218 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. .Dec. 13,
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JO T!l.^BDS
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Val d'Astico resembled forms published by
Brander from the London clay of Hamp-
shire. M. Brongniart*, however, first sy-
stematically classified these strata as older
tertiary, and described their organic re-
mains, whilst our associate Dr. Buckland
arrived, about the same time, at a like con-
clusion in his general survey of the Alpsf.
But although there could be little doubt,
from the absence of cretaceous fossils, and
the presence of a multitude of genera having
a tertiary facies, that these shelly masses
were younger than the chalk, the great
desideratum still remained of natural exhi-
bitions of the true relations of these strata
to the inferior or secondary rocks. These
were the more called for, as some leading
geologists considered all the nummulite de-
posits of the Vicentine to be of cretaceous
age. In our rapid survey of parts of the
Vicentine in 1828, Sir C. Lyell and myself,
having visited the principal localities de-
scribed by Brongniart as '^ calcareo-trap-
peens," found these shelly deposits so com-
mingled with and interrupted by basaltic
.and other eruptive rocks, that we were
unable, any more than our precursor, to de-
tect an order of succession. It was after
my colleague had proceeded on his journey
to the south of Italy and Sicily, that in
returning to England across the Venetian
Alps, I obtained the desired proofs of that
order, in the clear and instructive natural
sections on the banks of the Brenta near
Bassano, and again between Possagno and
Asolo. I there saw the same nummulitic
and shelly beds as those of the adjacent
Vicentine, entirely free from igneous intru-
sions, reposing conformably on the scaglia
or the Italian equivalent of the chalk, and
passing upwards into strata of younger ter-
tiary age, the whole upraised in lines par-
allel to the direction of the Alpine chain.
The figures of the remarkable sections
near Bassano were published in the ' Philo-
sophical Magazine,' but as that work is in

• Memoire sur les Terrains de Sediment supe-
  

rieurs calcareo-trappeens du Vicentin, par Alex-
andre Brongniart, Paris, 1823.