Section Of Terrace Research Articles

THE DONETSK NEOLITHIC CULTURE SITE OF BONDARIKHА II

The Neolithic site Bondarikha ІІ was explored 70 years ago by D. Ya. Telegin. The materials of the site were not processed utilizing modern methods. The authors of the paper re-examined and analyzed the site’s materials using current methodologies.
 The Bondarikha II site is set along a natural boundary on what is now the south-eastern outskirts of the modern city of Izium, Kharkiv region. The location of the site is a section of an over-flooded terrace that stretches along the left bank of the River Siversky Donets, and a section of an older river bed named the Willow Pit. In the north, sections of the terrace were crossed by an unnamed stream, and its southern boundary defined by floodplains. The lowlands nearest the terrace are primarily comprised of wetlands.
 It is quite clear that the Willow Pit was once an active river and seasonally may have transformed into a lake during times of flooding. The site is located approximately 7 m above the current floodplain. The general site position is typical for the Neolithic sites of Donetsk Culture, with the vast majority of which are located on terraces above the floodplain lakes of Siversky Donets, with the habitational remains occupying the highest areas of terraces, or the periphery / edges of such terraces.
 The interpretation of Bondarikha material culture was quite simple. The presence of pencil-like blade cores, oblique truncated points of the Abuzova Balka and Donetsk types, a series of blades displaying abrupt retouch on edges, along with bilateral burins, scrapers on flakes, and ovate axes are attestation that the assemblage and complex are connected with the advanced stages of Donetsk Culture.
 The estimation of the site’s age is possible only by the principles of relative chronology. The Mariupolian origin of the trapeze projectiles allows us to establish the earliest age range of the complex within the beginning of the VI millennium BC. However, the utilization of trapeze projectiles with flat dorsal retouch that spread in the basin of Siversky Donets in the third quarter of VI millennium BC is not present. Accordingly, we can safely place the age of the site within the first half of VI millennium BC.

Desain High Temperature Gas-Cooled Reactor (HTGR) Model Geometri Heksagonal Dua Dimensi dengan Bahan Bakar Thorium Hasil Daur Ulang

The Research about the design of high temperature helium gas-cooled reactor (HTGR) terraces with thorium fuel recycled using the SRAC program has been completed. This research includes the percentage of fuel enrichment, reactor core size, reactor core configuration, criticality, and the distribution of the power density. The calculation of reactor core is done in two dimensions \sfrac{1}{6} hexagonal terrace section with a triangular mesh. The fuel is used, i.e. thorium with a burn-up of 20 GWd/t and 30 GWd/t, and helium gas as a cooler. The results obtained in this study show that the ideal HTGR reactor core design with reactor core size and configuration are (x) 22 cm at point (y) = 2035,05 cm and at (y) 11 cm at point (x) = 2035,05 cm, then enrichment in fuel 8%. The result of maximum power density is 550.3685 Watt/cm3 where the position at (x) = 22 cm and axis (y) = 11 with the effective multiplication factor value keff of 1,0000002.

Determining the Age of Terrace Formation Using Luminescence Dating—A Case of the Yellow River Terraces in the Baode Area, China

Dating fluvial terraces has long been a challenge for geologists and geomorphologists, because terrace straths and treads are not usually directly dated. In this study, the formation ages of the Yellow River terraces in the Baode area in China were determined by dating fluvial deposits overlying bedrock straths using optically stimulated luminescence (OSL) dating techniques. Seven terraces (from the lowest terrace T1 to the highest terrace T7) in the study area were recognized, and they are characterized by thick fluvial terrace deposits overlaid by loess sediments. Twenty-five samples from nine terrace sections were dated to about 2–200 ka. The OSL ages (120–190 ka) of the fluvial samples from higher terraces (T3–T6) seem to be reliable based on their luminescence properties and stratigraphic consistency, but the geomorphologic and stratigraphic evidence show that these ages should be underestimated, because they are generally similar to those of the samples from the lower terrace (T2). The formation ages of the terrace straths and treads for the T1 terrace were deduced to be about 44 ka and 36 ka, respectively, based on the deposition rates of the fluvial terrace deposits, and the T2 terrace has the same strath and tread formation age of about 135 ka. The incision rate was calculated to be about 0.35 mm/ka for the past 135 ka, and the uplift rate pattern suggests that the Ordos Plateau behaves as a rigid block. Based on our previous investigations on the Yellow River terraces and the results in this study, we consider that the formation ages of terrace straths and treads calculated using deposition rates of terrace fluvial sediments can overcome problems associated with age underestimation or overestimation of strath or fill terraces based on the single age of one fluvial terrace sample. The implication is that, for accurate dating of terrace formation, terrace sections should be systematically sampled and dated.

