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1. |
Stable isotope data of Bergslagen carbonates and their potential use for sulphide ore prospecting |
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Geologiska Föreningen i Stockholm Förhandlingar,
Volume 107,
Issue 3,
1985,
Page 169-173
Kjell Billström,
Göran Åberg,
AndersG. Nord,
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摘要:
A preliminary investigation of carbon and oxygen isotopes in ore-associated carbonates from Bergslagen, south-central Sweden, reveals a large spread in isotopic composition: δ13C ranges from - 7 to + 65%, and δ18O between + 4 and + 26% (rel. SMOW). However, each locality seems to be characterized by a unique isotopic composition. It is suggested that the isotopic composition of the carbonates originally had a uniform marine signature, and that the present variability in isotopic composition is due to secondary alteration effects. The extent of alteration, and consequently the observed isotopic compostion of the carbonates, is a function of the ore-forming activity and the post-depositional history of each district and it is thus suggested that carbon and oxygen isotope studies may be useful tools for sulphide ore prospecting.
ISSN:0016-786X
DOI:10.1080/11035898609453049
出版商:Taylor & Francis Group
年代:1985
数据来源: Taylor
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2. |
The Saxberget sulfide deposit |
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Geologiska Föreningen i Stockholm Förhandlingar,
Volume 107,
Issue 3,
1985,
Page 174-174
Stefan Selkman,
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ISSN:0016-786X
DOI:10.1080/11035898609453050
出版商:Taylor & Francis Group
年代:1985
数据来源: Taylor
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3. |
Geochemistry and clay mineralogy of argillites in the Late Proterozoic Almesåkra group, south Sweden |
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Geologiska Föreningen i Stockholm Förhandlingar,
Volume 107,
Issue 3,
1985,
Page 175-182
Agnes Rodhe,
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摘要:
A study of major element and Rb, Sr geochemistry as well as clay mineralogy in argillites from the dolerite-intruded, Late Proterozoic fluviatile Almesåkra group of Sweden is reported. The contents and proportions of the alkalis in the potassic, mainly non-calcareous argillites are determined largely by the composition of the associated feldspathic sandstones. The basic intrusions influenced the oxidation level in the red argillites with reduction of hematite in greyish to blackish contact rocks. In red argillites, least influenced by the intrusions, the clay mineralogy is virtually illitic and the illite crystallinity indicates a deep-diagenetic to diagenetic degree of metamorphism. Chlorites, like illite crystallinity, are best developed in argillites closest to the intrusions. The Sr-level in contact argillites is much higher than in other Precambrian shales. It is significantly lower in the red argillites. The difference in Sr-contents is suggested to be due mainly to a transfer of Sr from the melts which were comparatively high in this element.
ISSN:0016-786X
DOI:10.1080/11035898609453051
出版商:Taylor & Francis Group
年代:1985
数据来源: Taylor
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4. |
Post-granitoid basic plutonics in the Småland—Värmland belt |
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Geologiska Föreningen i Stockholm Förhandlingar,
Volume 107,
Issue 3,
1985,
Page 183-184
Anders Wikström,
Kristian Annertz,
Carl-Henric Wahlgren,
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ISSN:0016-786X
DOI:10.1080/11035898609453052
出版商:Taylor & Francis Group
年代:1985
数据来源: Taylor
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5. |
An occurrence of apatite-rich rocks of carbonatitic affinity near the Jotnian graben structure in Gävle, central Sweden |
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Geologiska Föreningen i Stockholm Förhandlingar,
Volume 107,
Issue 3,
1985,
Page 185-195
JanOlov Nyström,
Nils-Bertil Svensson,
Göran Åberg,
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摘要:
An occurrence of apatite-rich rocks of carbonatitic affinity at Främlingshem, SW of Gävle, central Sweden, is reported. Boulders and cobbles of two lithologically related types (dominated by apatite-calcite and chlorite-apatite, respectively) have been found. Major constituents are fluorapatite with a87Sr/86Sr ratio of 0.7027, Sr-rich calcite (2600 ppm) with (δ13C = -3.9 ± 0.2% vs PDB and δ18O = 14.9 ± 0.5% vs SMOW, chlorite completely replacing biotite or phlogopite, and fragments of granitoids and other rocks. The apatite-rich rocks were apparently emplaced as a ‘crystal-mush’, at a low temperature. They are post-Svecokarelian in age, probably formed between 1750 Ma and 1100 Ma ago, a timespan comprising two or more periods of tensional movements in central Sweden. The location of the Främlingshem rocks near a graben structure is consistent with their carbonatitic affinity.
