Petrogenesis and evolution of an early Proterozoic collisional orogenic belt: The granulite belt of Lapland and the Belomorides (Fennoscandia)

Barbey, Pierre; Convert, J.; Moreau, B.; Capdevila, R.; Hameurt, Jean

doi:10.17741/bgsf/56.1-2.010

Cited by 74 publications

(13 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…at this stage the KGB acted as a basal detachment zone. Such a transcurrent phase may, for example, be related to somewhat later (than D 1 ) approximately N-S collision in the Lapland-Kola Orogen in the south (e.g., Barbey et al 1984;Gaàl & Gorbatschev 1987;Gaàl et al 1989;Gorbatschev & Bogdanova 1993). According to Nironen (1997), the D 1 -D 2 collision occurred during 1.90-1.87 Ga, when NE-SW shortening in the northern part of the Svecofennian Orogen resulted in initial orogen-normal shortening and subsequent clockwise rotation, the latter leading to dextral transpression.…”

Section: Discussionmentioning

confidence: 99%

“…1; e.g., Gorbatschev & Bogdanova 1993). It records crustal mobilization, tectonic reworking and stabilization of dominantly juvenile Archaean and Palaeoproterozoic lithosphere during a 2.1-1.7-Ga cycle of rifting, contraction, and subsequent stabilization and uplift (e.g., Barbey et al 1984;Krill 1985;Marker 1985;Berthelsen & Marker 1986a;Berthelsen 1987;Gaàl & Gorbaschev 1987;Gorbatschev & Bogdanova 1993). In northern Norway, this orogen consists of linear segments of highly strained rocks that are separated by N-S-striking, east-dipping thrust zones (Fig.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Structure and stratigraphy of the Palaeoproterozoic Karasjok Greenstone Belt, north Norway - regional implications

Braathen¹,

Davidsen²

2000

Norsk Geologisk Tidsskrift

View full text Add to dashboard Cite

The Karasjok Greenstone Belt of the northwestern Baltic/Fennoscandian Shield forms the westernmost unit in a Palaeoproterozoic tectonic belt, recording crustal mobilization, tectonic reworking and metamorphism of the Archaean and Palaeoproterozoic lithosphere during a 2.1-1.7-Ga tectonic episode. In northern Norway, this 100 km-wide tectonic belt consists of linear segments of highly strained rocks that are separated by N-S-striking thrust zones. The lowest unit, the Karasjok Greenstone Belt, consists of lowto medium-grade volcanogenic and sedimentary rocks. Excellent exposures in the northern part of the greenstone belt reveal a continuous lithostratigraphic section towards the core of a major recumbent synform, which is related to the regional D 1 deformation episode. This episode is responsible for transposition of primary features and formation of an east-dipping penetrative foliation and banding, with a well-developed east-plunging stretching lineation. Major D 1 shear zones, marked by mylonites and blastomylonites, are found (i) locally at the base of the belt, (ii) at high tectonostratigraphic levels, and (iii) at the upper boundary of the greenstone belt. Shear-sense indicators support west-directed displacement along the thrusts. The superimposed D 2 episode is evident as eastplunging folds, whereas a major D 2 thrust with top-to-the-SSW shear occurs near the base of the greenstone belt. The younger D 3 episode is manifested by N-S-trending folds of the former (D 1 and D 2 ) structures. All fold systems are truncated by steep NE-SWstriking brittle faults of D 4 affinity. The polyphase deformation seen in the Karasjok Greenstone Belt supports a model in which the assembling of the Karasjok Greenstone Belt, the Tanaelv Migmatite Complex and the Levajok Granulite Complex occurred from major orogen-normal E-W contraction (collision) during the D 1 episode. At this stage the greenstone belt was isoclinally folded and welded to overlying units during west-directed overthrusting of the medium-to high-grade complexes. From then on the greenstone belt acted as a basal detachment zone. The D 2 episode of NNE-SSW shortening and SSW-directed thrust emplacement suggest dextral and orogen-oblique movement patterns, prior to continued orogen-perpendicular E-W shortening during the D 3 episode. The final faulting (D 4 ) may relate to a post-orogenic, shield-scale strike-slip event.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Structure and stratigraphy of the Palaeoproterozoic Karasjok Greenstone Belt, north Norway - regional implications

