Lower Terrace Research Articles

Comment on Souza and Perez Filho (2019) "Late Holocene Coastal Dynamics, Climate Pulses and Low Terraces in the Coast of the State of São Paulo, Southeast Brazil"

Comment on Souza and Perez Filho (2019) "Late Holocene Coastal Dynamics, Climate Pulses and Low Terraces in the Coast of the State of São Paulo, Southeast Brazil"

Особенности геохимического состава почв прибрежной части юго-западного Приморья

The large diversity of the soil cover in the southern regions of Primorye makes it difficult to assess the current ecological state of soils on the basis of data from single background pits. More than 220 samples taken from topsoils of main types of background soils were analyzed by atomic absorption by atomic method to reveal the geochemical composition of soils in the coastal territory of the region, the background content of heavy metals was established. The features of accumulation of pollutant elements in the surface layer are revealed. The content of vanadium, chromium, cobalt, nickel, copper, zinc, cadmium, and lead is much lower clark. No significant difference was found between the content of heavy metals in the soils of high and low sea terraces (Histosoils, Gleysols), riverine plains (Fluvisols, Histosoils,) and outlier uplands (Albic Stagnoso, Cambisols). A series of the intensity of accumulation of total forms of elements Cu > Zn > V > Cd > Co > Ni > Pb > Сr was determined. The average values of the various geochemical indices indicate the absence of pollution and a low level of potential ecological risk of the soils of the study area, therefore, using the received data as background data is correct. The territories of neighboring states can be a potential source of pollution of the region during atmospheric transport due to the higher content of pollutant elements in soils.

Плотность потока радона-222 в почвах Тобольского района Тюменской области

The aim of the work is to determine potentially radon dangerous areas for the local population on the territory of Kondinskaya lowland within the boundaries of Tobolsk district of Tyumen region with the help of radon monitoring complex “CAMERA-01”. The density of the radon-222 flux was defined at the soil depth from 0 to 100 cm in 10 plots. The plots are located on the low above floodplain terrace, in the levee and central floodplains of the Irtysh River and a tributary of the Tobol River – the Suklyomka River. The highest average value of radon-222 exhalation from the soil surface was found in the vicinity of Makedonova village – 39 mBq/(m2·s), in the rest of the tested soil plots it was not more than 18 mBq/(m2·s). The received data on density of radon-222 flux from the surface of soils of the investigated plots make it possible to say that they do not refer to potentially radon-hazardous. At the same time it is found that the territories around the village Usharovo, the village of Makedonova and settlement Savinsky Zaton (floodplain terraces of the Irtysh River) at a depth of 40 to 100 cm have average values of the flux density of natural radionuclide exceeding 200 mBq/(m2·s). Only in soils of the floodplain terrace of the river Suklyomka – a tributary of the Tobol river the radon– 222 flux density below 80 mBq/(m2 s) – I class of radon-hazard was fixed at the whole investigated depth. The highest average density of the radon–222 flow (1200 mBq/(m2·s)) at the depth of 100 cm was found in the vicinity of the settlement Savinsky Zaton, probably associated with the transfer of radon-222 from groundwater of the liquidated well, near which the sampling of radon-222 was made.