ISSN:0016-786X
DOI:10.1080/11035898609453053
出版商:Taylor & Francis Group
年代:1985
数据来源: Taylor
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6. |
Literature Review |
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Geologiska Föreningen i Stockholm Förhandlingar,
Volume 107,
Issue 3,
1985,
Page 196-196
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摘要:
Aston, S. R. (ed.), 1983:Silicon geochemistry and biogeochemistry.248 sidor, 79 figurer, 41 tabeller. Academic press, London. ISBN 0-12-065620-5. Pris GBP 23,50. Reviewed by Ulf Sturesson
ISSN:0016-786X
DOI:10.1080/11035898609453054
出版商:Taylor & Francis Group
年代:1985
数据来源: Taylor
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7. |
Further radiometric dating of the Karlshamn granite, south Sweden |
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Geologiska Föreningen i Stockholm Förhandlingar,
Volume 107,
Issue 3,
1985,
Page 197-202
Göran Åberg,
Karl-Axel Kornfält,
AndersG. Nord,
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摘要:
Radiometric dating of the reddish grey, medium- to coarse-grained Karlshamn granite, south Sweden, yields an intrusive age of c. 1400 Ma. During later activity and block movements rest solutions from the crystallizing magma intruded along fault zones, giving rise to small bodies of leucogranite. Activity in the Protogine zone and intrusion of finegrained granitic dikes in the Vånga granite 1250–1200 Ma ago further lowered the K-Ar biotite ages in the Karlshamn and leucogranites.
ISSN:0016-786X
DOI:10.1080/11035898609453055
出版商:Taylor & Francis Group
年代:1985
数据来源: Taylor
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8. |
Geological interpretation of gravity and aeromagnetic surveys over the Fellingsbro—Blixterboda granite |
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Geologiska Föreningen i Stockholm Förhandlingar,
Volume 107,
Issue 3,
1985,
Page 203-213
JosefA. Zuber,
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摘要:
Results of gravity and aeromagnetic measurements have been used for studying the subsurface shape of the Fellingsbro-Blixterboda granite massif, which was formed during the late stages of the Svecofennian orogeny, approximately 1800 Ma ago. The large negative gravity anomaly (ca. -120 gu) over the massif is interpreted to be caused by the relatively low density of the granite itself. The shape and size of the anomaly indicate that the exposed granite is thickest at its southern margin, reaching a depth of at least 15 km and possibly 20 km. To the north a considerable drop occurs in the gravity anomaly, suggesting a laccolithic form for the central and northern part of the granite massif. A main feature of the aeromagnetic anomalies over the Fellingsbro-Blixterboda granite is that they are conspicuously higher over the laccolithic part of the granite than over the intrusive, deep-going, stock-shaped granite, indicating a low magnetization of the latter part. Results of susceptibility determinations support this assumption. The origin and emplacement of the Fellingsbro-Blixterboda granite is apparently closely connected with the late orogeny of south central Sweden. The general shape of this granite massif is consistent with a mechanism of diapiric emplacement and a flow favoured by a zone of weakness in the Svecofennian basement.
ISSN:0016-786X
DOI:10.1080/11035898609453056
出版商:Taylor & Francis Group
年代:1985
数据来源: Taylor
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9. |
Aeolian and beach sand on the glaciofluvial deposit Törnemon, Värmland, Sweden |
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Geologiska Föreningen i Stockholm Förhandlingar,
Volume 107,
Issue 3,
1985,
Page 215-219
Curt Fredén,
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ISSN:0016-786X
DOI:10.1080/11035898609453057
出版商:Taylor & Francis Group
年代:1985
数据来源: Taylor
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10. |
Literature Review |
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Geologiska Föreningen i Stockholm Förhandlingar,
Volume 107,
Issue 3,
1985,
Page 220-220
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摘要:
Stouge, S. S., 1984: Conodonts of the Middle Ordovician Table Head Formation, western Newfoundland.Fossils and Strata 16, 1–145; Pls. 1–18. Universitetsforlaget, Oslo. ISBN 82-0009548-7. Price NKR 180.00, USD 30.00. Reviewed by Maurits Lindström
ISSN:0016-786X
DOI:10.1080/11035898609453058
出版商:Taylor & Francis Group
年代:1985
数据来源: Taylor
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