scholarly journals AU-AG MINERALIZATION OF HS TYPE IN THE ARMAN VTD OF THE OKHOTSK�CHUKOTKA VOLCANIC BELT (NORTHEAST RUSSIA)

2016 ◽  
Author(s):  
Alexander Voikov
Keyword(s):  
Volcanic Belt ◽  
Northeast Russia ◽  
Chukotka Volcanic Belt

scholarly journals Age and paleomagnetism of the Okhotsk-Chukotka Volcanic Belt (OCVB) near Lake El'gygytgyn, Chukotka, Russia

2009 ◽  
Vol 4 ◽  
pp. 243-260 ◽  
Author(s):  
D. B. Stone ◽  
P. W. Layer ◽  
M. I. Raikevich
Keyword(s):  
Volcanic Belt ◽  
Pole Position ◽  
The Arctic ◽  
The South ◽  
Northeast Russia ◽  
The Pacific ◽  
Lake El’Gygytgyn ◽  
Ocean Region ◽  
Chukotka Volcanic Belt ◽  
Magnetic Vectors

Abstract. Paleomagnetic results from the upper two thirds of the whole section of the Okhotsk-Chukotka Volcanic Belt (OCVB) volcanics exposed in the area around Lake El'gygytgyn, Chukotka yield stable, consistent magnetic vectors and well-preserved reversed directions. The magnetostratigraphy and 40Ar/39Ar geochronologic data reported here indicate that the sampled OCVB volcanics were erupted between about 90 and 67 Ma, and show no significant change in the apparent pole position over that time. The OCVB extends from northeast China, across Northeast Russia to the Bering Straight. This belt is made up of both extrusive and intrusive rocks, with the extrusive rocks and their associated sediments being dominant. The whole belt important in interpreting the paleogeography of the region because it overlies many of the accreted terranes of Northeast Russia. Most importantly, it overlies parts of the Chukotka-Alaska block which is thought to have moved out of the Arctic Ocean region, as well as terranes accreted from the south. These latter terranes have been rafted northwards on the paleo-plates of the Pacific, implying that the present relative paleogeography of all of the terranes overlain by the OCVB were essentially in place by 67 Ma, and possibly as early as 90 Ma. However, comparing our paleomagnetic pole position for the OCVB with those for North America and Eurasia (a proxy for Siberia) shows a statistically significant displacement of the OCVB pole to the south west. This implies that not only the OCVB, but the underlying terranes of northeast Russia, experienced southerly displacement with respect to the Siberian and North American platforms since the Late Cretaceous.

The Chingandzha flora of the Okhotsk-Chukotka volcanic belt

Palaeobotany ◽  
2019 ◽  
Vol 10 ◽  
pp. 13-179
Author(s):  
L. B. Golovneva
Keyword(s):  
River Basin ◽  
Volcanic Belt ◽  
Flowering Plants ◽  
Sedimentary Deposits ◽  
North East ◽  
The North ◽  
Magadan Region ◽  
Chukotka Volcanic Belt ◽  
Systematic Composition ◽  
Coastal Lowlands

The Chingandzha flora comes from the volcanic-sedimentary deposits of the Chingandzha Formation (the Okhotsk-Chukotka volcanic belt, North-East of Russia). The main localities of the Chingandzha flora are situated in the Omsukchan district of the Magadan Region: on the Tap River (basin of the middle course of the Viliga River), on the Kananyga River, near the mouth of the Rond Creek, and in the middle reaches of the Chingandzha River (basin of the Tumany River). The Chingandzha flora includes 23 genera and 33 species. Two new species (Taxodium viligense Golovn. and Cupressinocladus shelikhovii Golovn.) are described, and two new combinations (Arctopteris ochotica (Samyl.) Golovn. and Dalembia kryshtofovichii (Samyl.) Golovn.) are created. The Chingandzha flora consists of liverworts, horsetails, ferns, seed ferns, ginkgoaleans, conifers, and angiosperms. The main genera are Arctop teris, Osmunda, Coniopteris, Cladophlebis, Ginkgo, Sagenoptepis, Sequoia, Taxodium, Metasequoia, Cupressinocladus, Protophyllocladus, Pseudoprotophyllum, Trochodendroides, Dalembia, Menispermites, Araliaephyllum, Quereuxia. The Chingandzha flora is distinct from other floras of the Okhotsk-Chukotka volcanic belt (OCVB) in predominance of flowering plants and in absence of the Early Cretaceous relicts such as Podozamites, Phoenicopsis and cycadophytes. According to its systematic composition and palaeoecological features, the Chingandzha flora is similar to the Coniacian Kaivayam and Tylpegyrgynay floras of the North-East of Russia, which were distributed at coastal lowlands east of the mountain ridges of the OCVB. Therefore, the age of the Chingandzha flora is determined as the Coniacian. This flora is assigned to the Kaivayam phase of the flora evolution and to the Anadyr Province of the Siberian-Canadian floristic realm. The Chingandzha flora is correlated with the Coniacian Aleeky flora from the Viliga-Tumany interfluve area and with other Coniacian floras of the OCVB: the Chaun flora of the Central Chukotka, the Kholchan flora of the Magadan Region and the Ul’ya flora of the Ul’ya Depression.

