Some Salient Points in the Science of the EarthDawson, John William, Sir
Science
Some Salient Points in the Science of the Earth
Dawson, John William, Sir
Geology; Paleontology
When my paper was written I had not seen the account published by the
able Swiss palæobotanist Heer, of the remarkable Devonian flora of Bear
Island, near Spitzbergen.[91] From want of acquaintance with the older
floras of America and Western Europe, Heer fell into the unfortunate
error of regarding the Bear Island plants as Lower Carboniferous, a
mistake which his great authority has tended to perpetuate, and which
has even led to the still graver error of some European geologists, who
do not hesitate to regard as Carboniferous the fossil plants of the
American deposits from the Hamilton to the Chemung groups inclusive,
though these belong to formations underlying the oldest Carboniferous,
and characterized by animal remains of unquestioned Devonian age. In
1872 I addressed a note to the Geological Society of London on the
subject of the so-called "Ursa stage" of Heer, showing that though it
contained some forms not known at so early a date in temperate Europe,
it was clearly Devonian when tested by North American standards; but
that in this high latitude, in which, for reasons stated in the report
above referred to, I believed the Devonian plants to have originated,
there might be an intermixture of the two floras. But such a mixed
group should in that latitude be referred to a lower horizon than if
found in temperate regions.
[91] Trans. Swedish Academy, 1871, _Journal London Geological Society_,
vol. xxvlii.
Between 1870 and 1873 my attention was turned to the two sub-floras
intermediate between those of the Devonian and the coal formation, the
floras of the Lower Carboniferous (Sub-carboniferous of some American
geologists) and the Millstone Grit, and in a report upon these[92]
similar deductions were expressed. It was stated that in Newfoundland
and Northern Cape Breton the coal formation species come in at an
early part of that period, and as we proceed southward they belong to
progressively newer portions of the Carboniferous system. The same fact
is observed in the coal beds of Scotland, as compared with those of
England, and it indicates that the coal formation flora, like that of
the Devonian, spread itself from the north, and this accords with the
somewhat extensive occurrence of Lower Carboniferous rocks and fossils
in the Parry Islands and elsewhere in the Arctic regions.[93]
[92] "Fossil Plants of Lower Carboniferous and Millstone Grit
Formations of Canada," pp. 47, 10 plates. Montreal, 1873.
[93] G. M. Dawson, "Report on Arctic Regions of Canada."
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