Towards a better
understanding of the Superior Province
Robert Marquis
Géologie Québec
|
Figure 1 :
The Superior Province is a vast region whose specific geological
characteristics make it especially attractive for mineral exploration.
This map of the Superior Province shows the main subdivisions, which
include the Abitibi sub-province, the La Grande sub-province and
the Grenville Front. |
The Superior Province is a vast region whose specific
geological characteristics make it especially attractive for mineral exploration
(Figure 1). It contains large areas of ancient volcanic rock over 2,700,000,000
years old likely to contain gold, copper and zinc deposits, magmatic rock
rich in nickel and platinum, Algoma-type iron formations, and diamond-bearing
kimberlite bodies from a more recent period than the volcanic rock.
This year, Québec
Exploration 2004 will include a technical session that will look specifically
at the Superior Province. Speakers from Québec, Ontario and Manitoba
will discuss the geological evolution, detailed internal structure and
mineral potential of this geological province. The traditional focus on
Québec and Ontario will be extended to include Manitoba, offering
participants a technical session that will cover the whole of the Superior
Province. The topics covered will include different types of mineralization,
especially orogenic gold deposits, internal subdivisions and the nature
of contact with adjacent geological provinces.
Historical background
Québec and Ontario have worked together to disseminate
geological knowledge about the Superior Province for over 20 years.
In 1984, the first geological map covering the entire Abitibi greenstone
belt to a scale of 1/500 000 was published jointly by the Québec
department of Energy and Resources and the Ontario Geological Survey (OGS).
At the time, the focus was on the Abitibi greenstone belt (Figure 2)
because of its high concentration of rich metal deposits, in production
since the early 20th century.
|
Figure 2 : The Abitibi greenstone
belt is especially important from an economic point of view, because
of its high concentration of rich metal deposits, in production
since the early 20th century. This photo shows the types of transportation
used to gain access to the remotest areas.
|
In 2000, Québec and Ontario also collaborated
to present a special technical session devoted to the Abitibi
greenstone belt and adjacent areas in the Superior Province.
This technical session was given in Québec as part of the
annual information seminar on geological research. Later, fourteen scientific
papers derived from the technical sessionwere published in a special issue
of the journal Precambrian Research for 2002, co-edited by W. U. Mueller
(Université du Québec à Chicoutimi), R. Marquis
(Ministère des Ressources naturelles de la Faune et des Parcs)
and P. Thurston (OGS).
In Québec, between 1995 and 2002, a detailed mapping
program at a scale of 1/50 000 was carried out in the Baie James area (Figures
3 and 4) to improve the cartographical, geochronological and metallogenic
data available, and to create a new overview for the sectors of the La
Grande and Eastmain rivers, two regions of the Superior Province with
strong mineral potential.
|
|
Figure 3 :
A geologist crosses a gigantic rocky outcrop in the Baie James area,
in the promising exploration sector of the Rivière Eastmain.
|
Figure 4 :
In the Baie James area, the detailed 1/50 000 mapping program required
the sampling and analysis of many different rock samples, carefully
selected for their geological characteristics and economic potential.
|
During the same period, between 1998 and
2003, Québec conducted an ambitious mapping program of the eastern
section of the Superior Province, to the north of Baie James. The program,
known as “Projet Grand Nord”, led to completion of map coverage
at a scale of 1/250 000 and the initial metallogenic reconnaissance of
northern part of Québec (Figures 5 and 6). In addition to opening up new
areas for mineral exploration, this extensive program to acquire new knowledge
allowed considerable progress to be made in terms of the geological understanding
of northern lands. Rocks among the oldest in the world were discovered
along the Hudson Bay shoreline, and several thematic projects were conducted
in partnership with the Université du Québec à Montréal,
McGill University, Simon Fraser University and the Geological Survey of
Canada. The scope and complexity of the program mobilized practically
all the human and financial resources of Géologie Québec.
Currently, several geologists are still working to assemble all the information
gathered during the project.
|
|
Figure 5 :The
“Projet Grand Nord” led to completion of map coverage
at a scale of 1/250 000 and the initial metallogenic reconnaissance
of Nord-du-Québec. In this photo, one of the department’s
geologists carries out observations in the field, to the north of
the tree line.
|
Figure 6 :
The “Projet Grand Nord” opened up new areas for mineral
exploration. This photo shows a temporary summer camp, set up for
10 weeks to house an 18 member geological team.
|
|
Figure 7 :
In the Chibougamau sector, the current program
of work is intended to gather more precise information about the
contact between the Superior Province and the Grenville Province.
In this photo, a group of geologists discusses the economic potential
of the outcrop in the foreground. |
A continually
renewed approach
In 2003, detailed work at a scale of 1/50 000 was carried
out in the Chibougamau sector (Figure 7), giving a more precise view of
the t
pe of contact between the southern edge of the Superior Province and the
Grenville Province, an ancient, highly eroded mountain range that brings
to the surface rocks formed deep in the earth’s crust.
In the Abitibi greenstone belt, in both
Québec and Ontario, current work involves compiling the data needed
to update the 1984 Ontario-Québec map and completing targeted cartographical
projects and highly detailed metallogenic overviews of various mining
camps (Figure 8). In Québec, as part of the metallogenic overviews,
special attention is paid to integrating public databases, allowing 3D
modelling in partnership with the Université du Québec en
Abitibi-Témiscamingue that proves extremely useful in determining
new exploration targets.
|
Figure 8 :
In the Abitibi greenstone belt, highly detailed metallogenic overviews
integrate public databases containing information from a number
of mining camps and 3D modelling, especially useful for determining
new exploration targets. A young geologist from the department shows
a detailed geological map to colleagues from the mining industry.
|
In addition to a technical session to look specifically
at the Superior Province, Québec Exploration 2004 will include
two multimedia workshops to present results from detailed surveys carried
out by MRNFP geologists. The workshops will be conducted by the MRNFP
geologists responsible for each project. The first workshop will examine
recent discoveries in the Rouyn-Noranda region, where the Blake River
Group is under intensive scrutiny to identify new sources of copper ore.
The second workshop will deal with the Chibougamau area, and more specifically
will look at mineral potential on the Grenville Front, the boundary between
the Superior Province and the younger Grenville Province.
You are warmly invited to attend these interactive workshops.
Références
1994, Géologie du Québec, Les
publications du Québec, pages 7 to 46.
2002, Evolution of the Archean Greenstone Belt and
adjacent terranes: New Insights from Geochronology, Geochemistry, Structure
and Facies Analysis, Precambrian Research, Special Issue, volume 115,
371 p.
MERQ-OGS, 1983, Carte lithostratigraphique de la
sous-province de l’Abitibi : ministère de l’Énergie
et des Ressources du Québec/Ontario Geological Survey: 1:500 000,
catalogué "DV83-16" à Québec et "Map 2484"
en Ontario.

|