scholarly journals Palynostratigraphy, Paleoecology and Paleoclimatology of Early Pleistocene Based on Pollen Study of Pucangan Formation in Sangiran Area

2019 ◽  
Vol 20 (3) ◽  
pp. 133
Author(s):  
Eko Yulianto ◽  
Woro Sri Sukapti ◽  
Ruly Setiawan
Keyword(s):  
High Frequency ◽  
Mangrove Forest ◽  
Volcanic Eruptions ◽  
Montane Forest ◽  
Early Pleistocene ◽  
Middle Pleistocene ◽  
Montane Forests ◽  
Lowland Forest ◽  
Psilotum Nudum ◽  
Stratigraphic Position

A pollen study has been conducted on samples taken from Pucangan Formation in Sangiran area. This study aims to reconstruct palynostratigraphy and to reveal environmental dynamics along with the deposition of Pucangan Formation with an emphasis on the influence of high frequency volcanism to the vegetational landscape in the montane area. The co-occurrence of Phyllocladus hypophyllus and Podocarpus imbricatus indicates Plistocene age of samples, and their stratigraphic position overlied by Middle Pleistocene Kabuh Formation leads to a conclusion of Early Pleistocene. All samples are included in Monoporites annulatus Peak Zone and subdivided into three Peak Subzone i.e. Polypodisporites radiates, Psilotum nudum, Magnastriatites grandiosa, Cyathea sp. and Laevigatosporites sp. Concurrent Peak Subzone, Interval Subzone between two Peak Subzones i.e. Polypodisporites radiates, Psilotum nudum, Magnastriatites grandiosa, Cyathea sp., Laevigatosporites sp. Concurrent Peak Subzone and Casuarina sp. Peak Subzone. Along with the deposition of Pucangan Formation, savannah with sparse swamp, riparian and lowland forest spreaded out around particularly on lowland, while few mangrove forest grew on muddy sea-land interface environment and heterogenous montane forests occupied highland. During the deposition of stratigraphic profile, savannah got flourished on new emerged land due to regression. Frequent volcanic eruptions along with the deposition of the upper stratigraphic profile has destroyed heterogenous montane forest and led to the homogenous Casuarina junghuniana forest.Keywords: Palynology, Early Pleistocene, vegetational landscape, savannah, montane forest, regression, volcanism

scholarly journals Palynostratigraphy, Paleoecology and Paleoclimatology of Early Pleistocene Based on Pollen Study of Pucangan Formation in Sangiran Area

2019 ◽  
Vol 20 (3) ◽  
pp. 133
Author(s):  
Eko Yulianto ◽  
Woro Sri Sukapti ◽  
Ruly Setiawan
Keyword(s):  
High Frequency ◽  
Mangrove Forest ◽  
Volcanic Eruptions ◽  
Montane Forest ◽  
Early Pleistocene ◽  
Middle Pleistocene ◽  
Montane Forests ◽  
Lowland Forest ◽  
Psilotum Nudum ◽  
Stratigraphic Position

A pollen study has been conducted on samples taken from Pucangan Formation in Sangiran area. This study aims to reconstruct palynostratigraphy and to reveal environmental dynamics along with the deposition of Pucangan Formation with an emphasis on the influence of high frequency volcanism to the vegetational landscape in the montane area. The co-occurrence of Phyllocladus hypophyllus and Podocarpus imbricatus indicates Plistocene age of samples, and their stratigraphic position overlied by Middle Pleistocene Kabuh Formation leads to a conclusion of Early Pleistocene. All samples are included in Monoporites annulatus Peak Zone and subdivided into three Peak Subzone i.e. Polypodisporites radiates, Psilotum nudum, Magnastriatites grandiosa, Cyathea sp. and Laevigatosporites sp. Concurrent Peak Subzone, Interval Subzone between two Peak Subzones i.e. Polypodisporites radiates, Psilotum nudum, Magnastriatites grandiosa, Cyathea sp., Laevigatosporites sp. Concurrent Peak Subzone and Casuarina sp. Peak Subzone. Along with the deposition of Pucangan Formation, savannah with sparse swamp, riparian and lowland forest spreaded out around particularly on lowland, while few mangrove forest grew on muddy sea-land interface environment and heterogenous montane forests occupied highland. During the deposition of stratigraphic profile, savannah got flourished on new emerged land due to regression. Frequent volcanic eruptions along with the deposition of the upper stratigraphic profile has destroyed heterogenous montane forest and led to the homogenous Casuarina junghuniana forest.Keywords: Palynology, Early Pleistocene, vegetational landscape, savannah, montane forest, regression, volcanism

scholarly journals Seasonality, drivers, and isotopic composition of soil CO<sub>2</sub> fluxes from tropical forests of the Congo Basin

