Late Pleistocene–Holocene environmental changes in ultra-continental subarid permafrost-affected landscapes of the Terekhol' Basin, South Siberia Maria Bronnikova a, ⁎, Andrey Panin b , Ol'ga Uspenskaya c , Yuliya Fuzeina b , Irina Turova a a Institute of Geography, Russian Academy of Sciences, 119017, Staromonetnyj, 29, Moscow, Russia b Faculty of Geography, Moscow State University, 119992, Vorobjevy Gory, Moscow, Russia c Institute of Horticulture, Russian Academy of Agriculture, 140153, Moscow region, p/o Vereya, Building 500, Russia abstract article info Keywords: Paleo-archives Paleosols Paleoenvironment Pleistocene/Holocene transition Holocene South Siberia This study is an attempt to use closely related inter-complementary paleo-archives of a local landscape to access understanding of Late Pleistocene–Holocene environmental changes in the region. The study site is a small intermountain basin in the Sayan-Tuva Upland, 51°N., 97°E., 1300 m a.s.l. Paleo-archives covering about 13,000 yrs were studied: paleosol-sedimentary sequences on a delta-alluvial fan of a small river, lacustrine sedi- ments in bottom cores and on palsa-islands and soils of palsa-islands. The following sequence of environmental changes was established. The fluvial activity in the basin reached its maximum at the end of the Late Pleistocene. The sharp decrease of the fluvial activity is terminated by two successive paleosols of Pleistocene–Holocene tran- sition. The older paleosol indicates meadow-steppe (or tundra-steppe) conditions with a shallow permafrost table and impeded drainage. The younger paleosol testifies on sharp aridization, biological activity suppression, contrasting water regime, and warming. Dammed lake appeared in the midst of the trough about 11,000 cal yr BP. Sedimentation on delta-alluvial fan was fairly inconsiderable in Holocene. The first part of Holocene (before 4000 cal yr BP) was most balanced in annual distribution of precipitation. Runoff, even being prominently enhanced in a fluvial and relatively warm sub-phase 8000–6250 cal yr BP, was canalized, without giving seasonal floods. Sub-phase 6250–3800 is characterized by increased continentality and relative aridization caused reduc- tion of runoff, lowering of the lake level, and enhancement of cryogenic processes. The next phase 3800–2000 cal yr BP was more humid. It caused slight revival of fluvial processes and rise of lake level. The last 2000 years climate was more continental and the most arid within the studied period. The lake level and runoff values dropped again, and fluvial activity totally decreased. In contemporary soils aridization is reflected in widely spread Natric features and progressive salinization. © 2013 Elsevier B.V. All rights reserved. 1. Introduction Environmental changes and related evolution of soils in the late Pleistocene and the Holocene in South Siberia have not been studied satisfactory yet as far as the region is complicated and diverse in respect to landscapes and soils, and hardly reachable in some parts. Soils and pedosedimentary sequences of small intermountain basins of the South Siberia are one of still insufficiently developed and highly promising archives of the Late Pleistocene and Holocene environmental changes. Advantages of soil-sedimentary sequences for paleoenvironmental reconstructions in small inter-mountain basins were closely discussed by Vorob'eva (2010). Surface soils of such basins, as a rule, have got obvious evidences of polygenesis (recording more than one set of soil forming environmental conditions). Buried soils related to different pe- riods and environments are widespread in intrermountain basins due to dynamism of fluvial, lacustrine, slope sedimentation (interchanging intensive sedimentation and relatively continuous hiatuses) during Late Pleistocene and Holocene. There are only few studies on Holocene soil and environmental evolution based on the analysis of soil (or soil-sedimentary) records of the South Siberia (Dergacheva et al., 2006; Desjatkin, 1984, 2008; Vorob'eva, 2010). Some of these studies analyze local sources not correlating them with earlier produced data on environmental changes in a wider region or the data obtained from other environmental archives. Studies of different sedimentary Late Pleistocene and Holocene archives in the South Siberia and, taking a broader region, in arid sector of Central Asia are more in number (Blyakharchuk et al., 2004, 2007, 2008; Huang et al., 2009; Rudaya et al., 2009; Schwanghart et al., 2009; Vipper et al., 1976 and others). However the data on Late Glacial and Holocene obtained for different localities and applying different methods are often contradictory. Generalizations of data accumulated at the moment are still rare (Blyakharchuk et al., 2004; Zhao et al., Catena 112 (2014) 99–111 ⁎ Corresponding author. Tel.: +7 495 959 00 28; fax: +7 095 959 00 33. E-mail address: mbmsh@mail.ru (M. Bronnikova). 0341-8162/$ – see front matter © 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.catena.2013.08.020 Contents lists available at ScienceDirect Catena journal homepage: www.elsevier.com/locate/catena