This paper reviews the nature and origin of selected weathering features at small and large scales, and their use as indicators of the age of Quaternary glaciated and periglaciated land surfaces. Chemically weathered forms include crystaletching, boulder weathering rinds and surface relief; mechanically weathered forms include degrees of frost-weathering and associated rubble accumulations. Examples of their use as Quaternary geochonometers are drawn mainly from studies in the North American Cordillera and the highlands of eastern Canada. Alternative explanations of weathering differences in the latter area, specifically those emphasizing lithology, weathering environment, and glacial thermodynamics, are summarily reviewed and found to be inadequate when compared to a wealth of independent evidence that affirms the value of weathering features as chronological tools in eastern Canadian highlands, a value long recognized in the Cordillera.
This paper is the first published examination of the Paleozoic sedimentary sequence of southern Ontario as a radioactive waste disposal medium. A major asset in siting a repository in such a sequence is the ability to locate zones with favourable geotechnical properties in suitable hydrogeologic environments by application of a large data base to the relatively simple stratigraphie model. A review of the stratigraphy, and the geotechnical and hydrogeologic properties of shales in the sequence reveals several zones of interest for waste disposal purposes. The most significant factor controlling suitability of an area for reposi-tory siting is the regional flow pattern. Asa start in examining this factor, tenhydrostratigraphic units, distinguished by hydrogeologic properties alone, are proposed and used in a first attempt at evaluating the deep flow regime in southern Ontario.
In a previous article simple one dimensional models of metamorphic conditions were examined. In this article more realistic two-dimensional models are set up, to show the metamorphic effects of burial, intrusion and thrusting. Models in which erosion takes place demonstrate the development of a metamorphic faciès series and underline the importance of understanding regional stratigraphy in interpreting metamorphism.