Paleoenvironment of Kuan Kreng peat swamp, Southern Thailand

2020 ◽  
Author(s):  
Kannika Wangritthikraikul ◽  
Smith Leknettip ◽  
Sakonvan Chawchai
Keyword(s):  
Forest Fires ◽  
Agricultural Land ◽  
Plant Macrofossils ◽  
Grain Size Analysis ◽  
Geochemical Data ◽  
Size Analysis ◽  
Carbonate Content ◽  
Fire Control ◽  
Peat Swamp ◽  
Southern Thailand

<p>Peatlands have played an important role in the global carbon cycle. Tropical peatlands are one of the largest reserves of terrestrial organic carbon. Present-day tropical peat swamp forests are, however, under the threat of anthropogenic disturbance or have already been widely degraded. In Southeast Asia, very large areas of peatland have been deforested, drained, converted to extensive and intensive agricultural land uses and exposed to regular wildfires. Khuan Kreng peat swamp is the second largest protected wetland in Thailand. Recent studies in Khuan Kreng peat swamp has focused on present day drought and forest fires, but there is still lack of paleoenvironmental data. In this study, sediment and peat sequences were collected from Forest Fire Control Station area in Khuan Kreng peat swamp, and geochemical data (loss on ignition, grain size analysis and carbonate content) were analyzed. The age of early Holocene were determined based on plant macrofossils using Radiocarbon Dating (<sup>14</sup>C). The preliminary results indicate that this area was Tidal flats. The study of sediment/peat sequences using geochemical data can improve our understanding how past environmental have affected Khuan Kreng peat swamp ecosystems.</p>

Compositional data analysis of sedimentological, mineralogical and geochemical data for the evaluation of Austrian loess and loess loam deposits

2020 ◽  
Author(s):  
Heinz Reitner ◽  
Christian Benold ◽  
Peter Filzmoser ◽  
Maria Heinrich ◽  
Gerhard Hobiger ◽  
...  
Keyword(s):  
Information System ◽  
Statistical Analysis ◽  
Raw Materials ◽  
Analysis Data ◽  
Grain Size Analysis ◽  
Geochemical Data ◽  
Size Analysis ◽  
Compositional Data Analysis ◽  
Rock Composition ◽  
Log Ratio

<p>Austrian loess and loess loam deposits represent an important source of raw materials for the heavy clay industry for centuries. Building material quality of loess and loess loam deposits and their suitability for different applications is significantly influenced by their heterogeneous properties. These depend on the geology of the source area, climatic conditions, geomorphological location, stratigraphic position, intensity of weathering and redeposition potential. The description of occurrences, properties and availability of these raw materials is therefore an important prerequisite to meet the industrial quality requirements. A large number of different sub-datasets exist at the Geological Survey of Austria, which comprise grain-size analysis, bulk rock composition, clay mineralogy, and geochemistry data of loess and loess loam. Within our project, these individual data sets underwent a thorough examination and have been merged into a coherent database to enable the joint regional and statistical analysis of the data. By applying a log-ratio approach the compositional nature of the analysis data has been taken into account for multivariate statistical methods. <br>Within our study we focused on the classic Austrian loess regions in the Northern Alpine foreland areas of Upper and Lower Austria and in the Vienna Basin. By transferring the results of the statistical analysis to a Geographic Information System (GIS) these served as the fundamental basis for our categorization of the loess and loess loam occurrences. Taking into account previously published approaches based on soil profile classifications as well as trends and patterns derived from the analysis data, we finally were able to delineate different districts of brick raw materials deposits. These will be made publically accessible to the industry and interested parties as part of the web application of the Austrian Interactive Raw Material Information System IRIS-Online.</p>

scholarly journals From the Landslide to the Mangrove; Coupling Sediment Supply Pulses and River Sediment Deposits in the context of Climate Change in Thailand.

