration project

1980 ◽  
Vol 100 ◽  
pp. 83-86
Author(s):  
A. B Armour-Brown ◽  
T Tukiainen ◽  
B Wallin
Keyword(s):  
East Coast ◽  
Field Work ◽  
The South ◽  
North West ◽  
The North ◽  
South West ◽  
Uranium Mineralisation ◽  
Uranium Exploration ◽  
Detailed Nature ◽  
Sampling Survey

The SYDURAN project completed the airborne gamma-spectrometer and geochemical sampling survey over some 14 000 km2 of south-west Greenland from the fjord Sermiligarssuk in the north-west to Kap Farvel in the south and up the east coast as far as the southern shore of Lindenows Fjord. This covered all the Ketilidian structural zones and a small area of Archaean as classified by Allaart (1976) (fig. 29). Geological field work and prospecting of a more detailed nature was carried out in five areas where previous work indicated possibie uranium mineralisation.

scholarly journals Investigations of Tertiary volcanic rocks along the south coast of Nûgssuaq and in eastern Disko, 1987

1988 ◽  
Vol 140 ◽  
pp. 28-32
Author(s):  
L.M Larsen ◽  
A.K Pedersen
Keyword(s):  
Volcanic Rocks ◽  
Field Work ◽  
South Coast ◽  
The West ◽  
West Greenland ◽  
Early Tertiary ◽  
Composite Section ◽  
Greenland Basin ◽  
Volcanic Facies ◽  
Integrated Study

As a continuation of an integrated study of sedimentary and volcanic facies in the Cretaceous to Tertiary West Greenland basin (G. K.Pedersen, 1987; A. K. Pedersen & Larsen, 1987) early Tertiary volcanic rocks were studied in 1987 along a NW-SE trending composite section, about 120 km in length; on Niigssuaq and Disko. The study attempts to establish and describe lithostratigraphic volcanic units in the Tertiary volcanic formations, and through a combination of field mapping, photogrammetry and geochemistry to establish chronostratigraphic horizons through the early Tertiary deposits of the region. In this respect it is essential to identify the same eruptive units as subaeriallava facies and as subaqueous lava or hyaloclastite facies, and to trace subaerial tufts throughout the area. In the first part of the season localities along the Vaigat coast of Nûgssuaq from Kugssinerssuaq in the east to Nûssap qâqarssua in the west were investigated. In the second part of the season very poorly known areas in the western and southem part ofthe Kvandalen region on east Disko were investigated. The field work was supported by the Arctie Station in Godhavn and its cutter Porsild as well as by GGU's cutter J. F. Johnstrup.

scholarly journals Detailed mapping and lithogeochemistry of Neoarchean volcanic rocks: Beaulieu volcanic belt, Slave Craton, NWT

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Shelby Brandon Austin-Fafard ◽  
Michelle DeWolfe ◽  
Camille Partin ◽  
Bernadette Knox
Keyword(s):  
Volcanic Rocks ◽  
Volcanic Belt ◽  
Massive Sulfide ◽  
Lake Area ◽  
Density Currents ◽  
Volcanogenic Massive Sulfide ◽  
The South ◽  
Slave Craton ◽  
Volcaniclastic Rocks ◽  
Tuff Breccia

Neoarchean volcanic rocks of the Beaulieu River volcanic belt structurally overlie basement rocks of the Sleepy Dragon Complex (ca. 2.85 Ga), approximately 100 km east northeast of Yellowknife. The volcanic belt is comprised of complex lithofacies, including basalt, andesite, rhyolite, and associated volcaniclastic rocks, and hosts the Sunrise volcanogenic massive sulfide deposit. The absolute age of the volcanic strata is not known, nor is the stratigraphy well-defined; therefore, the Beaulieu River volcanic belt cannot be easily correlated to other greenstone belts within the Slave craton. The main objective of this study is to document the litho- and chemo-stratigraphy of the volcanic rocks, and particularly the rhyolite dome, located at the south end  of Sunset Lake to reconstruct their volcanic and petrogenetic evolution, and determine their relationship to the volcanic strata that hosts the Sunrise VMS deposit, located ~6km to the north of the study area. Detailed mapping (1:2000) was completed over two field seasons (2018 and 2019) and shows that the volcanic rocks in the south Sunset Lake area comprise a complex stratigraphy consisting of basaltic, andesitic and rhyolitic lithofacies. This includes massive to pillow basalt and andesite, with lesser amounts of massive to in-situ brecciated, weakly quartz-plagioclase porphyritic rhyolite, heterolithic tuff to lapilli- tuff and felsic tuff to tuff breccia. The felsic clasts within the felsic volcaniclastic rocks are similar in composition to the coherent rhyolite. Units have a trace element geochemical signatures that vary from tholeiitic to calc-alkaline, arc-like rocks. Volumetrically, the volcanic strata in the south Sunset Lake area has a significant amount of volcaniclastic rocks, ranging from tuff to tuff breccia units. The volcaniclastic rocks are interpreted to have been deposited by a series of debris flows and eruption-fed density currents. The stratigraphy of the volcanic rocks in south Sunset Lake is very similar to that of the stratigraphy that hosts the Sunrise VMS deposit. Evidence of a vent proximal environment (e.g. rhyolite dome, peperite, syn-volcanic intrusions) and porous, volcanic debris accumulating on the seafloor highlight conditions favourable for volcanogenic massive sulfide-type mineralization in the south Sunset Lake area.

