The Aunei floristic assemblage from the upper Cretaceous volcanic deposits of the Okhotsk-Chukotka volcanogenic belt

Palaeobotany ◽  
2013 ◽  
Vol 4 ◽  
pp. 96-115 ◽  
Author(s):  
L. B. Golovneva ◽  
S. V. Shczepetov
Keyword(s):  
River Basin ◽  
Early Cretaceous ◽  
Upper Cretaceous ◽  
Taxonomic Composition ◽  
Endemic Plants ◽  
Sedimentary Deposits ◽  
Volcanogenic Belt ◽  
Volcanic Deposits

The Aunei floristic assemblage comes from volcanic-sedimentary deposits of the Aunei unit. The locality is situated in the middle course of the Eropol River (Anadyr River basin). This area belongs to the Anadyr segment of the Okhotsk-Chukotka volcanogenic belt (Belyi, 1977). The Aunei floristic assemblage consists of 21 species. Among them gymnosperms (Phoenicopsis ex gr. angustifolia Heer, Podozamites sp., Elatocladus zheltovskii Philipp., Elatocladus sp., Araucarites subacutensis Philipp., Sequoia sp., Metasequoia sp., Cupressinocladus sp., Pityophyllum sp., Pityostrobus sp., Pityolepis sp.) predominate. Ferns (Tchaunia tchaunensis Samyl. et Philipp., Kolymella raevskii Samyl. et Philipp., Cladophlebis tschuktschorum Philipp.) and angiosperms (Trochodendroides microphylla Philipp., Trochodendroides sp. 1, 2, Dicotylophyllum nanum Golovn., Dicotylophyllum sp. 1, 2, Quereuxia angulata (Newb.) Krysht. ex Baik.) are not abundant. This assemblage is characterized by presence of the Early Cretaceous relicts (Phoenicopsis and Podozamites), by rarity of angiosperms and by small sizes of their leaves. Taxonomic composition of the Aunei floristic assemblage most closely resembles the composition of the Chaun flora, which comes from the Coniacian deposits of the Chaun Group of Central Chukotka. From 21 species of the Aunei assemblage 14 species are common with the Chaun ones. Among them there are the characteristic endemic plants of the Chaun flora: Tchaunia tchaunensis, Kolymella raevskii, Araucarites subacutensis, Elatocladus zheltovskii, Trochodendroides microphylla. The great systematic similarity of these floras indicate that they were even-aged and belonged to the single regional Chaun flora, which was distributed not only at Central Chukotka but also at area of the Anadyr segment of the Okhotsk-Chukotka volcanogenic belt. Age of the Aunei floristic assemblage is also determined as the Coniacian.

New data about the Late Cretaceous floras of the Ulya depression (western coast of Sea of Okhotsk)

Palaeobotany ◽  
2013 ◽  
Vol 4 ◽  
pp. 148-167 ◽  
Author(s):  
L. B. Golovneva
Keyword(s):  
River Basin ◽  
Early Cretaceous ◽  
Late Cretaceous ◽  
Sea Of Okhotsk ◽  
Northeastern Russia ◽  
Western Coast ◽  
Fossil Plants ◽  
Sedimentary Deposits ◽  
Volcanogenic Belt ◽  
Systematic Composition

New investigation of fossil plants from volcanic-sedimentary deposits of the Amka Formation in Ulya River basin (southern part of the Okhotsk-Chukotka volcanogenic belt, Northeastern Russia) shows, that the Arinda, Uenma, Ust-Amka and Gyrbykan floristic assemblages from diff erent localities of this formation have very close systematic composition. We propose to joint these assemblages in the single regional flora, which is named the Ulya flora. The Ulya flora consists of almost 40 species. The majority of them are represented by new undescribed taxa. In this flora gymnosperms (Phoenicopsis ex gr. speciosa Heer, Ginkgo ex gr. adiantoides (Ung.) Heer, G. ex gr. sibirica Heer, Sphenobaiera sp., Podozamites sp., Elatocladus spp., Araucarites sp., Sequoia sp., Metasequoia sp., Cupressinocladus sp., Ditaxocladus sp., Pityophyllum sp., Pityostrobus sp.) predominate. Ferns (Asplenium dicksonianum Heer, Arctopteris sp., Cladophlebis spp. and several undescribed taxa) and angiosperms (Trochodendroides spp., undetermined Platanaceae, Dicotylophyllum spp., Quereuxia angulate (Newb.) Krysht. ex Baik.) are not abundant. This flora is characterized by presence of the Early Cretaceous relicts (Phoenicopsis, Sphenobaiera and Podozamites), by rarity of angiosperms and by high endemism. On the base of comparison of the Ulya flora with other floras from middle and northern parts of the Okhotsk-Chukotka volcanogenic belt, the age of the Ulya flora is estimated as the Coniacian.