Mineralogy of the Svetloye epithermal district, Okhotsk-Chukotka volcanic belt, and its insights for exploration

2021 ◽  
pp. 104257
Author(s):  
Tamara Yu. Yakich ◽  
Yury S. Ananyev ◽  
Alexey S. Ruban ◽  
Roman Yu. Gavrilov ◽  
Dmitry V. Lesnyak ◽  
...  
Keyword(s):  
Volcanic Belt ◽  
Chukotka Volcanic Belt

scholarly journals Золотая минерализация штокового рудного поля (Магаданская область)

2021 ◽  
pp. 13-29
Author(s):  
A. N. Glukhov ◽  
◽  
M. I. Fomina ◽  
E. E. Kolova ◽  
◽  
...  
Keyword(s):  
Volcanic Belt ◽  
Rare Metal ◽  
Geological Structure ◽  
Physicochemical Conditions ◽  
Epithermal Mineralization ◽  
Ore Bodies ◽  
Mineral Associations ◽  
Rare Metal Mineralization ◽  
Chukotka Volcanic Belt ◽  
Formation Conditions

The authors briefly characterize the geology and structure of the Shtokovoye ore field attached to the area where the Khurchan-Orotukan zone of tectonic-magmatic activation overlays the structures of the Yana-Kolyma ore-bearing belt. Studied are mineral associations and physicochemical conditions of gold ore bodies, located both in granites and in hornfelsed sedimentary masses. By the main features of its geological structure, ore composition, and physicochemical formation conditions, the Shtokovoye ore field mineralization corresponds to the "depth" group of the gold-rare-metal formation, analogous to the Butarnoye, Basugunyinskiye, Dubach, and Nadezhda occurrences. Its ores are peculiar in the late epithermal mineralization, which is associated with the Okhotsk-Chukotka volcanic belt and overlays the sinaccretional gold-rare-metal mineralization.

Mixed local and ultra-distal volcanic ash deposition within the Upper Cretaceous Kanguk Formation, Sverdrup Basin, Canadian Arctic Islands

2019 ◽  
Vol 156 (12) ◽  
pp. 2067-2084 ◽  
Author(s):  
Michael A Pointon ◽  
Michael J Flowerdew ◽  
Peter Hülse ◽  
Simon Schneider ◽  
Martin J Whitehouse
Keyword(s):  
Upper Cretaceous ◽  
Volcanic Ash ◽  
Tectonic Setting ◽  
Active Continental Margin ◽  
Far East ◽  
Canadian Arctic ◽  
Volcanic Belt ◽  
Geochemical Data ◽  
Sverdrup Basin ◽  
Chukotka Volcanic Belt