2021 ◽  
Author(s):  
Jerome Curoy ◽  
Raymond Ward ◽  
John Barlow
Keyword(s):  
Grain Size ◽  
Google Earth ◽  
Sediment Supply ◽  
Aerial Photographs ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Negative Power ◽  
Scaling Properties ◽  
Surface Areas ◽  
Southern Thailand

<p>In Thailand landslides and flooding are two major natural disasters affecting more than 11 million people living in coastal provinces. Such events have significant human and economic impacts. For example, in 1988, landslides resulted in 373 deaths and caused up to US$80 million in damage (Tanavud, 2008); in 2011, floods and landslides affected more than two million people and killed 53 across Southern Thailand with a village of about 100 households being buried by one large slide (EarthObservatory, 2021). Landslides in the Krabi province in Thailand are predominantly shallow and rainfall-induced, they also represent the main source of sediment pulses for coastal environments such as mangroves and beaches. This study aims at investigating the link between sediment availability from 3 river catchments in the province of Krabi in Southern Thailand and sedimentation rate evolution in mangroves directly downstream in order to understand coastal the sediment shortages and therefore coastal erosion in that area.</p><p>Landslide inventories were evaluated using high resolution imagery (<10m) such as aerial photographs, Theos and EO-1 satellite imagery, Google Earth historical tool covering a time period from 2007 to present. Calculations of the surface areas and volumes of landslides was calculated in ArcMap using the formulae developed by Larsen et al. (2010). Landslide erosion was modelled using an approach based upon the negative power law scaling properties of rockfall magnitude–frequency distribution to establish total volumes of sediment for specific years or seasons.</p><p>Core samples taken in the mangroves near the river mouths were used to identify markers of landslide events and associated sediment cascades based on grain size distribution and <sup>137</sup>Cs dating.</p><p>Preliminary results show sedimentation rates in the mangroves from 0.9 to 2 mm/year since 1963 and sediment volumes made available to transport from 0.3 to 68300 m<sup>3</sup>/year since 2007 across the 3 catchments.</p><p>Grain size analysis shows variations of the D<sub>50</sub> and the sorting coefficient throughout the sediment recording indicators of landslides and high intensity rainfall events.</p>

Tephra analysis of sediments from Midge Lake (South Shetland Islands) and Sombre Lake (South Orkney Islands), Antarctica

1998 ◽  
Vol 10 (1) ◽  
pp. 13-20 ◽  
Author(s):  
Dominic A. Hodgson ◽  
Coral L. Dyson ◽  
Vivienne J. Jones ◽  
John L. Smellie
Keyword(s):  
Sediment Cores ◽  
South Shetland Islands ◽  
Grain Size Analysis ◽  
Geochemical Data ◽  
Size Analysis ◽  
Shetland Islands ◽  
Orkney Islands ◽  
Signy Island ◽  
South Orkney Islands ◽  
Synchronous Time

Lake sediment cores from Midge Lake, Livingston Island, South Shetland Islands and Sombre Lake, Signy Island, South Orkney Islands were analysed for volcanic tephra using light microscopy and magnetic susceptibility. Cores were dated using published 14C and 210Pb chronologies. Electron probe microanalyses of discrete tephra glass shards were undertaken to characterise the tephra geochemically in order to identify possible source volcanoes and refine tephrochronological data for the region. Results identified five tephra horizons in a core from Midge Lake. Four of these tephra at 3–4 cm, 8–9 cm (c. 450 yr BP), 15–16 cm (c. 755 ± 105 yr BP) and 21–22 cm (c. 1340 ± 100 yr BP) consisted of sodic basaltic to basalticandesitic glasses, containing abundant labradoritic feldspar inclusions, and a single ‘acidic’ tephra was found at 2–3 cm. Seven tephra horizons were identified in the Sombre Lake core including three basaltic tephra at 3–9 cm (30 ± 4 yr BP to 125 ± 25 yr BP), 31–32 cm and 44–46 cm (1325 ± 50 14C yr BP) and four acidic tephra at 21–22 cm and 24–25 cm, 33–36 cm (c. 1021 14C yr BP) and 54–56 cm (c. 1450 14C yr BP). These are the first tephra to be identified from the South Orkney Islands. Geochemical and grain size analysis indicated that the analysed Midge Lake tephra were derived from the Quaternary Deception Island volcano. Smaller grain sizes, congruent geochemical data and prevailing wind directions also indicate this volcano as the likely source of Sombre Lake tephra. Results highlight the importance of establishing geochemical consistency between tephra deposited across wide geographical areas, during apparently synchronous time periods, if they are to be used in a regional tephrochronology.