The Envymaam floristic assemblage from the Upper Cretaceous deposits of the Okhotsk-Chukotka volcanogenic belt

Palaeobotany ◽  
2014 ◽  
Vol 5 ◽  
pp. 42-59 ◽  
Author(s):  
L. B. Golovneva ◽  
S. V. Shczepetov
Keyword(s):  
River Basin ◽  
Early Cretaceous ◽  
Upper Cretaceous ◽  
Isotopic Data ◽  
Basaltic Rocks ◽  
Volcanogenic Belt ◽  
The Poor ◽  
Palynological Assemblages ◽  
Systematic Composition ◽  
Cretaceous Deposits

The Envymaam floristic assemblage occurs from basaltic rocks of the Envymaam Formation in the Envymaam River basin, Central Chukotka segment of the Okhotsk-Chukotka volcanogenic belt. This assemblage consists of 18 taxa: Hepaticites sp., Coniopteris tschuktschorum (Krysht.) Samyl., Phoenicopsis ex gr. angustifolia Heer, Cupressinocladus enmyvaamensis Golovn., sp. nov., Araliaephyllum philippoviae Golovn., sp. nov. Among them, two species are fi rstly described. The Envymaam assemblage is characterized by presence of the Early Cretaceous relicts (Phoenicopsis), by rarity of angiosperms and by small sizes of their leaves. Age of the Envymaam floristic assemblage is determined as the late Campanian on the basis of systematic composition, palynological, paleomagnetic and isotopic data. Direct continuity between the Envymaam and the Ust’-Emuneret floristic assemblages from the subjacent Emuneret Formation it isn’t observed that is caused probably by the poor composition of the Envymaam floristic assemblage. Palynological assemblages from the Envymaam, Ust’-Emuneret, Ola and Arkagala Formations are very similar.

The Oloy floristic assemblage from the Cretaceous deposits of the Il’guveem river head, Northeastern Russia

Palaeobotany ◽  
2015 ◽  
Vol 6 ◽  
pp. 68-79
Author(s):  
L. B. Golovneva
Keyword(s):  
Volcanic Belt ◽  
Taxonomic Composition ◽  
Northeastern Russia ◽  
Endemic Plants ◽  
Sedimentary Deposits ◽  
Chukotka Volcanic Belt ◽  
Cretaceous Deposits

The Oloy floristic assemblage comes from volcanic-sedimentary deposits of the Teleneut Unit, distributed in the Il’guveem river head, at the Oloy, Great Anuy and Yablon Rivers interfluve area. This area belongs to the Anadyr segment of the Okchotsk-Chukotka volcanic belt (Belyi, 1977). The Oloy floristic assemblage consists of 15 species. Equisetopsida: Equisetum sp. Polypodiopsida: Cladophlebis sp., Coniopteris sp., Tchaunia tchaunensis Samyl. et Philipp. Czekanowskiopsida: Phoenicopsis ex gr. angustifolia Heer. Cycadophytes: Heilungia oloensis Samyl. et Philipp., Taeniopteris sp., Pterophyllum sp. Ginkgoopsida: Ginkgo sp., Sphenobaiera sp. Pinopsida: Pagiophyllum zhuravlevii Golovn., Araucarites sp., Taxodium sp., Sequoia sp., Pityophyllum sp. Among them gymnosperms predominate. Angiosperms are not revealed. Cycadophytes are represented by three genera (Heilungia, Taeniopteris and Pterophyllum). Taxonomic composition of the Oloy floristic assemblage most closely resembles the composition of the Chaun flora, which comes from the Coniacian deposits of the Chaun Group of Central Chukotka. From 15 species of the Oloy assemblage 13 species are common with the Chaun ones (besides Taeniopteris иPterophyllum). Among common taxa there are the characteristic endemic plants of the Chaun flora: Tchaunia tchaunensis and Pagiophyllum zhuravlevii. The great systematic similarity of these floras indicate that they were even-aged and belonged to the single phytogeographic area – the Chukotka subprovince of the Mountain Okchotsk-Chukotka province (Golovneva, 2014b).

