DOI Page / Citation link:
https://doi.org/10.11588/diglit.748#0219
176 ARCHAEOLOGICAL INSTITUTE.
The formation is chiefly an incoherent conglomerate, consisting
for the most part of light-colored fragments of limestone. These
are imbedded with more or less of the first trachyte in a whitish
marly groundmass, which is sometimes free from pebbles, and
appears like a soft sandstone. Some of the calcareous fragments
are very hard and heavy; most of them, including a few pebbles
from metamorphic rocks, are subangular, varying in size up to
twenty centimetres in diameter. The thickness of the whole mass
is not over five metres, and it is about 225 metres above the sea
level.
The best exposures are at the east end of the Turkish cemetery,
where the formation appears to lie upon the second trachyte. These
deposits contain no good evidence of their age, but they are closely
connected with others further eastward, the relations of which to
the other rocks are easily determined. The conglomerate at the
cemetery is not distinctly stratified, but the same formation near by
is plainly arranged in strata. We may therefore feel sure that the*
deposit was made under the influence of water.
According to the researches of Tchihatcheff, the sedimentary de-
posits, a part of which we are considering, were placed provisionally
in the middle tertiary, and thought to be of fresh-water origin. But
few fossils have been found in this formation, yet it is hoped that
those secured by the present Expedition, in connection with some
already collected by others, may be sufficient to determine the age
of the formation more definitely. It is the upper portion of the
middle tertiary that rests upon the second trachyte at the Turkish
cemetery ; and it appears probable, from facts which will be here-
after mentioned, that the first and second trachytes were extra-
vasated shortly before the close of the middle tertiary period. The
disturbance at the time of the eruption of these trachytes did not
result in unconformability between the different members of the
formation. It was at the close of the period in which the great
masses of the third trachyte were extruded, that the whole of
the Southern Troad was raised above the sea.
The formation is chiefly an incoherent conglomerate, consisting
for the most part of light-colored fragments of limestone. These
are imbedded with more or less of the first trachyte in a whitish
marly groundmass, which is sometimes free from pebbles, and
appears like a soft sandstone. Some of the calcareous fragments
are very hard and heavy; most of them, including a few pebbles
from metamorphic rocks, are subangular, varying in size up to
twenty centimetres in diameter. The thickness of the whole mass
is not over five metres, and it is about 225 metres above the sea
level.
The best exposures are at the east end of the Turkish cemetery,
where the formation appears to lie upon the second trachyte. These
deposits contain no good evidence of their age, but they are closely
connected with others further eastward, the relations of which to
the other rocks are easily determined. The conglomerate at the
cemetery is not distinctly stratified, but the same formation near by
is plainly arranged in strata. We may therefore feel sure that the*
deposit was made under the influence of water.
According to the researches of Tchihatcheff, the sedimentary de-
posits, a part of which we are considering, were placed provisionally
in the middle tertiary, and thought to be of fresh-water origin. But
few fossils have been found in this formation, yet it is hoped that
those secured by the present Expedition, in connection with some
already collected by others, may be sufficient to determine the age
of the formation more definitely. It is the upper portion of the
middle tertiary that rests upon the second trachyte at the Turkish
cemetery ; and it appears probable, from facts which will be here-
after mentioned, that the first and second trachytes were extra-
vasated shortly before the close of the middle tertiary period. The
disturbance at the time of the eruption of these trachytes did not
result in unconformability between the different members of the
formation. It was at the close of the period in which the great
masses of the third trachyte were extruded, that the whole of
the Southern Troad was raised above the sea.