The Lower Rhine (Germany) in Late Antiquity: a time of dissolving structures

Abstract From the middle of the 1st century AD, the Lower Rhine was part of the frontier of the Roman Empire (Limes). However, this Limes was not an impermeable line, but rather an open corridor that served as march area and as a trade and supply route for the adjacent military and civilian settlements as well as the hinterland. This required access to the river and permanent harbours. When planning military camps and towns along the Rhine, the existing topography and the challenge of a dynamic riverine landscape had to be taken into account. The prefered location for forts and towns were the raised edges of the Lower Terraces close to the undercut bank of a meander. For many years, research assumed that the river bend adjacent to a Roman site had to be an oxbow lake. The main argument being that only an oxbow situation would have protected the Roman sites against strong currents and the risk of demolition of land and settlements by the main stream (abandoned channel hypothesis). A re-evaluation of the extensive archaeological, sedimentological and palynological archive and published data from the Rhine plain, as well as of supplementary data from new boreholes, lead to a considerable increase in the previously incomplete knowledge of the fluvial history, especially regarding the timing of palaeomeander infilling. It showed that most of the meanders and river bends of the Rhine with Roman settlements on their banks not silted up before Late Antiquity (from the end of the 3rd century AD on). Before that those meanders were part of the main stream. The advantage of steep undercut banks was that a quay could be built on a location that ensured mooring all year round, even at low water level. However, it was necessary that stabilising bank protections were present in order to avoid shifting the course of the river with subsequent destruction of the infrastructure. Such an antique bank protection construction (a so called “Packwerk”) could be recognised in front of the Colonia Ulpia Traiana (CUT, Xanten). With this knowledge in mind, other excavated structures on the banks of palaeomeanders, previously mostly interpreted as Roman harbour remains, could be interpreted as bank protections. At Wesel near the strategically important mouth of the Lippe, the archaeological, sedimentological and palynological data showed that a meander that had silted up in Prehistoric times (Bronze Age) had been reactivated in Roman times and silted up again in Late Antiquity. A man-made diversion (perhaps by building a groyne) of the main stream could have been responsible for this. With the beginning of the Late Antiquity crisis of the Roman Empire at the end of the 3rd century, it presumably became increasingly difficult to maintain these water works. This enabled the river to regain its morphodynamics, by cutting of the meanders that were active during Roman times. We hypothesise that this increase in fluvial activities of the Lower Rhine from the end of the 3rd century onwards is due to an anthropogenic trigger: the collapse of the Roman Empire.

Exploring RPAS potentiality using a RGB camera to understand short term variation on sandy beaches

Remotely Piloted Aircraft Systems (RPAS) is a low-cost and useful alternative to track spatial-temporal variations in a rapidly changing environment. However, there is a lack of studies on beach geomorphology characterization in association with visible spectrum reflectance potentialities. The objective of this study was to embrace this technology for coastal change detection. For this purpose, the data set samples are covering the winter season of 2019. The materials used were digital orthophotos, digital terrain models, and geomorphological parameters, such as the Relative Tide Range (RTR) and Omega (Ω). The goals are to (i) classify the beach morphodynamics; (ii) identify the berms, cusps, and rip current channels; (iii) extract RGB indexes to detect the shoreline variability; (iv) assess beach profiles and (v) evaluate the volume of sediments. The study area, Paiva beach, is located in the Northeast of Brazil, which presents significant morphodynamic variations. The results indicate three morphodynamic stages, namely: Rhythmic Bar and Beach (RBB); Transverse Bar and Rip (TBR), and Low Tide Terrace (LTT). The wave climate for the region averaged Dir of 120°, Tp of 9 s, and Hs of 1.8 m. Between June and July, the shoreline had the most significant advance with 51% of the beach extension. On the other hand, between July and August, the beach registered a considerable 88% retreat. The profiles showed a maximum variation of 1.5 m vertically on the berm, a common characteristic of winter profiles, detected in August. For the sediment volume, July and August showed erosion processes with sediment loss of 12,508.58 m3 in the south sector and accretion of 23,052.97 m3 in the north. The planimetric and altimetric mean square error were 2.7 and 4.5 cm, respectively, showing the advantage of high spatial resolution data for morphodynamic classification, and combining it to identify vegetation indexes to detect shoreline variability.

