scholarly journals Greenhouse conditions in lower Eocene coastal wetlands? – Lessons from Schöningen, Northern Germany

2020 ◽  
Author(s):  
Olaf K. Lenz ◽  
Walter Riegel ◽  
Volker Wilde
Keyword(s):  
Coastal Wetland ◽  
Middle Eocene ◽  
Nutrient Deficiency ◽  
Coastal Vegetation ◽  
Temperate Climate ◽  
Mining District ◽  
Northern Germany ◽  
Lower Eocene ◽  
Successional Stages ◽  
Warm Temperate

AbstractThe Paleogene succession of the Helmstedt Lignite Mining District in Northern Germany includes coastal peat mire records from the latest Paleocene to the middle Eocene at the southern edge of the Proto-North Sea. Therefore, it covers the different long- and short-term climate perturbations of the Paleogene greenhouse. 56 samples from three individual sections of a lower Eocene seam in the record capture the typical succession of the vegetation in a coastal wetland during a period that was not affected by climate perturbation. This allows facies-dependent vegetational changes to be distinguished from those that were climate induced. Cluster analyses and NMDS of well-preserved palynomorph assemblages reveal four successional stages in the vegetation during peat accumulation: (1) a coastal vegetation, (2) an initial mire, (3) a transitional mire, and (4) a terminal mire. Biodiversity measures show that plant diversity decreased significantly in the successive stages. The highly diverse vegetation at the coast and in the adjacent initial mire was replaced by low diversity communities adapted to wet acidic environments and nutrient deficiency. The palynomorph assemblages are dominated by elements such as Alnus (Betulaceae) or Sphagnum (Sphagnaceae). Typical tropical elements which are characteristic for the middle Eocene part of the succession are missing. This indicates that a more warm-temperate climate prevailed in northwestern Germany during the early lower Eocene.

scholarly journals Greenhouse conditions in lower Eocene coastal wetlands?—Lessons from Schöningen, Northern Germany

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0232861
Author(s):  
Olaf K. Lenz ◽  
Walter Riegel ◽  
Volker Wilde
Keyword(s):  
Coastal Wetland ◽  
Middle Eocene ◽  
Nutrient Deficiency ◽  
Coastal Vegetation ◽  
Temperate Climate ◽  
Mining District ◽  
Northern Germany ◽  
Lower Eocene ◽  
Successional Stages ◽  
Warm Temperate

The Paleogene succession of the Helmstedt Lignite Mining District in Northern Germany includes coastal peat mire records from the latest Paleocene to the middle Eocene at the southern edge of the Proto-North Sea. Therefore, it covers the different long- and short-term climate perturbations of the Paleogene greenhouse. 56 samples from three individual sections of a lower Eocene seam in the record capture the typical succession of the vegetation in a coastal wetland during a period that was not affected by climate perturbation. This allows facies-dependent vegetational changes to be distinguished from those that were climate induced. Cluster analyses and NMDS of well-preserved palynomorph assemblages reveal four successional stages in the vegetation during peat accumulation: (1) a coastal vegetation, (2) an initial mire, (3) a transitional mire, and (4) a terminal mire. Biodiversity measures show that plant diversity decreased significantly in the successive stages. The highly diverse vegetation at the coast and in the adjacent initial mire was replaced by low diversity communities adapted to wet acidic environments and nutrient deficiency. The palynomorph assemblages are dominated by elements such as Alnus (Betulaceae) or Sphagnum (Sphagnaceae). Typical tropical elements which are characteristic for the middle Eocene part of the succession are missing. This indicates that a more warm-temperate climate prevailed in northwestern Germany during the early lower Eocene.

scholarly journals The recolonisation of volcanically disturbed Eocene habitats of Central Europe: the maar lakes of Messel and Offenthal (SW Germany) compared

2020 ◽  
Vol 100 (4) ◽  
pp. 951-973 ◽  
Author(s):  
Maryam Moshayedi ◽  
Olaf K. Lenz ◽  
Volker Wilde ◽  
Matthias Hinderer
Keyword(s):  
Central Europe ◽  
Middle Eocene ◽  
Recovery Phase ◽  
Lower Eocene ◽  
Clastic Sediments ◽  
Bituminous Shale ◽  
Maar Lake ◽  
Successional Stages ◽  
Disturbed Habitats ◽  
Nmds Analysis

AbstractTo reconstruct the palaeoenvironment and changes within the vegetation, 68 core samples were analysed palynologically from the lacustrine filling of the Eocene maar lake of Offenthal (Hesse, SW Germany). The lacustrine succession includes 16 m of clastic sediments overlain by 13 m of finely laminated bituminous shale. Based on a revised 40Ar/39Ar age of ~ 47.8 ± 0.3 Ma, the lacustrine filling at Offenthal can be dated as uppermost lower Eocene to lowermost middle Eocene which is almost coeval to part of the nearby lacustrine succession at Messel. Cluster and non-metric multidimensional scaling (NMDS) analyses of well-preserved palynomorph assemblages reveal successional stages during the recolonisation of the maar lake and its surroundings which are related to lithological changes. Furthermore, the palynomorph assemblages from Offenthal are compared with assemblages from Messel by NMDS analysis to find similarities and differences during the recolonisation of volcanically disturbed habitats in Central Europe during Paleogene greenhouse conditions. Based on the similar succession in the vegetation at both lakes, four different phases can be distinguished during recolonisation and reestablishment of the vegetation at these sites: (1) an initial phase, (2) a recolonisation phase, (3) a recovery phase, (4) a climax phase.

