Rare metal granites and ongonites of the Badzhalsky ore area (the
National university of mineral resources «Mining», Saint-Petersburg,
The discovery of both rare
metal granites with accessory minerals such as Nb, Ta, Sn, W etc., and
their shallow analogues - ongonites, elvanites, kalgutytes,
xianghualingites was made in the latter half of the 20th
century through research of A.A. Beus, A.I. Ginzburg, V.I. Kovalenko,
N.V. Vladykin, Yu.B. Marin, V.S. Antipin, V.B. Dergachev, A.G. Vladimirov,
to name but a few. It gives us an insight into the special ongonite
magmatism characteristic of the postorogenic stage of continental earth
crust development (Vladimirov et all., 2007). In the last twenty years
the ongonitic bodies in form of small intrusions of zinnwaldite granites
relating to the lithium-fluoric geochemical type were found in the Far
East in close proximity to the largest tin ore deposits - Pyrkakajsky,
Pravourmijsky, Xianghualing (Brusnitsyn et all., 1993; Alekseev, 2011;
Zhu et all., 2011).
The Badzhalsky volcanic
zone is located in the upper part of the Amgun river. It represents a
nidal structure born during a Mesozoic activization of the junction zone
between the Hercynian Sikhote-Alin folded area and the Precambrian
Bureinsky massif. The unique feature of the area is an outstanding scale
of acid and plutonic rocks cluster, the origin of which is hard to
explain even from the earth crust palingenesis point of view: the area
of the Badzhalsky zone makes up 5350 km2, the thickness of
extrusive rocks reaches 1,5–2 km. By the nineties the idea of the
genetic relation between Badzhalsky granitoids and extrusive rocks as
well as of the existence of andezite-granodiorites and ryolite-granites
volcano-plutonic associations was introduced. At an early Late
Cretaceous stage of
geological history (110-80 million years) the intrusion of the major
part of rhyolitic and younger trachyandesitic melts occurred, which led
to the formation of the Badzhalsky rhyolite-biotite granite complex and
the Silinsky (Levoyarapsky) complex of subvolcanic trachyandesite and
monzonitoide respectively (Gonevchuk, 2002). In 1987-1990 by efforts of
the Leningrad mining institute expedition under the direction of Yu.B. Marin
a special mapping of the Verhneurmijsky ore knot was carried on. In the
east exocontact of the Verhneurmijsky massif fine-grained subalkaline
albitic granites dykes breaking through all earlier known granitoids
were established. A conclusion was drawn that ore-bearing
lithium-fluoric granites are present on the depth of the dome (Marin et
all., 1990). Rare metal granites composition data was published in 1993
(Brusnitsyn et all., 1993).
zinnwaldite-albitic granites, which form an independent, the youngest,
Pravourmiysky intrusive complex, were located. The complex area is
associated with «the Urmijsky alkaline zone», marked of be V.G. Kryukov
in the east exocontact of the Verhneurmijsky massif (Kryukov, Shcherbak,
1987), and is situated in the epicenter of a Badzhalsky criptobatholite
ledge in the middle reaches of the Irungda-Makit river. The area
structure includes a poorly eroded Dozhdlivy massif of medium-grained
zinnwaldite granites and low-thickness ongonite dykes. The area of
ongonitic body emergence is less than 1% of the Badzhalsky zone area.
The area zonality is determined: the dome of zinnwaldite granites which
might be an eroded ledge of sublatitudinal ridge-like intrusion is
bordered by ongonite dykes field. Enclosing rhyolite ignimbrite in the
near exocontact area of the intrusion is under the processes of an
intense recrystallization, microclinization and greisenization. As
concerns zinnwaldite granites, along the contacts with biotite granites
and rhyolites a banding is developing as well as zones of pegmatoids –
block, graphic types and stockscheiders. Ongonitic intrusive-dykes belt
is limited on flanks and in the north by cross-sectional dyke swarms of
monzogranite- and granosyenite-porphyries of the Silinsky complex, which
are distributed in heavy pitching rupture zones of the north-north-west
strike. The material peculiarity of rare metal granites and ongonites of
the Badzhalsky area consists in the leading role of albite, white
microcline and zinnwaldite. They differ from the Mongolian and
Transbaikalian analogues by the absence of amazonite and a low content
of topaz. The accessory complex of these rocks is unusual, including
minerals of niobium, tungsten, yttrium, and rare-earth elements:
Y-fluorite, cyrtolite, monazite-(Ce), samarskite-(Yb), ishikawaite,
ferberite, wolframoixiolite, scheelite, xenotime-(Y), allanite-(Y),
fluocerite, tveitite-(Y), struverite, chernovite-(Y), fergusonite-(Y),
In the Badzhalsky area two
consecutive petrochemical series of granitoides are found side by side:
1) normal biotite granites of the standard geochemical type, intruded in
comagmatic rhyolites in form of large plutons; 2) subalkaline biotite
granosyenites and zinnwaldite granites of latite and plumasite
geochemical types respectively, which form small intrusions. The
geochemical evolution of normal granites is oriented on an increase of
agpaite features: normal granites are combined with subalkaline
leucogranites. A transition to a rare metal stage is accompanied by a
sharp decrease of agpaite features, connected with an intrusion of
granosyenite-porphyritic dykes. The subalkaline granitoides evolution
follows the line of increase of agpaite and aluminous features,
accumulation of rare elements - W, Nb, Y, F, Sn, Li, Rb and others
(fig., a). It is characteristic, that ongonites differ from
lithium-fluoric granites by decreased aluminous features that reflect in
a lowered content of topaz. Yttrium and niobium distribution in granites
gives evidence of the formation of biotite granites and monzonitoides in
the conditions of an active continental margin; the latter show
formation signs of passive margins. Rare metal granites and ongonites
are formed in within-plate conditions and correspond to granites of
A-type with a mainly crust substance source (fig., b). However
accumulation of niobium and a close association with monzonitoides,
enriched by K, P, Ba and granitophylic elements (Li, Rb, F, W), point at
the presence of mantle component in an initial melt (Eby, 1992).