Surf and Swash Dynamics on Low Tide Terrace Beaches

Low tide terrace (LLT) beaches are characterised by a moderately steep beach face and a flat shallow terrace influencing the local hydro-morphodynamics during low tide. The upper beachface slope (β) and the terrace width (Lt) are the main morphological parameters that define the shape of LTT cross-shore beach profiles. This work aims at better understanding the behaviour of β and Lt and their link with the incoming wave forcing. For this purpose, our results are based on 3.5 years times series of daily beach profiles and wave conditions surveys at two different microtidal LTT beaches with similar sediments size but different wave climate, one at Nha Trang (Vietnam) and the other one at Grand Popo (Benin). While they look similar, two contrasting behaviour were linked to two sub-types of LTT regimes: the first one is surf regulated beaches (SRB) where the swash zone is highly regulated by the surf zone wave energy dissipation on the terrace, and the second is swash regulated beaches (SwRB) acting in more reflective regime where the terrace is not active and the energy dissipation is mainly produced in the swash zone, the terrace becomes a consequences of the high dynamics in the swash zone. Finally, extending the common view of an equilibrium beach profile as a power law of the cross-shore distance, the ability of a simple parametrized cubic function model with the Dean number as unique control parameters is proposed and discussed. This simple model can be used for the understanding of LLT environments but it can not be extended to the whole beach spectrum.

Morphological, hydrodynamic and sedimentary characteristics of the Northeastern coast of Cuba

The absence of the marine platform, the presence of emerged and submerged terraces with tide notches on its front face and the increase in the number of beaches constituted by terrigenous sands towards the east end of this coastal stretch are the main geomorphological features that characterize the northeastern coast of Cuba. The lower rocky terrace is the best represented type of coastline on the Northeastern coast, exposed to the direct action of ocean waves. Considering the inland coast, mangroves are the most abundant type of coast and occupy most of the bays on this coastal stretch. From the hydrodynamic point of view, the highest wave heights of the north coast of Cuba take place there. In addition, the biggest tidal range of the Cuban archipelago is recorded. From the sedimentary point of view, these beaches have a greater amount of fragments of mollusks and corals and fewer fragments of calcareous algae than the other beaches of the Cuban archipelago. These beaches, unlike the other beaches of Cuba, show cumulative processes at the end of winter and early spring, with a maximum accumulation in April, while eroding at the beginning of autumn, with maximum values in the months of September and October. Keywords: Coastal characteristic, beach, genesis sand, Northeastern coast of Cuba.

О СТРАТИГРАФИЧЕСКОМ ЗНАЧЕНИИ НИЗКИХ ТЕРРАС СУЗУНСКОЙ ТОЛЩИ ВЕРХНЕГО ПРИОБЬЯ

Studies of the end of the 20th century showed that there are no sediments of the glacial-dammed lakesea, as well as sediments of periglacial alluvium in sections of low terraces of the Upper Ob River region, known as the Suzun Strata. The lower stage of terraces is composed of alluvial sediments, and the upper one is epresented by subaerial complex, which includes both deluvium and aeolian deposits. The height of areas varies significantly and is predetermined by thickness of the subaerial complex in each particular area. Сonsequently, the geomorphological principle does not work when differentiating the Suzun Strata into heterochronous geological bodies of accumulative terraces above the flood-plain.

Food sources of common carp in a Hani Terrace integrated rice-fish system (Yunnan Province, China)

Integrated rice-carp farming is commonly employed on Hani terraces in China. However, the altitude within a Hani terrace can vary greatly, and thus the solutions for such a farming approach must vary with altitude. Research on common carp food sources in an integrated rice-carp farm at different altitudes helps to understand the food requirements of carp across periods and provides guidance for production. In this study, the composition of eukaryotic food sources of common carp (Cyprinus carpio) growing on Hani rice terraces at low and high altitudes (570 m and 1840 m) from May to August 2019 was surveyed by high-throughput DNA sequencing. The 18 s v4 gene sequences were amplified to provide 2243,095 valid reads and 2485 operational taxonomic units. In addition, the relative abundance of the gut contents of each food source varied by month and altitude. Chlorella, Necator, Oedogonium, Oryza and Scenedesmus were the dominant C. carpio food sources at the high altitude, while Chironomus, Gieysztoria, Scenedesmus, Oryza, and Lemna were the dominant species at the low altitude. The Lemna biomass identified in the C. carpio gut contents in the low altitude terrace decreased from 39.75% in June to 0.05% in August, while the Oryza biomass increased with time. The Oryza biomass observed in the gut contents of C. carpio growing in high and low altitude terraced fields increased with time. Rice pests, including the rice gall midge, rice bugs, nematodes, and chironomid larvae were found in the stomachs of C. carpio in the high and low altitude terraced fields. The maximum proportion of chironomid larvae in the gut contents of C. carpio in the low altitude terraces reached 39.29%, while the maximum proportion of nematodes was 5.38%. However, only chironomid larvae and nematodes were found in the gut contents of C. carpio growing in the high altitude terrace, reaching maximum proportions of 0.17% and 3.63%, respectively. Furthermore, a variety of rice pests were detected in the gut contents of C. carpio, indicating that C. carpio effectively preyed on rice pests and reduced rice diseased in the integrated rice-carp farming terraces.