AbstractThe Upper Cretaceous Kanguk Formation of the Sverdrup Basin, Canadian Arctic Islands, contains numerous diagenetically altered volcanic ash layers (bentonites). Eleven bentonites were sampled from an outcrop section on Ellesmere Island for U–Pb zircon secondary ion mass spectrometry dating and whole-rock geochemical analysis. Two distinct types of bentonite are identified from the geochemical data. Relatively thick (0.1 to 5 m) peralkaline rhyolitic to trachytic bentonites erupted in an intraplate tectonic setting. These occur throughout the upper Turonian to lower Campanian (c. 92–83 Ma) outcrop section and are likely associated with the alkaline phase of the High Arctic Large Igneous Province. Two thinner (<5 cm) subalkaline dacitic to rhyolitic bentonites of late Turonian to early Coniacian age (c. 90–88 Ma) are also identified. The geochemistry of these bentonites is consistent with derivation from volcanoes within an active continental margin tectonic setting. The lack of nearby potential sources of subalkaline magmatism, together with the thinner bed thickness of the subalkaline bentonites and the small size of zircon phenocrysts therein (typically 50–80 μm in length) are consistent with a more distal source area. The zircon U–Pb age and whole-rock geochemistry of these two subalkaline bentonites correlate with an interval of intense volcanism in the Okhotsk–Chukotka Volcanic Belt, Russia. It is proposed that during late Turonian to early Coniacian times intense volcanism within the Okhotsk–Chukotka Volcanic Belt resulted in widespread volcanic ash dispersal across Arctic Alaska and Canada, reaching as far east as the Sverdrup Basin, more than 3000 km away.

scholarly journals New data on the age of magmatic events in Oloy tectonic zone, West Chukotka area (evidences from zircon U-Pb dating)

2019 ◽  
Vol 489 (2) ◽  
pp. 161-165
Author(s):  
T. V. Kara ◽  
P. L. Tikhomirov ◽  
A. D. Demin
Keyword(s):  
Volcanic Belt ◽  
Volcanic Field ◽  
Tectonic Zone ◽  
Chukotka Volcanic Belt ◽  
Plutonic Rocks ◽  
Magmatic Event

Zircons from volcanic and plutonic rocks of Nembonda volcanic field (the part of Anadyr segment of the Okhotsk-Chukotka volcanic belt) yield the following SHRIMP U-Pb ages, Ma: 147,72; 123,81,7; 119,31,7; 9,80,5; 80,550,96. These results confirm the hypothesis about the significant Aptian magmatic event in Verkhoyansk-Chukotka tectonic province, and give rise to the revision of the boundaries of the Okhotsk-Chukotka belt.

The distribution of Sphenobaiera biloba Prynada in the Cretaceous of Northeastern Asia

Palaeobotany ◽  
2018 ◽  
Vol 9 ◽  
pp. 18-31
Author(s):  
N. V. Nosova ◽  
L. B. Golovneva
Keyword(s):  
River Basin ◽  
Volcanic Belt ◽  
Northeastern Russia ◽  
Eastern Siberia ◽  
Northeastern Asia ◽  
Epidermal Structure ◽  
Northern Asia ◽  
Lena River ◽  
Chukotka Volcanic Belt ◽  
Volcanogenic Deposits

A revision of Sphenobaiera biloba Prynada from Northeastern Asia is based on restudy of the type material from the Zyryanka River Basin (Prynada’s collection), as well as additional specimens from the type locality (Samylina’s collection) and collections from the Ul’ya and Anadyr rivers. A new extended diagnosis of S. biloba based on the leaf morphology and epidermal structure is proposed. Geographic and stratigraphic distribution of this species in Northern Asia is discussed. S. bilobais known in the Aptian of Eastern Siberia (Lena River Basin) and from the early-middle Albian to Coniacian of northeastern Russia. In the Late Cretaceous this species was considered as relict and related with volcanogenic deposits of the Okhotsk-Chukotka volcanic belt.

New species of the genus Sequoia Endlicher (Cupressaceae) from the Late Cretaceous deposits of the Northeastern Russia

Palaeobotany ◽  
2015 ◽  
Vol 6 ◽  
pp. 80-95 ◽  
Author(s):  
D. A. Yudova ◽  
L. B. Golovneva
Keyword(s):  
New Species ◽  
River Basin ◽  
Late Cretaceous ◽  
Volcanic Belt ◽  
Northeastern Russia ◽  
Eastern Siberia ◽  
New Siberian Islands ◽  
Chukotka Volcanic Belt ◽  
Epidermal Features ◽  
Cretaceous Deposits

New species Sequoia ochotica Yudova et Golovn. (Pinopsida, Cupressaceae) from the Turonian-Coniacian deposits of the Arman and Chingandzha Formations of the Okhotsk-Chukotka volcanic belt is described based at morphological features of leaves and shoots. Two other Late Cretaceous species of this genus: S. minuta Sveshn. from the Vilyui River basin of Eastern Siberia and S. tenuifolia (Schmalh.) Sveshn. et Budants. from the New Siberian Islands have comparable shoot morphology, but these species were described based at epidermal features.

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