4c) The tuff also contains thick-medium bedded tuffite
The volcanic and volcano-sedimentary units in which Mn mineralization occurred mostly consist of mega-porphyritic andesite, spilitic lavas, tuffite
, and tuff.
The matrix of the huge limestone slab is mainly some brown-green tuffite
Six widely-spaced holes have been completed to date targeting the Key Tuffite
In the upper part of the tuffite
series, a 6-m-thick basalt layer was drilled.
The first holes are scheduled on the East Block where a zinc tuffite
was intersected four times by diamond drilling, followed by other drilling targets on the East Block, and finally the drill will be moved to the West Block where the DeepEM "in-loop" anomaly of 600 m length revealed in 2003 was confirmed and more precisely located by an InfiniTEM survey just completed.
1993), the boundary interval is characterized by three main facies: (1) volcanoclastics and basaltic rocks with subordinate shallow-water limestones, (2) shales and cephalopod limestones and (3) mostly shale facies with tuffite
layers without carbonates.
The flysch series having mixed volcanic material composed of conglomerate, green and black sandstone, shale, marl, limestone, andesite, tuff and tuffite
are deposited in the Upper Cretaceous limestone.
Overburden layers reach up to 50 m in thickness; of all, 30-40 m of the profile is represented by tuff and tuffite
layers usually several decimetres thick.
The first three holes are located in the eastern block of the Du Dome-Matagami Property where a zinc tuffite
was intersected twice by diamond drilling in 2004; they have intersected the tuffite
at two other locations.
Good continuity is interpreted between this hole and the mineralization intersected at the Key tuffite
exhalite interface in hole MC-04-07.
The first three holes are all located inside the eastern block of the Du Dome-Matagami Property where a zinc tuffite
was intersected twice by diamond drilling in 2004.