An Account of Chiral Metal Surfaces and Their Enantiospecific Chemistry

ConspectusMolecular chirality has been of scientific interest since 1848 when Pasteur demonstrated its direct connection to the rotation of light by solutions of chiral compounds. In the 1960s the connection was made between the chirality of pharmaceutical compounds and their physiological impact; one enantiomer can be therapeutic while the other is toxic. That realization prompted enormous effort in the synthesis of enantiomerically pure compounds for bioactive use (a $300B/yr market). Until relatively recently, metals were ignored as potential substrates for asymmetric surface chemistry because metals have highly symmetric, achiral bulk structures and the premise was that they could not expose chiral surfaces. In 1996, we demonstrated that the high Miller index surfaces of metals can be chiral, existing in two enantiomeric forms M(hkl)R&S, and we hypothesized that they exhibit enantiospecific interactions with chiral adsorbates. Most such intrinsically chiral metal surfaces have ideal structural motifs based on low Miller index terraces separated by kinked monatomic steps. This Account begins with a short tutorial on the ideal and real structures of chiral metal surfaces to provide a firm basis for understanding the origin of their chirality. It then chronicles the evolution of our understanding of their enantiospecific interactions with chiral adsorbates.Detecting, quantifying, and understanding enantiospecific surface chemistry on intrinsically chiral metal surfaces has been far more challenging than coming to the realization that such surfaces exist. The first successes came from measurements and modeling of the enantiospecific adsorption energetics of small chiral molecules such as propylene oxide and trans-1,2-dimethylcyclopropane. These revealed one of the core challenges to observing enantiospecificity, the fact that the enantiospecificities of reaction energetics and barriers tend to be small, i.e., a few kJ/mol. Measurements of the enantiospecific adsorption energetics of R-3-methylcyclohexanone on seven different Cu(hkl)R&S surfaces demonstrated their sensitivity to surface structure, but again revealed variations of only a few kJ/mol. One of the most important advances in our understanding of chiral surface chemistry is that the limitations imposed by weakly enantiospecific interactions can be circumvented by processes with nonlinear kinetics or equilibria. As an example, the surface explosion mechanism of d- and l-tartaric acid decomposition on Cu(hkl)R&S surfaces leads to enantiospecific rates that differ by almost 2 orders of magnitude, in spite of the fact that the rate constants are only weakly enantiospecific. More surprising is the observation that equilibrium adsorption of nonracemic mixtures of d- and l-aspartic acid can lead to autoamplification of enantiomeric excess, even on achiral Cu(111) surfaces. Again, this arises from a nonlinear adsorption isotherm. Most recently, we have developed a high throughput method for identification of the most enantiospecific surface orientation for a given reaction from the continuum of Cu(hkl)R&S surface orientations. These developments, and others described in this Account, firmly establish some of the basic principles of chiral surface chemistry.

