Description: Publication year: 2011 Source: Quaternary International, Available online 29 December 2011 Margarita A. Erbajeva, Fedora I. Khenzykhenova, Nadezhda V. Alexeeva The features of the earliest climate aridization and the onset of the arid open landscapes in the Transbaikalian region are shown by the early Early Pleistocene mammalian faunas of the Itantsinian Complex, and by geological data. The climate deterioration intensified through the Middle and Late Pleistocene. The uplift of mountains surrounding Lake Baikal is considered to be the main cause for the deep aridization of the Western Transbaikalia, because they became the major orographic barrier preventing humid West Atlantic cyclones from reaching the Transbaikalian area. Comparative analyses of successive Early, Middle and Late Pleistocene faunas have shown that they differ significantly in species composition and in stages of the evolution of taxa belonging to different lineages. However, the dominant species of faunas demonstrate similar evolutionary trends, such as the development of complex-shaped teeth structure due to adaptation to feeding on coarse grass and to inhabit arid landscapes.

Description: Publication year: 2011 Source: Quaternary International, Available online 29 December 2011 Mikhail S. Blinnikov, Chelsey M. Bagent, Paul E. Reyerson Researchers frequently assume that phytolith assemblages in modern soils reflect composition of recent vegetation because of the direct deposition of silica into the soil, once plants decay. This paper tests this assumption and determines whether temperate grasslands of different composition can be reliably detected based on their silica record in topsoil in a controlled experiment. The differences in total biogenic opal concentration (TBOC) and diversity of morphotypes were assessed in the Biodiversity II experiment (E120) at Cedar Creek Ecosystem Science Reserve, Minnesota, USA, where controlled mixtures of C3grasses, C4grasses, legumes, non-legume forbs, and woody shrubs (Quercus) were grown for a period of eight years. The plots have been manually maintained to contain the target species, and thus provide an opportunity to test numerous hypotheses regarding phytolith production patterns under diverse mixtures of plants. Soil samples were obtained from plots representing a variety of functional group mixtures. Pinch soil samples of 20 g from 10 random locations inside each plot were obtained. Phytoliths were extracted from each sample by chemically removing organics and carbonates and using heavy liquid flotation. A chemical dissolution method was used to obtain estimates of TBOC. Morphotypes were counted under a microscope. Morphotypes were analyzed on all plots against each other and against the morphotypes expected in the plants that grow on each plot using ANOVAs, linear regression, PCA and cluster analysis. Average above-ground biomass of expected phytolith producers was weakly but positively correlated with the TBOC values (R=0.42). The morphotype analysis showed that species’ composition was most accurately reflected in the phytolith assemblages on grass-dominated plots. For example, it was possible to distinguish C3, C4, or mixed grass-dominated plots from each other. Although the majority of phytoliths were from Poaceae, large shares were also from forbs and woody plants. Plots without any grasses still had some presence of grass phytoliths suggesting limited horizontal translocation and/or inheritance.

Description: Publication year: 2012 Source: Quaternary International, Volume 247, 9 January 2012, Pages 1-9 María Gema Chacón, Manuel Vaquero, Eudald Carbonell

Description: Publication year: 2011 Source: Quaternary International, Available online 24 December 2011 Yan Zeng, Jingan Chen, Zhengjie Zhu, Jian Li, Jingfu Wang, ... Although temperature decreased in a similar trend in many regions around the word during the Little Ice Age (LIA), the reconstructed humidity is remarkably different from region to region. The precipitation history during the LIA is poorly understood as compared to the temperature history in tropical South China. In this study, a sediment core with a length of 117.5 cm was recovered in the central part of Huguangyan Lake in tropical South China. Total organic carbon (TOC), total nitrogen (TN), inorganic carbon (IC) and non-residual strontium (Sr) were analyzed at approximately 1 cm intervals to study the regional precipitation changes during the LIA. Generally, Sr-containing minerals are sensitive to chemical weathering which is dominated by the precipitation in tropical South China. Thus the non-residual Sr in Huguangyan sediments can be used as an indicator of precipitation changes, which is also verified by the downcore variations of TOC, TN and IC in Huguangyan Lake. The non-residual Sr correlated positively with TOC and TN but negatively with IC in the sediment profile. TOC, TN, IC and the non-residual Sr jointly demonstrated a wet period from AD 1500 to 1750, which corresponds to the LIA. Coincidently, both the total solar irradiance (TSI) and Northern Hemisphere temperature have the lowest values between AD 1500 and 1750 over the past millennium. Therefore, the wet LIA in tropical South China was most likely caused by the low solar irradiation. During the LIA, the low solar irradiation likely resulted in the decrease of the Northern Hemisphere temperature, which weakened the intensity of the East Asian summer monsoon (EASM) and synchronously moved the north edge of the Asian summer monsoon southward, leading to an increase in the precipitation in tropical South China.

