Base de données de recherche des TNO

étiquettes: water quality, diamond exploration, kimberlite

Objectif(s): To study the potential source of kimberlite (diamond) indicator minerals, and to improve the understanding of the geological history of Banks Island, and how this relates to off-shore geology and regional hydrocarbon systems.

Description du projet: The proposed research seeks to resolve the nature and potential source of kimberlite (diamond) indicator minerals, and to improve our understanding of the geological history of Banks Island, and how this relates to off-shore geology and regional hydrocarbon systems. For the kimberlite (diamond) indicator mineral study, the research team will take up to 100 small (10-20 kg) samples of stream sediments and various surface glacial deposits using hand shovels and sieves in areas where industry has previously identified kimberlite indicator minerals, and in other areas that are important to understanding their potential source and movement. These samples will then be shipped south to commercial labs for processing and analysis. Sampling of exposed sections (rock, sediment and ice) will also help to understand these different potential sources of diamond indicator minerals. The research team will revisit the two former lakes (now submerged by the sea) off of Sachs Harbour that has been previously identified as having the production of gas. Using the winter ice cover as a coring platform, the team will drill holes in the center of each basin so that measurements of water chemistry (temperature, conductivity, pH) can be taken and water samples collected from various depths for detailed chemical and gas analysis. The research team will also install a year-long monitoring system in each of the two basins - this involves lowering a rope with a weight attached to its bottom to the base of each basin (12 and 16 m deep) that has 10 small (20 cm long) sealed data loggers attached to it, suspended by a float (below the maximum depth of winter ice). These data loggers are able to record daily to hourly changes in water chemistry, and when retrieved in one year (summer 2016), will allow the team to understand how coastal erosion and flooding of former lake basins creates the unusual conditions that exist in these basins today, including the production of gas bubbles. Other sites where gas bubbles have been reported in lakes on Banks Island will be visited, and if possible samples of the gas will be collected into small (200 ml) bottles for isotopic analysis - this should tell us how the gas is being produced, and where it has been sourced from. Studies of the geological history will require study and measurement of exposed sections of rock, collection of small (fist-sized) samples for lab analysis including possible dating, and the identification of fossil plant (pollen) and other remains (foraminifera) to determine environments in which the rocks formed. The research team have begun consultation with the two closest communities, including a visit and consultation with Sachs Harbour this past June (2014). The team plan to continue engagement activities throughout the duration of this project and are hoping to make a return visit to the community of Sachs Harbour. Local wildlife monitors will help maintain the connection with the communities and their involvement in the research activities. Updates of each season's activities will be provided to the communities, and copies of all publications and presentations will be provided to them. The fieldwork for this study will be conducted from May 7, 2015 to July 24, 2015.