Abstract
THE New Quebec Crater is a circular lake-filled depression, two miles in diameter, in the acid Archaean gneisses of northern Quebec (61.3° N., 73.6° W.). A bedrock rim encircles the crater rising 1,300 ft. above the crater floor, and 300 ft. above the surrounding barren lands. The rocks of the rim consist of quartzo-feldspathic gneisses identical to those outside the rim except for various degrees of hydrothermal alteration. The structure of the rim is unique, and is a relatively recent deformation of the regional Precambrian structure. Curviplanar structure elements are shown in Fig. 1. The vertical north-trending gneissosity common to the gneisses of this region is systematically deformed in the rim such that strikes are radial to the crater. Precambrian faults crossing the rim are deflected as much as 30° toward the centre of the crater. Analysis of the grid defined by gneissosity and faulting shows that the diametrical distance between two points on opposite sides of the crater has been decreased 2,500 ft. by this deformation. Rock sheeting is approximately horizontal outside the rim, but in the rim dips radially outward at angles varying from 10° to 85°, averaging about 33° (ref. 1). These results show that the rim is the remnant of a structural dome, approximately a spherical cap 18,000 ft. in diameter and 2,000 ft. high. The arc distance across this cap is 2,600 ft. longer than the diameter, and the inclination at the edge is 33°.
Similar content being viewed by others
Article PDF
References
Currie, K. L., and Dence, M. R., Nature, 198, 80 (1963).
Millman, P. M., Pub. Dom. Obs. Ottawa, 18, No. 4 (1956).
Shoemaker, E. M., Amer. Sci., 50, No. 1, 124 (1961).
Innes, M. J. S., J. Geophys. Res., 66, No. 7, 2227 (1961).
Innes, M. J. S., Meteoritics (in the press).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
CURRIE, K. Rim Structure of the New Quebec Crater, Canada. Nature 201, 385 (1964). https://doi.org/10.1038/201385a0
Issue Date:
DOI: https://doi.org/10.1038/201385a0
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.