Disciplinarian of soil nutrient in the surface of terrace wall

In loess tableland area, farmers usually collected the soil in the surface of terrace section (or called “terrace wall”) as fertilizer. Actually it contains abundant nitrogen and potassium. As fertilizer, it would be used as new and ecological materials in crop production. In order to analyse the disciplinarian of soil nutrient in the surface of terrace wall, soil samples were divided into three different ages: one year, five years, above ten years; different two slope aspects: sunny- and shady slop; three ground level: 0.2m, 1m, 1.8m above ground; and three vertical depths: 0-1 cm, 1-5 cm, 5-10 cm. The results showed: with the increase of age and ground level, soil nutrients, such as total nitrogen, available phosphorus and potassium were activated and accumulated in the surface of terrace wall under the effect of solar-thermal resources. In the sunny slope, soil nutrients were much higher than those in the shady slope caused by radiation. Soil nutrients were decreased with the increase of sampling vertical depth, most soil nutrients were found in the section surface, which proved soil nutrients were mainly accumulated in the surface of terrace wall.

İKLİM KONTROLÜNDE ŞEKİLLENEN AKARSU SEKİLERİ VE SEKİLERİN BEŞERİ KULLANIMI

Climate and tectonism are most important control mechanisms which monitor for-ming fluvial terraces. The influence of the climatic changes on the fluvial systems causes different terraces in terms of sedimantological and morphological structures. This difference reveals the importance of fluvial architecture for the paleo-environment analysis. However the information of he interaction between climate and fluvial system is not clean everytime. For instance, it is one of the most impor-tant questions that the terrace sedimantation that formed in a climatic cycle (sequ-ential warm and cold periods) can be formed by the tectonic accumulation-erosion processes or by the different factors like as the lateral migration of the rivers. Besi-des the other discussing topics which reverse the simplex for the interaction of cli-mate-river systems are below.a.Is there any characteristic sedimantary structure in the terrace sections? Can be de-termined accurately the forming mechanism of every sedimantary layers. b.What are the relative ages of the sedimantary layers and their erosive phases which formed in a fluvial incision-accumulation cycle? Which processes and phases are consistent? c.Which scenarios can analysed the preservation of the terraces sequences which re-lated to the climatic cycle?d.How the finding about human usage of fluvial areas can obtain, and which infor-mation can be derived from these findings? This article aims to search the answers for these questions.

La arquitectura escalonada como generatriz de la ciudad-paisaje (1907-1964)

This article is aimed at establishing the importance of stepped-back architecture in the conceptualization of the landscape-city during the sixties. Particularly so, since its setback terrace section was persistently used as the matrix to shape mega-structures, undoubtedly the most innovating proposals for the epoch. The article discusses the relationships between this formal vocation and the stepped-back architecture that developed during the interwar period. This was architecture’s way to deal with the concerns regarding public health in the planning of cities and work, and found its best models in hospital architecture. This was the case of the Freilufthaus which resulted from a formal adaptation of the tuberculosis sanitarium to the requirements of 20th century heliotherapy.