2020 ◽  
Vol 17 (23) ◽  
pp. 6207-6218
Author(s):  
Simon Baumgartner ◽  
Matti Barthel ◽  
Travis William Drake ◽  
Marijn Bauters ◽  
Isaac Ahanamungu Makelele ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Soil Respiration ◽  
Tropical Forests ◽  
Montane Forest ◽  
Congo Basin ◽  
Co2 Fluxes ◽  
Soil Co2 ◽  
Montane Forests ◽  
Lowland Forest ◽  
Lowland Forests

Abstract. Soil respiration is an important carbon flux and key process determining the net ecosystem production of terrestrial ecosystems. To address the lack of quantification and understanding of seasonality in soil respiration of tropical forests in the Congo Basin, soil CO2 fluxes and potential controlling factors were measured annually in two dominant forest types (lowland and montane) of the Congo Basin over 2 years at varying temporal resolution. Soil CO2 fluxes from the Congo Basin resulted in 3.45 ± 1.14 and 3.13 ± 1.22 µmol CO2 m−2 s−1 for lowland and montane forests, respectively. Soil CO2 fluxes in montane forest soils showed a clear seasonality with decreasing flux rates during the dry season. Montane forest soil CO2 fluxes were positively correlated with soil moisture, while CO2 fluxes in the lowland forest were not. Smaller differences of δ13C values of leaf litter, soil organic carbon (SOC), and soil CO2 indicated that SOC in lowland forests is more decomposed than in montane forests, suggesting that respiration is controlled by C availability rather than environmental factors. In general, C in montane forests was more enriched in 13C throughout the whole cascade of carbon intake via photosynthesis, litterfall, SOC, and soil CO2 compared to lowland forests, pointing to a more open system. Even though soil CO2 fluxes are similarly high in lowland and montane forests of the Congo Basin, the drivers of them seem to be different, i.e., soil moisture for montane forest and C availability for lowland forest.

Early Pleistocene−to−present paleoclimate archive for the American Southwest from Stoneman Lake, Arizona, USA

2021 ◽  
Author(s):  
Spencer E. Staley ◽  
Peter J. Fawcett ◽  
R. Scott Anderson ◽  
Gonzalo Jiménez-Moreno
Keyword(s):  
Late Pleistocene ◽  
Climate Model ◽  
Volcanic Eruptions ◽  
American Southwest ◽  
Early Pleistocene ◽  
Middle Pleistocene ◽  
Future Climate Change ◽  
Radiocarbon Dates ◽  
Middle And Late Pleistocene ◽  
Natural Climate

Long, continuous records of terrestrial paleoclimate offer insights into natural climate variability and provide context for geomorphological studies, climate model reconstructions, and predictions of future climate change. STL14 is an 80 m lacustrine sediment core that archives paleoenvironmental changes at Stoneman Lake, Coconino County, Arizona, from the early Pleistocene (ca. 1.3 Ma) to present. Full-core sedimentology was analyzed using smear slides and core face observations. Lithofacies strongly correlate with wet bulk density and bulk magnetic susceptibility (MS), and these data resemble a sawtooth pattern characteristic of glacial-interglacial climate cycles. A linkage between deep to shallow lake depth transitions and glacial terminations is supported by an age model that incorporates accelerator mass spectrometry radiocarbon dates and tephrochronology of ashes from the Lava Creek B and multiple Long Valley, California, volcanic eruptions. We correlated middle and late Pleistocene glacial maxima to deep lake deposits defined by well-preserved bedding, increased biosilica, boreal pollen taxa (i.e., Picea), and lower density and MS. Interglacial periods are associated with shallow-water deposits characterized by banded-to-massive siliciclastic material, some authigenic calcite, the alga Phacotus, and higher density and MS. Prior to the marine isotope stage (MIS) 24−22 interval, smaller-amplitude changes in the lake environment suggest milder glacial conditions compared to those of the middle and late Pleistocene. Thus, abrupt intensification of glacial conditions may have occurred ca. 900 ka in the American Southwest, mirroring a global characteristic of the mid-Pleistocene transition. The STL14 record suggests that lake environments throughout the history of this small (3.5 km2), internally drained, basaltic catchment are sensitive to the regional hydrologic balance, which, at orbital time scales, is largely influenced by the northern cryosphere and associated changes in atmospheric circulation. The predominance of quartz in sediment throughout the record indicates significant eolian inputs. Few paleoclimate records from this region extend beyond the last glacial cycle, let alone the middle Pleistocene, making STL14 a valuable resource for studying environmental responses to a range of natural climate states and transitions throughout much of the Quaternary.