Stratigraphy and geochemistry of the Early Carboniferous Clyde Plateau Lavas in south Bute, Midland Valley of Scotland

2010 ◽  
Vol 148 (4) ◽  
pp. 597-618 ◽  
Author(s):  
G. M. YOUNG ◽  
W. G. E. CALDWELL
Keyword(s):  
Volcanic Rocks ◽  
Early Carboniferous ◽  
Hydrothermal Activity ◽  
The South ◽  
Basaltic Rocks ◽  
Weathering Processes ◽  
The North ◽  
Lower Division ◽  
Sandstone Formation ◽  
Mafic Lavas

AbstractA succession of Viséan (mid- to late Holkerian) volcanic rocks up to 340 m thick is preserved in three fault-blocks at the south end of the Isle of Bute in the Firth of Clyde, Scotland. These rocks form part of the Clyde Plateau Volcanic Formation, which, in this area, disconformably overlies sandstones of the lower Millport Member of the Clyde Sandstone Formation. The lower part of the volcanic succession in south Bute,c. 140 m thick, corresponds to the lower Strathgryfe lavas of the Renfrewshire Hills. This part of the succession is composed dominantly of feldspar-macrophyric and feldspar-microphyric basaltic rocks and mugearites. It is present in all three fault-blocks, whereas the succeeding volcanic rocks (middle and upper divisions) are only preserved in the median St Blane's block where they have a combined thickness of about 200 m. The two younger subdivisions are respectively correlative to the Misty Law Trachytic Centre, which forms a lens between the lower and upper Strathgryfe Members, and the upper Strathgryfe Member of the North Ayrshire section. Lavas of the lower division are feldspar-macrophyric and feldspar-microphyric basaltic rocks and mugearites, but those of the middle and upper divisions display a wider compositional spectrum, including feldspar-macro- and microphyric rocks but ranging from olivine-augite-macrophyric and olivine-augite-feldspar-macrophyric basalts to trachytes. The mafic lavas of south Bute have chondrite-normalized multi-element plots similar to those of ocean island basalts, with enrichment in incompatible elements. The trachytic lavas have similar patterns but are strongly depleted in Sr, P and Ti, reflecting fractionation of such minerals as plagioclase, apatite and magnetite/ilmenite during evolution of the parent magmas. Distribution of high field strength elements favours a within-plate origin for the south Bute lavas and supports derivation from a relatively deep (>50 km) mantle source (garnet lherzolite). Chondrite-normalized REE plots for basaltic lavas of the lower division show enrichment in LREEs and lack strong Eu anomalies. Strong positive Eu anomalies in both felsic and mafic lavas of the middle and upper divisions may be attributable to high oxygen fugacities, but hydrothermal activity or feldspar fractionation may also have played a role. Fe-rich weathering profiles attest to intermittent extrusion and intense weathering processes.

scholarly journals New methods for the geological analysis of Tertiary volcanic formations on Nuussuaq and Disko, central West Greenland, using multi-model photogrammetry

1992 ◽  
Vol 156 ◽  
pp. 19-34
Author(s):  
A.K Pedersen ◽  
K.S Dueholm
Keyword(s):  
Volcanic Eruption ◽  
Field Work ◽  
South Coast ◽  
The South ◽  
West Greenland ◽  
Model Method ◽  
New Methods ◽  
Clastic Sediments ◽  
Series Of Experiments ◽  
Flow Directions

A series of experiments with multi-model photogrammetry were made during the compilation of a 80 km long section along the south coast of Nuussuaq. The section covers a range of Tertiary volcanic lithologies which overlie Mesozoic to Tertiary clastic sediments. The multi-model method allows the geological analyses of flat-lying lithologies in steep or inaccessible terrain and the compilation of detailed sections, profiles, and block diagrams. Drawing of sections or maps is combined with accurate structural measurements to document the flow directions of both subaerial and subaqueous volcanic units and to demonstrate syn-and post-volcanic basin movements and the location of volcanic eruption sites. Multi-model photogrammetry experiments made by compiling the geology of areas already covered by field work has led to major new discoveries. Similar experiments made on areas, which had not been visited in the field before the compilation, but which were visited later, demonstrates that the method is an important new tool in geological reconnaissance.