Groundwater contamination risk assessment using a modified DRATICL model and pollution loading: A case study in the Guanzhong Basin of China

Groundwater contamination risk assessment is not only the basis for groundwater management, but also an effective tool for groundwater pollution control and prevention. However, only groundwater vulnerability assessment is not enough to prove the risk of groundwater contamination. Therefore, this study describes an evaluation method combining aquifer intrinsic vulnerability and pollution source loading to evaluate groundwater contamination risk in Guanzhong Basin on a macro scale. A modified DRATICL model was introduced to evaluate the intrinsic vulnerability, and the analytic hierarchy process (AHP) and the entropy weight method were combined to determine the weight of each evaluation factor. Pollution loading was evaluated by quantifying the characteristics of potential pollution sources, mainly including pollutant toxicity, pollutant release possibility and potential pollutant release amount. Finally, total iron, Cl−, SO42−, F−, COD (Chemical Oxygen Demand), NO3−, NO2− and TDS (Total Dissolved Solids) are used to calculate the water quality index and verify the model results. The results showed that industries were the most harmful potential pollution sources in the study area, followed by landfills. Very high vulnerability areas were mainly situated around Huazhou District, Huayin and Dali County, as well as the low terraces around Zhouzhi County and Hu County, which are mainly caused by shallow groundwater depth and high net recharge. The final groundwater contamination risk results showed the high groundwater contamination risks are detected around Xi'an City, Xianyang City, Hancheng City and Dali County. Both high vulnerability and high pollution loading were present at the Jingwei District in the north of Xi'an City, where a priority attention should be given.

ABOUT DATING OF PETROGLYPHS OF GOBUSTAN (AZERBAIJAN)

Since the discovery of the petroglyphs of Gobustan, there have been numerous studies of petroglyphs, field work on documentation, and archeological excavations. Despite the extensive literature on Gobustan, the issue of dating the rock paintings remains controversial. The author of the paper, using the results of radiocarbon dating and the 3D Studio Max software, classifies the petroglyphs by periods. As a result, the oldest date – 13 610 CD (calibrated date) – was revealed in Gobustan in the rocky shelter of Gaya Arasi on the Kichikdash mountain. The next oldest date is approximately 10,600 CD, which was obtained from the cultural layer of the Ana-zaga cave of the Beyukdash mountain. Considering that the Late Khvalyn transgression took place nearly 14,000 years ago, and during this period the waters of the Khvalyn Sea washed the Beyukdash, Kichikdash and Dzhingirdag mountains, the interval between these dates may be due to the fluctuations of the sea level. Based on the research carried out and the dates obtained, the author singles out 9 stylistic and chronological trends in the petroglyphs of Gobustan, including the period of the Middle Ages and the Modern Age. The author emphasizes that the uniqueness of the Gobustan archaeological complex lies in the fact that separate stones with petroglyphs identical to the rock carvings on the walls of the caves were discovered from dated cultural layers. In addition, stylistic and comparative analysis allowed the author to date the rock carvings of Gobustan.
 As a result of the research, it has been revealed that the settlements of the end of the Upper Paleolithic and Mesolithic Ages were mainly located on the upper terraces of the mountains. In the Neolithic and Eneolithic Ages, with the rise in the level of the Caspian Sea, the caves retained the status of the main place of residence. With the lowering of the sea level in the Bronze Age, the middle and lower terraces were inhabited. During this period, the settlers of Gobustan, who were engaged in cattle breeding, painted images of bezoar goats with large curved horns on the rocks. At the foot of the mountains, the round settlements and the tradition of kurgan burials emerged.

