Problems in the Stone Age of South-East Asia

1993 ◽  
Vol 59 ◽  
pp. 1-15 ◽  
Author(s):  
T. E. G. Reynolds

Whilst research has shown many faults with the Movius scheme of a Middle Pleistocene group of Chopper/Chopping tool industries in South-East Asia, it remains a fact that pebble tool industries are still the dominant characteristic of the South-East Asian record. Exploration has now revealed hundreds of Late Pleistocene and Holocene sites in Mainland South-East Asia and these are archaeologically very different from cave sites in Europe. Further problems exist with the current nomenclature of later industries, such as the Hoabinhian and the Neolithic, for there is a large amount of overlap between such assemblages. Should such factors as economy, site location, etc. be used to assist clarification of such problems?This paper outlines some of these issues and reveals that the pebble tool tradition as it is widely known in South-East Asia is a relatively recent phenomenon dating back to the Last Glacial Maximum (LGM). A possible reason for the change from flake to pebble tool industrial types and in the visibility of sites is the environmental changes and rise in sea level which submerged over half the available land area in the region during the Late Pleistocene. An existing broad spectrum system of exploitation was likely to have been intensified as a result of this.

2020 ◽  
pp. 1-14
Author(s):  
Thomas A. Minckley ◽  
Mark Clementz ◽  
Marcel Kornfeld ◽  
Mary Lou Larson ◽  
Judson B. Finley

Abstract Limited numbers of high-resolution records predate the Last Glacial Maximum (LGM) making it difficult to quantify the impacts of environmental changes prior to peak glaciation. We examined sediments from Last Canyon Cave in the Pryor Mountains of Montana and Wyoming to construct a >45 ka environmental record from pollen and stable isotope analysis. Artemisia pollen was hyper-abundant at the beginning of the record. Carbon isotope values of bulk organic matter (>40 ka) showed little variation (-25.3 ± 0.4‰) and were consistent with a arid C3 environment, similar to today. After 40 cal ka BP, Artemisia pollen decreased as herbaceous taxa increased toward the LGM. A significant decrease in δ13C values from 40–30 cal ka BP (~1.0‰) established a new baseline (-26.6 ± 0.2‰), suggesting cooler, seasonally wetter conditions prior to the LGM. These conditions persisted until variation in δ13C values increased significantly with post-glacial warming, marked by two spikes in values at 14.4 (-25.2‰) and 13.5 cal ka BP (-25.4‰) before δ13C values dropped to their lowest values (-26.9 ± 0.2‰) at the onset of the Younger Dryas (12.8 ka). These results provide insights into late Pleistocene conditions and ecological change in arid intermontane basins of the Rocky Mountains.


Oryx ◽  
2021 ◽  
pp. 1-6
Author(s):  
Paul J. J. Bates ◽  
Pipat Soisook ◽  
Sai Sein Lin Oo ◽  
Marcela Suarez-Rubio ◽  
Awatsaya Pimsai ◽  
...  

Abstract The Hkakabo Razi Landscape, in northern Kachin, Myanmar, is one of the largest remaining tracts of intact forest in South-east Asia. In 2016, we undertook a survey in its southern margins to assess bat diversity, distribution and ecology and evaluate the importance of the area for global bat conservation. Two collecting trips had taken place in the area in 1931 and 1933, with four bat species reported. We recorded 35 species, 18 of which are new for Kachin. One species, Murina hkakaboraziensis, was new to science and three, Megaerops niphanae, Phoniscus jagorii, Murina pluvialis, were new records for Myanmar. Our findings indicate high bat diversity in Hkakabo Razi; although it comprises only 1.7% of Myanmar's land area, it is home to 33.6% of its known bat species. This emphasizes Hkakabo Razi's importance for conserving increasingly threatened, forest-interior bats, especially in the families Kerivoulinae and Murininae. There is also a high diversity of other mammals and birds within the Hkakabo Razi Landscape, which supports its nomination as a World Heritage Site.


1991 ◽  
Vol 4 (3) ◽  
pp. 499 ◽  
Author(s):  
GI Jordan ◽  
RS Hill

Subtribe Banksiinae of the Proteaceae was diverse in Tasmania in the early and middle Tertiary, but is now restricted to two species, Banksia marginata and B. serrata. Rapid and extreme environmental changes during the Pleistocene are likely causes of the extinction of some Banksia species in Tasmania. Such extinctions may have been common in many taxonomic groups. The leaves and infructescences of Banksia kingii Jordan & Hill, sp. nov. are described from late Pleistocene sediments. This is the most recent macrofossil record of a now extinct species in Tasmania. Banksia kingii is related to the extant B. saxicola. Banksia strahanensis Jordan & Hill, sp. nov. (known only from a leaf and leaf fragments and related to B. spinulosa) is described from Early to Middle Pleistocene sediments in Tasmania. This represents the third Pleistocene macrofossil record of a plant species which is now extinct in Tasmania.