scholarly journals Laser-Induced Breakdown Spectroscopy—An Emerging Analytical Tool for Mineral Exploration

Minerals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 718 ◽  
Author(s):  
Russell Harmon ◽  
Christopher Lawley ◽  
Jordan Watts ◽  
Cassady Harraden ◽  
Andrew Somers ◽  
...  
Keyword(s):  
Mineral Exploration ◽  
Grain Size Analysis ◽  
Geochemical Data ◽  
Laser Induced Breakdown Spectroscopy ◽  
Size Analysis ◽  
Green Technologies ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown ◽  
Rock Characterization

The mineral exploration industry requires new methods and tools to address the challenges of declining mineral reserves and increasing discovery costs. Laser-induced breakdown spectroscopy (LIBS) represents an emerging geochemical tool for mineral exploration that can provide rapid, in situ, compositional analysis and high-resolution imaging in both laboratory and field and settings. We demonstrate through a review of previously published research and our new results how LIBS can be applied to qualitative element detection for geochemical fingerprinting, sample classification, and discrimination, as well as quantitative geochemical analysis, rock characterization by grain size analysis, and in situ geochemical imaging. LIBS can detect elements with low atomic number (i.e., light elements), some of which are important pathfinder elements for mineral exploration and/or are classified as critical commodities for emerging green technologies. LIBS data can be acquired in situ, facilitating the interpretation of geochemical data in a mineralogical context, which is important for unraveling the complex geological history of most ore systems. LIBS technology is available as a handheld analyzer, thus providing a field capability to acquire low-cost geochemical analyses in real time. As a consequence, LIBS has wide potential to be utilized in mineral exploration, prospect evaluation, and deposit exploitation quality control. LIBS is ideally suited for field exploration programs that would benefit from rapid chemical analysis under ambient environmental conditions.

Late Tortonian – Piacenzian multi-proxy record of Asian southwest monsoon intensification: evidence from Coastal Makran, southeast Iran

2019 ◽  
Vol 56 (4) ◽  
pp. 347-362
Author(s):  
Mohammad Hadi Modarres ◽  
Hamid Alizadeh Ketek Lahijani ◽  
Nasser Keshavarz ◽  
Yann Lahaye ◽  
Kira Rehfeld ◽  
...  
Keyword(s):  
Organic Matter ◽  
Chemical Weathering ◽  
Gamma Ray ◽  
Southwest Monsoon ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Carbonate Content ◽  
High Precipitation ◽  
Physical And Chemical ◽  
Late Tortonian

This study presents a long-term, multi-proxy reconstruction of the Asian southwest monsoon during the Tortonian to Piacenzian, based on a 4.78 Ma record from Coastal Makran, northwestern Gulf of Oman, southeast Iran. The integration of humidity proxies (clay minerals, Th/K, volume magnetic susceptibility, and grain size analysis), marine redox sensitivity (Th/U), total organic matter, carbonate content, 87Sr/86Sr ratio, and spectral gamma-ray data conducted here provide valuable information that fill the existing gap in marine palaeoclimate records. The results show that a strong winter monsoon condition associated with relatively low precipitation and subsequently low physical and chemical weathering dominated the region during late Tortonian – late Messinian (7.65–5.83 Ma). However, a few episodes of intense physical and chemical weathering related to high precipitation are observed during this period (6.23–6.01 Ma), which is consistent with increased organic matter input from continental reservoirs to the oceans. In addition, the data indicate that from the latest Messinian (5.82–5.33 Ma) to Zanclean–Piacenzian (5.33–2.87 Ma), a strong summer monsoon accompanied by a relatively wetter condition and higher physical and chemical weathering resulted in a high detrital input into the basin. This higher weathering period is associated with the highest rate of Himalayan uplift, causing enhanced precipitation. Wavelet analysis of spectral gamma-ray data revealed notable periodicities at 750 Ka and 1.7 Ma, with significant periodicities centered around 5.75–6.03 Ma over the latest Messinian – Zanclean. Comparison with palaeoclimate records from other sites indicates a teleconnection with respect to precipitation, weathering, and productivity, especially during the Messinian–Zanclean transition.

