scholarly journals Sm-Nd isotopic study on mafic volcanic rocks from the Rankin Inlet and Tavani regions, District of Keewatin, Northwest Territories

1997 ◽  
Author(s):  
R J Thériault ◽  
S Tella
Keyword(s):  
Northwest Territories ◽  
Volcanic Rocks ◽  
Isotopic Study

Provenance of Paleozoic sedimentary rocks in the Canadian Cordilleran miogeocline: a Nd isotopic study

1997 ◽  
Vol 34 (12) ◽  
pp. 1603-1618 ◽  
Author(s):  
Carmala N. Garzione ◽  
P. Jonathan Patchett ◽  
Gerald M. Ross ◽  
JoAnne Nelson
Keyword(s):  
British Columbia ◽  
Northwest Territories ◽  
Middle Devonian ◽  
Volcanic Rocks ◽  
Sedimentary Rocks ◽  
Canadian Shield ◽  
Isotopic Study ◽  
Middle Ordovician ◽  
Southern Alberta ◽  
T Values

Nd isotopes and trace elements in sedimentary rocks of the Yukon, the Northwest Territories, and northern British Columbia are used to examine the source of sediments in the Canadian Cordilleran miogeocline. Previous Nd isotope studies in southern Alberta demonstrated that strata of Neoproterozoic to Late Ordovician age were derived from Archean and Proterozoic Canadian Shield sources, whereas by the Late Devonian, a shift of 6 εNd units to younger crustal sources (εNd (T) = −6 to −9) had occurred. In this study, we found that the shift to younger crustal Nd isotopic signatures in the Yukon and Northwest Territories occurred much earlier than in southern Alberta. Cambrian and older strata have εNd(T) values of −10.0 to −21.1, consistent with derivation from Canadian Shield sources. Lower Ordovician through Permian strata in the Yukon and Northwest Territories, including the Innuitian-derived Imperial Assemblage, have εNd(T) values of −5 to −11.4. In northern British Columbia, the shift to a younger source reflects a wider range of εNd(T) values, from -−8.7 to −14.6 in Middle Ordovician through Middle Devonian strata, suggesting continued input from Canadian Shield sources. By the Middle Devonian, a complete shift to younger crustal signatures (εNd(T) = −5.9 to −10.5) had occurred in northern British Columbia. Several sources for the more juvenile sediments include (1) a mixture of locally erupted volcanic rocks with Canadian Shield sources, (2) a Grenville source, and (3) an Innuitian source. We propose that Ordovician to Lower Devonian strata were derived from a mixture of locally erupted, juvenile volcanics and pre-Cambrian Canadian Shield sources, and post-Middle Devonian strata were sourced from the Innuitian orogen in the Canadian Arctic.

A Sr, Nd, and Pb isotopic study of mantle domains and crustal structure from Miocene volcanic rocks in the Mojave Desert, California

2000 ◽  
Vol 112 (8) ◽  
pp. 1264-1279 ◽  
Author(s):  
J. S. Miller ◽  
A. F. Glazner ◽  
G. L. Farmer ◽  
I. B. Suayah ◽  
L. A. Keith
Keyword(s):  
Crustal Structure ◽  
Mojave Desert ◽  
Volcanic Rocks ◽  
Isotopic Study

U–Pb zircon geochronology, geochemistry and Nd isotopic study of Neoproterozoic bimodal volcanic rocks in the Kangdian Rift of South China: implications for the initial rifting of Rodinia

2002 ◽  
Vol 113 (1-2) ◽  
pp. 135-154 ◽  
Author(s):  
Xian-hua Li ◽  
Zheng-Xiang Li ◽  
Hanwen Zhou ◽  
Ying Liu ◽  
Peter D. Kinny
Keyword(s):  
South China ◽  
Volcanic Rocks ◽  
Zircon Geochronology ◽  
Isotopic Study

scholarly journals The Song Da magmatic suite revisited: A petrologic, geochemical and Sr–Nd isotopic study on picrites, flood basalts and silicic volcanic rocks

2011 ◽  
Vol 42 (6) ◽  
pp. 1341-1355 ◽  
Author(s):  
Tran Viet Anh ◽  
Kwan-Nang Pang ◽  
Sun-Lin Chung ◽  
Huei-Min Lin ◽  
Tran Trong Hoa ◽  
...  
Keyword(s):  
Volcanic Rocks ◽  
Flood Basalts ◽  
Isotopic Study ◽  
Silicic Volcanic ◽  
Magmatic Suite

