scholarly journals Supplemental Material: Orbital control of Pleistocene euxinia in Lake Magadi, Kenya

2021 ◽  
Author(s):  
Daniel Deocampo ◽  
et al.
Keyword(s):  
Statistical Analyses ◽  
Geochemical Data ◽  
Orbital Parameters ◽  
Orbital Control ◽  
Lake Magadi

Comparison of Lake Magadi euxinia with global paleoclimate and orbital parameters, photography of selected core intervals, geochemical data, and statistical analyses.<br>

scholarly journals Supplemental Material: Orbital control of Pleistocene euxinia in Lake Magadi, Kenya

2021 ◽  
Author(s):  
Daniel Deocampo ◽  
et al.
Keyword(s):  
Statistical Analyses ◽  
Geochemical Data ◽  
Orbital Parameters ◽  
Orbital Control ◽  
Lake Magadi

Comparison of Lake Magadi euxinia with global paleoclimate and orbital parameters, photography of selected core intervals, geochemical data, and statistical analyses.<br>

ORBITAL CONTROL OF EUXINIA IN LAKE MAGADI OVER THE PAST 1 MILLION YEARS: MOLYBDENUM, ARSENIC, AND VANADIUM RECORDS

2018 ◽  
Author(s):  
Daniel M. Deocampo ◽  
◽  
R. Bernhart Owen ◽  
Tim K. Lowenstein ◽  
Robin W. Renaut ◽  
...  
Keyword(s):  
The Past ◽  
Orbital Control ◽  
Lake Magadi

scholarly journals Sedimentological processes and environmental variability at Lake Ohrid (Macedonia, Albania) between 637 ka and the present

2016 ◽  
Vol 13 (4) ◽  
pp. 1179-1196 ◽  
Author(s):  
Alexander Francke ◽  
Bernd Wagner ◽  
Janna Just ◽  
Niklas Leicher ◽  
Raphael Gromig ◽  
...  
Keyword(s):  
Primary Productivity ◽  
Environmental Variability ◽  
Geochemical Data ◽  
Nutrient Concentrations ◽  
Silty Clay ◽  
Lake Ohrid ◽  
Scientific Drilling ◽  
Orbital Parameters ◽  
Tephra Layers ◽  
Deep Site

Abstract. Lake Ohrid (Macedonia, Albania) is thought to be more than 1.2 million years old and host more than 300 endemic species. As a target of the International Continental scientific Drilling Program (ICDP), a successful deep drilling campaign was carried out within the scope of the Scientific Collaboration on Past Speciation Conditions in Lake Ohrid (SCOPSCO) project in 2013. Here, we present lithological, sedimentological, and (bio-)geochemical data from the upper 247.8 m composite depth of the overall 569 m long DEEP site sediment succession from the central part of the lake. According to an age model, which is based on 11 tephra layers (first-order tie points) and on tuning of bio-geochemical proxy data to orbital parameters (second-order tie points), the analyzed sediment sequence covers the last 637 kyr. The DEEP site sediment succession consists of hemipelagic sediments, which are interspersed by several tephra layers and infrequent, thin (< 5 cm) mass wasting deposits. The hemipelagic sediments can be classified into three different lithotypes. Lithotype 1 and 2 deposits comprise calcareous and slightly calcareous silty clay and are predominantly attributed to interglacial periods with high primary productivity in the lake during summer and reduced mixing during winter. The data suggest that high ion and nutrient concentrations in the lake water promoted calcite precipitation and diatom growth in the epilimnion during MIS15, 13, and 5. Following a strong primary productivity, highest interglacial temperatures can be reported for marine isotope stages (MIS) 11 and 5, whereas MIS15, 13, 9, and 7 were comparably cooler. Lithotype 3 deposits consist of clastic, silty clayey material and predominantly represent glacial periods with low primary productivity during summer and longer and intensified mixing during winter. The data imply that the most severe glacial conditions at Lake Ohrid persisted during MIS16, 12, 10, and 6, whereas somewhat warmer temperatures can be inferred for MIS14, 8, 4, and 2. Interglacial-like conditions occurred during parts of MIS14 and 8.

scholarly journals Geochemistry water of the Camaquã das Lavras and Hilário streams, Lavras do Sul-RS: anthropogenic or natural?

