382 
THE GEOLOGIST. 
4. " On the Probable Events which succeeded the Close of the Cretaceous 
Period." J3y S. V. Wood, jun., Esq. Communicated by S. V. Wood, Esq., 
P.G.S. 
Tlie object of this paper was to show that the close of tlie Secondary period 
was followed by the formation of a continent having a great extent from east 
to west, and at that time chiclly occupying low latitudes ; tiiat this direction 
of continent prevailed throughout the Tertiary period ; and that in certain por- 
tions of the southern hemisphere, particidarly m Australia and New Zealand, 
there have been preserved portions of the Secondary continent with isolated 
remnants of the Secondary mammalia and gigantic birds. These conclusions 
were arrived at by a consideration of the direction of the principal volcanic 
axes in the Secondary and Tertiary periods. The Secondary continent was 
(the author considered) mainly inllueneed in the northern hemisphere by vol- 
canic axes which came into action at the close of the Carboniferous, and 
continued through the Secondary Period. These axes were that of the 
Oural, that of the north of England prolonged into Portugal, and that of the 
Alleghanies, having all a north and south direction, supervening upon volcanic 
axes having a direction at right angles to them, which had prevailed during the 
Newer Palajozoic period. From this circumstance an inference was drawn 
that the Secondary continents had generally a trend from north to south, 
governed by volcanic bands having this direction; while, as the Secondary 
formations indicate a great extent of sea over the northern hemisphere, the 
bulk of the Secondary continent lay in the southern hemisphere. 
The elevation of the bed of the Cretaceous sea, it was inferred, was due to 
volcanic forces acting from east to west ; and the author adduced evidence of 
this action having become perceptible during the later part of the Cretaceous 
period. He considered that the direction of all the Post-cretaceous lines of 
volcanic action governed the direction of the continent during the Post- 
cretaceous period, and pointed out that these were all in an easterly and 
westerly direction, coincideut with the existing volcanic band which extends 
from tlie Azores to the Caspian, and thence (with an interval of intense earth- 
quake action between the Caspian and Bengal) extends to the Society Isles. 
He concluded tliat they gave rise to a continent extending from the Carribbean 
Sea to the Society Isles — many reasons uniting to show a land-connexion be- 
tween America and Europe at the da\vii of the Tertiary period, the submerged 
continent of Oceanica also indicating the easterly extension of Southern Asia ; 
and that, since this continent receded to the north at the dawTi of the Tertiary 
period before the inroad of the Nummulitie Sea (which stretched from the 
south-east through Western Asia and Southern Europe, and was, as the author 
conceives, the oceanic equivalent of the Eocene basins of Europe) the greater 
portion of the deposits formed in the interval between Cretaceous and Eocene 
times must be now under the Southern Oceans. 
The author then adverted to the circumstance that the recent great wingless 
birds and the nearest living affinities of all the Secondary mammalia yet knovm 
occur only in the southern hemisphere. Erom this, and from some considera- 
tions as to the vegetation, he concluded that, while ]iarts of the Secondary con- 
tinent yet remain m that hemisjihcre incorporated more or less into the Post- 
cretaceous continent, otiier parts of it, such as Australia and New Zealand, 
have remained isolated up to the present time to an extent sufficient to pre- 
clude the migration of manmialia and wingless birds. He inferred that the 
wingless birds, excepting the swift Struthionida;, have been preserved solely 
bv isolation from the carnivora, which do not appear as an important family 
until the Pliocene age ; and he instanced the Gastrornis of the Eocene (which 
had affinities with the Solitaire and Notornis) as evidence that the apterous 
birds had survived until that period. 