GROUNDWATER RUNOFF IN THE PIVDENNYI BUH RIVER BASIN IN CONDITIONS OF GLOBAL WARMING

This paper analyses changes in the calculated values of the specific runoff of unconfined and confined groundwaters to the rivers Pivdennyi Buh (Khmilnyk town) and Zhar (a tributary of the Pivdennyi Buh; Vinnytsia and Khmelnytsky regions) by seasons and long-term stages, for a total of 38 years (1980-2017). Regularities of seasonal changes in groundwater runoff in areas with different relief and average long-term groundwater levels (0.5-1.5; 0.8-2.5 and 2.7-4.5 m) are revealed. These changes have been shown to be closely related to abnormal air temperature fluctuations. There are four stages of successive changes in the regime of groundwater and in the volume of their runoff to rivers: I. 1980-1989 (1990) — traditionally minimal winter and autumn underground runoff, moderate summer and predominant spring runoff, dominance of runoff from the area with high GWT; ІІ. 1990-1998 — growth and advantages of groundwater runoff from the area with low GWT, reduction to the long-term minimum of groundwater runoff in the area with high GWT (0.8-2.5 m); III. From 1999 to 2014 — the predominant dominance of winter runoff over spring, slow growth of groundwater runoff in a limited area of the catchment with levels of 0.8-2.5 m; high-amplitude fluctuations of runoff and GWT with the achievement of long-term maximums in the area with GWT = 2.5-4.0 m; IV. 2015-2019 — the most intense reduction of GWT, and in the upper reaches of small rivers — of underground runoff to rivers.There is a progressive decrease in the specific flow of groundwater to rivers, and consequently of their resources — primarily for the aquifers in the upper reaches of rivers with GWT 0.5-1.5 m with no pressure recharge. Aquifers of ground water fed by confined aquifers (mainly within floodplains and the first low terraces of rivers) in the studied area of the Ukrainian massif of fracture waters have greater stability of the level regime on the background of rising temperatures and decreasing precipitation (recorded by 2020) than shallow water (0.5-2.0 m) without signs of such recharge.

Soil cover of the Southern Ladoga region

The buried soils of the North-West of Russia are the cornerstone for reconstruction of the history of development of the Southern Ladoga region landscapes and their exploration by ancient man. Specialists from the V. V. Dokuchaev Central Museum of Soil Science and students of the St. Petersburg State University, including the author, uncovered 42 profiles of daytime and buried soils on the territory of the Southern Ladoga region and identified such types of soils as podzols, sod-podzols, sod-podzolic, gray-humus, dark-humus, and peat eutrophic soils, among which podzols were the predominant type. Based on the studied soil characteristics, we can assume that the conditions for formation of the buried soils were not significantly different from the modern ones and in the Southern Ladoga region the following landscapes were present: spruce and pine forests on the upper terraces and deciduous forests along rivers at the medium terraces. Meadows and moisture-loving vegetation were common on low terraces. The buried soils of Staraya Ladoga could have been used by the inhabitants of early medieval settlements in a very diverse way, and vivianite in the soils of the Earthen Settlement is most likely of anthropogenic nature.

Step Bunches, Nanowires and Other Vicinal “Creatures”—Ehrlich–Schwoebel Effect by Cellular Automata

Different patterns can be created on the surface of growing crystals, among which the step bunches and/or step meanders are two of the most studied. The Ehrlich–Schwoebel effect at the surface steps is considered one of the “usual suspects” of such patterning. A direct step barrier is when it is easier to attach a particle to the step from the lower terrace than from the upper terrace. Thus, during the process of crystal growth leads to the formation of meanders, while an inverse barrier leads to step bunching. Based on our vicinal Cellular Automaton model, but this time in (2 + 1)D, we show that the combination of a direct and inverse step barrier and the proper selection of the potential of the well between them leads to the formation of bunched step structures. Following this is the formation of anti-bands. In addition, changing the height of the direct step barrier leads to the growth of nanocolumns, nanowires, and nanopyramids or meanders, in the same system.

РОСТ ОДНОЛЕТНИХ СЕЯНЦЕВ КРУПНОПЛОДНЫХ СОРТОВ ЯБЛОНИ В ПРИГОРОДНОЙ ЗОНЕ КРАСНОЯРСКА

The article presents a study of the growth rates of annual seedlings of large-fruited varieties of domestic apple (Malus domestica Borkh), grown in the conditions of the upper terrace of the Botanical Garden named after M. Kru-tovsky, Krasnoyarsk. The seeds for cultivation were collected from mother trees growing on the lower and upper terrac-es of the garden. The height of the terraces differs by 28 m. It was revealed that the phenological form of apple varie-ties also affects the growth rates of seed progeny. Large size of aboveground part and weight of one leaf is noted in seedlings of winter varieties. The presence of intervarietal variability in indicators of apple seedlings was established. Fast-growing varieties (Anisik ordinary, Antipaskhalnoe, Papirovka, Pepin saffron) and individual half-sibs (Papirovka No. 44, Cinnamon striped No. 30, Grushovka Moskovskaya No. 34, White filling No. 8 and 27, Slavyanka No. 28, Aport Central Russian No. 1, Titovka No. 1, General Orlov No. 43, variety No. 22 No. 29, etc.), characterized by a greater height and diameter of the stem of annual seedlings, for further selection research

