Presents an examination of field relationships along the northern margin of Baker Lake Basin, Nunavut, with the goal of establishing the stratigraphy of the Dubawnt Supergroup in relation to paleogeography, depositional setting, and provenance. Includes information on the regional geology, local geology (Christopher Island Formation sedimentary & volcanic rocks, the newly named Amarook Formation, and the overlying Pitz and Thelon formations), and discusses faulting during the development of the Baker Lake Basin.
The Slave Province is a relatively small but well-exposed Archean craton in the north-west part of the Canadian Shield. Mapping of quartzite & banded iron formation occurrences throughout the Province since the 1970s has resulted in the conclusion that the overall topology of all greenstone belts in the central & western parts of the Province permits all such occurrences to be correlated into a single cover sequence, the Central Slave Cover Group. Following a brief historical overview, this paper presents field evidence for the discovery & successful correlation of that cover sequence across much of the craton. It then presents detrital zircon data to bolster this correlation, in particular to show that what was earlier mapped as a Paleoproterozoic cover sequence in central Wopmay Orogen is in fact part of the Central Slave Cover Group. The extension of the Cover Group into the north-western Slave Province have implications for the architecture & evolution of continental crust older than 2.85 billion years.
The idea for a book on anorthosites came to me in January of 1986 while returning to Houston after holiday festivities in Dallas. The original idea was a review paper on anorthosites, but by the time I reached Houston, the subject material I contemplated induding was obviously too extensive for a single paper. The Director of the Lunar and Planetary Institute, Kevin Burke, was receptive to the idea of a book, and suggested that I contact Peter Wyllie, who serves as Editor of the Springer-Verlag series Minerals and Rocks. This effort, which I originally expected would take about a year, has taken nearly 6. I have many excuses- indolence, moving to another continent, other commitments, etc.-but the basic truth is that writing a book is much larger an undertaking than can be anticipated. Many people are aware of this, and I was duly forewarned. . But why write a book on anorthosites? This is a very good question, which I have considered from many angles. One rationale can be expressed in terms of a comparison between anorthosite and basalt. A first-order understanding of basalt genesis has been extant for many years. By contrast, there is little agreement about the origin of anorthosite. There are good reasons for studying and writing about basalt: it is the most abundant rock type on the Earth's surface, and is also plentiful on the surfaces of the other terrestrial planets.
A number of small lead/zinc occurrences are hosted by grey plant-debris-rich sandstone of the Late Carboniferous of the Canadian Maritimes. This paper documents field observations on the geological environment of one of these occurrences at Meadowville, Nova Scotia. The aim of the paper is to comment on the possible extent of this occurrence, to provide field criteria for exploration for Carboniferous sandstone lead/zinc deposits, and to provide data for genetic modelling of this type of deposit.
This report presents findings of a bedrock geological mapping project carried out in 2003 in the Ferguson Lake area, located about 200 kilometres west of Rankin Inlet, Nunavut. The project was initiated to provide better understanding of the geology & deformation history of the area and to put a local nickel-copper-platinum group element deposit into a regional context. The main part of the report describes the rock units exposed in the area (metamorphosed supracrustal rocks and intrusive rocks) and the area's structural elements (gneissosity, folds, foliation, shear zones, faulting). An attempt is then made to correlate the deformational features observed in the area with those documented by other researchers. Finally, implications of the findings for the timing of mineralization are briefly discussed.
This report is part of an ongoing study to characterize both sequence stratigraphy and chronostratigraphy of the Baker Lake Basin, Nunavut. The investigators examined well-exposed segments of the basin in detail, emphasizing sequence stratigraphic analysis to identify genetic packages of strata related to tectonically controlled basin-filling rhythms. Three sections exposed at the western edge of Thirty Mile Lake have been measured and correlated, yielding data on five depositional sequences. After an introduction on the geologic setting of the study area, the report provides facies assemblage descriptions and interpretations of the five depositional sequences of the lower Baker Lake Group. Finally, the accommodation (or space made available for a sedimentary system to fill) cycle in the basin is discussed and conclusions are drawn regarding the subsidence mechanism in the basin.