scholarly journals Seasonality, drivers, and isotopic composition of soil CO<sub>2</sub> fluxes from tropical forests of the Congo Basin

2020 ◽  
Author(s):  
Simon Baumgartner ◽  
Matti Barthel ◽  
Travis W. Drake ◽  
Marijn Bauters ◽  
Isaac Ahanamungu Makelele ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Soil Respiration ◽  
Tropical Forests ◽  
Montane Forest ◽  
Congo Basin ◽  
Co2 Fluxes ◽  
Soil Co2 ◽  
Montane Forests ◽  
Lowland Forest ◽  
Lowland Forests

Abstract. Soil respiration is an important carbon flux and key process determining the net ecosystem production of terrestrial ecosystems. To address the enormous lack of quantification and understanding of seasonality in soil respiration of tropical forests in the Congo Basin, soil CO2 fluxes and potential controlling factors were measured for the first time annually in two dominant forest types (lowland and montane) of the Congo Basin during three years at varying temporal resolution. Soil CO2 fluxes from the Congo Basin resulted in 3.69 ± 1.22 and 3.82 ± 1.15 µmol CO2 m−2 s−1 for lowland and montane forests, respectively. Respiration in montane forest soils showed a clear seasonality with decreasing flux rates during the dry season. Montane forest soil CO2 fluxes were positively correlated with soil moisture while CO2 fluxes in the lowland forest were not. Paired ẟ13C values of soil organic carbon (SOC) and soil CO2 indicated that SOC in lowland forests is more decomposed than in montane forests, suggesting that respiration is controlled by C availability rather than environmental factors. In general, C in montane forests was more enriched in 13C throughout the whole cascade of carbon intake via photosynthesis, litterfall, SOC, and soil CO2 compared to lowland forests, pointing to a more open system. Even though soil CO2 fluxes are similarly high in lowland and montane forests of the Congo Basin, the drivers of them were different, i.e. soil moisture for montane forest and C availability for lowland forest.

Facies Composition and Stratigraphic Position of the Quaternary Upper Yenisei Sequence in the Tuva and Minusa Depressions

2021 ◽  
Vol 62 (10) ◽  
pp. 1127-1138
Author(s):  
I.D. Zol’nikov ◽  
I.S. Novikov ◽  
E.V. Deev ◽  
A.V. Shpansky ◽  
M.V. Mikharevich
Keyword(s):  
Late Pleistocene ◽  
Lacustrine Sediments ◽  
Alluvial Fan ◽  
Luminescence Dating ◽  
Middle Pleistocene ◽  
Mountainous Area ◽  
Gorny Altai ◽  
Stratigraphic Position ◽  
Geochronological Dating ◽  
Current Ripples

