scholarly journals Late Holocene wetland transgression and 500 years of vegetation and fire variability in the semi-arid Amboseli landscape, southern Kenya

AMBIO ◽  
2018 ◽  
Vol 47 (6) ◽  
pp. 682-696 ◽  
Author(s):  
Esther N. Githumbi ◽  
Colin J. Courtney Mustaphi ◽  
Kevin J. Yun ◽  
Veronica Muiruri ◽  
Stephen M. Rucina ◽  
...  
Keyword(s):  
Late Holocene ◽  
Semi Arid

Palaeohydrologic interpretations of Holocene wet episodes recorded in stalagmites from Soreq Cave, Israel: Linking the magnetic and isotopic properties of speleothems

2021 ◽  
Author(s):  
Yuval Burstyn ◽  
Ron Shaar ◽  
Jonathan Keinan ◽  
Yael Ebert ◽  
Avner Ayalon ◽  
...  
Keyword(s):  
Late Holocene ◽  
Magnetic Particles ◽  
Eastern Mediterranean ◽  
Magnetic Data ◽  
Turnover Rates ◽  
Climate Fluctuations ◽  
Arid Conditions ◽  
Soil Organic Matter Turnover ◽  
Hydrological System ◽  
Semi Arid

<p>Soil-derived magnetic particles trapped in speleothems can retain valuable information on the physiochemical conditions of the overlying soil and changes in the hydrological system. However, a direct link between magnetic and isotopic properties of speleothems has been only qualitatively established and is known to vary regionally. Here we investigate two Holocene speleothems from Soreq Cave, Israel and provide evidence for strong coupling over centennial to millennial timescales between the inflow of magnetic particles (quantified using the magnetic flux index, IRM<sub>flux</sub>), δ<sup>13</sup>C, and rainfall amounts. The two stalagmites formed at separate intervals: one at ~9.5 ky BP capturing the transition from pluvial Eastern Mediterranean conditions associated with Sapropel 1 (S1) and a second at 5.4 ky BP recording mid-Holocene wet-dry cycles.</p><p>The late-Holocene speleothem shows an anomalously high δ<sup>13</sup>C episode that is correlated with extremely low IRM<sub>flux</sub>, indicating minimal contribution from overlying soils due to either (1) recently denuded soils, or (2) high overland and vadose runoff. By contrast, the mid-Holocene sample shows saw-tooth cycles in both δ<sup>18</sup>O and δ<sup>13</sup>C, which are interpreted as rapid climate fluctuations associated with rainfall changes. IRM<sub>flux</sub> during this period varies in-phase with the δ<sup>13</sup>C cycles; however, the peaks in IRM<sub>flux</sub> values precede those of the isotope values. The apparent lag in isotopic values may be explained by the faster response of the IRM<sub>flux </sub>to increased rainfall resulting from the rapid physical translocation of overlying soil particles via groundwater, compared with slower soil organic matter turnover rates, which may vary on timescales of up to thousands of years.</p><p>The separate palaeohydrological scenarios resolved from the two speleothems demonstrate how magnetic data can act as a powerful paleo-hydrology proxy, even in weakly-magnetized speleothems growing under semi-arid conditions.</p>

Palynological evidence for vegetation patterns in the Transvaal (South Africa) during the late Pleistocene and Holocene

Bothalia ◽  
1983 ◽  
Vol 14 (3/4) ◽  
pp. 445-449 ◽  
Author(s):  
L. Scott
Keyword(s):  
Late Holocene ◽  
Vegetation Type ◽  
Late Quaternary ◽  
Vegetation Patterns ◽  
Vegetation Types ◽  
Maximum Period ◽  
Plant Migrations ◽  
The Last Glacial Maximum ◽  
Semi Arid ◽  
The Last Glacial

Palynological evidence relating to the nature of Late Quaternary vegetation types and plant migrations in the Transvaal is briefly summarized. It is suggested that, after an early temperate, relatively moist phase and a subsequent relatively dry phase lasting until about 25 000 yr B.P., a vegetation-type with ericaceous elements developed. It resembled belts presently occurring above the treeline and was possibly widespread over the plains of the Transvaal during the last glacial maximum period. In the central parts of the province, warm semi-arid savanna subsequently expanded during the early Holocene and was followed by a more broad-leafed type of woodland in the late Holocene. This change probably resulted from slightly wetter and, at times, also slightly warmer and cooler conditions.

