scholarly journals Thermotectonic History of the Kluane Ranges and Evolution of the Eastern Denali Fault Zone in Southwestern Yukon, Canada

Tectonics ◽  
2019 ◽  
Vol 38 (8) ◽  
pp. 2983-3010 ◽  
Author(s):  
Robert G. McDermott ◽  
Alexis K. Ault ◽  
Jonathan Saul Caine ◽  
Stuart N. Thomson
Keyword(s):  
Fault Zone ◽  
Denali Fault ◽  
History Of

Age and origin of the Dover Fault: tectonic boundary between the Gander and Avalon Zones of the northeastern Newfoundland Appalachians

1981 ◽  
Vol 18 (9) ◽  
pp. 1431-1442 ◽  
Author(s):  
R. D. Dallmeyer ◽  
R. F. Blackwood ◽  
L. Odom
Keyword(s):  
Fault Zone ◽  
Country Rock ◽  
Regional Metamorphism ◽  
Tectonic Activity ◽  
Small Scale ◽  
Present Position ◽  
History Of ◽  
Scale Structures ◽  
Tectonic Boundary ◽  
Small Scale Structures

The Dover Fault forms a tectonic boundary between northern portions of the Gander and Avalon Zones of the Newfoundland Appalachians. A systematic geochronological investigation across the mylonitic fault zone has been carried out to clarify the origin and history of tectonic activity along this important Appalachian structure.Zircon fractions from the mylonitic Lockers Bay Granite (Gander Zone) record individually discordant U–Pb dates, but yield a well-defined upper concordia intercept age of 460 ± 20 Ma. Hornblende (1 sample) and biotite (11 samples) from variably mylonitic Gander Zone lithologies (plutonic and metamorphic) adjacent to the fault zone record undisturbed 40Ar/39Ar age spectra with plateau ages of 395 and 365–383 Ma, respectively. Together with field and petrographic characteristics, the new geochronologic data suggest that the Lockers Bay Granite originated as an anatectic melt during high-grade regional metamorphism of the country rock terrane at approximately 460 Ma. The crystal-rich magma was subsequently emplaced into its present position thereby producing local discordance with small-scale structures in host gneisses.Following its emplacement, the Lockers Bay Granite and country rock terrane were maintained at elevated postmetamorphic temperatures for a prolonged interval until they underwent rapid strain during Acadian (Devonian) juxtaposing of the northern Gander and Avalon Zones along the Dover Fault. Sudden Acadian uplift along the fault is suggested because of the rapid cooling of the northern Gander Zone through temperatures required for argon retention in hornblende and biotite. Post-mylonite brecciation may have locally affected argon isotopic systems of phyllitic lithologies adjacent to the fault zone in the study area.

scholarly journals Deformation history of the eclogite- and jadeitite-bearing mélange from North Motagua Fault Zone, Guatemala: insights in the processes of a fossil subduction channel

2009 ◽  
Vol 44 (2) ◽  
pp. 167-190 ◽  
Author(s):  
Michele Marroni ◽  
Luca Pandolfi ◽  
Gianfranco Principi ◽  
Alessandro Malasoma ◽  
Francesca Meneghini
Keyword(s):  
Fault Zone ◽  
Deformation History ◽  
Subduction Channel ◽  
History Of

scholarly journals Exhumation history of the Karakoram fault zone mylonites: New constraints from microstructures, fluid inclusions, and 40Ar-39Ar analyses

Lithosphere ◽  
2012 ◽  
Vol 4 (3) ◽  
pp. 230-241 ◽  
Author(s):  
Barun K. Mukherjee ◽  
Koushik Sen ◽  
Himanshu K. Sachan ◽  
Sudip K. Paul
Keyword(s):  
Fault Zone ◽  
Fluid Inclusions ◽  
History Of ◽  
Karakoram Fault ◽  
Exhumation History

Reactivation history of the long-lived Billefjorden Fault Zone in north central Spitsbergen, Svalbard

1996 ◽  
Vol 133 (1) ◽  
pp. 63-84 ◽  
Author(s):  
Andrew J. McCann ◽  
Winfried K. Dallmann
Keyword(s):  
Fault Zone ◽  
Geological Mapping ◽  
The Arctic ◽  
Late Devonian ◽  
Slight Variation ◽  
North Central ◽  
History Of ◽  
The Many ◽  
West Spitsbergen ◽  
Extensional Structures

AbstractNew geological mapping has revealed further details of the tectonic and stratigraphic effects of Devonian and later reactivations of the Billefjorden Fault Zone, one of a number of important north—south trending lineaments in Svalbard. Analysis of offsets along the many steeply-dipping faults within the zone, and effects on the subsidence and deformation of the adjacent crustal blocks, is presented as a series of tectonic maps from the Late Devonian through to the Tertiary. Late Devonian sinistral transpression, suggested previously, cannot be ruled out, and Carboniferous reactivation was dominated by extension, with possibly a slight dextral strike-slip component. After Late Carboniferous to Early Cretaceous platform subsidence, during which the fault zone had little effect on sedimentation, development of the Tertiary West Spitsbergen Fold Belt (related to the opening of the Arctic Ocean) involved compressive (and transpressive?) reactivation of basement-seated structures further east, including the Billefjorden Fault Zone. In the Billefjorden—Austfjorden area this produced a large monoclinal fold across the fault zone, which was later cross-cut by extensional structures to produce the present day Billefjorden syncline. This localized late extension is related to a slight variation in the trend of the Billefjorden Fault Zone through this area.

Faulting of a Middle Jurassic, ultramafic dyke in the Picton Quarry, Picton, southern Ontario

1990 ◽  
Vol 27 (11) ◽  
pp. 1536-1540 ◽  
Author(s):  
G. H. McFall
Keyword(s):  
Fault Zone ◽  
Middle Jurassic ◽  
Southern Ontario ◽  
Prince Edward County ◽  
Dyke Rock ◽  
Tectonic History ◽  
History Of ◽  
East West

A fault zone coinciding with a Middle Jurassic, ultramafic dyke exposed in the Picton Quarry in Prince Edward County, Ontario, is marked by steeply dipping, generally east–west-striking fractures. The dyke has been affected by faulting, as evidenced by the presence of subhorizontal slickensides on fractures cutting the dyke rock. This discovery constitutes the first known example of Middle Jurassic or younger faulting having affected Paleozoic strata of southern Ontario and indicates that the structural and tectonic history of the region is more complex than commonly believed.

Sign in / Sign up

Export Citation Format

Share Document