U–Pb, Pb–Pb, and K–Ar isotopic study and petrography of uraniferous phosphate-bearing rocks in the Thelon Formation, Dubawnt Group, Northwest Territories, Canada

1989 ◽  
Vol 26 (5) ◽  
pp. 867-880 ◽  
Author(s):  
A. R. Miller ◽  
G. L. Cumming ◽  
D. Krstic
Keyword(s):  
Northwest Territories ◽  
Tectonic Setting ◽  
Uranium Mineralization ◽  
Isotopic Study ◽  
Thelon Basin ◽  
Wide Range ◽  
Minimum Age ◽  
Basal Conglomerate

The Thelon Formation, uppermost unit of the Dubawnt Group, overlies a regionally extensive paleoweathered zone developed on a wide range of lithochronological units including formations in the lower Dubawnt Group. Authigenic uraniferous phosphate minerals, fluorapatite and goyazite, cementing Thelon conglomerate–sandstone and filling fractures in the underlying paleoweathered zone, were dated in an attempt to better constrain the age of Thelon sedimentation and diagenesis. The oldest age, 1720 ± 6 Ma, derived from phosphate-cemented sediments, is interpreted as a minimum age for diagenesis and therefore brackets initial Thelon sedimentation between emplacement of fluorite-bearing granites at 1753 Ma and authigenic phosphate cementation at 1720 Ma. Additional ages of 1685 ± 4 and 1647 Ma are interpreted as remobilization or subsequent cementation events. K–Ar ages on illite, 1386 ± 37 and 1266 ± 31 Ma, from the paleoweathered zone and basal conglomerate, respectively, are significantly younger than ages derived from coexisting phosphate. These K–Ar ages record hydrothermal events that may be related to processes associated with unconformity-type uranium mineralization at approximately 1400–1300 Ma.Ages from the Thelon Basin permit geochronologic correlations with the Athabasca and Hornby basins, long correlated on the basis of similarities in sedimentation, stratigraphy, and tectonic setting.

A strontium isotopic study of the volcanic rocks of the Myoko volcano group, central Japan

1977 ◽  
Vol 63 (3) ◽  
pp. 295-307 ◽  
Author(s):  
K. Ishizaka ◽  
T. Yanagi ◽  
K. Hayatsu
Keyword(s):  
Volcanic Rocks ◽  
Isotopic Study ◽  
Central Japan

Observations on the Proterozoic Seton Formation, East Arm of Great Slave Lake, Northwest Territories

1972 ◽  
Vol 9 (9) ◽  
pp. 1110-1123 ◽  
Author(s):  
M. A. D. Olade ◽  
R. D. Morton
Keyword(s):  
Northwest Territories ◽  
Volcanic Rocks ◽  
Chemical Analyses ◽  
Quartz Porphyry ◽  
Shallow Marine ◽  
Hypabyssal Intrusions ◽  
Lake Region ◽  
Great Slave Lake ◽  
Marine Sedimentation ◽  
Partial Chemical

The Proterozoic (Aphebian) Seton Formation is shown to extend across almost the entire length of the East Arm structural subprovince of the Great Slave Lake region, Northwest Territories. Earlier described as greenstones or basalts and recently as an andesite–rhyolite suite, the volcanic rocks which characterize the Seton Formation are clearly of spilitic–keratophyric affinity. The formation is composed of a sequence of marine to subaerial, spilitic basalt flows, trachytic flows, quartz keratophyric–and spilitic–basic pyroclastics, volcanic sandstones, jasper, banded ironstones, and intercalated marine epiclastic sedimentary rocks. Small hypabyssal intrusions of albite granophyre, albite, and quartz porphyry represent minor subvolcanic phases. Petrographic descriptions of the lavas and pyroclastic rocks from Toopon Lake, the Fort Reliance area, and Seton Island are augmented by partial chemical analyses of 15 lavas from the latter locality. The volcanic–sedimentary Seton Formation, 1300 m thick in the SW of the East Arm, and 40 m thick in the Fort Reliance district, should be classified as a member of the Sosan Group, being in part laterally equivalent to the Akaitcho River Formation and the upper Kluziai Formation. The Aphebian Coronation Geosyncline during Seton times was thus characterized by effusive (partially submarine) island volcanism in the SW of the region, contemporaneous with shallow marine sedimentation towards the northeast part of the basin.

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