Abstract —The paper concerns the sediment sequence, which is widespread in the Yenisei valley and in the Tuva and Minusa depressions and also present in the valleys of the southern Chulym plain. The sediments of this sequence were previously described as “Neogene mud-shedding”, as well as moraines, alluvial fan deposits, alluvium of Middle Pleistocene high terraces, and lacustrine sediments. The giant ripple marks on the Upper Yenisei terraces was commonly interpreted as ribbed moraines; however, in recent studies, these ridges have been repeatedly referred to as marks of giant current ripples. Besides, some recently published papers provide description of geology of this sequence fragments suggesting its deposition by cataclysmic floods. Geomorphological analysis of the area shows Pleistocene glaciers to have been localized within the medium–high mountainous areas. The glaciers did not reach the Tuva and Minusa depressions and occupied large areas only in the Todzha basin and on the periphery of the Darkhat basin, forming a glacial dam at its outlet, which resulted in glacial-dammed lakes filling the basin completely. These lakes outburst, and the resultant flooding led to the deposition of megaflood sediments, which we refer to here as the Upper Yenisei sediment sequence. A detailed analysis of its facies architecture revealed similarity of these sediments to those of the Sal’dzhar and Inya sequences in Gorny Altai. Most of the Upper Yenisei megaflood sediments are localized in topographic lows of the Tuva and Minusa depressions. Beyond the Altai–Sayan mountainous area, the megaflood sediments of the Upper Yenisei sequence compose high terraces of the Yenisei, Chulym, Chet’, and Kiya rivers in the southern Chulym plain. The formation of Upper Yenisei sequence dates to the first half of the Late Pleistocene, inasmuch as it contains inset alluvial sediments of the second terrace of the Yenisei River. The available data allow suggesting that the Upper Yenisei sequence formed in the first Late Pleistocene regional glaciation. The Sal’dzhar sequence in Gorny Altai and the fourth terrace of the Ob’ River on the Fore-Altai plain are stratigraphic analogs of the Upper Yenisei sequence. The Upper Yenisei and Sal’dzhar sequences can thus be considered future regional markers serving as a link for the local stratigraphic schemes of the Altai–Sayan mountainous area and adjacent West Siberian plains. The results obtained call for verification by geochronological dating, first of all, by modern luminescence dating methods covering a wider chronological interval than radiocarbon dating.

Aeolian influx and related environmental conditions on Gran Canaria during the early Pleistocene

2018 ◽  
Vol 91 (1) ◽  
pp. 35-50 ◽  
Author(s):  
Inmaculada Menéndez ◽  
José Mangas ◽  
Esperança Tauler ◽  
Vidal Barrón ◽  
José Torrent ◽  
...  
Keyword(s):  
Late Quaternary ◽  
Textural Analysis ◽  
Climatic Conditions ◽  
Saharan Dust ◽  
Early Pleistocene ◽  
Middle Pleistocene ◽  
Quartz Content ◽  
Gran Canaria ◽  
Climatic Oscillations ◽  
Climatic Variations

AbstractThe island of Gran Canaria is regularly affected by dust falls due to its proximity to the Saharan desert. Climatic oscillations may affect the Saharan dust input to the island. Geochemical, mineralogical, and textural analysis was performed on a well-developed and representative early Pleistocene paleosol to examine Saharan dust contribution to Gran Canaria. Significant and variable Saharan dust content was identified in addition to weathering products such as iron oxides and clay minerals. Variations in quartz and iron oxide concentrations in the paleosol likely reflect different Saharan dust input in more/less-contrasted rhexistasic/biostatic climatic conditions. Linking the quartz content in Canarian soils, the Ingenio paleosol, and two Canarian loess-like deposits to different ages from the Quaternary, we hypothesized that the dust input should be lower (about 33–38%) throughout the early to middle Pleistocene than during the late Quaternary. The Saharan dust input to the Gran Canaria profile in the Pleistocene persisted in spite of climatic variations.

scholarly journals Cosmogenic burial dating of in cave-deposited alluvium: unravelling long-term incision rates and complex speleogenesis in multi-level cave systems

2020 ◽  
Author(s):  
Gilles Rixhon ◽  
Didier L. Bourlès ◽  
Régis Braucher ◽  
Alexandre Peeters ◽  
Alain Demoulin
Keyword(s):  
Early Pleistocene ◽  
Middle Pleistocene ◽  
Fluvial Terrace ◽  
Base Level ◽  
Cave System ◽  
River Incision ◽  
Order Of Magnitude ◽  
History Of ◽  
Multi Level

