Encyclopaedia Britannica, 11th Edition | Page 2

through the Balkans by the
picturesque gorge of Iskretz. Somewhat similarly the Deli, or "Wild,"
Kamchik breaks the central chain of the Balkans near their eastern
extremity and, uniting with the Great Kamchik, falls into the Black Sea.
The Maritza, the ancient Hebrus, springs from the slopes of Musallá,
and, with its tributaries, the Tunja and Arda, waters the wide plain of
Eastern Rumelia. The Struma (ancient and modern Greek Strymon)
drains the valley of Kiustendil, and, like the Maritza, flows into the
Aegean. The elevated basins of Samakov (lowest altitude 3050 ft.), Trn

(2525 ft.), Breznik (2460 ft.), Radomir (2065 ft.), Sofia (1640 ft.), and
Kiustendil (1540 ft.), are a peculiar feature of the western highlands.
Geology.--The stratified formation presents a remarkable variety,
almost all the systems being exemplified. The Archean, composed of
gneiss and crystalline schists, and traversed by eruptive veins, extends
over the greater part of the Eastern Rumelian plain, the Rilska Planina,
Rhodope, and the adjacent ranges. North of the Balkans it appears only
in the neighbourhood of Berkovitza. The other earlier Palaeozoic
systems are wanting, but the Carboniferous appears in the western
Balkans with a continental facies (Kulm). Here anthracitiferous coal is
found in beds of argillite and sandstone. Red sandstone and
conglomerate, representing the Permian system, appear especially
around the basin of Sofia. Above these, in the western Balkans, are
Mesozoic deposits, from the Trias to the upper Jurassic, also occurring
in the central part of the range. The Cretaceous system, from the
infra-Cretaceous Hauterivien to the Senonian, appears throughout the
whole extent of Northern Bulgaria, from the summits of the Balkans to
the Danube. Gosau beds are found on the southern declivity of the
chain. Flysch, representing both the Cretaceous and Eocene systems, is
widely distributed. The Eocene, or older Tertiary, further appears with
nummulitic formations on both sides of the eastern Balkans; the
Oligocene only near the Black Sea coast at Burgas. Of the Neogene, or
younger Tertiary, the Mediterranean, or earlier, stage appears near
Pleven (Plevna) in the Leithakalk and Tegel forms, and between Varna
and Burgas with beds of spaniodons, as in the Crimea; the Sarmatian
stage in the plain of the Danube and in the districts of Silistria and
Varna. A rich mammaliferous deposit (Hipparion, Rhinoceros,
Dinotherium, Mastodon, &c.) of this period has been found near
Mesemvria. Other Neogene strata occupy a more limited space. The
Quaternary era is represented by the typical loess, which covers most of
the Danubian plain; to its later epochs belong the alluvial deposits of
the riparian districts with remains of the Ursus, Equus, &c., found in
bone-caverns. Eruptive masses intrude in the Balkans and Sredna Gora,
as well as in the Archean formation of the southern [v.04 p.0774]
ranges, presenting granite, syenite, diorite, diabase, quartz-porphyry,
melaphyre, liparite, trachyte, andesite, basalt, &c.

Minerals.--The mineral wealth of Bulgaria is considerable, although,
with the exception of coal, it remains largely unexploited. The minerals
which are commercially valuable include gold (found in small
quantities), silver, graphite, galena, pyrite, marcasite, chalcosine,
sphalerite, chalcopyrite, bornite, cuprite, hematite, limonite, ochre,
chromite, magnetite, azurite, manganese, malachite, gypsum, &c. The
combustibles are anthracitiferous coal, coal, "brown coal" and lignite.
The lignite mines opened by the government at Pernik in 1891 yielded
in 1904 142,000 tons. Coal beds have been discovered at Trevna and
elsewhere. Thermal springs, mostly sulphureous, exist in forty-three
localities along the southern slope of the Balkans, in Rhodope, and in
the districts of Sofia and Kiustendil; maximum temperature at
Zaparevo, near Dupnitza, 180.5° (Fahrenheit), at Sofia 118.4°. Many of
these are frequented now, as in Roman times, owing to their valuable
therapeutic qualities. The mineral springs on the north of the Balkans
are, with one exception (Vrshetz, near Berkovitza), cold.
Climate.--The severity of the climate of Bulgaria in comparison with
that of other European regions of the same latitude is attributable in
part to the number and extent of its mountain ranges, in part to the
general configuration of the Balkan Peninsula. Extreme heat in summer
and cold in winter, great local contrasts, and rapid transitions of
temperature occur here as in the adjoining countries. The local contrasts
are remarkable. In the districts extending from the Balkans to the
Danube, which are exposed to the bitter north wind, the winter cold is
intense, and the river, notwithstanding the volume and rapidity of its
current, is frequently frozen over; the temperature has been known to
fall to 24° below zero. Owing to the shelter afforded by the Balkans
against hot southerly winds, the summer heat in this region is not
unbearable; its maximum is 99°. The high tableland of Sofia is
generally covered with snow in the winter months; it enjoys, however,
a somewhat more equable climate than the northern district, the
maximum temperature being 86°, the minimum 2°; the air is