Summary of Scientific Activities

Throughout the year, scientific activities in all of the multidisciplinary studies of the project progressed well. Increased activity during the summer field season includes geological, geochemical and geophysical projects, undertaken by university scientists, which have a field component and are supported wholly or partially by the LITHOPROBE supporting geoscience program. Many contributions to field and laboratory studies from the GSC and provincial/territorial geological surveys are also being carried out. These activities are an integral part of the overall LITHOPROBE project; to mention them individually is not possible because they are so numerous and cover such a wide range of studies and field areas. On the academic side, 66 supporting geoscience awards were made for 1994-95 and most of these have a field component. Transects in which such studies are active are: Abitibi-Grenville, Trans-Hudson Orogen, Alberta Basement, Eastern Canadian Shield Onshore-Offshore, Slave-Northern Cordillera Lithospheric Evolution and Western Superior.

Five major geophysical surveys were completed during 1994: two seismic reflection surveys, two magnetotelluric surveys, and one UTEM electromagnetic survey.

Alberta Basement Transect

630 km of regional reflection data were acquired in the transect’s northern corridor, the Peace River Arch region, with 70% of the funding provided by a LITHOPROBE/GSC/Industry consortium and the remaining 30% made available through ISPG as an addition to the GSC’s usual contribution to seismic reflection studies. An "in-house" electromagnetic survey used the GSC’s LIMS very long period magnetotelluric (MT) instruments to enable signal detection through the overlying, conductive sediments. Site locations follow the 1992 and other reflection lines, but cover these regions as a swath rather than a profile to provide better constraints on 3-d variability of the conductivity structure of the Precambrian rocks.

Trans-Hudson Orogen Transect

955 km of regional reflection data were acquired along six separate lines. Two of these address the western boundary of the orogen with the Hearne-Rae craton; three lines address internal components of the orogen, two in the western part and one in the north central region; and the final line is situated over the eastern boundary zone, the extension of the Thompson belt below the Phanerozoic cover. In addition, 32 km of very high resolution data were acquired in the Athabasca Basin with funding provided by three uranium mining companies in association with the Saskatchewan Research Council. Twenty-four MT stations were situated along the reflection lines in the northwestern part of the transect to investigate conductivity signatures associated with the western boundary zone and internal components of the orogen. Data were acquired at six other stations deployed in the region of the 1991 reflection line in the Thompson Belt area to provide some clarifications required from earlier studies and to complement the higher frequency UTEM survey carried out earlier in 1994 as a cooperative project with industry. Four "vibroseis" trucks from Enertec Geophysical of Calgary on location in central Manitoba as part of the Trans-Hudson Orogen Transect seismic reflection studies. The trucks, vibrating synchronously, provide the sound energy source for the reflection survey. (Photo courtesy of David Baird, UBC).

The scientific synthesis for the Kapuskasing Structural Zone Transect is essentially complete with the availability in October of a Special Issue of the Canadian Journal of Earth Sciences, V. 31, No. 7 (July) 1994 dedicated to transect results. John Percival, GSC Ottawa, did an outstanding job as Guest Editor. During the year, manuscripts for the scientific synthesis of the Southern Cordillera Transect were completed. These are accepted, in revision or in review and we are hoping for a late 1995 publication date in CJES. Fred Cook is the Guest Editor. In the Lithoprobe East Transect, plans for the synthesis of results have been prepared and the procedure is just beginning.

Final processed seismic sections from the 1993 Abitibi-Grenville seismic reflection survey were available in 1994. The high quality images along two Grenville corridors in Quebec and the Abitibi-Opatica corridor show reflectivity throughout the crust and provide details on the complex interactions among the various tectonic units associated with each corridor. Preliminary manuscripts by the different working groups are in preparation.

Educational and Communication Activities

The LITHOPROBE PROJECT - "PROBING THE LITHOSPHERE", an educational set of 80 slides with an accompanying 36-page text of explanatory information and slide captions, is available. The package follows a theme of the mysteries of studying Earth and was prepared to provide earth science instruction material for senior high school and first or second year university use. It is based on LITHOPROBE results to early 1994 and includes a section of 24 slides (with explanations) illustrating the many earth science disciplines applied in the project.

Principally through the efforts of Horst Heise, our Communications Adviser, LITHOPROBE’s communication activities continue, with greater emphasis on the electronic media. This has resulted in some segments on local TV stations in Saskatoon, one carried also on CBC Newsworld. The new Canadian Discovery Channel started preparation of a 10-minute segment on LITHOPROBE to be aired in the first half of 1995. An article on LITHOPROBE is being prepared by a free-lance journalist for the Canadian Geographic magazine. We encourage such items not only to promote LITHOPROBE as a project but also better understanding of the Earth Sciences in Canada.

Organizational Activities

During 1994, two significant developments at the Secretariat took place. With the knowledge that the project is poised to continue into the next century, all computer systems were updated and we now have an on-ramp to the information highway which we will utilize to the benefit of the project. After almost eight years of enthusiastic dedication to LITHOPROBE as the Secretariat’s Administrative Assistant, Lilian Beames retired at the end of the year to devote her energy and efforts to other endeavours. Cecilia Li, formerly LITHOPROBE’s Secretary, became the new Administrative Assistant while Nancy Kan is the new Secretary.

The Scientific Committee of LITHOPROBE met in April, the Board of Directors in June and a joint meeting of both groups was held in December. Active transects held their annual workshops at different times throughout the year. SNORCLE Transect, looking at the Slave - northern Cordillera area of Canada had its first, formative workshop in April; Western Superior Transect, focusing on understanding the architecture and evolution of the Archean cratonic core of Canada, held its first transect workshop in October.

Ron Clowes

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