Pprxonfil and ^rientijic Nmos. 135 
stone, as is also the case with other areas, often of considerable size, 
of aiigen and syenitic gneiss, pyroxene and (juartz-feldspar, formerly 
also classed as pyroxenic and quartzose gneiss, and regarded as an 
integral |)ortion of the gneiss and limestone series. In regard to the 
structnre of the calcareous i)ortion the author held that tlie crystal- 
line limestones should be regarded as the upper member of the series 
entirely, instead of being ])laced at widely separated horizons in the 
orthoclase gneiss, and tliat there is a gradual passage downward from 
the calcareous rocks into the gneisses, by the interstratitications in the 
hnver part of thin bands of the latter. The foliation sometimes seen 
in the syenitic and augen-gneiss. and also in certain portions of the 
Anorthosite, is suj)posed to be due to the ])ressure by which the entire 
series was thrown into the crumpled state in which it is now found. 
Th( occurrence of economic minerals, such as apatite, graphite, 
mica and asbestos, is regarded as de])endent upon, or influenced by, 
the intrusions of pyroxene and (piartz-feldspar, or other igneous 
rocks, the apatite being always confined to the pyroxene dykes, 
except where it occurs in the form of crystals scattered through the 
limestone mass, or in veins in the i)yroxene which traverse that rock. 
The conclusion was stated that the series in ascending order is gneiss 
of various kinds, passing ujiward gradually into limestone, constitut- 
ing the Laurentian proper, and succeeded upward by the schists of 
tlie Hastings series of Vennor, which presumably constitute the low- 
est member of the lluronian system. 
KoBKRT Bell — The contact of the Laurentian and Huronian north 
of lake Huron. 
The writer gave a brief sketch of what he lias called "'The Great 
Belt of the lluronian rocks of Canada," which runs from lake Su- 
perior to lake ^listassini, a distance of 700 miles, following its general 
course. The so-called " ty})ical Huronian " of lake Huron is only a 
small section of this belt, and a passing protest was made against the 
use of this term. The general relation of the Huronian to the Laur- 
entian was next referred to. The question as to the conformity or 
otherwise of the two systems involves the admission that the Laur- 
entian is an altered sedimentary series. As a rule, the stratification 
of the latter, whether due to i)ressure-foliation or to sedimentation 
was conformable with the aqueous stratification of the Huronian and 
the few exceptions to this which iiad been observed in Canada ap- 
peared to be all due to faulting. 
^lany geologists a|)pear to su|)pose that the bedding of llic 
Huronian rocks along the north shore of lake Huron dips geiierally 
at low angles. Hut even if it did so, this would be merely a local 
accident of structure and of no signilicance from a chronological 
point of view. The dips, however, are not at moderate angles, except 
in some limited areas. As a rule, they are at very high angles, ap- 
proaching the vertical — higher indeed than that of the Laurentian 
gneisses to the eastward. 
In tracing the several bands of the Huronian series along the north 
shore, they are found lo strike with great regularity almost due east. 
Bui as they ap])roach the contact of the Laurentian they a[)|)ear to 
double round the east end of a great syncline, and part of them 
jn'obably round two or three secondary basins, opposite the eastern 
part of Grand Manitoulin island. 
From the eastern extremity of lake Sujierior, the Great Belt fol- 
lows the north shore of lake Huron to Killarney, at the commence- 
ment of Georgian bay. Thence its south-eastern border turns inland 
and runs north-eastward to the Ottawa river. .Vlong this boundary, 
on leaving lake Huron the stratification on either side is at first 
parallel or nearly so, but before we have followed the line of contact 