Quantifying the effectiveness of mountain terraces on soil erosion protection with sediment traps and dry-stone wall laser scans

Mountain depopulation in the Mediterranean region over the past decades has led to a decline in the use and maintenance of agricultural terraces and consequently the collapsing of dry-stone walls, which can increase soil erosion rates and downstream sedimentation. A field experiment has been set up on a degrading terraced hillslope in the Troodos Mountains of Cyprus, to quantify the effectiveness of terrace maintenance on protecting cultivated land against soil erosion. The monitored site is cultivated with grapes. The terrace riser (22 m long) that forms the linear outlet of the hillslope has 11.4 m of standing dry-stone wall and 10.6 m of collapsed wall. It has been instrumented with seven 1 m wide sediment traps, three on standing sections of the wall and four on collapsed sections. When dry, sediment was collected from the traps after rainfall events, from December 2015 to November 2017. Uncertainties in the drainage areas of the 31.5-m long slope were quantified both for the terrace wall and for the individual traps through hydrologic delineations based on a detailed topographic survey. The sediment data were complemented by laser scanner surveys that were conducted in November 2015, May 2016 and April 2017, on a dry-stone terrace wall upslope from the outlet section. Wall degradation was assessed from the consecutive 3D model reconstructions. Rainfall was 469 mm in the first year and 515 mm in the second year and the average erosivity was 1148 MJ mm ha−1 h−1 y−1. The average soil erosion rate was 2.4 Mg ha−1 y−1, when linear drainage areas are considered (693 m2), 3.2 Mg ha−1 y−1 when the borders are delineated with the topographic data (520 m2). Nearly half of the soil erosion (43%) occurred during two very intense rainfall events (maximum 30-min intensity exceeding 35 mm h−1), out of the 34 monitored events. Erosion from standing terrace sections was 3.8 less than the erosion from the collapsed sections. For the scanned terrace wall, soil erosion from the standing sections was 2.2 lower than from the degraded sections. The laser scanner surveys identified some preferential erosion paths, but failed to recognize single stone collapses, whereas possible wall displacement was masked by scanning artifacts. The sediment traps were found to be an effective method for understanding and quantifying soil erosion in terraced mountain environments, while further research is needed to develop a more rigorous acquisition procedure for laser scanner surveys to derive useful information on wall degradation.

New data on age and conditions of buried organic-rich sediments formation in the сentral Ob River

This article presents the results of a comprehensive geochronological study of gyttja deposits from a section of a terrace above a floodplain located on the right bank of the Ob River near the town of Kolpashevo. According to the 230Th/U dating, the age of the gyttja could be dated in the range of 110–95 kyr. The results of spore–pollen analysis suggest that the gyttja deposit was formed in the period of a wide distribution of middle taiga forest landscapes with the dominance of spruce; the climatic conditions were similar to modern ones. These events probably took place in the interstadial time during MIS-5c or at the end of Kazantsevo interglacial period.

Late Quaternary evolution of Tista River terraces in Darjeeling-Sikkim-Tibet wedge: Implications to climate and tectonics

Terraces in the Himalayas are important geomorphic archives which preserve the signature of tectonics and past environment. Terraces in eastern part of the Himalayan fold and thrust belt have not received much attention of the geologists. A geochemical approach using luminescence dating has been applied to understand the evolution of paired and deformed terraces between major thrust boundaries of the eastern Himalayas, on the either banks of the Tista River in Darjeeling-Sikkim-Tibet wedge. These terraces are located at the confluence of Tum Thang khola and the Tista River. Three levels of terraces are present in general and also in the study area. The terrace T3 was formed during last interglacial period and the T2 terrace during last glacial maximum (LGM) and in the humid phases after LGM. The top section of T2 terrace (∼2.5 m thick) was formed in the transition phase (arid to humid) after Younger Dryas event. The region has experienced several deformational events, (i) one after 45 ka which raised the T3 terrace to its present level, (ii) another one after 11.9 ka which raised the T2 to its present level and this event is also associated with the shifting of the Tum Thang khola, and (iii) the region is still tectonically active as shown by the warping of the T1 and T0 surfaces, which are of recent origin. These terraces have complex input of sediments from Higher Himalayan Crystalline (HHC) rocks and from locally present Lingtse granites.

