Korkino Gr

southern Primorye Basin (NW to NE of Vladivostok)

In the Partizansk Depression, it is composed of volcanogenic-terrigenous rocks with a total thickness up to 2650m (Turbin, 1994). The lower part of the group is designated as the Kangauz Fm. It consists of greenish-grey siltstones and sandstones with a total thickness of up to 650 m.

In the Radzolny Depression, the basal boundary onto the Galenki Fm is defined on the basal layer of conglomerates or coarse-grained tuffaceous sandstones commencing the new sedimentation rhythm (Volynets and Bugdaeva, 2017). The typical feature of this group is the abundant intercalations of red beds (tuffaceous siltstones and tuffites), rarely psammitic tuffs and whitish-grey tuffaceous sandstones. Its thickness is up to 300 m

The Kangauz flora assemblage is similar to the middle subassemblage of the Late Alchan flora assemblage (Volynets, 2006). The common taxa are Onychiopsis psilotoides, Anemia dicksoniana, Birisia alata, B. onychioides, Gleichenites porsildii, Onychiopsis psilotoides, Teilhardia tenella, Podozamites tenuinervis, P. ex gr. lanceolatus, Elatides asiatica, Sequoia reichenbachi, S. ambigua, Athrotaxites berryi, Sapindopsis variabilis, S. brevifolia, Sassafras aff. ussuriensis and representatives of the genera Marchantites, Isoetites, Lycopodites, Equisetum, Osmunda, Anemia, Coniopteris, Sagenopteris, Dictyozamites, Pagiophyllum, Pityostrobus, Sequoia, Sphenolepis, Vityphyllum, Celastrophyllum, Kenella. Based on this, the range of the Kangauz Formation is considered to be upper Albian.

In the Radzolny Depression, the Korkino flora assemblage was revealed from the deposits of the Korkino Group distributed on Markovski Cape, in the Peschanka River basin on the Muravyov-Amursky Peninsula and in the Amba River basin (Volynets and Bugdaeva, 2017). Two subassemblages were recognized. The Early Korkino subassemblage is characterized by low diversity (11 taxa) accompanied by ferns (9 taxa), single cycadophytes (2 taxa) and angiosperms (2 taxa). The common taxa are Elatides asiatica, Elatocladus obtusifolius, Sequoia ex gr. reichenbachi, Gleichenites aff. porsildii, Anemia dicksoniana. The typical feature of this subassemblage is the predominance of conifers and the sharp decrease of taxonomic diversity. The range of the subassemblage is considered as uppermost Albian (Volynets, 2006, 2013, 2014; Volynets and Bugdaeva, 2017). The Late subassemblage of the Korkino flora assemblage was derived from the siltstones and mudstones of the upper part of the Korkino Group. Taxonomic composition of this subassemblage is poor (16 taxa). Angiosperms dominate (7 taxa), Platanophyllum spp. occurs often, accompanied by Dicotylophyllum sp. and rarely Sapindopsis sp. Ferns are represented by Osmunda sp., Gleichenites sp., Anemia dicksoniana, Sphenopteris sp.; conifers are represented by Podozamites sp., Parataxodium sp., Taxites sp. The main feature of this subassemblage is the predominance of angiosperms represented by various platanoids (Volynets, 2013). From the upper part of the Korkino Group V.S. Markevich revealed the palynological assemblage of the upper Cenomanian (Volynets, 2013).