Over the past two decades, the Geological Survey of Canada has used a standardized suite of slim-hole geophysical tools to log 57 polyvinyl chloride cased boreholes drilled in the glacial sediments of southern Ontario. This article documents downhole tool responses (natural gamma, apparent conductivity, magnetic susceptibility, and seismic velocity) in the context of mineralogical characteristics of the region and grain-size data from 28 of the 57 boreholes. Characteristic geophysical properties and (or) patterns are identified within the units of a regional hydrostratigraphic framework in southern Ontario. The importance of a calibrated suite of tools is emphasized, as stratigraphic units may have variable response from site to site. The use of a high-sensitivity magnetic susceptibility induction probe is shown to be an important tool in the log suite for lithostratigraphic interpretation, and more broadly, for provenance studies of source rock across the region. Ranges of compressional (P) and shear (S) wave velocities and their ratios are provided for each of the hydrostratigraphic units. Case studies are presented to demonstrate how logs may assist in the interpretation of glacial processes at lithological boundaries.

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The 28 February 1925 magnitude 6.2 Charlevoix Earthquake occurred at 9:19 p.m. local time. The epicenter was beneath the St. Lawrence River in the Charlevoix-Kamouraska area. The shock was felt at more than 1000 km from the epicenter. In the following weeks, dozens of aftershocks continued to shake the area, keeping residents on both sides of the St. Lawrence River on high alert. Damage was reported on both sides of the River in the epicentral zone, as well as in the cities of Québec and Shawinigan. In these areas, chimneys and masonry buildings proved particularly sensitive to the ground vibrations. The 1925 earthquake is one of five known moment magnitude 5.5-7 events that have occurred in the Charlevoix Seismic Zone (CSZ) between 1663 and present. This Open File Report presents the macroseismic information and its ratings on the Modified Mercalli Scale for a total of more than 600 locations in Canada and some 180 in the United States (from NOAA). This report builds on the macroseismic information published in Cajka (1999) and adds descriptive information for each locality where damage occurred. For each location, the felt information is rated on the Modified Mercalli intensity (MMI) scale and tabulated in a Microsoft Excel sheet. Numerous images of clippings of newspaper articles are included and the descriptive text is added to the database. In addition, photographs of the earthquake damage are included. The Open File also provides a GoogleEarth kmz file that allows the felt information reports to be viewed in a spatial tool.