Geological Survey of Canada, Current Research (Online) no. 2005-A3


Book Description

This study was conducted in response to concerns raised by local residents about water quality in Fisherman Lake, located 18 kilometres north-west of Fort Liard, Northwest Territories. Field investigation of the lake revealed the existence of 13 gas seeps (largely methane) with distinct bubble trains rising continuously to the surface. This paper presents results of analyses of the gas & of the lake water and the determination, through isotope analyses, of whether the gas is of biogenic origin (related to the decomposition of organic matter) or thermogenic origin (representing a seep from geological strata of the gas field below the lake). The possible effects of methane on the lake water are also discussed and recommendations are made for further research.







Geological Survey of Canada, Current Research (Online) no. 2005-C3


Book Description

This paper describes a novel, high-resolution application of cross-borehole seismology at the Snap Lake diamond mine, Northwest Territories, to assess whether the relatively thin kimberlite dyke that hosts the diamonds could be mapped underground with sufficient resolution to accurately estimate its volume and to guide mining. Subsequent mining and mapping with the 50-by-70-metre test panel indicated whether the technique was able to map the top & bottom surfaces of the dyke and to identify ramps, pinch-outs, and cross-cutting fracture planes. The tests also compared the performance of that new technique with two other geophysical methods, high-frequency vibrating seismic surveying and ground penetrating radar.






















Measuring Discharge with Acoustic Doppler Current Profilers from a Moving Boat


Book Description

The mission of the U.S. Geological Survey (USGS) Water Resources Discipline is to provide the information and understanding needed for wise management of the Nation's water resources. Inherent in this mission is the responsibility of collecting data that accurately describe the physical, chemical, and biological attributes of water systems. These data are used for environmental and resource assessments by the USGS, other government agencies and scientific organizations, and the general public. Reliable and quality-assured data are essential to the credibility and impartiality of the water-resources appraisals carried out by the USGS.