scholarly journals GEOCHEMICAL AND MINERALOGICAL ANALYSIS OF SEDIMENTS FROM THE GULF OF ELEFSINA -STUDY OF THE ANTHROPOGENIC IMPACT

2018 ◽  
Vol 36 (1) ◽  
pp. 164 ◽  
Author(s):  
Γ. Κανελλοπούλου ◽  
Β. Περδικάτσης ◽  
Α. Φώσκολος
Keyword(s):  
Organic Matter ◽  
Sandy Loam ◽  
Grain Size Analysis ◽  
Geochemical Data ◽  
Size Analysis ◽  
Winter Period ◽  
Anoxic Conditions ◽  
Average Value ◽  
Black Layer ◽  
The Impact

Mineralogical and geochemical data on sediment of three sampling locations in the gulf of Elefsina, have been studied in order to access the impact of inorganic pollutants. The gulf is relatively shallow in depth and is connected to Saronicos bay with two shallow channels. This bottom physiography, worses the depositional environment since it receives pollutants of both the city and the industry without having wide towards the open sea. Grain size analysis of the surface sediments indicates that they are classified as sandy loam. However the main characteristic is the widespread appearance of a silty black layer, rich in organic matter. The thickness of the layer is 12 cm and is related to the oxic-anoxic conditions of the surface of the sediments. During the summer period the anoxic conditions promote an increase of the concentration of the organic matter in the bottom sediments which results in the widespread black coloring. The existence of a black layer in the first 10 to 12 cm of the cored sample is attributed to human activity. During the winter period, in which sampling took place, the increase in soluble O2 was responsible for the appearance of a thin brownish color top of the black layer. The thickness of this coloration is 0.5 mm. The pH of the sediments fluctuated between 7.4 and 8.5. The lower pH values are obtained in the top of the sediments while the higher ones in the bottom of the sediments. Data from the cation exchange capacity measurements have asserted the predominant of clays in the west side of the gulf. The distribution of total organic values yields higher values in the eastern side of the gulf (average value 4%) from the western side (average value 2.5%). Mineralogical composition of the sediments yielded the following minerals; quartz, calcite, dolomite, chlorite, illite, albite and alunite. A characteristic fluctuation of the soluble metals Pb, Ni, Zn, Cu, Μη, Cr, Hg and Cd, was observed, which characterize the environmental condition and pollution of the gulf of Elefsina

Grain-size analysis of surficial sediments from Golfo San Jorge, Argentina

2003 ◽  
Vol 83 (6) ◽  
pp. 1193-1197 ◽  
Author(s):  
M. Fernández ◽  
A. Roux ◽  
E. Fernández ◽  
J. Caló ◽  
A. Marcos ◽  
...  
Keyword(s):  
Third Sector ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Carbonate Content ◽  
Hydrodynamic Conditions ◽  
Surficial Sediments ◽  
Weight Percentage ◽  
Carbonate Concentration ◽  
Components Analysis ◽  
Granulometric Fraction

A detailed cartography of surficial sediments from Golfo San Jorge, Argentina is presented. Cluster analysis and principal components analysis (PCA) were applied considering the weight percentage of every granulometric fraction, carbonate concentration and the depth of 39 stations carried out during research cruises on board the RV ‘Captain Oca Balda’ (INIDEP).  The results defined three sectors: Sector 1, an area near the coast including Dos Bahías and Tres Puntas capes; Sector 2, a deep area far from the coast; and Sector 3, a coastal area and a south-east area between Tres Puntas cape and the inner area of the gulf. The first sector is characterized by the predominance of a coarse granulometric fraction and carbonate content. The second is defined by depth and presence of a fine granulometric fraction; while the third sector is considered a transitional sector, between the first and the second, dominated by fine sands. Sectors belong to environments of different kinds of energy or hydrodynamic conditions.