&lt;p&gt;Multi-level cave systems record the history of regional river incision in abandoned alluvium-filled phreatic passages which, mimicking fluvial terrace sequences, represent former phases of fluvial base-level stability. In this respect, cosmogenic burial dating of in cave-deposited alluvium (usually via the nuclide pair &lt;sup&gt;26&lt;/sup&gt;Al/&lt;sup&gt;10&lt;/sup&gt;Be) represents a suitable method to quantify the pace of long-term river incision. Here, we present a dataset of fifteen &lt;sup&gt;26&lt;/sup&gt;Al/&lt;sup&gt;10&lt;/sup&gt;Be burial ages measured in fluvial pebbles washed into a multi-level cave system developed in Devonian limestone of the uplifted Ardenne massif (eastern Belgium). The large and well-documented Chawresse system is located along the lower Ourthe valley (i.e. the main Ardennian tributary of the Meuse river) and spans altogether an elevation difference exceeding 120 m.&lt;/p&gt;&lt;p&gt;The depleted &lt;sup&gt;26&lt;/sup&gt;Al/&lt;sup&gt;10&lt;/sup&gt;Be ratios measured in four individual caves show two main outcomes. Firstly, computed burial ages ranging from ~0.2 to 3.3 Ma allows highlighting an acceleration by almost one order of magnitude of the incision rates during the first half of the Middle Pleistocene (from ~25 to ~160 m/Ma). Secondly, according to the relative elevation above the present-day floodplain of the sampled material in the Manants cave (&lt;35 m), the four internally-consistent Early Pleistocene burial ages highlight an &amp;#8220;anomalous&amp;#8221; old speleogenesis in the framework of a gradual base-level lowering. They instead point to intra-karsting reworking of the sampled material in the topographically complex Manants cave. This in turn suggests an independent, long-lasting speleogenetic evolution of this specific cave, which differs from the &lt;em&gt;per descensum&lt;/em&gt; model of speleogenesis generally acknowledged for the regional multi-level cave systems and their abandoned phreatic galleries. In addition to its classical use for inferring long-term incision rates, cosmogenic burial dating can thus contribute to better understand specific and complex speleogenetic evolution.&lt;/p&gt;

scholarly journals Chronic nitrogen addition causes a reduction in soil carbon dioxide efflux during the high stem-growth period in a tropical montane forest but no response from a tropical lowland forest in decadal scale

2009 ◽  
Vol 6 (5) ◽  
pp. 8633-8660
Author(s):  
B. Koehler ◽  
M. D. Corre ◽  
E. Veldkamp ◽  
J. P. Sueta
Keyword(s):  
Growth Period ◽  
Montane Forest ◽  
Stem Growth ◽  
Soil Co2 Efflux ◽  
Co2 Efflux ◽  
N Addition ◽  
Soil Co2 ◽  
Lowland Forest ◽  
Soil Carbon Dioxide ◽  
Decadal Scale

Abstract. Atmospheric nitrogen (N) deposition is rapidly increasing in tropical regions. We studied the response of soil carbon dioxide CO2 efflux to long-term experimental N-addition (125 kg N ha−1 yr-1) in mature lowland and montane forests in Panamá. In the lowland forest, on soils with high nutrient-supplying and buffering capacity, fine litterfall and stem-growth were neither N- nor phosphorus-limited. In the montane forest, on soils with low nutrient supplying capacity and an organic layer, fine litterfall and stem-growth were N-limited. Our objectives were to 1) explore the influence of soil temperature and moisture on the dynamics of soil CO2 efflux and 2) determine the responses of soil CO2 efflux from an N-rich and N-limited forest to elevated N input. Annual soil CO2-C efflux was larger from the lowland (15.20±1.25 Mg C ha−1) than the montane forest (9.36±0.29 Mg C ha−1). In the lowland forest, soil moisture explained the largest fraction of the variance in soil CO2 efflux while soil temperature was the main explanatory variable in the montane forest. Soil CO2 efflux in the lowland forest did not differ between the control and 9–11 yr N-addition plots, suggesting that chronic N input to nutrient-rich tropical lowland forests on well-buffered soils may not change their C balance in decadal scale. In the montane forest, first year N addition did not affect soil CO2 efflux but annual CO2 efflux was reduced by 14% and 8% in the 2- and 3 yr N-addition plots, respectively, compared to the control. This reduction was caused by a decrease in soil CO2 efflux during the high stem-growth period of the year, suggesting a shift in carbon partitioning from below- to aboveground in the N-addition plots where stem diameter growth was promoted.

