47
infrequent and rare earth’s elements, especially, niobium, tantalum,
rubidium, zirconium and cerium are connected.
On the contrary, the deposits of Cretaceous and Paleogene
tectono-
magmatic activaties dominate on the platforms of the disintegrated
supercontinent
Gondwana. They are represented by the richest diamond
kimberlites and lamproites on Southern and Central Africa, Western
Australia, Northern America. There are rare metal, uranium carbonatite and
rare-earth’s nepheline syenites, as well as vastly deposits of aluminium,
nickel, cobalt in laterite weathering crusts and industrial placers of
diamonds, gold, cassiterite, wolframite, uranenite, thorite, monazite, zircon
and ilmenite.
V. 2. G e o s y n c l i n a l – f o l d i n g s y s t e m s. The mineral
deposits associated with geosynclinal systems of Mesozoic-Cenozoic cycle
of development of the Earth, are subdivided into three global metallogenic
megabelts: Mediterranean, East Asian and West American. In limits of
these megabelts the deposits, bound with Kimmerian, Alpinian and
Pacifican
stages of tectogenesis, are emphasized.
V.2.1. M e d i t e r r a n e a n metallogenic megabelt includes
geosynclinal systems of the sub-latitudinal ocean Тetis, that overspreads
from the Caribbean islands and Central America in west up to the island
Timor of Indonesian archipelago in the east edge, on the distance more than
20,000 km
.
Metallogenic image of the Mediterranean megabelt in the Kimmerian
stage is determined by the formation of comparatively large deposits of
chromite among hyperbasites (island Тrodos, Gellenids); hydrothermal
polymetallic deposits in connection with granitoids and keratophyres;
sulphureous sulfide and copper sulfide deposits among sedimentary -
volcanogenic depositions; zinc-lead stratiformal deposits (Northwest
Africa). Minor deposits of iron-ore skarn and hydrothermal ore displayed by
molibden, tin, tungsten, uranium, gold, cobalt and copper have subservient
value in connection with intrusions of granites. Seldom there are the giant
deposits of hydrargyrum (Аlmaden) and fluorite in zones of activating of
the median massifs.
The Alpine tectonic-magmatic cycle of the Mediterranean megabelt
differs from Kimmerian by appearance of numerous hydrothermal deposits
rich of gold, molybdenum, copper, hydrargyrum, antimony, arsenic, nickel
and cobalt. The skarn deposits of моlybdenite, scheelite, magnetite, copper,
are genetically bound with granites and small subvolcanic intrusions.
Besides, there are a lot of rich copper-sulfide deposits among volcanogeno-
sedimentary depositions and chromite ores in connection with hyperbasites.
In weathering crusts on the ultrabasic rocks large deposits of silicate-nickel
ores had been formed on island Cuba and on Indonesian archipelago.
Placers of fine diamonds were found in Armenia and on island Borneo.
V.2.2. P a c i f i c Mesozoic - Cenozoic geosynclinal megabelt
encompasses the Pacific ocean by two branches, from which the East -
Asian belt is arranged along east outskirts of the continent Asia, and the
West-American belt is found in western part of the continents
Northern and
48
Southern America, that ended in the south on the Earth Greyam in Antarctic
continent. The outspread of these belts
is submeridional,
and the total length
exceeds 40,000 km at a width from 200 up to 2,000 km.
The Russian Academician S.S.Smirnov at the first time in 1946 has
created the conception about planetary structure of the Pacific ore’s
megabelt composed from two contrast metallogenic zones in relation to
oceanic depressiоn: the exterior is essential tin and the internal is essential
copper. Now within the limits of the East - Asian belts there are installed
three types of crust - continental, transitory and oceanic; whereas on the
asymmetric to them West-American megabelt there are only two types -
oceanic and continental, that are hard adjoining with each other. In this
connection the metallogenic features of these belts have been explained.
V.2.2.1. E a s t – A s i a n (exterior) мetallogenic belt has the
continental crust in the fundament and extends from north to south as a
global arc, convex to northwest, from Chukotskiy peninsula and
Verkhoyansk mountains through Transbaikalian, Sikhote-Alin, East Chine,
Malaysia to the island Borneo. The total length of this megabelt exceeds
12,000 km, and its width is varied from 200 up to 2,500 km.
Metallogeny of the East - Asian megabelt is determined by granite
magmatism of Kimmerian and Alpine stages of formation the geosynclinal
systems and tectono-magmatic activating. Withim the limit of this megabelt
the following мetallogenic provinces have been selected: 1. Verkhoyansk-
Chukchian – of tin-tungsten and gold; 2. Transbaikalian - of tin-tungsten,
gold-molybdenum, polymetallic and fluorite; 3. Sikhote-Alinian - of tin-
tungsten, gold-argentine; 4. East-Chinese - of tin – tungsten, gold -
molybdenum; 5. South-East Chinese - of tin–tungsten, hydrargyrum-
antimony; 6. Маlaysian - of tin-tungsten.
In the indicated provinces rich deposits of tin (Deputy, Ege-Khaya,
Sinancha, Koster, Lyakhov, Kovalerov) are being opened and exploited.
Then, the tin and tungsten (Iultin, Chaun, Amguem); gold (Darasun,
Kimchjon); gold and argentum (Аgat, Maemi, Sopka Rudnaya);
hydrargyrum (Rauchuan); molybdenum and tungsten (Djedin); lead and
zinc (Теtjukha); antimony (Su-Guan-Shan); antimony and hydrargyrum
(Khunan, Guansi, Yunnan) and several others deposits are being found.
The South-Weast Asia is the richest tin–tungsten province, producing up to
75 % of a world mining of these metals; about 50 % of antimony, and there
are also a lot of bismuth, hydrargyrum and molybdenum resources. The
largest reserves of tungsten are concentrated in the province of Tszyansy
(China). Malaysia is especially rich in tin, as well as the province Yunnan
(China), the islands Banka and Billiton (Indonesia). In southeast districts of
Asia from placers up to 25 % tungsten and not less than 60 % of world
produce of tinstone are being mined. The southeast provinces of China are
very rich by antimony and hydrargyrum. The largest in the world antimony
deposit Su-Guan-Shan produces up to 50 % of world mining of antimony.
V.2.2.2. О k h o t s k o– C h u k o t s k i y volcanogenic marginal
belt occupies the intermediate position between Yana-Kolymskiy and
Chukotskiy Mesozoic fold zones and Каmchatka-Koryaksky Cenozoic