Description: Publication year: 2011 Source: Quaternary International, Available online 21 December 2011 Jessica C. Thompson, Alex Mackay, David K. Wright, Menno Welling, Amanda Greaves, ... J. Desmond Clark and his colleagues were first to investigate the rich Middle Stone Age (MSA - from ca. 285 – 30,000 years ago) deposits in the Karonga District of northern Malawi in the 1960s. This work demonstrated the enormous potential of the area to inform about Middle to Late Pleistocene hominin lifeways, but further studies were hindered by difficulties in dating the sites and understanding their fine-scale depositional and paleoenvironmental contexts. With the advances that have been made in the fields of geoarchaeology, lithic analysis, palaeoenvironments, and geochronology over the last fifty years, the time is ideal to renew these investigations. Recent survey and excavation in Karonga, Malawi show that MSA lithic artifacts are preserved in a variety of stratified sedimentary contexts and that they exhibit limited weathering or other indications of post-depositional transport. These deposits are in close proximity to the high-resolution paleoenvironmental records derived from sediments at the bottom of nearby Lake Malawi, which provide context for the human behavior recorded by the artifacts. Results of excavations at one of these stratified sites – the Airport Site – are detailed here. This provides a renewed example of the site formation and behavioral data available in the region.

Description: Publication year: 2011 Source: Quaternary International, Available online 22 December 2011 A.A. Kakroodi, S.B. Kroonenberg, R.M. Hoogendoorn, H. Mohammd Khani, M. Yamani, ... The Caspian Sea is well-known for its rapid sea level change. During 1929 to 1995, a full sea level cycle was observed. First, the sea level dropped ∼3 m with a lowstand in 1977, followed by a 3 m rise to 1995, after which the sea level has been relatively stable. These oscillations are a specific feature of the Caspian Sea and its sedimentary record. The main purpose of this study is to reconstruct the sea-level curve in the Holocene by using sedimentological and biostratigraphic analysis and radiocarbon dating along the Iranian part of the Caspian shore. Remote sensing images and historical maps show that two lagoons totally emerged, and the Gorgan delta prograded rapidly at a rate of around 160 m yuntil the 1975 lowstand. Gorgan Bay was reduced in size considerably and the connection to the sea was blocked due to growth of a spit and change in base level. When sea level started to rise again, the coastal morphology rapidly changed and the Gorgan delta retrograded at the rate of around 140 m y. These sedimentary dynamics can be recognized in the preserved deposits. In addition to the recent dynamics, core data from the southeastern lowlands show four earlier highstands. Using characteristic barrier-lagoon deposits, early Holocene sea level rose until a highstand was reached of ca. -34 m. This phase was followed by fluvial deposition in the Goragn delta associated with a base level fall. There is also an evidence of sea level rise between 5000 and 2300 BP at ca. -27.7 m. On top of these deposits there is evidence of a highstand between 2700-2300 BP at ca. -23.5 m. The fourth highstand from the core data is dated to the Little Ice Age at ca. -24 m. Data from these last two highstands correspond well with other observations from the Caspian region.

Description: Publication year: 2011 Source: Quaternary International, Available online 22 December 2011 Uğur Doğan, Ali Koçyiğit, Baki Varol, İsmail Özer, Anatoly Molodkov, ... The coastal belt of Hatay-Samandağı in the East Mediterranean is marked by the intersection of the African-Arabian and Eurasian (Anatolian platelet) plates, where several Quaternary shorelines related to relative sea-level changes can be seen above the current sea level. In this study, the most common and best preserved high sea-level markers of the Marine Isotope Stage (MIS) 5 and MIS 3 shorelines were dated for the first time using the mollusc-based electron spin resonance (ESR) method. As a result of this research, the age of the late MIS 5 and MIS 3 sea-level highstands in the Eastern Mediterranean, the elevation of the corresponding shoreline at Samandağı coast, and the vertical component of the late Quaternary tectonic movements, which has an impact on shoreline, were determined. The shorelines at 48-43 m elevations between Çevlik and Samandağı, at 58.6 m in Tekebaşı and at 21 m at Keldağ have been dated to approximately 72 ka and, therefore, are correlated with MIS 5a. The shoreline at 40-39 m elevations between Çevlik and Samandağı hae been dated to approximately 53 ka and, therefore, is correlated with MIS 3. According to the position of these MIS 5a shorelines, the uplift rate over the last 72 ka was 0.88 mm/y between Çevlik and Samandağı, 1.08 mm/y in Tekebaşı, and 0.56 mm/y in Keldağ, yielding a 0.84 mm/y average. This rather fast uplift appears to be related to the vertical component of the strike-slip active faults in the Samandağı-Antakya Fault Zone.