Supplementary material to "Climate changes in interior semi-arid Spain from the last interglacial to the late Holocene"

2019 ◽  
Author(s):  
Dongyang Wei ◽  
Penélope González-Sampériz ◽  
Graciela Gil-Romera ◽  
Sandy P. Harrison ◽  
I. Colin Prentice
Keyword(s):  
Late Holocene ◽  
Climate Changes ◽  
Last Interglacial ◽  
Supplementary Material ◽  
Semi Arid

The role of fire in the late Holocene forest decline in semi-arid North China

The Holocene ◽  
2015 ◽  
Vol 26 (1) ◽  
pp. 93-101 ◽  
Author(s):  
Yi Yin ◽  
Hongyan Liu ◽  
Qian Hao
Keyword(s):  
Late Holocene ◽  
Forest Decline ◽  
North China ◽  
Semi Arid

Coarse-grained mineral dust deposition in alpine lakes provide evidence of increased windspeeds associated with more intense cyclogenesis during warmer intervals of the late Holocene period in arid and semi-arid tracts of North America.

2020 ◽  
Author(s):  
Atreyee Bhattacharya ◽  
Anne Bennett ◽  
Thomas Marchitto ◽  
Elana Leithold
Keyword(s):  
Grain Size ◽  
North America ◽  
Late Holocene ◽  
Mineral Dust ◽  
Fine Fraction ◽  
Dust Deposition ◽  
Size Fractions ◽  
Grain Sizes ◽  
Dust Generation ◽  
Semi Arid

<p>Mineral dust accumulation is often causally associated with aridity, with higher dust deposition rates are assumed to reflect increasing magnitude of aridity. However, the relation between dust deposition and aridity is not straightforward; grain sizes play a crucial role in processes associated with mineral dust generation, transportation and deposition in sedimentary settings.</p><p>In this study, we apply grain-size analyses in six well-studied cores (spanning the late Holocene) previously collected from alpine lake sites distributed across the arid and semi-arid regions of west, southwest, and the Great Plains of North America. Previous work with these cores has demonstrated that the lake sediments are predominantly detrital, windblown particles and little to no impact of fluvial proceeses . We find that the most commonly occurring grain sizes are a fine fraction (typically <4 microns, which is easily lofted and transported long distances) and a coarse fraction (typically >25 microns and in some cases with a distinct peak at 100 microns, both of which are are too large to be carried long distances and suggest short distance transportation). We used grain size separation techniques to separate the two size fractions and geochemically fingerprinted those from three sites.</p><p>We find that more rapid accumulation of the coarser coarser-grain size fractions occurred during wetter intervals in the Holocene. Furthermore, the geochemistry of the coarse fractions indicates regional rather than local sourcing of the material from bedrock weathering. We do not find any clear relationships between the fine fraction and aridity patterns, nor a clear source region for this material.</p><p>We hypothesize that the increase in coarser dust deposition during wetter intervals is related to either intensification of land-use patterns associated with agriculture and/or to episodically strong winds. Warmer and wetter intervals in the areas under consideration have been associated with intensified cyclogenesis. Our study demonstrates the critical need to incorporate grain-size analysis as well as geochemical fingerprinting of the different size fractions in interpreting mineral dust record.</p><p> </p><p>Acknowledgement: James Sickman, Jason Neff (for sharing samples), Jacob Ashford, Tyler Vollmer, Audriana Pollen, Alejandra Pedrazza, (for assistance with analyses and archival visits), John Morton, Wendy Freeman (for assisting students in the laboratory), Aradhna Tripati and Juan Lora (for assisting with data interpretation).</p><p> </p>

scholarly journals Topographic Thresholds and Soil Preservation along the Southern High Plains Eastern Escarpment, Northwest Texas, USA

Geosciences ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 476
Author(s):  
Travis Conley ◽  
Stance Hurst ◽  
Eileen Johnson
Keyword(s):  
Late Pleistocene ◽  
Late Holocene ◽  
High Plains ◽  
Buried Soils ◽  
Lateral Migration ◽  
South Fork ◽  
The South ◽  
Southern High Plains ◽  
Middle Holocene ◽  
Semi Arid

