Interpreting the history of the southern part of the Eastern Segment, the Sveconorwegian Orogen of southwestern Sweden: A reply

GFF ◽  
1996 ◽  
Vol 118 (3) ◽  
pp. 189-192 ◽  
Author(s):  
Karl‐Inge Åhäll
Keyword(s):  
Eastern Segment ◽  
History Of ◽  
Sveconorwegian Orogen

Interpreting the history of the southern part of the Eastern Segment, the Sveconorwegian Orogen of southwestern Sweden: A discussion

GFF ◽  
1996 ◽  
Vol 118 (3) ◽  
pp. 187-192 ◽  
Author(s):  
Leif Johansson ◽  
Charlotte Möller ◽  
Ulf Söderlund ◽  
Anders Lindh ◽  
Xiang‐Dong Wang
Keyword(s):  
Eastern Segment ◽  
History Of ◽  
Sveconorwegian Orogen

A Sveconorwegian deformation zone (system?) within the Eastern Segment, Sveconorwegian orogen of SW Sweden ‐ a first report

GFF ◽  
1997 ◽  
Vol 119 (1) ◽  
pp. 73-78 ◽  
Author(s):  
Charlotte Möller ◽  
Jenny Andersson ◽  
Ulf Söderlund ◽  
Leif Johansson
Keyword(s):  
Deformation Zone ◽  
First Report ◽  
Eastern Segment ◽  
Sveconorwegian Orogen

scholarly journals The Early Silurian Gabbro in the Eastern Kunlun Orogenic Belt, Northeast Tibet: Constraints on the Proto-Tethyan Ocean Closure

Minerals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 794
Author(s):  
Wenxiao Zhou ◽  
Haiquan Li ◽  
Feng Chang ◽  
Xinbiao Lv
Keyword(s):  
Evolutionary History ◽  
Orogenic Belt ◽  
Early Paleozoic ◽  
High Field Strength ◽  
Geochemical Composition ◽  
Eastern Segment ◽  
History Of ◽  
Formation And Evolution ◽  
Light Rare Earth Elements ◽  
Final Closure

The early Paleozoic is a crucial period in the formation and evolution of the Eastern Kunlun Orogenic Belt (EKOB), and is of great significance for understanding the evolutionary history of the Proto-Tethyan Ocean. This paper presents new petrography, geochemistry, zircon U–Pb dating, and Lu–Hf isotopic research on the Yuejingshan gabbro from the eastern segment of the EKOB. Zircon U–Pb data suggests that the gabbro formed in the Early Silurian (435 ± 2 Ma). All samples have relatively low TiO2 contents (0.45–2.97%), widely varying MgO (6.58–8.41%) and Mg# (58–65) contents, and are rich in large ion lithophile elements (LILE such as Rb, Ba, Th, and U) and light rare earth elements (LREE). This indicates that it has a similar geochemical composition to island arc basalt. The major element features indicate that the formation of this gabbro underwent fractional crystallization of clinopyroxene, olivine, and plagioclase. The depletion of high field strength elements (HFSE, such as Nb, Ta, and Ti), and a slightly positive Hf isotope (with εHf(t) ranging from 1.13 to 2.45) may be related to the partial melting of spinel-bearing peridotite, led by slab fluid metasomatism. The gabbro likely represents magmatic records of the latest period of the early Paleozoic oceanic crust subduction in the Eastern Kunlun. Therefore, the final closure of the Proto-Tethyan Ocean and the beginning of collisional orogeny occurred before the Early Silurian.

Chapter 14 Regional context and lithotectonic framework of the 1.1–0.9 Ga Sveconorwegian orogen, southwestern Sweden

2020 ◽  
Vol 50 (1) ◽  
pp. 337-349 ◽  
Author(s):  
Michael B. Stephens ◽  
Ulf Bergström ◽  
Carl-Henric Wahlgren
Keyword(s):  
High Pressure ◽  
Tectonic Evolution ◽  
Shear Zones ◽  
Crustal Extension ◽  
Frontal Part ◽  
Eastern Segment ◽  
Mountain Belts ◽  
Sveconorwegian Orogen ◽  
Scale Shear ◽  
Early Neoproterozoic

