Deposits of the Kazantsevo Transgression (MIS 5) in the Northern Yenisei Region

Abstract

Dating of marine sediments and faunal remains they contain in stratotype and reference sections by the methods of infrared optically stimulated luminescence (IR-OSL) of K-feldspar, optically stimulated afterglow (OSA) of quartz, electron spin resonance (ESR), and 230Th/U provides new constraints on deposition in the Yenisei mouth during the Kazantsevo interglacial. The luminescence and U–Th ages in the 120–68 ka range and 93–70 ka ESR ages show that the deposition spanned the whole marine isotope stage (MIS) 5. The sediment structures and textures, grain sizes and mineralogy, and faunal records indicate tidal and shelf deposition environments. The sampled assemblages of marine mollusks comprise taxa that typically live in relatively shallow and warm water, as well as abundant subarctic and boreal species, including the Arctica islandica index species. The variations of faunal patterns, more likely, had facies rather than climatic controls, while the sediments were deposited during transgression, in a warm climate, when the area was ice-free.

A multiproxy record of sedimentation, pedogenesis, and environmental history in the north of West Siberia during the late Pleistocene based on the Belaya Gora section

“…It is interesting to note clear similarities of our results with the palynological record from the Kazantsevo marine sediments along the Arctic coast of West Siberia (Yenisei River mouth) (Gusev et al 2016). Abundant pollen of Picea and other tree species was encountered there throughout the whole MIS 5 sequence.…”

“…Farther to the north, in the Arctic coastal region of West Siberia, MIS 5 is represented by marine sediments with boreal fauna (Gusev et al, 2016). Part of these sediments were earlier attributed to MIS 3, the Karginsky interstadial, but were redated (Astakhov and Nazarov, 2010); this is also what happened to the MIS 5 paleosols and peat of middle Ob terraces.…”

“…In fact, geological archives for the northern part of West Siberia are still relatively scarce, and cases of their multiproxy analysis are even fewer. During the last decades, the number of study sites increased in the northernmost part of the region: the lower Ob basin and Arctic Ocean coast and shelf (Astakhov and Nazarov, 2010; Laukhin, 2011; Gusev et al 2016). However, more to the south, in the middle Ob basin and Siberian Uval upland, quite low site density is evident (Shpolyanskaya, 2014; Streletskaya et al, 2015; Sheinkman et al 2016).…”

Conditions of the Bering Sea Subarctic Deposition of Marine Isotope Stage 5

“…Cl. [6] и положения в разрезах комплекса 1, то уровень моря в это время был выше современного примерно на +10 м, что хорошо увязывается с глобальными данными по трансгрессии начала позднего плейстоцена [11]. Среднегодовая температура на побережье Анадырского залива могла превышать современную на 3-5 °С, что обеспечивало по данным палинологии присутствие в регионе темнохвойной тайги с участием и березово-лиственичных пород [4,5,9,10], а в Анадырском заливе моллюсков c ключевым видом Arctica islandica Linnaeus и фораминифер, обитающих ныне в северной части Японского моря [4,5].…”

“…Среднегодовая температура на побережье Анадырского залива могла превышать современную на 3-5 °С, что обеспечивало по данным палинологии присутствие в регионе темнохвойной тайги с участием и березово-лиственичных пород [4,5,9,10], а в Анадырском заливе моллюсков c ключевым видом Arctica islandica Linnaeus и фораминифер, обитающих ныне в северной части Японского моря [4,5]. Аналогичные климатические параметры получены по Енисейскому северу Сибири, где детально изучены казанцевские отложения с комплексом бореальных двустворчатых моллюсков с тем же характерным видом Arctica islandica Linnaeus [11] и отложения диатомовой зоны Proboscia curvirostris северо-западной части Тихого океана [6].…”