The eastern escarpment of the Southern High Plains (USA) is today a semi-arid erosional landscape delineated by canyon breaks and topographic relief. A series of buried soils were identified, described, and sampled at 19 soil profile localities exposed along terraces of the South Fork of the Double Mountain Fork of the Brazos River (South Fork) and two associated tributaries (Spring Creek and Macy 285 drainage). Radiocarbon dating revealed late-Pleistocene to early Holocene (~12,580–9100 14C B.P.), middle-Holocene (~6025–4600 14C B.P.), and late-Holocene (~2000–800 14C B.P.) buried soils. The late-Pleistocene to middle-Holocene soils were preserved only at higher elevations within the upper section of the South Fork and Spring Creek. A topographic position analysis was conducted using GIS to identify and examine the impacts of a soil topographic threshold on the preservation and distribution of buried soils within this geomorphic system. Above the identified ~810 m threshold, lateral migration of channels was constrained. Extensive channel migration below the threshold removed older terraces that were replaced with late-Holocene terraces and associated buried soils. Landscape topography constraints on geomorphic processes and soil formation impacted the preservation of archaeological sites in this semi-arid region.

Quartz and silcrete raw material use and selection in late Holocene assemblages from semi-arid Australia

2016 ◽  
Vol 424 ◽  
pp. 12-23 ◽  
Author(s):  
Matthew J. Douglass ◽  
Simon J. Holdaway ◽  
Justin Shiner ◽  
Patricia C. Fanning
Keyword(s):  
Late Holocene ◽  
Raw Material ◽  
Semi Arid

Thirsty work: Testing the risk reduction model of mid- to late-Holocene stone points with distance decay from freshwater in northern Australia

The Holocene ◽  
2021 ◽  
pp. 095968362110331
Author(s):  
Tim Ryan Maloney
Keyword(s):  
Risk Reduction ◽  
Late Holocene ◽  
Arid Regions ◽  
Water Sources ◽  
Stone Tool ◽  
Northern Australia ◽  
Risk Minimisation ◽  
The World ◽  
Primary Water ◽  
Semi Arid

A key tenant of risk reduction models in archaeology the world over is that changes in resource availability drove mobility increases and created a need for an extension of stone tool use life. This manuscript directly addresses the question, is retouch intensity of tools related to distance from freshwater, by using extant localities of major Gorges, Rivers and water holes in the southern Kimberley region of northern Australia. Previous research has argued that retouched stone points during the mid to late-Holocene were part of a risk minimisation strategy, within broader technological organisation models. Modelling the distance from primary water sources, in arid to semi-arid regions of the southern Kimberley, reduction intensity of points is found to increase with distance from water sources consistently. This research provides an appropriate test of existing risk minimisation models and highlights global significance for similar studies where retouch tool reduction and forager mobility are linked to environmental change.

scholarly journals The prehistory of Aboriginal landuse on the upper Flinders River, North Queensland Highlands

1990 ◽  
Vol 7 ◽  
pp. 3-56 ◽  
Author(s):  
M.J. Morwood
Keyword(s):  
Late Holocene ◽  
New Technologies ◽  
Social Economic ◽  
New South ◽  
Arid Zones ◽  
South Wales ◽  
History Of ◽  
Material Evidence ◽  
Semi Arid ◽  
Aboriginal Subsistence

A general theme in Australian prehistory is the development of the distinctive social, economic and technological systems observed in recent Aboriginal societies.  Research has demonstrated significant change in the Australian archaeological sequence and general trends of such are shared by numerous regions.  Most that have been investigated indicate low density occupation during the Pleistocene and early Holocene with significant increases in site numbers, increased artefact discard rates and dissemination of new technologies and artefact types in mid-to-late Holocene times (e.g. Lourandos 1985).  On the other hand, each region has a unique prehistory, range of material evidence and research potential.  Our knowledge of Holocene developments in aboriginal subsistence systems, for instance, is largely based upon the history of cycad exploitation in the central Queensland Highlands (Beaton 1982), the appearance of seed grindstones in arid and semi-arid zones (Smith 1986) and evidence for increased emphasis on small-bodied animals in N.E. New South Wales and S.E. Queensland (McBryde 1977:233; Morwood 1987:347).

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