skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Texture and elastic anisotropy of a mylonitic anorthosite from the Morin Shear Zone (Quebec, Canada)

ORCiD logo; ;
Publication Date:
Sponsoring Org.:
OSTI Identifier:
Grant/Contract Number:
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Journal of Structural Geology
Additional Journal Information:
Journal Volume: 71; Journal Issue: C; Related Information: CHORUS Timestamp: 2016-09-04 18:32:28; Journal ID: ISSN 0191-8141
Country of Publication:
United Kingdom

Citation Formats

Gómez Barreiro, Juan, Wenk, Hans-Rudolf, and Vogel, Sven. Texture and elastic anisotropy of a mylonitic anorthosite from the Morin Shear Zone (Quebec, Canada). United Kingdom: N. p., 2015. Web. doi:10.1016/j.jsg.2014.07.021.
Gómez Barreiro, Juan, Wenk, Hans-Rudolf, & Vogel, Sven. Texture and elastic anisotropy of a mylonitic anorthosite from the Morin Shear Zone (Quebec, Canada). United Kingdom. doi:10.1016/j.jsg.2014.07.021.
Gómez Barreiro, Juan, Wenk, Hans-Rudolf, and Vogel, Sven. 2015. "Texture and elastic anisotropy of a mylonitic anorthosite from the Morin Shear Zone (Quebec, Canada)". United Kingdom. doi:10.1016/j.jsg.2014.07.021.
title = {Texture and elastic anisotropy of a mylonitic anorthosite from the Morin Shear Zone (Quebec, Canada)},
author = {Gómez Barreiro, Juan and Wenk, Hans-Rudolf and Vogel, Sven},
abstractNote = {},
doi = {10.1016/j.jsg.2014.07.021},
journal = {Journal of Structural Geology},
number = C,
volume = 71,
place = {United Kingdom},
year = 2015,
month = 2

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1016/j.jsg.2014.07.021

Citation Metrics:
Cited by: 1work
Citation information provided by
Web of Science

Save / Share:
  • U-Pb zircon ages of samples of anorthosite, pyroxene monzodiorite (jotunite), and pyroxene quartz monzonite (quartz mangerite) of the Morin anorthosite complex, Grenville Province, Quebec, are 1155 {plus minus} 3, 1146 {plus minus} 4 and 1135 {plus minus} 3 Ma, respectively. These dates are very similar to available dates for equivalent units of the Lac St-Jean and Adirondack anorthosite suite occurrences and slightly predate estimates of 1075-1100 Ma for peak metamorphic conditions during the Grenville orogeny in this region. {sup 87}Sr/{sup 86}Sr initial ratios of 0.7048-0.7051 for the three Morin units sampled permit a comagmatic origin if the different emplacement ormore » cooling times can be reconciled. The mangerite sampled cannot have been formed by fusion of the upper crust, but may have been derived from a relatively juvenile crust at depth. All three units have interacted with continental crust, given the likely depleted nature of the mantle in this region.« less
  • Airborne SAR images provided essential clues to the tectonic setting of (1) the MbLg 6.5 Saguenay earthquake of 25 November 1988, (2) the Charlevoix-Kamouraska seismic source zone, and (3) some of the low *eve* seismic activity in the Eastern seismic background zone of Canada. The event occurred in the southeastern part of the Canadian Shield in an area where the boundary between the Saguenay graben and the Jacques Cartier horst is not well defined. These two tectonic blocks are both associated with the Iapetan St-Lawrence rift. These blocks exhibit several important structural breaks and distinct domains defined by the lineamentmore » orientations, densities, and habits. Outcrop observations confirm that several lineament sets correspond to Precambrian ductile shear zones reactivated as brittle faults during the Phanerozoic. In addition, the northeast and southwest limits of recent seismic activity in the Charlevoix-Kamouraska zone correspond to major elements of the fracture pattern identified on the SAR images. These fractures appear to be related to the interaction of the Charlevoix astrobleme with the tectonic features of the area. 20 refs.« less
  • Permafrost temperatures from the surface down to about 20 m from 10 boreholes distributed around three villages on the coast of Hudson Strait (Salluit, Kangiqsujuaq, and Quaqtaq) were recorded and analyzed for the period 1988-1993. The results indicate that the permafrost has been regularly cooling along the southern shore of Hudson Strait. The observed trend in the order of 0.05{degrees}C yr{sup {minus}1} at the 20-m depth is consistent with the long-term regional cooling observed in air temperatures. It also coincides with an increased rate of cooling since the mid-1980s, which has been interpreted in the literature as being related tomore » recurrent changes in the thermohaline circulation in the Arctic and North Atlantic oceans. The weak variation observed in the active-layer thickness at the study sites leads to the conclusion that the climatic cooling takes place principally through longer and colder winters. 23 refs., 7 figs., 5 tabs.« less
  • Two pollen diagrams from lakes north of treeline in northwestern Quebec indicate that Picea never extended north of its present-day limit during the past 6000 yr BP. Alnus crispa was slightly more abundant around 5000 BP, but there are few major changes in the vegetation of the region during the Holocene. A third site in the tundra along Hudson Bay has a slightly longer sequence (7000 yr BP) which indicates more open conditions in the early and recent part of the record. Picea may have been more abundant locally around 3000 BP. Few major changes in these diagrams can bemore » unequivocally attributed to local changes in plant abundance; changes in tree and shrub pollen abundance parallel those seen south of treeline.« less
  • Elemental concentrations of Al, Ba, Cd, Cu, Mg, Mn, Pb, Rb, Sr, and Zn, as well as Pb and Sr isotopic compositions were determined in samples of snowpack obtained along two main transects from the province of Quebec (Canada); one north-south (between 47 N and 55 N; 1994) and the other within the St. Lawrence Valley (1997). Median enrichment factors (relative to upper crustal abundances) for Cd, Cu, Mn, Pb and Zn for all samples range from {approx}300 to {approx}42,000 and are indicative of an anthropogenic origin. Pb isotopes ratios for snow samples retrieved in 1994 are highly variable ({supmore » 206}Pb/{sup 207}Pb = 1.148 to 1.193) and are characterized by the most radiogenic Sr isotope values ({sup 87}Sr/{sup 86}Sr {ge} 0.710). In contrast, the Pb and Sr isotope results for 1997 snow samples collected along the St. Lawrence Valley (below latitude 47 N), yield the most radiogenic Pb isotope ratios ({sup 206}Pb/{sup 207}Pb = 1.160 to 1.180) for 1997 samples collected north of latitude 47 N indicate input of an additional anthropogenic component, possibly that of Eurasian pollution being transported over the high Arctic during the winter season. A comparison of the Pb isotope results between lichens and snow samples from identical sample locations indicate that these either overlap (along St. Lawrence Valley), or are significantly different (north-south transect). The latter discrepancy may be attributed to either: (1) different time scales for the integration of the atmospheric signal (months for snow vs. years for lichens); (2) recording of the atmospheric signal at substantially different altitudes; or (3) the presence of an important, local point source of atmospheric pollution. Annual depositional budgets have been estimated for Pb, Cd, Zn, Cu, and Mn, and average values (g/km{sup 2} yr) are 1,500, 130, 196,000, 1,900, and 6,400, respectively. Compared to previous depositional fluxes (1993--1994) estimated from adjacent regions in North America, those reported here are slightly lower with the exception of Mn and Zn. The nondecrease in depositional fluxes of Mn may be attributed to combustion of Mn-bearing fossil fuels by automotive vehicles. The exact cause for the elevated annual depositional values for Zn, however, remains enigmatic.« less