Development of the alluvial and lacustrine terraces on the northern margin of the Hetao Basin, Inner Mongolia, China: Implications for the evolution of the Yellow River in the Hetao area since the late Pleistocene

Terrace formation processes can reflect the evolution of large rivers. The Hetao Basin is a floodplain of the Yellow River, and there are two to three terraces that extend E–W on the northern margin. Based on a detailed field geological survey and measurement of the terrace sections, combined with sedimentological and chronological analyses, we reconstructed the developmental processes of the three terraces and inferred that three river terraces were formed by the Yellow River. The OSL dating results show that the time of deposition of terrace 3 was prior to 118kaBP. Subsequently, the terrace began to experience incision and formed the geomorphic surface of terrace T3. Similarly, terrace 2 and terrace 1 were mainly deposited from ~109 and 59ka, respectively; and began to be incised prior to 71 and 46ka, respectively. The three terraces in the northern Hetao Basin are the products of the combined actions of climatic shifts and tectonic uplift. The Yellow River's evolutionary history in the Hetao area since the Late Pleistocene is discussed. Before about 120kaBP, the Yellow River may have flowed through the northern Hetao Basin. Between 110 and 70kaBP, the Yellow River experienced at least two changes between river and lake sedimentation. From 60 to 50ka, a very large river-connected lake of the Yellow River was developed in the Hetao Basin. After 50ka, the Hetao river-connected paleolake of the Yellow River gradually dried.

Holocene Vegetation and Climate History of the Cheshskaya Bay Region, SE Barents Sea, Inferred from the First Pollen Archives

First high-resolution micropaleontologic investigation was carried out for bottom sediments of the Cheshskaya Bay (SE Barents Sea) and marine beds exposed in abrasive terrace along the eastern coast of the Kanin Peninsula. Sediments from 2 gravity cores and a 7.5-m thick terrace section were analyzed for pollen and non-pollen palynomorphs (NPP), including spores, freshwater green algae and cysts of marine dinoflagellates. The age of the sediments was constrained by the reference to the regional sea-level history from the earliest Holocene to present, thus the pollen records reveal the environmental history for the last ca. 10.0 ka. Sparse treeless vegetation with dwarf Betula and halophytic inhabitants of seaside watts (cereals, wormwood and sedges) indicating arctic desert environment with colder and drier than present climate dominated the Cheshskaya Bay coast during the early Preboreal period. Gradual advance of shrubby-birch and piny forest-tundra with alder communities along river valleys resulted from significant climate amelioration which concurred with the Pholas inundation since the Boreal period. Postdated expansion of tree-birch inland the Kanin Peninsula and firry-birch light-forests along the Cheshskaya Bay coast marked the Holocene regional climate optimum. Re-establishment of the dwarf-birch and piny forest tundra signalized vegetation feedback to the cooling since the end of Atlantic period.

Late Quaternary river terraces in the Central Mountain Range of Taiwan: A study of cover sediments across a terrace section along the Tachia River

The existence of fluvial terraces in the high mountains of Taiwan has been known for a long time already, but these terraces have not yet been studied in detail. This paper studies cover sediments across a terrace section in the Central Mountain Range located at the midstream reaches of the Tachia River at an elevation of 1430m asl. Sediments were dated by means of optically stimulated luminescence and radiocarbon dating, yielding robust ages between 54.8±7.0ka and 0.42±0.09cal. ka BP. These dates are in good agreement with ages known for the laterite terraces (LT) in the mountain foreland. Deeply weathered reddish soils, comparable to those in the mountain forelands, are absent. Hence, in stratigraphic terms, the terraces in the high mountains cannot be correlated with those in the mountain foreland. Cover sediments comprise eolian sand and silt and various colluvial layers. Eolian sediments provide paleoenvironmental evidence of a relatively dry phase in early MIS 3 that coincides with the maximum extent of the glaciations in the Hsueh Shan Mountain area. Widespread colluvial sediments indicate a high frequency of mass movements around 38.5ka, a period of time known to correlate with dominantly wet conditions. In the last 1000 years, wildfire appears as a possible trigger of mass movements. The geochronological data indicate a local bedrock strath incision rate of 0.8±0.1mmy−1, a value that appears to be in agreement with the local decadal scale erosion rate.

