Permo-Carboniferous sediments at Kraskov (borehole KS-1) and their source area

2015 ◽  
Author(s):  
Marcela Stárková ◽  
Štěpánka Mrázová ◽  
Tamara Sidorinová
Keyword(s):  
Source Area

The Distribution of Volatile Organics in a Leachate Plume, Gloucester, Ontario

1987 ◽  
Vol 22 (1) ◽  
pp. 49-64 ◽  
Author(s):  
J.F. Devlin ◽  
W.A. Gorman
Keyword(s):  
Organic Contaminants ◽  
Source Area ◽  
Unconfined Aquifer ◽  
High Concentration ◽  
Organic Contamination ◽  
Aquifer System ◽  
Aquifer Systems ◽  
Volatile Organic ◽  
Volatile Organic Contaminants ◽  
Aquifer Sediments

Abstract The Gloucester Landfill is located near Ottawa, Ontario, on a northeast trending ridge of Quaternary age. The ridge comprises outwash sediments which make up two aquifer systems. A confined system exists next to bedrock, and is overlain by a silty-clayey stratum (the confining layer) which is, in turn, overlain by an unconfined aquifer system. Two independent volatile organic plumes have previously been identified at the landfill: the southeast plume, which has penetrated the confined aquifer system, and the northeast plume which is migrating in the unconfined aquifer. The distribution of volatile organic contaminants at the northeast plume site appears to be a function of two factors: (1) heterogeneities in the aquifer sediments are causing the channeling of contaminants through a narrow path; (2) the low fraction of organic carbon in the unconfined aquifer sediments at the northeast site is resulting in little retardation of the contaminants there, relative to those at the southeast site. Acetate was the only volatile fatty acid detected in the leachate. It was measurable only in areas where the volatile organic contamination was significant. Although methane was detected in the contaminated sediments, suggesting that microbial activity was present, the high concentration of acetate (>1000 ppm) which was detected down-gradient from the source area indicates that any biodegradation which is occurring is proceeding at a very slow rate.

scholarly journals Correction of Eddy Covariance Based Crop ET Considering the Heat Flux Source Area

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 281
Author(s):  
Stuart L. Joy ◽  
José L. Chávez
Keyword(s):  
Heat Flux ◽  
Eddy Covariance ◽  
Agricultural Land ◽  
Flux Measurement ◽  
Source Area ◽  
Mean Bias Error ◽  
Bias Error ◽  
Crop Water ◽  
The Past ◽  
Measurement Results

Eddy covariance (EC) systems are being used to measure sensible heat (H) and latent heat (LE) fluxes in order to determine crop water use or evapotranspiration (ET). The reliability of EC measurements depends on meeting certain meteorological assumptions; the most important of such are horizontal homogeneity, stationarity, and non-advective conditions. Over heterogeneous surfaces, the spatial context of the measurement must be known in order to properly interpret the magnitude of the heat flux measurement results. Over the past decades, there has been a proliferation of ‘heat flux source area’ (i.e., footprint) modeling studies, but only a few have explored the accuracy of the models over heterogeneous agricultural land. A composite ET estimate was created by using the estimated footprint weights for an EC system in the upwind corner of four fields and separate ET estimates from each of these fields. Three analytical footprint models were evaluated by comparing the composite ET to the measured ET. All three models performed consistently well, with an average mean bias error (MBE) of about −0.03 mm h−1 (−4.4%) and root mean square error (RMSE) of 0.09 mm h−1 (10.9%). The same three footprint models were then used to adjust the EC-measured ET to account for the fraction of the footprint that extended beyond the field of interest. The effectiveness of the footprint adjustment was determined by comparing the adjusted ET estimates with the lysimetric ET measurements from within the same field. This correction decreased the absolute hourly ET MBE by 8%, and the RMSE by 1%.

CERAMIC SEQUENCE, CHRONOLOGY, AND CULTURAL DYNAMICS OF THE UCAREO-ZINAPÉCUARO, MICHOACÁN OBSIDIAN SOURCE AREA

2021 ◽  
pp. 1-21
Author(s):  
Dan M. Healan ◽  
Christine Hernández
Keyword(s):  
Source Area ◽  
Central Mexico ◽  
Cultural Dynamics ◽  
Postclassic Period ◽  
Radiocarbon Dates ◽  
Pottery Analysis ◽  
Ceramic Chronology ◽  
Cross Dating ◽  
Obsidian Source

Abstract This article presents the ceramic sequence and chronology resulting from a multi-year program of survey, excavation, and analysis of pre-Hispanic settlement and exploitation within the Zinapécuaro-Ucareo (“U-Z”), Michoacan obsidian source area. Pottery analysis and classification aided by seriation analysis identified nine ceramic complexes and seven ceramic phases and sub-phases that both expand and refine the ceramic sequence previously established for the region by Gorenstein's (1985) investigations at nearby Acámbaro, Guanajuato. Initially established by ceramic cross-dating, the U-Z ceramic chronology has been largely confirmed by 30 radiocarbon dates and spans over 2,000 years of pre-Hispanic settlement, which included at least two notable episodes of trait-unit and site-unit intrusion from the eastern El Bajío and central Mexico. One of these episodes involved the appearance of two enclaves settled by individuals from the Acambay valley c. 90 km to the East, most likely from the site of Huamango, which our data indicate would have been occupied during the Middle Postclassic period.

scholarly journals Rutile Mineral Chemistry and Zr-in-Rutile Thermometry in Provenance Study of Albian (Uppermost Lower Cretaceous) Terrigenous Quartz Sands and Sandstones in Southern Extra-Carpathian Poland

Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 553
Author(s):  
Jakub Kotowski ◽  
Krzysztof Nejbert ◽  
Danuta Olszewska-Nejbert
Keyword(s):  
High Temperature ◽  
Source Area ◽  
Bimodal Distribution ◽  
Provenance Study ◽  
Eastern Group ◽  
Western Group ◽  
Quartz Sands ◽  
Probable Source ◽  
Eclogite Facies ◽  
Zr In Rutile

The geochemistry of detrital rutile grains, which are extremely resistant to weathering, was used in a provenance study of the transgressive Albian quartz sands in the southern part of extra-Carpathian Poland. Rutile grains were sampled from eight outcrops and four boreholes located on the Miechów, Szydłowiec, and Puławy Segments. The crystallization temperatures of the rutile grains, calculated using a Zr-in-rutile geothermometer, allowed for the division of the study area into three parts: western, central, and eastern. The western group of samples, located in the Miechów Segment, is characterized by a polymodal distribution of rutile crystallization temperatures (700–800 °C; 550–600 °C, and c. 900 °C) with a significant predominance of high-temperature forms, and with a clear prevalence of metapelitic over metamafic rutile. The eastern group of samples, corresponding to the Lublin Area, is monomodal and their crystallization temperatures peak at 550–600 °C. The contents of metapelitic to metamafic rutile in the study area are comparable. The central group of rutile samples with bimodal distribution (550–600 °C and 850–950 °C) most likely represents a mixing zone, with a visible influence from the western and, to a lesser extent, the eastern group. The most probable source area for the western and the central groups seems to be granulite and high-temperature eclogite facies rocks from the Bohemian Massif. The most probable source area for the eastern group of rutiles seems to be amphibolites and low temperature eclogite facies rocks, probably derived from the southern part of the Baltic Shield.

scholarly journals Environmental Changes and Cultural Transitions in SW Iberia during the Early-Mid Holocene

2021 ◽  
Vol 11 (8) ◽  
pp. 3580
Author(s):  
Cristina Val-Peón ◽  
Juan I. Santisteban ◽  
José A. López-Sáez ◽  
Gerd-Christian Weniger ◽  
Klaus Reicherter
Keyword(s):  
Dietary Habits ◽  
Environmental Changes ◽  
Source Area ◽  
Direct Access ◽  
Special Focus ◽  
Early Neolithic ◽  
Archaeological Data ◽  
Local Resources ◽  
Climate Events ◽  
The Impact

The SW coast of the Iberian Peninsula experiences a lack of palaeoenvironmental and archaeological data. With the aim to fill this gap, we contribute with a new palynological and geochemical dataset obtained from a sediment core drilled in the continental shelf of the Algarve coast. Archaeological data have been correlated with our multi-proxy dataset to understand how human groups adapted to environmental changes during the Early-Mid Holocene, with special focus on the Mesolithic to Neolithic transition. Vegetation trends indicate warm conditions at the onset of the Holocene followed by increased moisture and forest development ca. 10–7 ka BP, after which woodlands are progressively replaced by heaths. Peaks of aridity were identified at 8.2 and 7. 5 ka BP. Compositional, textural, redox state, and weathering of source area geochemical proxies indicates abrupt palaeoceanographic modifications and gradual terrestrial changes at 8.2 ka BP, while the 7.5 ka BP event mirrors a decrease in land moisture availability. Mesolithic sites are mainly composed of seasonal camps with direct access to the coast for the exploitation of local resources. This pattern extends into the Early Neolithic, when these sites coexist with seasonal and permanent occupations located in inland areas near rivers. Changes in settlement patterns and dietary habits may be influenced by changes in coastal environments caused by the sea-level rise and the impact of the 8.2 and 7.5 ka BP climate events.

scholarly journals A review of modelling methodologies for flood source area (FSA) identification

2021 ◽  
Author(s):  
Amrie Singh ◽  
David Dawson ◽  
Mark Trigg ◽  
Nigel Wright
Keyword(s):  
Flood Risk ◽  
Risk Mitigation ◽  
Ground Cover ◽  
Source Area ◽  
Urban Environments ◽  
Weather Patterns ◽  
Complex Process ◽  
Average Annual Loss ◽  
Flood Source ◽  
Modelling Approaches

AbstractFlooding is an important global hazard that causes an average annual loss of over 40 billion USD and affects a population of over 250 million globally. The complex process of flooding depends on spatial and temporal factors such as weather patterns, topography, and geomorphology. In urban environments where the landscape is ever-changing, spatial factors such as ground cover, green spaces, and drainage systems have a significant impact. Understanding source areas that have a major impact on flooding is, therefore, crucial for strategic flood risk management (FRM). Although flood source area (FSA) identification is not a new concept, its application is only recently being applied in flood modelling research. Continuous improvements in the technology and methodology related to flood models have enabled this research to move beyond traditional methods, such that, in recent years, modelling projects have looked beyond affected areas and recognised the need to address flooding at its source, to study its influence on overall flood risk. These modelling approaches are emerging in the field of FRM and propose innovative methodologies for flood risk mitigation and design implementation; however, they are relatively under-examined. In this paper, we present a review of the modelling approaches currently used to identify FSAs, i.e. unit flood response (UFR) and adaptation-driven approaches (ADA). We highlight their potential for use in adaptive decision making and outline the key challenges for the adoption of such approaches in FRM practises.

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