2021 ◽  
Author(s):  
Janina J. (Bösken) Nett ◽  
Frank Lehmkuhl ◽  
Erik J. Schaffernicht ◽  
Stephan Pötter ◽  
Philipp Schulte ◽  
...  

<p>Loess is an important archive of environmental change covering approximately 10% of the Earth’s terrestrial surface. Numerous studies have analyzed loess deposits and in particular loess-paleosol sequences. To analyze these sequences, it is important to know the spatial distribution of aeolian sediments, their location relative to potential source areas, and the geomorphology of the sink area. We investigated these aspects by compiling a new map of aeolian sediments in Europe using highly resolved geodata from 27 countries (Lehmkuhl et al., in press). To determine the most relevant factors for the European loess distribution, we further mapped potential source areas and divided the map into different facies domains. We analyzed the geomorphological and paleoenvironmental effects on the deposition and preservation of Late Pleistocene loess. Finally, the geodata-based results were compared with results obtained from high-resolved regional numerical climate-dust experiments for the Last Glacial Maximum (LGM) in Europe, which were performed with the LGM-adapted Weather Research and Forecasting model coupled with Chemistry (WRF-Chem-LGM; Schaffernicht et al., 2020).  Complementing the mapping-based findings with the WRF-Chem-LGM experiments results in an improved understanding of the Late Pleistocene loess landscape in Europe.</p><p> </p><p>References:</p><p>Lehmkuhl, F., Nett, J.J., Pötter, S., Schulte, P., Sprafke, T., Jary, Z., Antoine, P., Wacha, L., Wolf, D., Zerboni, A., Hošek, J., Marković, S.B., Obreht, I., Sümegi, P., Veres, D., Zeeden, C., Boemke, B., Schaubert, V., Viehweger, J., Hambach, U. (in press). Loess landscapes of Europe – Mapping, geomorphology, and zonal differentiation. Earth-Science Reviews. Doi: https://doi.org/10.1016/j.earscirev.2020.103496</p><p>Schaffernicht, E.J., Ludwig, P., Shao, Y., 2020. Linkage between dust cycle and loess of the last Glacial Maximum in Europe. Atmospheric Chemistry and Physics 20, 4969–4986. Doi:10.5194/acp-20-4969-2020.</p>


2018 ◽  
Vol 5 (6) ◽  
pp. 180145 ◽  
Author(s):  
Matthew J. Wooller ◽  
Émilie Saulnier-Talbot ◽  
Ben A. Potter ◽  
Soumaya Belmecheri ◽  
Nancy Bigelow ◽  
...  

Palaeoenvironmental records from the now-submerged Bering Land Bridge (BLB) covering the Last Glacial Maximum (LGM) to the present are needed to document changing environments and connections with the dispersal of humans into North America. Moreover, terrestrially based records of environmental changes are needed in close proximity to the re-establishment of circulation between Pacific and Atlantic Oceans following the end of the last glaciation to test palaeo-climate models for the high latitudes. We present the first terrestrial temperature and hydrologic reconstructions from the LGM to the present from the BLB's south-central margin. We find that the timing of the earliest unequivocal human dispersals into Alaska, based on archaeological evidence, corresponds with a shift to warmer/wetter conditions on the BLB between 14 700 and 13 500 years ago associated with the early Bølling/Allerød interstadial (BA). These environmental changes could have provided the impetus for eastward human dispersal at that time, from Western or central Beringia after a protracted human population standstill. Our data indicate substantial climate-induced environmental changes on the BLB since the LGM, which would potentially have had significant influences on megafaunal and human biogeography in the region.


Atmosphere ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 146 ◽  
Author(s):  
Xugeng Cheng ◽  
Xiaoning Xie ◽  
Zhengguo Shi ◽  
Xinzhou Li ◽  
Tianliang Zhao ◽  
...  