Late Holocene marine terraces of the Cartagena region, southern Caribbean: The product of neotectonism or a former high stand in sea-level?

Abstract The detailed stratigraphic survey and paleontological study (mollusks, corals, foraminifera and ostracods) of four low-level, ∼3 m, marine terrace sections: Punta Canoas, Manzanillo del Mar, Playa de Oro, and Tierra Bomba Island, from the Cartagena region, southern Caribbean, supplemented with 22 radiocarbon dates, reveals that the northern terraces were deposited as parasequences in a clastic depositional system compared to the Tierra Bomba Island succession that was deposited in a carbonate depositional system between ∼3600 and ∼1700 cal yrs BP. Drier conditions and the southern location of the ITCZ at about 3 ka triggered stronger easterly Trades and more dynamic southwestward sediment drift fed by the Magdalena River mouth, thus promoting the formation of sand spits that ultimately isolated the Cienaga de Tesca coastal lagoon from the Caribbean Sea. Our estimates support the hypothesis that the present position of the terraces is the product of neotectonism rather than a higher 3 ka, sea-level. Upheaval of the terraces varies between ∼3.8 mmyr −1 at Punta Canoas and ∼2.2 mmyr −1 at Tierra Bomba to ∼1.5 mmyr −1 at Manzanillo del Mar and Playa de Oro terraces. Our study corroborates previous contentions on the role of mud diapirism and the dynamics of the Dique Fault as late Holocene upheaval mechanisms.

Optically stimulated luminescence dating of sediments from the Yellow River terraces in Lanzhou: Tectonic and climatic implications

The stratigraphic chronology of Yellow River terraces was investigated and studied in Lanzhou Basin, western Chinese Loess Plateau. The optically stimulated luminescence (OSL) dating results show that terraces T 1, T 2 and T 3 formed at 8 ka, 20 ka and 70 ka, respectively. Lateral accretion of the riverbed facies gravel sediments occurred during interglacial periods while vertical aggradations of the terrace sediments deposited predominantly under cold and dry glacial period. A thick layer of aeolian loess with a basal age about 35 ka indicates a remarkable drop of air temperature and a dry, cold climate. The temporal correlation between terrace formation and tectonic movement has not yet been established in this research, but the stratigraphic chronology of the terrace sections provides the timing of the terrace formation, the incision rate of the Yellow River, and the slip rate of the fault horizon.

FORAMINIFERAL EVIDENCE OF HOLOCENE SUBSIDENCE AND FAULT DISPLACEMENTS, COASTAL SOUTH OTAGO, NEW ZEALAND

Foraminiferal assemblages preserved in estuarine sedimentary sequences along the coast of South Otago, New Zealand, provide evidence for three Holocene fault-displacements and associated earthquakes within the 250 km-wide continental collision zone along the Australian-Pacific plate boundary. The modern analogue technique was used to estimate paleotidal elevations of the fossil foraminiferal faunas, based on an analogue set of 334 modern New Zealand faunas (including data from three new intertidal transects taken from the studied estuaries). These elevation estimates provide a record of abrupt changes in tidal elevation, which are inferred to have been produced by vertical displacements on nearby faults. The foraminiferal record in cores (0.75–2.8 m long) from Akatore Estuary identify the previously recognized last rupture (,1100 cal yrs BP) on the Akatore Fault, with ,0.4 m of subsidence on the western side produced by actual downthrow or shaking-related compaction of underlying sediment. The foraminiferal record in cores (1.4– 7.0 m long) and in an uplifted terrace section from tidal Catlins Lake provides the first evidence of Holocene fault rupture and major earthquake risk south of the Clutha River mouth. Three displacement events on the Settlement Fault, which forms the eastern margin of Catlins Lake, are recognized. The youngest (,1000 cal yrs BP) resulted in 0.4 m of subsidence (downthrow or compaction) on its west side. The penultimate (,3600 cal yrs BP) resulted in ,1.2 m of uplift of an extensive terrace on the east side of the fault with consequent narrowing of the estuarine entrance and reduced salinity in the tidal lake (recorded by foraminiferal faunas). The earliest event (,5000–4500 cal yrs BP) is recognized by ,1 m of abrupt subsidence on the west (Catlins Lake) side of the fault. Foraminiferal faunas in the upper parts of the majority of cores (from high tidal salt meadows) also document ,0.3 m of sea-level rise within the last 150 years.