Приозерное поселение начала эпохи железа в уральской тайге

The article presents the characteristics of the multi-temporal settlements that existed in the 8th—3rd centuries BC on the ruins of Shaitanskoe Lake II, a unique sanctuary of the beginning of the Bronze Age in the vicinity of the village Neivo-Rudyanka, Sverdlovsk Region. This is the first most fully investigated (1149 sq. m) site of the early Iron Age of the mountain-forest Trans-Urals, located on a low lakeside terrace. The ceramic and tool complexes of the Gamayun culture, descendants of the taiga tribes of Western Siberia, who came from the north, as well as the communities of the local Itkul’ and heterogeneous Iset’ cultures, characterize the inhabitants of the settlements as settled fishermen and hunters who were familiar with the basic producing economy (livestock maintenance, copper foundry). The absence of long-term stationary dwellings and a powerful cultural layer is typical for ancient seasonal summer camps and villages. The presence of a small amount of ceramics from Gorokhovo and Baitovo cultures documents forced relocation of a part of the population from the Tobol region into the Trans-Ural taiga in the 5th—3rd centuries BC, under the pressure of cattle-breeding tribes of the Sargat culture, ancient ancestors of the Hungarians, moving from the Ishim-Irtysh forest-steppe.

Landscape evolution and unusual geomorphological-pedological-chronological relations in an alluvial plain associated with early Amerindian settlement in southeastern Brazil

This article deals with geomorphological, sedimentary, paleopedological, chronological (OSL and 14C) and archaeological records within a segment of the Jacaré-Guaçu River alluvial plain in southeast Brazil, aiming to evaluate climatic, hydrological and landscape transformations over the past 115 ka. The results show alternations between humid and drier climates that contribute to different drainage conditions, accounting for seven paleosurfaces and five paleosols amid sandy and gravel deposits along Late Pleistocene and Holocene. Micromorphological and OSL data characterize a humid and warm phase in the Eemian associated to the formation of a paleosol under good drainage conditions, followed between 111 ka and the end of Pleistocene by sandy deposition intercalated with the genesis of two new soils and by a sedimentary discontinuity. The lithics artifacts records of Amerindian settlements since the Pleistocene–Holocene transition contributed to the demarcation of paleosurfaces that formed concurrently with landscape and river level changes, and the density of human activities was found to vary simultaneously with environmental transformations in the area. A phase of ephemeral torrential channels under a drier climate, and predominance of grassland vegetation in the Pleistocene end (~12.4 ka) was followed by the set up of perennial meandering channels of dimensions four times greater than that of the current Jacaré-Guaçu river, formed under increase of forestal associations and rise in water table, with aggradation of up 7 m, sandy deposition and formation of two new soils in the Early Holocene; from Middle Holocene, the fluvial system experienced incision (<8.5 m), avulsion (<600 m), decrease of channel size and uneven erosion of the deposits and paleosols previous formed in the area. Such changes in the landscape contributed to the establishment of lower terraces with older (115–111 ka) deposits and paleosols linked to good drainage conditions and higher terraces with newer (12.4–8.0 ka) deposits and paleosols linked to poor drainage conditions. This pattern of connections between terrace levels, soil types and ages of deposits is different from that previously registered in the alluvial plains of southeast Brazil.