Description: Publication year: 2011 Source: Quaternary International, Available online 20 December 2011 Maria Rita Palombo Mode and time of the first hominin diffusion in Eurasia, dispersal routes along geographical gradients, and factors promoting such dispersal are a hotly debated matter. Despite the growing amount of data, researchers are still far from deciphering the multifaceted relationships between climate changes and vegetation, fauna, and human evolutionary dynamics during the latest Cenozoic. A number of evidence suggests that it was not only climate, which shaped the evolutionary history of our own genus and affected hominin behaviour and dispersals and that hominin movements cannot always be placed in the wider context of roughly contemporaneous changes of range of large mammalian taxa. In order to develop a more comprehensive understanding of the generality and underlying causal mechanisms for this complex scenario, a new, more integrated research agenda is recommended which requires the cultural and methodological support of disciplines of apparently remote, specialized sectors, such as geochemistry, sedimentology, geodynamics, palaeontology, palaeoecology, palaeonthropology, palinology, palaeobiology, and phylogeography. As all hypotheses about the environmental effects on evolution depend on temporal correlation, the central challenges should be: to finely resolve the chronological framework, to understand the nature of diachroneity among bioevents across geographical and ecological boundaries, to be able to make correlations between distant sequences, as well as to remove the sometimes confusing taxonomical treatments of some mammalian species, to improve understanding of the ecological settings where hominins evolved through advanced palaeoecological approaches (including both classic ecomorphological analysis and new biological and chemical techniques), and to provide high-resolution and integration of discontinuous climatic data, by developing a large, multidisciplinary database.

Description: Publication year: 2011 Source: Quaternary International, Available online 21 December 2011 L.X. Zhao, L.Z. Zhang The present paper reports the recently discovered fossil teeth of Early PleistoceneGigantopithecus blackiand associated mammalian fauna from Baeryan Cave, Bijie County in Guizhou Province, and also reviews briefly the known fossil sites ofGigantopithecusin south China of Pleistocene. In Early Pleistocene,Gigantopithecushad a wider distribution, but withdrew southward in Middle Pleistocene to a limited area mainly in South China, and it disappeared in the Late Pleistocene according to the present fossil records. Diet and habitat analysis from carbon isotope evidence is used to investigate the reasons for the extinction ofGigantopithecus, which fed on a pure C3diet and lived in a forest habitat. It was clearly different from early hominins in South and East Africa, such asAustralopithecus africanus,Paranthropus robustusandParanthropus boisei,which had C4diets. The extinction ofGigantopithecuswas also related to the great changes of climate and environment of the Pleistocene, especially the last one million years, during whichHomobecame more and more prosperous and exerted great pressure onGigantopithecus blacki.

Description: Publication year: 2011 Source: Quaternary International, Available online 21 December 2011 Daniela Sauer, Peter Finke, Rolf Sørensen, Ragnhild Sperstad, Isabelle Schülli-Maurer, ... The first results of modeling soil development in marine sediments in S Norway using the model SoilGen are compared to measured properties of two soil chronosequences, on the western and eastern side of Oslofjord, respectively. The aim of this work is to test how well soil development under well-defined environmental conditions can be modeled. Such testing reveals to what degree soil-forming processes are understood, allowing formulation of adequate calculations reflecting these processes.The model predicts particle size distribution reasonably well, although clay depletion in the upper parts of the soils as a result of clay migration is overestimated. The model tends to underestimate contents of organic carbon and CEC in the A horizons: below, modeled CEC matches well with measured CEC. Base saturation is overestimated in the upper 40 cm and underestimated below. Apparently, leaching of bases proceeds less rapidly in reality than is predicted by the model, due to strong soil structure of the B horizons, causing preferential flow and base leaching around the aggregates, whereas bases inside the aggregates are only slightly affected by leaching.Difficulties and possibilities for improvements are identified, some related to model input data and some to the model itself. Input data could be improved by determining the amounts of organic carbon in organic surface horizons and by quantifying effects of bioturbation. A big challenge is the implementation of soil structure formation in the model. Quantitative data on the development of soil structure with time that can be included in a model are required. Amounts, distribution and connectivity of macro pores need to be defined for each stage of soil development, and zones of low and high base leaching need to be distinguished in the model for each time step.The long-term aim of this work is to model soil development with different sets of soil-forming factors, e.g. different climatic conditions in order to reliably predict soil development under different climate scenarios and related sets of soil forming factors. The results of the first model runs and the identified possible improvements suggest that this aim is generally achievable.