scholarly journals An investigation of the igneous rocks on Hareøen and western Nûgssuaq, West Greenland

1971 ◽  
Vol 35 ◽  
pp. 11-13
Author(s):  
N Hald
Keyword(s):  
East Coast ◽  
Geological Mapping ◽  
Igneous Rocks ◽  
South Coast ◽  
The South ◽  
West Greenland ◽  
North West ◽  
North East ◽  
The North ◽  
Basaltic Lavas

Hareøen is an island north-west of Disko in western Greenland. It has the form of a plateau, whose highest point - 512 metres - is found near the south coast. Like the neighbouring parts of Nugssuaq and Disko, Hareøen consists chiefly of Tertiary basaltic lavas. The island first attracted attention on account of the presence of interbasaltic, coal-bearing sediments on the north-east coast. These were already examined by Giesecke in 1811 (Giesecke, 1910) and later among others by Steenstrup (1874) and B.E. Koch (1959). A petrographie investigation of the basalts was first undertaken by Holmes (1919), who described loose fragments rich in K2O. Lavas from the south coast, colleeted and analysed by Pedersen (1970), also have a high content of potash. V. Miinther in the years 1948-49 untertook geological mapping of the island, on which the present investigation is supported (Miinther, in press).

scholarly journals High temperature pyrrhotite and telluric iron mineralisations in western Disko, central West Greenland

1975 ◽  
Vol 75 ◽  
pp. 51-53
Author(s):  
F Ulff-Møller
Keyword(s):  
High Temperature ◽  
West Coast ◽  
Field Work ◽  
The South ◽  
The West ◽  
Joint Zone ◽  
West Greenland

The main purpose of the summer field work was to carry out a detailed investigation of the high temperature niekeliferous pyrrhotite and tellurie iron mineralisation whieh oeeurs in the subvolcanie intrusions of the Hammers Dal Complex (Pedersen, this report, and in press), and to seareh for other occurrenees with an econornic evaluation in view. The dyke-like intrusions are mainly found in gorges in the south facing slope of the E-W trending Hammers Dal, about 10 km from the west coast of Disko. They are exposed only in the upper 400 m of the Rinks Dal Member. The depth of the intrusions was thus 400-500 m below the palaeosurfaee, marked by the weakly eontaminated basalts and more strongly eontaminated 'andesites' of the Niaqussat Member which are considered to be the extrusive equivalents of the intrusions. The magma seems to have intruded along a joint zone dipping about 70° WSW forming pipes or dyke-like bodies plunging gently NNW.

scholarly journals Border relations between the amphibolite facies Finnefjeld gneiss complex and granulite facies grey gneisses in the Fiskefjord area, southern West Greenland

1988 ◽  
Vol 140 ◽  
pp. 49-54
Author(s):  
M Marker ◽  
A.A Garde
Keyword(s):  
Granulite Facies ◽  
Field Work ◽  
Geological Mapping ◽  
Amphibolite Facies ◽  
The South ◽  
West Greenland ◽  
South Eastern ◽  
Gneiss Complex ◽  
Eastern Boundary ◽  
The 1950S

The authors carried out geological mapping in August 1987 at the south-eastern boundary of the Finnefjeld gneiss complex around 65°N. The field work was supported by the GGU cutter 'J. F. Johnstrup'. Based on reconnaissance mapping in the 1950s Berthelsen (1951, 1957,1962) divided the Archaean gneiss terrain in the southem Sukkertoppen district between Godthåbsfjord and Søndre Isortoq into three major tectonic units: the Nordland, the Finnefjeld and the Alangua complexes. This division was also followed by Noe-Nygaard & Ramberg (1961).

Notes on the Petrology of the Bufumbira Volcanic Rocks of Uganda

1930 ◽  
Vol 67 (11) ◽  
pp. 491-499 ◽  
Author(s):  
W. C. Simmons
Keyword(s):  
Volcanic Rocks ◽  
Field Work ◽  
Volcanic Field ◽  
Geological Survey ◽  
The South ◽  
The West ◽  
South West ◽  
Short Summary ◽  
Belgian Congo

In view of the probability that there is likely to be some little delay in publishing the official Memoir on the Bufumbira volcanic rocks, which is in course of preparation by Mr. A. D. Combe and the writer, with, we hope, collaboration with authorities in England, permission has been given to publish a short summary of the results so far obtained in the investigation of these rocks. Mr. Combe has made a careful geological survey of the ground and has separated on his map forty-nine flows from nearly forty different centres situated at the south-west corner of the Uganda Protectorate. The remainder of this large volcanic field lies in the Belgian Congo to the west and south, and though all of those volcanoes, several of which are still active, have been visited by geologists and specimens of the rocks obtained, no very detailed field-work has been published on them, either by us or any other observers up to the present time; so far as is known to the writer.

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