In
the southern parts, as near Csik Szereda, the trachyte encloses large
masses, sometimes forming even small hillocks, of that variety of which
millstones are made, having quartz crystals disseminated through it, and
in general indurated by silicious matter in so fine a state of division
that the parts are nearly invisible. The latter substance seems to be
the result of a kind of sublimation which took place at the moment of
the formation of the trachyte.... Distinct craters are only seen at the
southern extremity of the chain. One of the finest observed by Dr Bone
was to the south of Tusnad. It was of great size and well characterised,
surrounded by pretty steep and lofty hills composed of trachyte. The
bottom of the hollow was full of water. The ground near has a very
strong sulphureous odour. A mile to the SSE. direction from this point
there are on the tableland two large and distinct _maars_ like those of
the Eifel--that is to say, old craters, which have been lakes, and are
now covered with a thick coat of marsh plants. The cattle dare not graze
upon them for fear of sinking in. Some miles farther in the same
direction is the well-known hill of Budoshegy (or hill of bad smell), a
trachytic mountain, near the summit of which is a distinct rent,
exhaling very hot sulphureous vapours.... The craters here described
have thrown out a vast quantity of pumice, which now forms a deposit of
greater or less thickness along the Aluta and the Marosch from Tusnad to
Toplitza.
Pages:
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195