Discovery of a potential source of cement stone
in the Percé area
A large limestone deposit, considered to be a promising
resource of cement stone, has been discovered in the Percé
area. This deposit was found during work on industrial minerals
and construction materials carried out by the Ministère des
Ressources naturelles, de la Faune et des Parcs. The results were
revealed during Québec Exploration 2004, held in
Québec from November 22 to 25, 2004.
A summary evaluation of the limestone indicates
grades of CaO (48–50%), Na2O+K2O (< 0.6%),
MgO (< 2.5%), S (< 0.2%), and Cl (< 30 ppm)
that satisfy the requirements of the cement industry. Easily accessible
resources are estimated at several hundreds of millions of tonnes.
In addition, the potentially exploitable limestone units are located
a few kilometers from the coast and near a railway.
Nature of the work
During the summer of 2004, the Ministère
des Ressources naturelles, de la Faune et des Parcs updated the
inventory of quarries in the Bas-Saint-Laurent and Gaspésie
regions. At the same time, a summary evaluation of the composition
of White Head Formation limestone was carried out in order to check
the potential of the sequence for cement production. The Nouvelle,
Chandler, and Percé sectors were chosen because, in these
areas, the formation outcrops fairly close to the coast, thereby
increasing the likelihood of production (PDF Format,
131 Kb - Available in French). Hand sampling was carried
out on a limited number (25) of outcrops. As the White Head limestone
sequence is composed of thin limestone beds alternating with mudstone
beds, the analyzed samples contain, unless otherwise noted, representative
proportions of the two lithologies (PDF Format,
19,3 Kb - Available in French).
In the Percé area, the White Head Formation
outcrops in a mountainous corridor about 1.5 km wide that
crosses the region in a northwest-southeast direction (PDF Format, 587 Kb
- Available in French). The formation is divided into
four members. The Burmingham, Irlande, and Des Jean members
distinguish the formation. They are composed mainly of thin
calcilutite beds and friable mudstone interbeds. (photo 1)
The Côte de la Surprise Member is a mudstone marker
horizon separating the Burmingham and Irlande members.
Distinctive appearance of the White Head
Formation, Cap Blanc quarry. Resistant calcilutite beds alternate
with friable mudstone interbeds.
Samples from four quarries have been analyzed.
The results have been used to estimate the composition of the Irlande
and Des Jean members. According to the results, these units have
similar chemical compositions, with a CaO grade of about 50% (PDF Format,
19,3 Kb - Available in French). In addition, the alkali-element,
magnesium, sulfur, and chlorine concentrations are suitable for
the cement industry. It is noteworthy that the two units constitute
a limestone sequence whose stratigraphic thickness is estimated
at more than 600 m (Kirkwood, 1989). The Burmingham Member,
located at the base of the White Head and about 140 m thick,
was not analyzed. However, it compares lithologically to the upper
limestone units, and it is likely that its composition is also suitable.
Chandler and Nouvelle areas
In the Chandler and Nouvelle areas, the White
Head Formation appears to be distinctly less calcareous than
at Percé. Most commonly, the formation is banded and
composed of limestone beds and argillaceous interbeds, which
are welded together producing a massive sequence. The analytical
results show that the CaO grade is generally less than 40%
19,3 Kb - Available in French). In the Nouvelle
area, a grab sample from a calcilutite bed gave a CaO grade
facies of the White Head Formation in the Chandler region.
An adequate evaluation of the potential of these
areas would require more detailed work. Stratigraphic horizons richer
in carbonate should be sought.
Kirkwood, D., 1989. Géologie de la région
de Percé. Ministère de l’Énergie et des
Ressources, Québec; ET 87-17, 33 pages.