Braathen¹,

Davidsen²

2000

Norsk Geologisk Tidsskrift

View full text Add to dashboard Cite

show abstract

“…, 1990), imply a sedimentary protolith. The disposition of these rocks has been interpreted to be the result of Palaeoproterozoic collisional orogenic processes (Priyatkina and Sharkov, 1979; Barbey et al. , 1984).…”

Section: Geological Frameworkmentioning

confidence: 99%

Age and provenance of early Precambrian metasedimentary rocks in the Lapland–Kola Belt, Russia: evidence from Pb and Nd isotopic data

et al. 2001

View full text Add to dashboard Cite

207Pb/206Pb ages are presented for detrital zircons (Laser Ablation Microprobe ICP‐MS) and whole‐rock Nd isotopic determinations (TIMS) from samples of Neoarchean and Palaeoproterozoic metasedimentary rocks from the Umba granulite terrane and the Keivy domain of the Central Kola composite terrane, Kola Peninsula, north‐western Russia. Three are samples of rocks from the Umba granulite terrane that were deposited ≈ 2.20–1.90 Ga; they contain Archaean detritus, much of it older than 3.0 Gyr, as well as abundant 2.20–1.95‐Gyr‐old material. Deposition may have occurred on the margin of an Archaean craton with an exposed Palaeoproterozoic magmatic arc source, possibly during orogenesis. Two samples from the Keivy domain have remarkably similar, dominantly Archaean detrital zircon age spectra. One was deposited pre‐2.4 Ga, whereas the other was probably deposited post‐2.01 Ga. Both had similar sources, compatible with the proximal country rocks, and possible shallow‐water (?) cratonic margin depositional settings.

show abstract

“…The Angeli anorthosite massif of 225 km2 is located at the western border of the LGB 0 1996 Blackwell Science Ltd, Terra Nova,8,[48][49][50][51][52][53][54][55][56][57][58] 49 (Merilainen, 1976). Different plate tectonic reconstructions for the LGB are given for example by Krill (1985), Barbey et al (1984) and Marker (1990). These are reviewed by Marker (1991).…”

Section: Tectonic Setting Of the Lapland Granulite Beltmentioning

confidence: 99%

Field, petrophysical and carbon isotope studies on the Lapland Granulite Belt: implications for deep continental crust

et al. 1996

View full text Add to dashboard Cite

The Palaeoproterozoic Lapland Granulite Belt is a seismically reflective and electrically conductive sequence of deep crustal (6–9 kbar) rocks in the northern Fennoscandian Shield. It is composed of garnet‐sillimanite gneisses (khondalites) and pyroxene granulites (enderbites) which in certain thrust sheets form about 500 m thick interlayers. The structure was formed by the intrusion of intermediate to basic magmas into turbiditic sedimentary rocks under granulite facies metamorphism accompanied by shearing of the deep crust about 1.93–1.90 Gyr ago (Gal. Granulites were upthrust 1.90–1.87 Ga and the belt was divided by crustal scale duplexing into four structural units whose layered structure was preserved. The thrust structures are recognized by the repetition of lithological ensembles and by discordant structural patterns well distinguishable in airborne magnetic and electromagnetic data. Thrusting gave rise to clockwise pressure‐temperature evolution of the belt. However, some basic rocks possibly record an isobaric cooling path. The low bulk resistivity of the belt (200–1000 Ωm) is caused by interconnected graphite and subordinate sulphides in shear zones. On the basis of carbon isotope ratios this graphite is derived mostly from sedimentary organic carbon. The seismic reflectivity of the belt may be caused by velocity and density differences between pyroxene granulites and khondalites, as well as by shear zones.

show abstract

Petrogenesis and evolution of an early Proterozoic collisional orogenic belt: The granulite belt of Lapland and the Belomorides (Fennoscandia)

Cited by 74 publications

References 0 publications

Structure and stratigraphy of the Palaeoproterozoic Karasjok Greenstone Belt, north Norway - regional implications

Structure and stratigraphy of the Palaeoproterozoic Karasjok Greenstone Belt, north Norway - regional implications

Age and provenance of early Precambrian metasedimentary rocks in the Lapland–Kola Belt, Russia: evidence from Pb and Nd isotopic data

Field, petrophysical and carbon isotope studies on the Lapland Granulite Belt: implications for deep continental crust

Contact Info

Product

Resources

About