Seawater and depositional variations across the Slave craton: insight from banded iron formation and associated rocks
Principal Investigator: Haugaard, Rasmus RH (2)
Licence Number: 15263
Organization: Department of Earth and Atmospheric Sciences, University of Alberta
Licenced Year(s): 2013 2012
Issued: Jun 13, 2013
Project Team: Department of Earth and Atmospheric Sciences, University of Alberta (Department of Earth and Atmospheric Sciences, University of Alberta)

Objective(s): To conduct detailed field mapping and sampling of the Archean Banded Iron Formation (BIF) from the Central Slave Cover Group.

Project Description: In the previous year, research work were started on some of the new occurrences of 2.9 - 2.6 Ga old banded iron formations in the NWT. This opened an exceptional opportunity to study ocean chemistry directly preceding the Great Oxidization Event (GOE). In this regard, the research group has been engaged with the Northwest Territories Geoscience Office (NTGO) to undertake field and laboratory studies of Archean BIF from the Central Slave Cover Group. The BIF from the NWT will provide important environmental information regarding the late Archean oceans (e.g., sea-level fluctuations, volcanism, biology, oxygen level and climate). As this project builds on last year’s project, it is the goal of this project to study in more details selected outcrops. So, this year the research team will be visiting fewer locations to better conduct detailed field mapping and sampling.

Field observations, rock relations, sample collections and microscopical studies are fundamental to this study. Preferable analytical techniques will be measurements such as 1) electron microprobe for elemental maps and major element quantification and, 2) ion probe micro-analyses for better accuracy on measurements and possibly isotopic analyses (TIMS) for dating and characterize the source input to the oceans. However, conventional major and trace element measurement may be required. The research group has published extensively on BIF in recent years, and all results will be published in international scientific journals.

The rocks north of Yellowknife contains possible evidence for the earliest photosynthetic activities on the Planet, the research project will shed light on the unanswered questions regarding the evolution of Earth's oldest aerobic ecosystems, as well as on the biosphere-ocean-atmosphere feedback system that led to the oxygenation of the atmosphere ca. 2.5 Gyr ago. The NWT rocks also contain some significant gold reserves, and thus, contribute to understanding the composition of these BIF and will add to the work of other scientists working on such gold-hosted deposits. Thus, the project will not only be an important contribution to current research in the field of Geology/Geobiology, but also to the potential development of the economy and society of the NWT.

The project and the results will be presented at the big Geoscience Forum conference in Yellowknife. Ongoing results are already being addressed and some of these results will be presented at the Geoscience forum, 2013. The project is still in close collaboration with one of the local geologist at the Geological Survey in Yellowknife so the communication of results will also be on the local level, and, in particularly, if the results are going to be fruitful.

The fieldwork for this study will be conducted from June 20, 2013 to July 20, 2013.