Sediment provenance of late Quaternary morainic, fluvial and loess‐like deposits in the southwestern Verkhoyansk Mountains (eastern Siberia) and implications for regional palaeoenvironmental reconstructions

AbstractA provenance analysis of late Quaternary deposits from tributaries of the Aldan and Lena rivers in Central Yakutia (eastern Siberia) was carried out using analysis of heavy minerals and clay mineralogy. Cluster analysis revealed one assemblage that is characterized by relatively high proportions of amphibole, orthopyroxene and garnet as well as pedogenic clay minerals, reflecting a sediment provenance from the wide catchment area of the Lena and Aldan rivers. In contrast, the three other clusters are dominated by stable heavy minerals with varying amounts of clinopyroxene, apatite and garnet, as well as high percentages of illite and chlorite that are indicative of source rocks of the Verkhoyansk Mountains. Glacial moraines reveal the local mountain source signal that is overprinted by the Lena‐Aldan signal in the oldest moraines by reworking processes. Alluvial sediments in the Verkhoyansk Foreland show a clear Lena source signal through intervals of the middle and late Pleistocene, related to a stream course closer to the mountains at that time. Loess‐like cover sediments are characterized by the dominant Lena provenance with increasing proportions of local mountain sources towards the mountain valleys. Aeolian sands in an alluvial terrace section at the mountain margin covering the time between 30 ka and 10 ka BP reflect temporarily dominant inputs of aeolian materials from the Lena Plains. Copyright © 2007 John Wiley & Sons, Ltd.

Crop and soil variability on terraces in the highlands of SW Uganda

AbstractTerrace benches on the hillslopes of Western Uganda exhibit a crop‐yield gradient: upper portions of terraces produce less than the lower sections. We investigated the soil factors responsible for this yield variation on 30 terraces along 5 toposequences in what was predominantly a Ferralsol. Two levels of spatial analysis were conducted: (1) variation within individual terraces; and (2) differences across hill‐slope positions. A greenhouse experiment further examined this fertility gradient using soils extracted from the upper, middle and lower parts of the terrace. This included a nitrogen (N) treatment of 70 mg N kg−1 soil. In the fields sorghum (Sorghum bicolor) grain yield differed significantly (p ≤ 0·05) across terraces, increasing from 0·4 Mg ha−1 on the upper 40 per cent of terrace to 2·5 Mg ha−1 on the lower 40 per cent. Soil bulk density decreased down the terraces from 1·41 g cm−3 to 1·18 g cm−3, causing an increase of hydraulic conductivity from 1·6 cm h−1 to 7·3 cm h−1, from the upper to the lower part, respectively. Organic carbon (C) and total N increased from upper to lower terrace sections. In the greenhouse, sorghum growing on soils from which the soil physical limitations have been removed did not show significant yield differences across a terrace as observed in the field. Response to N was most pronounced on the upper terrace sections, increasing sorghum dry matter from 3 g pot−1 to 15 g pot−1. On the lower terrace, N amendment increased dry matter from 4 g pot−1 to 11 g pot−1. Technologies to improve the adverse soil physical conditions and the N limitations on upper terrace parts while preventing tillage‐ and soil‐erosion‐induced terrace scouring are required. Copyright © 2005 John Wiley & Sons, Ltd.

