Fault zone and differing geology under the Charlevoix impact structure.
I superimposed a schematic of the geologic faulting under the Charlevoix crater onto this aeronautical chart of the crater area. A line drawn west to east on the chart corresponds to the physical position of the schematic illustrating the fault zone and differing geology under the crater.
Structural cross-section B-B’ restored by flattening on the Sundance datum to remove the effects of Laramide deformation. Formation symbols are identified in the figure to the left. (Stone et al 2003).
DES PLAINES STRUCTURE
St. Martin impact structure – preserved with 100 m of Jurassic sediment cover.
Ground penetrating radar survey and interpretation of the Bloody Creek structure. Ground-penetrating radar traverses were obtained when the site was frozen in winter. They confirm the crater morphology of the structure, and the distinction of the shallow levels from the undisturbed bedrock. (Spooner et al 2009)
Image showing the remnants of a crater that UAlberta researchers theorize was left by a massive meteorite strike sometime in the last 70 million years. Colour variation shows metres above sea level.
A. 200 kHz single-beam bathymetry] B. Residual magnetic field. C. N-S chirp seismic profile (Suttaket al, 2013)
(after McCabe, 1982)
Howell Creek Structure Geological map. (BC Ministry of Energy and Mines, 2001).
Seismic data in the James River 3-D volume. Several interpreted horizons are shown. The upper horizon corresponds to the top of the Cambrian, the middle horizon corresponds to the Cambrian ‘event’, and the lower horizon corresponds to the Precambrian. Faulting in the James River dataset is divided between shallow rim faults and deep central and rim faults.
Generalized geologic and topographic map of the Merewether (possible) impact crater and vicinity. Traced from vertical photograph USAF T.P.12, run #22-209.
The layers of sedimentary rock that covered the crater sagged, stretching the rock at the rim causing differencial cracking. The fractures (joints) developed above the rims of the crater were eroded during the last ice age. The glacial erosion of the joints which formed about the crater rim formed the course of the Esopus and Woodland Creeks.
The Victoria Island structure is characterized by a concentric, annular, terraced rim and trough surrounding a structurally uplifted central peak. Contour lines of equal thickness over an area (Isopach map) of interval between upper Nortonville Shale marker and lower Domengine Formation marker, showing series of concentric circular ridges and troughs, together with positions of several major, curvilinear normal faults that surround the structure and cut the lower part of the isopached interval.