In this study, using the fourth version of the Community Atmosphere Model (CAM4) with a bulk aerosol model parameterization (BAM) for dust size distribution (CAM4-BAM), East Asian dust and its direct radiative feedbacks (DRF) during the Last Glacial Maximum are analyzed by intercomparing results between the experiments with (Active) and without (Passive) the DRF. This CAM4-BAM captures the expected characteristics that the dust aerosol optical depth and loading over East Asia during the Last Glacial Maximum (LGM) were significantly greater compared to the current climate. A comparative analysis of the Active and Passive experiments reveals that consideration of the dust–radiation interaction can significantly reduce dust emissions and then weaken the whole dust cycle, including loading, transport, and dry and wet depositions over East Asia. Further analysis of the dust–radiation feedback shows that the DRF decreases surface sensible heat, mainly owing to the negative surface forcing induced by dust with a value of −11.8 W m−2. The decreased surface sensible heat weakens the turbulent energy within the planetary boundary layer and the surface wind speed, and then reduces the regional dust emissions. This process creates a negative DRF–emission feedback loop to affect the dust cycle during the LGM. Further analysis reveals that the dust emissions in the LGM over East Asia were more reduced, with amounts of −77.2 Tg season−1 by the negative DRF–emission feedback, compared to the current climate with −6.8 Tg season−1. The two ratios of this reduction to their emissions are close to −10.7% for the LGM and −7.5% for the current climate.


1985 ◽  
Vol 24 (3) ◽  
pp. 285-294 ◽  
Author(s):  
A. B. Kazanskiy

A theory of the world's sea-level fluctuations during late Pleistocene time, based on the analysis of the general equation of the mass balance between ocean water and inland water, suggests that the exchange of water masses between the ocean and the land, where at continental glaciation periods water is stored as ice, occurs only as a result of global climatic changes. The tectonic effect is considered insignificant for late Pleistocene time. The proposed theory explains the asymmetric character and the sawlike shape of the curve of the main cycles of sea-level fluctuations. The theory also makes it possible to construct a diagram of sea-level fluctuations from the last glacial maximum to the present time. This diagram is governed by two parameters, the amount of the average “effective” evaporation from the world's ocean surface (evaporation minus rainfall) and the rate of the sea-level rise at the present time. The resulting theoretical curve agrees well with known estimates of sea level within the time span being considered. The comparison of the theoretical curve with these estimates eliminates the apparent discrepancy between data obtained by different methods: measurements of old coastline and the isotopic composition of bottom sediments.


2020 ◽  
Author(s):  
Soledad García-Gil ◽  
Víctor Cartelle ◽  
Castor Muñoz-Sobrino ◽  
Natalia Martínez-Carreño ◽  
Iria García-Moreiras

<p>Understanding coastal responses to relative sea level rise is key to be able to plan for future changes and develop a suitable managing strategy. The sedimentary record of the Late-Pleistocene and Holocene transgression provides a natural laboratory to study the long-term changes induced in coastal landscapes by the rapid sea level rise. As sea level rises, coastal morphology continually adapts towards equilibrium changing the landscape and reshaping the distribution of sedimentary environments.<br>The Ría de Ferrol is a confined tide-dominated incised valley located in the mesotidal passive Atlantic margin of western Galicia (NW Spain).  A multidisciplinary approach was used to identify the elements of sedimentary architecture within its sedimentary record since the Last Glacial Maximum. The sedimentary evolution was reconstructed combining seismic and sedimentary facies analysis with radiocarbon, geochemical and pollen data.<br>The Ría de Ferrol is characterised by a particular morphology with a rock-incised narrow channel in the middle of the basin (the Ferrol Strait) connecting an inner shallower sector with an outer deeper sector. The inner sector is characterised by low energetic conditions and is where the main fluvial inputs occur. The outer sector is connected to the shelf.<br>The main factor influencing the sedimentary evolution of the Ría de Ferrol incised valley was Late Pleistocene and Holocene sea-level rise. However, this evolution was modulated by the antecedent morphology, particularly once the middle strait became flooded during the Holocene transgression. Three main phases of evolution are distinguished: a fluvial valley drained by a braided river system, a tide-dominated estuary and a shallow marine basin (ria).<br>During the lowstand of the Last Glacial Maximum (ca 20 kyr BP), the ria was a fluvial valley whose sediments are mainly preserved in the inner sector. Sediments cores recovered sediments from ponds and stagnant areas, dated to be older than 10790-11170 cal yr BP.<br>During the Holocene, the basin turned into a tide-dominated estuary whose facies distribution was conditioned by the strait. The strait acted as a rock-bounded tidal inlet enhancing tidal erosion and deposition at both ends, where an ebb-tidal delta and tidal sandbanks appear. At this time, extensive tidal flats occupied most of the inner sector, dissected by estuarine channels of varied dimensions. Radiocarbon data showed ages from 8610-8910 to 5760-5940 cal yr BP.<br>An erosive episode is identified after 6 cal kyr BP with the formation of a ravinement surface. Wave and tidal energy were split by the middle strait. A wave ravinement surface is identified in the outer sector, while a coetaneous tidal ravinement surface occurs in the inner sector.<br>Slow sea-level rise after ca 4 ka BP finally forced rivers to retreat to the present position, causing the dispersion of their energy and leading to the final evolution of the area into a fully marine system.</p>


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