scholarly journals GEOLOGICAL AND MAGNETIC SUSCEPTIBILITY MAPPING OF MOUNT GIOUCHTA (CENTRAL CRETE)

2017 ◽  
Vol 43 (1) ◽  
pp. 289 ◽  
Author(s):  
E. Kokinou ◽  
E. Kamberis ◽  
A. Sarris ◽  
I. Tzanaki
Keyword(s):  
Magnetic Susceptibility ◽  
Spatial Distribution ◽  
Stress Field ◽  
Magnetic Measurements ◽  
Strain Analysis ◽  
Geological Structure ◽  
Early Pleistocene ◽  
Middle Pleistocene ◽  
Western Slope ◽  
Strain Pattern

Giouchta Mt. is located south of Heraklion city, in Crete. It is an N-S trending morphological asymmetric ridge, with steep western slope whilst the eastern slope represents a smoother relief, composed of Mesozoic limestone and Eocene- lower Oligocene flysch sediments of the Gavrovo -Tripolis zone. The present study focuses on the geological structure of Mt. Giouchta. Field mapping and tectonic analysis is performed for this purpose. The dominant structures are contractional in nature, deformed by normal faulting related to the extensional episodes initiated in Serravallian times. The strain pattern in the area is revealed from strain analysis. It is inferred that the orientation of the stress field in the area has changed several times: the N-S, stress field which was dominant during Late Serravallian times changed to NE-SW (in Late Serravallian? - Early Tortonian) and subsequently to WNW-ESE (Early to Middle Tortonian) to become NW-SE in Late Tortonian. This orientation changed also during the Quaternary times trending from NW-SE (Early Pleistocene) to ENE-WSW (Middle Pleistocene-Holocene). In addition to the above, surface soil samples were collected in the wider area of mount Giouchta and they were analyzed in order to determine the magnetic susceptibility. GIS techniques were used for mapping the spatial distribution of the geological features and the magnetic measurements on the topographic relief of the area. Statistical analysis techniques were also applied in order to investigate the relation of faulting and magnetic susceptibility. Maps representing the spatial distribution of the above measurements were created by using appropriate interpolation algorithms.

scholarly journals Elephant bones for the Middle Pleistocene toolmaker

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0256090
Author(s):  
Paola Villa ◽  
Giovanni Boschian ◽  
Luca Pollarolo ◽  
Daniela Saccà ◽  
Fabrizio Marra ◽  
...  
Keyword(s):  
Upper Paleolithic ◽  
Raw Material ◽  
General Idea ◽  
Early Pleistocene ◽  
Stone Tool ◽  
Middle Pleistocene ◽  
Medium Size ◽  
Bone Tools ◽  
Lithic Industry ◽  
Taphonomic Analysis

The use of bone as raw material for implements is documented since the Early Pleistocene. Throughout the Early and Middle Pleistocene bone tool shaping was done by percussion flaking, the same technique used for knapping stone artifacts, although bone shaping was rare compared to stone tool flaking. Until recently the generally accepted idea was that early bone technology was essentially immediate and expedient, based on single-stage operations, using available bone fragments of large to medium size animals. Only Upper Paleolithic bone tools would involve several stages of manufacture with clear evidence of primary flaking or breaking of bone to produce the kind of fragments required for different kinds of tools. Our technological and taphonomic analysis of the bone assemblage of Castel di Guido, a Middle Pleistocene site in Italy, now dated by 40Ar/39Ar to about 400 ka, shows that this general idea is inexact. In spite of the fact that the number of bone bifaces at the site had been largely overestimated in previous publications, the number of verified, human-made bone tools is 98. This is the highest number of flaked bone tools made by pre-modern hominids published so far. Moreover the Castel di Guido bone assemblage is characterized by systematic production of standardized blanks (elephant diaphysis fragments) and clear diversity of tool types. Bone smoothers and intermediate pieces prove that some features of Aurignacian technology have roots that go beyond the late Mousterian, back to the Middle Pleistocene. Clearly the Castel di Guido hominids had done the first step in the process of increasing complexity of bone technology. We discuss the reasons why this innovation was not developed. The analysis of the lithic industry is done for comparison with the bone industry.

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