Geological Survey Of Canada Current Research Online No 2000 C8

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.

A well-exposed section about 250 metres wide below the high water line of the Jennings River, Teslin Lake map area in northern British Columbia shows part of the Teslin Fault and provides an opportunity to constrain the fault's kinematic history by direct ground observations. This report describes preliminary structural observations of this section of the Teslin Fault, including the rock types involved, mylonitic & ultramylonitic structures, and deformation. Indications of two main episodes of shearing are 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.

The use of static global positioning system (GPS) equipment for accurate horizontal & vertical positioning in field geology operations at high latitudes is made difficult by the need to set up & operate a GPS reference station and limitations on the distance between the reference station & field GPS due to errors introduced by the ionosphere. Dual-frequency GPS receivers have the potential to eliminate these problems since they can eliminate ionospheric errors and thereby increase baseline lengths, thus potentially permitting the use of existing GPS reference stations. This paper describes the use of a dual-frequency receiver for establishing benchmarks along the Yukon River as a field trial of this technology. Field methods and post-processing of the data using GPS data from permanent receiving stations are described, and baseline results are presented. The derived benchmarks will be applied to a survey of fill thickness below the Yukon River.

The final year of the Nechako NATMAP project to study the geology of central British Columbia was used to research information collected in the field & laboratory, and to compile & document the study results. This article includes a review of upcoming publications & other products, by type of product: maps, journal articles, conference presentations, and computer products, as well as ongoing research on petrology, palaeontology, terrane characterization, tectonics & structure, and Quaternary geology.