Paleoflooding and paleoclimate of the Lower Meuse during the Allerød-early Holocene

2020 ◽  
Author(s):  
Fei Peng ◽  
Cornelis Kasse ◽  
Maarten Prins ◽  
John Van der Woude ◽  
Nathalie Van der Putten ◽  
...  
Keyword(s):  
Younger Dryas ◽  
Early Holocene ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Carbonate Content ◽  
Second Phase ◽  
High Accumulation ◽  
The Core ◽  
Core Site ◽  
Isotope Record

<p>Lateglacial climatic oscillations exerted profound impacts on the earth surface. In the Lower Meuse Valley (southern Netherlands), geomorphological studies in the last decades mainly centered on Lateglacial vegetation evolution, channel pattern changes and river terrace formation. Little information has been reported with respect to the paleohydrology and its relation with local and regional climate system. This study investigates a sediment core that contains flood sediments deposited from the Allerød to the middleHolocene. We conducted grain-size analysis, thermogravimetric analysis (organic matter and calcium carbonate content), pollen counting, macro fossils analysis, and oxygen and carbon stable isotopes analysis of the biogenic carbonate. Plant species variations in each pollen assemblage zone represent the local and regional vegetation development. The pollen and macro fossil studies reveal that the core site was in a lake and marsh environment through the Allerød-early Holocene period. The oxygen isotope record is believed to have captured the intra-Allerød Cold Period, its synchronous variation with the carbon isotope record indicates a dominant evaporation effect on the lake during the warm Allerød period. By highlighting the coarser components (flood signal) of the fine and coarse end members, two flooding energy indexes were constructed separately. The hydrological processes in the first phase of the Younger Dryas were characterized by rapidly increased flooding conditions and high accumulation rates. In the second phase of the Younger Dryas, an addition of aeolian sediments to the core site complicates the paleoflood identification. This work expands the paleoflooding reconstruction to a more broadly deposition setting where only fine or coarse fluvial sediment is the dominant component. The nearly synchronous changes of the increased flooding with the abruptly enhanced westerlies at the Allerød-Younger Dryas transition indicates a link between the Lower Meuse catchment and the regional North Atlantic climatic system</p>

scholarly journals Grain size analytical and geochemical data of sediments from Ishakare and Alatan streams in Akungba-Akoko, Southwestern Nigeria

2021 ◽  
Vol 6 (2) ◽  
pp. 44-50
Author(s):  
Olumuyiwa A. Odundun ◽  
Keyword(s):  
Grain Size ◽  
Mean Value ◽  
Grain Size Analysis ◽  
Geochemical Data ◽  
Size Analysis ◽  
Dispersal Pattern ◽  
Southwestern Nigeria ◽  
Elemental Concentrations ◽  
Major Oxide ◽  
Geochemical Analyses

The identification of anomalous elemental concentrations and the prediction of their dispersal pattern play a key role in geochemical exploration. Stream sediments are important focus in this aspect. Nine (9) sediment samples collected from Ishakare and Alatan Streams in Akungba-Akoko were subjected to grain size and inorganic geochemical analyses in order to determine their grain sizes distribution, travel distances, elemental concentrations and origin. Results of grain size analysis show that streams sediments are mostly medium-grained, poorly-moderately sorted and ranged from fine to strongly coarse skewed suggesting that they have been transported relatively not too far away from their sources under high to low energy. SiO2 is a dominant major oxide with concentration values ranging between 64.81 and 71.59 wt.% with a mean value of 68.07 wt.%. Abundance of Al2O3 indicates that samples are from Aluminum-rich source bed rock. The weights of Fe2O3 and TiO2 also point to gneissic rocks as a probable source. Generally, concentrations of trace elements were found to be low indicating that the contamination statue of the sediments ranges from unpolluted to moderately polluted

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