Basaltic glass with high-temperature equilibrated immiscible sulphide bodies with native iron from disko, central West Greenland

1979 ◽  
Vol 69 (4) ◽  
pp. 397-407 ◽  
Author(s):  
Asger Ken Pedersen
Keyword(s):  
High Temperature ◽  
Basaltic Glass ◽  
West Greenland ◽  
Native Iron

scholarly journals Native Iron from West Greenland

Nature ◽  
1935 ◽  
Vol 136 (3430) ◽  
pp. 152-153 ◽  
Author(s):  
Harold Carpenter
Keyword(s):  
West Greenland ◽  
Native Iron

scholarly journals New investigations of the native iron bearing volcanic rocks of Disko, central West Greenland

1975 ◽  
Vol 75 ◽  
pp. 48-51
Author(s):  
A.K Pedersen
Keyword(s):  
Volcanic Rocks ◽  
Regional Mapping ◽  
Economic Potential ◽  
West Greenland ◽  
Native Iron ◽  
Iron Bearing

A reinvestigation of the native iron bearing rocks of northern Disko has been initiated as a follow up of new regional mapping. A variety of hypotheses as to formation have been put forward since the work of Steenstrup (1882a); a bibliography is given by Bøggild (1953) and a recent review by Pauly (1969). In addition to examination of the nature of the deposits as such, the purpose of the new investigations is twofold. (1) To map the native iron bearing volcanic rocks which ean be used as stratigraphical marker horizons. (2) To investigate the possibie economic potential of segregations of native iron and sulphides found in these rocks.

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 Palaeodirectional and palaeointensity results of Paleocene and Eocene basalts from West Greenland

1999 ◽  
Vol 46 ◽  
pp. 69-78
Author(s):  
Janna Riisager ◽  
Mireille Perrin
Keyword(s):  
High Temperature ◽  
Remanent Magnetization ◽  
Dipole Moments ◽  
Early Eocene ◽  
Flood Basalts ◽  
West Greenland ◽  
Three Samples ◽  
Geomagnetic Polarity ◽  
Geomagnetic Polarity Time Scale ◽  
High Median

Twelve sites (57 drill cores) from two lava series and one dike were sampled for a palaeomagnetic study of the late Paleocene and early Eocene West Greenland flood basalts. Most of the rocks exhibited well-defined one component remanent magnetization with high unblocking temperatures (mostly above 500°C) and high median destructive fields (30–40 mT). All the rocks are reversely magnetized and, when combined with 40Ar/39Ar ages (Storey et al. 1998), a direct correlation with the geomagnetic polarity time scale can be made. Rock magnetic experiments indicate varying degree of both high temperature (deuteric) and low temperature (hydrothermal) oxidation of primary titanomagnetite. Twenty-three samples with high Curie point (~570°C) were chosen for Thellier palaeointensity experiments. Eleven of them, coming from three different cooling units, yielded reliable palaeointensity estimates. The results are reasonably coherent within sites, and the site-mean virtual dipole moments (VDM) are 1.8, 9.0 and 15.4×1022Am2 . The lowest VDM most probably corresponds to the ~94 ka long C24n.1r subchron, while the two other VDM’s close to present-day and higher than present-day values correspond to chrons C26r and C24r respectively.

scholarly journals New investigations of Tertiary lavas and dykes in the area around Disko Fjord, central West Greenland

1979 ◽  
Vol 95 ◽  
pp. 30-34
Author(s):  
F Ulff-Møller
Keyword(s):  
Field Work ◽  
Sulphide Mineral ◽  
Surrounding Area ◽  
West Greenland ◽  
Native Iron ◽  
Mineral Assemblages

The purpose of the summer's field work was twofold: (a) to search for native iron and sulphide mineral assemblages in the northem extension of the Kitdlit dyke (Fundal, 1975; Pedersen, 1977a & 'a' in figs 10 & 11) and other related (sediment contaminated) dykes, and (b) to map the surrounding area as a contribution to the map sheet Diskofjord (69 V. 1 N, fig. 2). About 600 km2 were mapped in detail and 1500 km2 briefly surveyed.

Origin of Middle Jurassic and Lower Cretaceous fuller's earths in England

Clay Minerals ◽  
1977 ◽  
Vol 12 (1) ◽  
pp. 11-44 ◽  
Author(s):  
C. V. Jeans ◽  
R. J. Merriman ◽  
J. G. Mitchell
Keyword(s):  
High Temperature ◽  
Lower Cretaceous ◽  
Middle Jurassic ◽  
Alkali Feldspar ◽  
Igneous Rocks ◽  
Basaltic Glass ◽  
Volcanic Origin ◽  
Fuller’S Earth

AbstractThe controversy on the origin of the English Mesozoic fuller's earths is reviewed. Findings of (1) unaltered, devitrified, zeolitized and argillized glass, (2) fragments of holocrystalline and hypocrystalline igneous rocks, and (3) high temperature feldspar and sphene, conclusively demonstrate their volcanic origin. The bulk chemistries of the Bathonian and Lower Cretaceous earths are similar and suggest derivation from ash of trachytic composition. The two earths can be differentiated mineralogically and petrographically by: (a) the presence of sphene, and zeolites replacing glass in the Lower Cretaceous earths; (b) the presence of minor amounts of basaltic glass in the Bathonian earths.K/Ar radioisotope dating on high-temperature alkali feldspar gives (1) 152–159 Ma for the Bathonian fuller's earth, and (2) 118–125 Ma and 142–148 Ma for the Lower Cretaceous fuller's earths. The distribution of the Mesozoic fuller's earths and the origin of their parent ash is discussed.

scholarly journals The border relations of the dunite at Siorarssuit, Sukkertoppen District, West Greenland

1954 ◽  
Vol 6 ◽  
pp. 1-47
Author(s):  
H Sørensen
Keyword(s):  
High Temperature ◽  
Regional Metamorphism ◽  
Granulite Facies ◽  
Chemical Changes ◽  
West Greenland

The dunite at Siorarssuit is conformably enclosed by granulite facies gneisses from which it is separated by a zone of bronzitite. The latter passes gradually into the dunite while it has a black-wall of phlogopitic mica against the gneiss. A rock consisting of bronzite, plagioc1ase, diopside and mica is occasionally found outside the black-wall. Joints and fractures in the dunite are occupied by rocks resembling those of the border. The bronzititic border is interpreted as a result. of reactions between gneiss and dunite at conditions of P, T corresponding to the granulite facies of regional metamorphism. The chemical changes are discussed, and it is shown that the Mg/Fe ratio of the bronzite decreases when passing from the dunite to the gneiss. The "dykes" in the dunite are regarded as results of similar reactions along the fractures in the ultrabasic mass. The reactions between ultrabasics and surroundings at different conditions of P, T are discussed, and it is emphasized that the zone of bronzitite is a high temperature equivalent of the more familiar zones of chrysotile, actinolite, talc. etc. formed at lower temperatures.

Sign in / Sign up

Export Citation Format

Share Document