Late Pleistocene invasion of Palaeo-Dead Sea into the lower Zin Valley, the Negev Highlands, Israel

Evidence of invasion of Lake Lisan, the Late Pleistocene precursor of the Dead Sea, is revealed within the valley of lower Nahal Zin that runs down to the Dead Sea from the Negev Highlands. The main proof of the invasion is presence of lacustrine sediments that are followed contin- uously along the Lower Zin valley for a distance of 25 km from the coast of the Dead Sea. Extending deep into the interior of the Nahal Zin valley, the lacustrine sediments are included in the terraces at relative heights of 16 and 28-32 m. They overlay alluvial bases of the terraces or interbed in al- luvial deposits. TL dating has demonstrated that age of the lacustrine sediments is of about 30 Ka. TL ages of the de- posits forming the alluvial bases of the terraces, which are covered by the lacustrine sediments, are of 40 to 60 Ka. Oth- erwise Pleistocene lacustrine sediments both in younger and older age are absent in the terrace sections of the Zin valley. The revealed lacustrine sediments are uppermost, known of this kind. They are tapered out at 130 m altitude, and de- posed during the highest stand of Lake Lisan, which is cor- related with the marine isotope stage 2. Other fluctuations in the level of the Dead Sea and its Pleistocene precursors also exerted an influence on the development of the Zin valley. However their evidence occurs only in the Dead Sea tectonic basin except of the deep interior of the valley.

Holocene Marine Terraces of Kunashiri Island, Kurile Islands.

Low marine terrace sequence of Kunashiri Island includes Atlantic, Subboreal and Subatlantic terraces, reflected sea level oscillations during Middle-Late Holocene. The section of Atlantic terrace (5-6m elevation) exposes storm ridge deposits, covered lacustric silts and peat. Pollen and diatom fossils and 14C-dates (5, 450-6, 070yrs BP) correspond to development of large barrier forms with lakes in the Holocene Optimum. The paleostraits existed in the place modern Sernovodsky and Kruglovsky Isthmuses. Ocean level rose to 2.5-3m a. m. s. l. A minor regression took place during Atlantic-Subboreal cooling. Drainage of inshore zone led to development of large dunes. Subboreal deposits record two high sea level positions: about 4, 010-3, 400yrs BP and 2, 950-2, 620yrs BP. Small estuarian lagoons and inlets developed in that time. The cooling and ocean level lowering at Subboreal-Subatlantic boundary accompanied by formation of dune fields and swamping of the lagoon coasts (2, 220±80yrs BP, 1, 440±60yrs BP, GIN-7895, GIN-7262). Subatlantic terrace (2.5m) formed during ocean level rise to 1m about 1, 170-820yrs BP. Dunes were formed during Little Ice Age regression. The terrace study indicates their weak tectonic deformation.

THE DESCRIPTION, CHRONOLOGY AND CORRELATION OF BURIED SOILS AND CULTURAL LAYERS IN A TERRACE SECTION, PEACE RIVER VALLEY, BRITISH COLUMBIA

A terrace section in the Peace River Valley of British Columbia contained seven buried paleosols developed in eolian material. Chemical, physical and micromorpholgical data showed the soils to be Chernozemic. The main soil-forming processes have been the leaching and reprecipitation of carbonates, the formation of mull aggregates, the weathering of primary minerals and the weak physical translocation of soil fabric. Five cultural components or levels had been identified in nearby archaeological excavations and these were correlated with the Ah horizons of five of the paleosols. However, none of these Ah horizons contained large amounts of organic P as have been found in cultural layers of other archaeological sections. The cultural components contained tools, flakes, shell beads, bones and projectile points. Radiocarbon dates from charcoal ranged from 5830 ± 80 yr B.P. in the second lowest paleosol to 1530 ± 70 yr B.P. in the second highest paleosol. They showed that most of the eolian material had been deposited on the terrace by about 4500 yr B.P.; that is, by the end of the Hypsithermal. The chronology of soil development and eolian deposition are discussed by applying a previously published system of horizon designations that combines and describes the gradational and pedomorphic features in soils.