2020 ◽  
Vol 15 (1) ◽  
pp. 1
Author(s):  
Cristiane Heredia Gomes ◽  
Arthur Pedroso Viçozzi ◽  
Guilherme Pazinato Dias ◽  
Diogo Gabriel Sperandio
Keyword(s):  
Electrical Conductivity ◽  
Clay Mineral ◽  
Human Activities ◽  
Distribution Patterns ◽  
Mineral Weathering ◽  
Statistical Analyses ◽  
Total Alkalinity ◽  
Mineral Deposits ◽  
Geochemical Data ◽  
The Many

 This article presents the first detailed geochemical data of the water from Camaquã das Lavras and Hilário Streams from Lavras do Sul-RS. Geochemical and statistical analyses were used in this study to establish the anthropogenic or natural influence on the region. The results classified the waters as soft and intermediate with acidic and neutral pH. The electrical conductivity varies from 37.2 to 62.9 μs cm-1 and the total alkalinity ranges from 4 to 30 mgL-1. The distribution patterns and ratios indicate that clay mineral weathering is dominant on the investigated samples. It is followed by feldspar weathering in an environment under temporary hardness conditions. Cu, Rh, and Cd enrichment is associated with the many mineral deposits of the region, lithological diversity and human activities. All the measured values conform with the standards set by Brasil-Ordinance nos. 2914/2011, 36-GM/1990 and 1469/2000.

scholarly journals Sedimentological processes and environmental variability at Lake Ohrid (Macedonia, Albania) between 640 ka and present day

2015 ◽  
Vol 12 (17) ◽  
pp. 15111-15156 ◽  
Author(s):  
A. Francke ◽  
B. Wagner ◽  
J. Just ◽  
N. Leicher ◽  
R. Gromig ◽  
...  
Keyword(s):  
Primary Productivity ◽  
Environmental Variability ◽  
Geochemical Data ◽  
Nutrient Concentrations ◽  
Silty Clay ◽  
Lake Ohrid ◽  
Scientific Drilling ◽  
Orbital Parameters ◽  
Tephra Layers ◽  
Deep Site

Abstract. Lake Ohrid (FYROM, Albania) is thought to be more than 1.2 million years old and hosts more than 200 endemic species. As a target of the International Continental Scientific Drilling Program (ICDP), a successful deep drilling campaign was carried out within the scope of the Scientific Collaboration on Past Speciation Conditions in Lake Ohrid (SCOPSCO) project in 2013. Here, we present lithological, sedimentological, and (bio-)geochemical data from the upper 247.8 m of the overall 569 m long DEEP site sediment succession from the central part of the lake. According to an age model, which is based on nine tephra layers (1st order tie points), and on tuning of biogeochemical proxy data to orbital parameters (2nd order tie points) and to the global benthic isotope stack LR04 (3rd order tie points), respectively, the analyzed sediment sequence covers the last 640 ka. The DEEP site sediment succession consists of hemipelagic sediments, which are interspersed by several tephra layers and infrequent, thin (< 5 cm) mass wasting deposits. The hemipelagic sediments can be classified into three different lithotypes. Lithotype 1 and 2 deposits comprise calcareous and slightly calcareous silty clay and are predominantly attributed to interglacial periods with high primary productivity in the lake during summer and reduced mixing during winter. The data suggest that high ion and nutrient concentrations in the lake water promoted calcite precipitation and diatom growth in the epilmnion in during MIS15, 13, and 5. Following a strong primary productivity, highest interglacial temperatures can be reported for MIS11 and 5, whereas MIS15, 13, 9, and 7 were comparable cooler. Lithotype 3 deposits consist of clastic, silty clayey material and predominantly represent glacial periods with low primary productivity during summer and longer and intensified mixing during winter. The data imply that most severe glacial conditions at Lake Ohrid persisted during MIS16, 12, 10, and 6 whereas somewhat warmer temperatures can be inferred for MIS14, 8, 4, and 3. Interglacial-like conditions occurred during parts of MIS14, and 8.

Structuring Situational Information

2015 ◽  
Vol 20 (3) ◽  
pp. 176-189 ◽  
Author(s):  
John F. Rauthmann
Keyword(s):  
Statistical Analyses ◽  
Current Work ◽  
Common Language ◽  
Road Map ◽  
Taxonomic Approach ◽  
Situational Information

Abstract. There is as yet no consensually agreed-upon situational taxonomy. The current work addresses this issue and reviews extant taxonomic approaches by highlighting a “road map” of six research stations that lead to the observed diversity in taxonomies: (1) theoretical and conceptual guidelines, (2) the “type” of situational information studied, (3) the general taxonomic approach taken, (4) the generation of situation pools, (5) the assessment and rating of situational information, and (6) the statistical analyses of situation data. Current situational taxonomies are difficult to integrate because they follow different paths along these six stations. Some suggestions are given on how to spur integrated taxonomies toward a unified psychology of situations that speaks a common language.

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