Bouguer gravity anomalies and speculations on the regional crustal structure of the Eurekan Orogen, Arctic Canada

R A Stephenson, B D Ricketts

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

Bouguer anomaly-topography profiles crossing three major structural elements of the Tertiary Eurekan Orogen in Arctic Canada have been constructed: the southwestern extension of Grantland Uplift on western Ellesmere Island and Princess Margaret Arch on north-central Axel Heiberg Island (from detailed gravity measurements taken along two transects in 1987), and Cornwall Arch on Cornwall Island (from pre-existing gravity data).
Gravity signatures beneath the three major uplifts, analyzed in the context of the gravitational effects of the observed near-surface geology of Cornwall and Princess Margaret arches, are consistent with a model of gradational change from isostatic compensation beneath the Grantland Uplift to antithetic isostatic compensation beneath Cornwall Arch. These signatures correspond to increasing distances westward, from the zone of maximum Eurekan compression. Thus, the area of Grantland Uplift has been tectonically thickened, whereas Cornwall Arch is underlain at depth by a broad crustal/mantle upwarp. Princess Margaret Arch is considered to be transitional between these two end-members, possibly being cored by a deep crustal upwarp, but also involving tectonic thickening, perhaps by stacking of thrust slices.
It is speculated that Cornwall and Princess Margaret arches may be the manifestation of crustal scale “folding” in response to in-plane compressional stresses developed during the Eurekan Orogeny. The distance between these two arches is about 200 km and is similar to the expected wavelength of deep crustal folding, given typical flexural rigidities for continental lithosphere.
Original languageEnglish
Pages (from-to)401-420
Number of pages20
JournalMarine Geology
Volume93
Issue number1-4
DOIs
Publication statusPublished - Jun 1990

Cite this

Bouguer gravity anomalies and speculations on the regional crustal structure of the Eurekan Orogen, Arctic Canada. / Stephenson, R A; Ricketts, B D .

In: Marine Geology, Vol. 93, No. 1-4, 06.1990, p. 401-420.

Research output: Contribution to journalArticle

@article{61462e748c834664bca3d1f1b62fd0b8,
title = "Bouguer gravity anomalies and speculations on the regional crustal structure of the Eurekan Orogen, Arctic Canada",
abstract = "Bouguer anomaly-topography profiles crossing three major structural elements of the Tertiary Eurekan Orogen in Arctic Canada have been constructed: the southwestern extension of Grantland Uplift on western Ellesmere Island and Princess Margaret Arch on north-central Axel Heiberg Island (from detailed gravity measurements taken along two transects in 1987), and Cornwall Arch on Cornwall Island (from pre-existing gravity data).Gravity signatures beneath the three major uplifts, analyzed in the context of the gravitational effects of the observed near-surface geology of Cornwall and Princess Margaret arches, are consistent with a model of gradational change from isostatic compensation beneath the Grantland Uplift to antithetic isostatic compensation beneath Cornwall Arch. These signatures correspond to increasing distances westward, from the zone of maximum Eurekan compression. Thus, the area of Grantland Uplift has been tectonically thickened, whereas Cornwall Arch is underlain at depth by a broad crustal/mantle upwarp. Princess Margaret Arch is considered to be transitional between these two end-members, possibly being cored by a deep crustal upwarp, but also involving tectonic thickening, perhaps by stacking of thrust slices.It is speculated that Cornwall and Princess Margaret arches may be the manifestation of crustal scale “folding” in response to in-plane compressional stresses developed during the Eurekan Orogeny. The distance between these two arches is about 200 km and is similar to the expected wavelength of deep crustal folding, given typical flexural rigidities for continental lithosphere.",
author = "Stephenson, {R A} and Ricketts, {B D}",
year = "1990",
month = "6",
doi = "10.1016/0025-3227(90)90095-2",
language = "English",
volume = "93",
pages = "401--420",
journal = "Marine Geology",
issn = "0025-3227",
publisher = "ELSEVIER SCIENCE BV",
number = "1-4",

}

TY - JOUR

T1 - Bouguer gravity anomalies and speculations on the regional crustal structure of the Eurekan Orogen, Arctic Canada

AU - Stephenson, R A

AU - Ricketts, B D

PY - 1990/6

Y1 - 1990/6

N2 - Bouguer anomaly-topography profiles crossing three major structural elements of the Tertiary Eurekan Orogen in Arctic Canada have been constructed: the southwestern extension of Grantland Uplift on western Ellesmere Island and Princess Margaret Arch on north-central Axel Heiberg Island (from detailed gravity measurements taken along two transects in 1987), and Cornwall Arch on Cornwall Island (from pre-existing gravity data).Gravity signatures beneath the three major uplifts, analyzed in the context of the gravitational effects of the observed near-surface geology of Cornwall and Princess Margaret arches, are consistent with a model of gradational change from isostatic compensation beneath the Grantland Uplift to antithetic isostatic compensation beneath Cornwall Arch. These signatures correspond to increasing distances westward, from the zone of maximum Eurekan compression. Thus, the area of Grantland Uplift has been tectonically thickened, whereas Cornwall Arch is underlain at depth by a broad crustal/mantle upwarp. Princess Margaret Arch is considered to be transitional between these two end-members, possibly being cored by a deep crustal upwarp, but also involving tectonic thickening, perhaps by stacking of thrust slices.It is speculated that Cornwall and Princess Margaret arches may be the manifestation of crustal scale “folding” in response to in-plane compressional stresses developed during the Eurekan Orogeny. The distance between these two arches is about 200 km and is similar to the expected wavelength of deep crustal folding, given typical flexural rigidities for continental lithosphere.

AB - Bouguer anomaly-topography profiles crossing three major structural elements of the Tertiary Eurekan Orogen in Arctic Canada have been constructed: the southwestern extension of Grantland Uplift on western Ellesmere Island and Princess Margaret Arch on north-central Axel Heiberg Island (from detailed gravity measurements taken along two transects in 1987), and Cornwall Arch on Cornwall Island (from pre-existing gravity data).Gravity signatures beneath the three major uplifts, analyzed in the context of the gravitational effects of the observed near-surface geology of Cornwall and Princess Margaret arches, are consistent with a model of gradational change from isostatic compensation beneath the Grantland Uplift to antithetic isostatic compensation beneath Cornwall Arch. These signatures correspond to increasing distances westward, from the zone of maximum Eurekan compression. Thus, the area of Grantland Uplift has been tectonically thickened, whereas Cornwall Arch is underlain at depth by a broad crustal/mantle upwarp. Princess Margaret Arch is considered to be transitional between these two end-members, possibly being cored by a deep crustal upwarp, but also involving tectonic thickening, perhaps by stacking of thrust slices.It is speculated that Cornwall and Princess Margaret arches may be the manifestation of crustal scale “folding” in response to in-plane compressional stresses developed during the Eurekan Orogeny. The distance between these two arches is about 200 km and is similar to the expected wavelength of deep crustal folding, given typical flexural rigidities for continental lithosphere.

U2 - 10.1016/0025-3227(90)90095-2

DO - 10.1016/0025-3227(90)90095-2

M3 - Article

VL - 93

SP - 401

EP - 420

JO - Marine Geology

JF - Marine Geology

SN - 0025-3227

IS - 1-4

ER -