features of rare metal granites and ongonites of the Badzhalsky area.
a – aluminous – agpaite
features in the diagram (Maniar, Piccoli, 1989) (A = Al2O3,
N= Na2O, K = K2O, C = CaO (mol.cont.)),
b – geodynamic types in the diagram (Pearce et al., 1984). Granitoides:
1 – biotite granites of the Badzhalsky complex, 2 – granosyenites
of the Silinsky complex, 3, 4 – zinnwaldite granites (3)
and ongonites (4) of the Pravourmijsky complex.
Thus, in the Mesozoic
history of the granite magmatism of the Amur River region the newest
ongonitic stage is specified as a result of tectono-magmatic
activization of the Sikhote Alin fold system during a subduction of the
Pacific plate under the continental margin of the East Asia. Ongonite
magmatism of the Amur River region had a mantle and crustal origin, a
nidal character, differed by the sodium petrochemical and rare metal
geochemical evolution of melts and eventuated in the formation of
zinnwaldite-microcline-albite granites and ongonites with a complex of
accessory minerals such as W, Nb, F, Y, REE. The Pravourmijsky ongonite
complex controls the largest tungsten-tin ore deposits of the Badzhalsky
area and is similar to rare metal complexes of Chukotka, Yakutia,
Primorsky Krai and China by geological-tectonic and petrological-geochemical
Researches are executed
at financial support of the Russian Federal Property Fund (the project
11-05-00868-а) and the Ministry of Education and Science of the Russian
Federation (the state contract № 14.740.11.0192).
Topaz granites and
ongonites of the Chaunsky ore area (the Chukotha) // Zapiski of the
Mining Institute. 2011. 194. P. 46-52. (in Russia).
Brousnicyn A.I., Panova E.G.,
Finds of lithium-fluoric geochemical type granites within the bounds of
the Verhneurmiysky ore cluster // Izvestiya VUZov. Geology and
prospecting. 1993. №6. P. 150-153. (in Russia).
Annikova I.Yu., Antipin V.S.
of the South Siberia // Litosfera, 2007. № 4. P. 21-40. (in
Tin-bearing igneous systems of the Far East: magmatism and ore genesis.
Vladivostok: Dalnauka, 2002. 298 p. (in Russia).
Kryukov V.G., Shcherbak L.I.
Geology and metallogeny of the Badzhalsky tin ore area (the Amur River
region) // Soviet geology. 1987. № 3. P. 55–65.
Marin Yu.B., Skublov G.T.,
Mineralogical-geochemical criteria of rare metal deposits local
forecasting / Mineralogical mapping and indicators of mineralization.
L.: Nauka, 1990. P. 67–94.
Chemical subdivision of the A-type granitoids: petrogenetic and tectonic
implications // Geology. 1992. Vol. 20. P. 641–644.
Maniar P.D., Piccoli P.M.
Tectonic discrimination of granitoids // Geol. Soc. Am. Bull. 1989.
Vol. 101. P. 635– 643.
Pearce J.A., Harris N.B.W.,
Trace element discrimination diagrams for the tectonic interpretation of
granitic rocks // Journal of Petrology. 1984. Vol. 25, № 4. P.
Zhu Jin-Chu, Wang Ru-Cheng,
Liu Jian-Jun et al.
Fractionation, Evolution, Petrogenesis and Mineralization of Laiziling
Granite Pluton, Southern Hunan Province // Acta Metallurgica Sinica.
17. № 3. P. 381–392.