AbstractThe 1.1–0.9 Ga Sveconorwegian orogen in southwestern Scandinavia belongs to the global system of mountain belts established during the assembly of the supercontinent Rodinia. An overall north–south structural trend and five lithotectonic units bounded by crustal-scale shear zones characterize this orogen. In Sweden, the Eastern Segment abuts the orogen's cratonic foreland eastwards and is separated from the Idefjorden terrane westwards by a ductile shear zone, up to 5 km thick, displaying a sinistral transpressive component. These two lithotectonic units differ on the basis of their pre-Sveconorwegian accretionary tectonic evolution, and the timing of Sveconorwegian high-pressure metamorphism, anatexis and polyphase deformation. High-pressure granulites and migmatites formed at c. 1.05–1.02 Ga in the Idefjorden terrane; eclogites, high-pressure granulites and migmatites at c. 0.99–0.95 Ga in the Eastern Segment. Magmatic activity and crustal extension progressed westwards at c. 0.98–0.92 Ga. Prior to or at 0.93–0.91 Ga, greenschist facies shear deformation with top-to-the-foreland movement affected the frontal part of the orogen. Geodynamic uncertainties concern the affinity of the Idefjorden terrane relative to Fennoscandia (Baltica), the character of the Sveconorwegian orogenesis, and the contiguous or non-contiguous nature of the erosional fronts of the late Mesoproterozoic–early Neoproterozoic orogens in Sweden and Canada.

scholarly journals Paleoseismological investigation of the eastern "segment" of the Heliki fault, Gulf of Corinth, Greece

2001 ◽  
Vol 34 (1) ◽  
pp. 199 ◽  
Author(s):  
Σ. ΠΑΥΛΙΔΗΣ ◽  
Ι. ΚΟΥΚΟΥΒΕΛΑΣ ◽  
Λ. ΣΤΑΜΑΤΟΠΟΥΛΟΣ ◽  
Δ. ΑΓΡΑΦΙΩΤΗΣ ◽  
Γ. Α. ΑΛΕΞΑΝΔΡΗΣ ◽  
...  
Keyword(s):  
Alluvial Plain ◽  
Unconsolidated Sediments ◽  
Geological Data ◽  
The Third ◽  
Gulf Of Corinth ◽  
Eastern Segment ◽  
History Of

Paleoseismological analysis based on geological data enable us to understand the recent seismic history of the Eliki fault. Along the eastern "segment (or strand)" scarp 5 trenches have been excavated (8x5x2m), their walls were mapped in scale 1:20 and further analyzed by precise tectono-stratigraphic methodology. The Kerynitis river, which crosses the Eliki fault from S to Ν and supplies the alluvial plain, has subsided at a rate of 1.4 mm/ yr. The river was running from west to east, resulting the fluvial conglomerates in the trenches, which have buried under the colluvial sediments. Based on colluvium stratigraphy, displacement of distinct horizons, deposition of sedimentary layers and C14 dating, faulting events have been identified affecting unconsolidated sediments in the trench. The penultimate 373 BC event and the two younger events with a throw of 0.93 m and 1.37 m respectively, the third event, with a throw of 0.44 m, suggest a variable seismic history.

scholarly journals The Early Silurian Gabbro in the Eastern Kunlun Orogenic Belt, Northeast Tibet: Constraints on the Proto-Tethyan Ocean Closure

2020 ◽  
Author(s):  
Wenxiao Zhou ◽  
Haiquan Li ◽  
Feng Chang ◽  
Xinbiao Lv
Keyword(s):  
Evolutionary History ◽  
Orogenic Belt ◽  
Early Paleozoic ◽  
High Field Strength ◽  
Geochemical Composition ◽  
Eastern Segment ◽  
History Of ◽  
Formation And Evolution ◽  
Light Rare Earth Elements ◽  
Final Closure

The early Paleozoic is a crucial period in the formation and evolution of the Eastern Kunlun Orogenic Belt (EKOB), and is of great significance for understanding the evolutionary history of the Proto-Tethyan Ocean. This paper presents new petrography, geochemistry, zircon U–Pb dating, and Lu–Hf isotopic research on the Yuejingshan gabbro from the eastern segment of the EKOB. Zircon U–Pb data suggests that the gabbro formed in the Early Silurian (435 ± 2 Ma). All samples have relatively low TiO2 contents (0.45–2.97%), widely varying MgO (6.58–8.41%) and Mg# (58–65) contents, and are rich in large ion lithophile elements (LILE such as Rb, Ba, Th, and U) and light rare earth elements (LREE). This indicates that it has a similar geochemical composition to island arc basalt. The major element features indicate that the formation of this gabbro underwent fractional crystallization of clinopyroxene, olivine, and plagioclase. The depletion of high field strength elements (HFSE, such as Nb, Ta, and Ti), and a slightly positive Hf isotope (with εHf(t) ranging from 1.13 to 2.45) may be related to the partial melting of spinel-bearing peridotite, led by slab fluid metasomatism. The gabbro likely represents magmatic records of the latest period of the early Paleozoic oceanic crust subduction in the Eastern Kunlun. Therefore, the final closure of the Proto-Tethyan Ocean and the beginning of collisional orogeny occurred before the Early Silurian.

Sign in / Sign up

Export Citation Format

Share Document