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.

Ginkgophytes of the Ul’ya flora (the Ul’ya depresiion, the Okhotsk-Chukotka volcanogenic belt)

Palaeobotany ◽  
2016 ◽  
Vol 7 ◽  
pp. 80-95 ◽  
Author(s):  
L. B. Golovneva
Keyword(s):  
New Species ◽  
Early Cretaceous ◽  
Late Cretaceous ◽  
Middle Part ◽  
Leaf Length ◽  
Volcanogenic Belt ◽  
Short Shoots ◽  
Volcanogenic Deposits

The Ul’ya flora comes from the Coniacian volcanogenic deposits of the Amka Formation (the Ul'ya depression, southern part of the Okhotsk-Chukotka volcanogenic belt). Ginkgoaleans are diverse in this flora and represented by three genera: Ginkgo, Sphenobaiera and Baiera. All specimens have no cuticle and were assigned to morphotaxa. Genus Ginkgo includes two species: G. ex gr. adiantoides (Ung.) Heer with entire leaves and G. ex gr. sibirica Heer with dissected leaves. Genus Sphenobaiera also consists of two species: S. ex gr. longifolia (Pom.) Florin with 4–8 leaf lobes and S. ex gr. biloba Prynada with two leaf lobes. Genus Baiera is represented by new species B. lebedevii Golovn., sp. nov.Leaves of this species are 25–30 cm long and 13–16 cm wide, narrowly wedge-shaped with flat slender petiole, dichotomously dissected 4–5 times into linear segments 3–6 mm wide with 6–12 veins. The length of ultimate segments is equal to about a half of leaf length. Leaves attached spirally to ovoid short shoots about 2 cm long. Among the Late Cretaceous floras similar diversity of ginkgoaleans was recorded only in the Turonian-Coniacian Arman flora from middle part of the Okhotsk-Chukotka volcanogenic belt (Herman et al., 2016). Four species of ginkgoaleans from the Ul’ya flora (except G. ex gr. adiantoides) are considered as the Early Cretaceous relicts.

The Gedan floristic assemblage from the Late Cretaceous deposits of the Kholchan Formation of the Okhotsk-Chukotka volcanogenic belt

Palaeobotany ◽  
2014 ◽  
Vol 5 ◽  
pp. 73-93 ◽  
Author(s):  
L. B. Golovneva ◽  
S. V. Shczepetov
Keyword(s):  
River Basin ◽  
Late Cretaceous ◽  
Middle Part ◽  
Isotopic Data ◽  
Volcanogenic Belt ◽  
Stratigraphic Position ◽  
Cretaceous Deposits

The Gedan floristic assemblage occurs from upper layers of the Kholchan Formation of the Okchotsk-Chukotka volcanogenic belt (OCVB). The locality is situated at the Gedan River in the middle part of the Arman River basin. The Gedan assemblage is composed of 6 taxa: Cladophlebis sp., Sphenobaiera sp., Ginkgo ex gr. adiantoides (Ung.) Heer, Taxodium amguemensis (Efimova) Golovn., Metasequoia sp., Pagiophyllum sp. The similarity of the Gedan floristic assemblage with the Karamken and the Khirumki floristic assemblages from the Kholchan Formation of the Okhotsk sector of the OCVB allows us to join them in the Kholchan flora. This flora is distinct from more ancient Arman flora, which dated as the Turonian-Coniacian and from younger Ola flora, which dated as the Santonian-early Campanian. The age of the Kholchan flora is estimated as the Coniacian on the basis of stratigraphic position, presence of Podozamites, Metasequoia and Quereuxia and also isotopic data. This flora is equivalent with the Chaun flora of Central Chukotka, with the Aleeki flora from the Villigha and Toomahni Rivers interfluve and with the Ulya flora from the southern part of the Okhotsk-Chukotka volcanogenic belt.

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