10. Gravity Studies of the Grenville Province: Significance for Precambrian Plate Collision and the Origin of Anorthosite

1985 ◽  
pp. 109-123 ◽  
Author(s):  
M. D. Thomas
Keyword(s):  
Grenville Province ◽  
Plate Collision

Grenville paleomagnetism and tectonics

1978 ◽  
Vol 15 (5) ◽  
pp. 687-695 ◽  
Author(s):  
M. O. McWilliams ◽  
D. J. Dunlop
Keyword(s):  
Paleomagnetic Data ◽  
Cooling Rates ◽  
Grenville Province ◽  
Plate Collision ◽  
Relative Chronology ◽  
Paleomagnetic Poles ◽  
Metamorphic Terranes ◽  
Local Uplift

The determination of magnetization age is fundamental to the understanding and interpretation of paleomagnetic data from metamorphic terranes such as the Grenville Province. Assignment of absolute magnetization ages in slowly cooled rocks, although indeed possible, is difficult in practice due to variability in blocking temperatures of both magnetic and isotopic systems, and in local uplift and cooling rates. Characteristic Grenville paleomagnetic poles of likely post-metamorphic age can be grouped in a relative chronology on the basis of equal age 'thermochron' contours. These pole groups define a post-Keeweenawan loop that can explain the apparently discordant poles without invoking plate collision. As poles postdate the Grenville event, it is unlikely that paleomagnetic data from within the Grenville itself will be useful in testing collisional models for the ca. −1000 Ma orogeny.

A U-Pb Geochronological Framework for the Pinware Terrane, Grenville Province, Southeast Labrador

1994 ◽  
Vol 102 (1) ◽  
pp. 67-78 ◽  
Author(s):  
Robert D. Tucker ◽  
Charles F. Gower
Keyword(s):  
Grenville Province

Geology and age of the Precambrian basement in the Windsor, Chatham, and Sarnia area, southwestern Ontario

1982 ◽  
Vol 19 (8) ◽  
pp. 1627-1634 ◽  
Author(s):  
A. Turek ◽  
R. N. Robinson
Keyword(s):  
Oil And Gas ◽  
Precambrian Basement ◽  
Grenville Province ◽  
Metasedimentary Rocks ◽  
Gas Drilling ◽  
Arch System ◽  
Grenvillian Orogeny ◽  
Anomaly Map ◽  
Paleozoic Rocks ◽  
Basement Surface

Precambrian basement in the Windsor–Chatham–Sarnia area is covered by Paleozoic rocks that are up to 1300 m thick. The basement surface is characterized by a northeast–southwest arch system with a relief of about 350 m. Extensive oil and gas drilling has penetrated and sampled this basement, and an examination of core and chip samples from 133 holes and an assessment of the magnetic anomaly map of the area have been used to produce a lithologic map of the Precambrian basement. The predominant rocks are granite gneisses and syenite gneisses but also significant are gabbros, granodiorite gneisses, and metasedimentary rocks. The average foliation dips 50° and is inferred to have a northeasterly trend. The Precambrian basement has been regarded as part of the Grenville Province. An apparent Rb–Sr whole rock isochron, for predominantly meta-igneous rocks, yields an age of 1560 ± 140 Ma. This we interpret as pre-Grenvillian, surviving the later imprint of the Grenvillian Orogeny. Points excluded from the isochron register ages of 1830, 915, and 670 Ma, and can be interpreted as geologically meaningful.

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