The role of bedrock and climate for the Late Quaternary erosive-depositional behavior of an intraplate tropical river: The Tietê River case, southeastern Brazil

The evolution of fluvial systems has been related to tectonics and climate controls across various spatiotemporal scales. Despite the growing efforts to investigate the effects of those controls in the fluvial dynamics, there is a lack of studies in intraplate tropical regions. Here, we applied geomorphological, sedimentological, and optically stimulated luminescence dating (OSL) techniques to investigate the effects of climate and tectonic factors on the evolution of the Upper and Middle Tietê River during the late Quaternary, especially concerning alluvial aggradation and terraces formation. The Tietê River is one of the most important rivers of southeast Brazil, flowing from crystalline steep to sedimentary low-relief intraplate terrains, in an area with evidence of Cenozoic tectonics and under tropical monsoon climate. We recognized one fluvial terrace level in the Upper Tietê valley and a sequence of seven terraces, from 2 to 105 m above the channel level, in the Middle Tietê. These terraces are formed by thin deposits (<10 m), composed of sandy and gravelly sediments. The terraces of the Upper Tietê and the high and intermediate terrace levels of the Middle Tietê River are strath, while the low terraces of the middle reach are cut-and-fill. Lithological shifts and structural features of the watershed terrain play a strong control in the occurrence and distribution of these terrace levels. The Serra de Paranapiacaba, a regional knickzone, hinders the lowering of the base level and the river incision to upstream, limiting the formation and preservation of terraces in high topographic levels in the Upper Tietê. The formation of seven terrace levels in the Middle Tietê River was controlled by the combination of low erosion resistance of the lithological substrate and high stream power and coarse bedload that increased the erosion efficiency of the channels. Thus, the influence of intraplate tectonics on the fluvial landscape is restricted to passive controls by exhumated basement structures from older tectonic events. OSL dating of sedimentary deposits in different terrace levels indicate five periods of aggradation in the Middle Tietê valley since 18 ka: 17.7 ± 1.7 ka; 9.8 ± 1.0 to 8.6 ± 0.8 ka; 7.1 ± 0.7 to 5.8 ± 0.5 ka; 4.2 ± 0.4 to 3.1 ± 0.3 ka; and 0.6 ± 0.06 ka. The results indicate that changes in the activity of the South American Monsoon System induced changes in vegetation cover and water discharge in the river valleys of southeastern Brazil over the past 18 ka. The aggradation periods are correlated with drier environmental conditions and sparser vegetation. In contrast, valley incision occurred under transitions to wetter environmental conditions and was potencialized by vegetation recovery. Therefore, climate-induced changes in the water discharge were the main allogenic control on the late Quaternary landscape evolution.

ASSESSMENT OF THE LARGE-FRUITED FRUIT OF THE APPLE TREE ON THE LOWER TERRACE OF THE VS. M. KRUTOVSKY BOTANICAL GARDEN

With the development of horticulture in the Siberian regions, cultivation and introduction of breeding developments, the demand and requirements for varieties have changed. Insufficient winter hardiness in critical winter periods, moral aging of varieties and minimal fruit weight indicate the need for further development and improvement of the assortment by creating new varieties based on the assessment of the existing assortment, which will help to increase the production of environmentally safe fruits and preserve the productivity of apple plantations in the harsh conditions of Siberia. The paper presents an assessment of apple fruits of different maturation periods growing on the lower terrace of the Vs. M. Krutovsky Botanical garden in the period from 2018 to 2020 according to the following biometric characteristics of large fruit: height, diameter, weight of fruits. As a result of the conducted observations, a significant variability in the size of apple fruits was revealed, depending on the varietal affiliation and the year of fruiting. Varieties and individual genotypes of different maturation periods growing on the territory of the lower terrace of the Botanical Garden with the maximum weight and size of fruits were selected: Antonovka vulgaris, Bely naliv, Bismarck, Krasnoyarsk Siberian, Papirovka, St. Petersburg summer, which shows a positive result under the influence of the features of the Siberian summer, namely, the insufficiency of the length of the frost- free period and the sum of positive temperatures, in a sharply continental climate. The studies also included an assessment of the taste qualities of fruits. Breeders of Siberia have created varieties whose fruits are similar in size to those of European varieties. Their high winter hardiness in the regions where breeding was carried out was confirmed in the climate conditions of the research area.