Paleoecology of Eocene lacustrine varves at Horsefly, British Columbia

1977 ◽  
Vol 14 (5) ◽  
pp. 953-962 ◽  
Author(s):  
M. V. H. Wilson
Keyword(s):  
British Columbia ◽  
Depositional Environment ◽  
Middle Eocene ◽  
Lacustrine Sediments ◽  
Late Summer ◽  
Coarse Grained ◽  
Temperate Climate ◽  
Fish Scales ◽  
Plant Remains ◽  
Warm Temperate

Middle Eocene lacustrine sediments, cropping out in the valley of the Horsefly River, British Columbia, contain abundant fossils of fishes, fish scales, fish coprolites, insects, leaves, and diatoms. The fish scales, insects, and leaves are preserved in at least three sequences of alternating light tuff and dark sapropel laminae, separated stratigraphically by coarse-grained structureless sequences. The proportions of the main types of fossils occurring in the light laminae compared with the dark laminae are significantly different, and are consistent with the hypothesis that the laminations are varves, with dark organic winter laminae and light inorganic summer laminae. Occasional graded sandy layers contain carbonized allochthonous plant remains and represent turbidity deposits caused by storms in the drainage basin.It is proposed here that the varves were deposited in the deeper regions of a stratified, monomictic or meromictic lake in a warm temperate climate. The depositional environment was anaerobic, containing abundant hydrogen sulphide, and was free of turbulence and benthos. Fish were entombed mostly during the winter, insects during the spring and summer, coprolites during the summer, and deciduous leaves during the late summer and autumn. The fish died of starvation and (or) overturn-induced anoxia.

scholarly journals Silicified serpentinite – a residuum of a Tertiary palaeo-weathering surface in the United Arab Emirates

2012 ◽  
Vol 150 (3) ◽  
pp. 385-395 ◽  
Author(s):  
ALICJA M. LACINSKA ◽  
MICHAEL T. STYLES
Keyword(s):  
United Arab Emirates ◽  
Middle Eocene ◽  
Temperate Climate ◽  
Mixing Zone ◽  
Saturated Zone ◽  
Near Surface ◽  
Silica Precipitation ◽  
Surface Mixing ◽  
Ph Conditions ◽  
Mineralizing Fluids

AbstractMineralogical studies of a silicified serpentinite from the United Arab Emirates throw light on the formative processes. The silicified serpentinite is a residuum of a palaeo-weathering surface that probably developed in a temperate climate with alternating wet and dry periods during middle Eocene to late Miocene times. The rock textures indicate that silicification occurred in a fluid-saturated zone. Silica precipitation is favoured at near-neutral pH. In this study we infer that these pH conditions of the mineralizing fluids could arise in a near-surface mixing zone where acidic meteoric and hyperalkaline groundwater fluids are mingled. This mingling is believed to have resulted from alternating processes of evaporation and precipitation that prevailed during dry and wet seasons, respectively. The silicified serpentinite is composed of > 95% quartz and exhibits a ghost texture of the protolith serpentinite. Preservation of the textures indicates an iso-volumetric grain-by-grain replacement by dissolution of Mg-silicate and simultaneous precipitation of either opal or microquartz as siliceous seeds. These were subsequently overgrown by silica that was probably remobilized from deeply weathered regolith elsewhere.

Evaluation of the allergenicity of various types of urban parks in a warm temperate climate zone

Aerobiologia ◽  
2018 ◽  
Vol 35 (1) ◽  
pp. 57-71 ◽  
Author(s):  
I. Kasprzyk ◽  
T. Wójcik ◽  
P. Cariñanos ◽  
K. Borycka ◽  
A. Ćwik
Keyword(s):  
Urban Parks ◽  
Temperate Climate ◽  
Climate Zone ◽  
Warm Temperate ◽  
Temperate Climate Zone

scholarly journals Vegetation and climate from Late Quaternary Thimi Formation (Phaidhoka Section), Bhaktapur, Nepal

2015 ◽  
Vol 50 (1) ◽  
pp. 1-12
Author(s):  
Deepak Banjade ◽  
Kabir Sharma ◽  
Khum N. Paudayal
Keyword(s):  
Late Quaternary ◽  
Middle Part ◽  
Temperate Climate ◽  
Silty Clay ◽  
Pollen Diagram ◽  
Formation Zone ◽  
Palynological Study ◽  
Deltaic Deposit ◽  
Warm Temperate ◽  
Vegetation And Climate

The Thimi Formation is fluvio-deltaic deposit that constitutes the uppermost part of the sedimentary sequence in the Kathmandu Basin, and is featured by carbonaceous and diatomaceous clay, silty clay, silt, fine to medium grained sand beds, and thin to medium lignite beds. The Phaidhoka Section is located on the way to Nala from Chyamasingh, and is one of the major exposures of the Thimi Formation. Forty four samples were collected from 25 m thick surface exposure for palynological study. The study revealed the dominance of gymnosperm over the angiosperm and herbaceous members. The pollen diagram suggested Pinus, Picea and Quercus as the most dominant trees whereas Poaceae is other dominant among the grasses. Three major pollen assemblage zones were marked in the Thimi Formation. Zone P-I indicated warm temperate climate, whereas zone P-II and P-III indicated cold temperate climate. Molluscan operculum in the upper part indicated shallow water condition. The Bovid molars, limb and pelvic bones from the middle part of the section confirm the early findings of molar bones in this area.

Optical properties of traditional clay tiles for ventilated roofs and implication on roof thermal performance

2018 ◽  
Vol 42 (4) ◽  
pp. 484-505 ◽  
Author(s):  
Elisa Di Giuseppe ◽  
Simona Sabbatini ◽  
Nikita Cozzolino ◽  
Pierluigi Stipa ◽  
Marco D’Orazio
Keyword(s):  
Optical Properties ◽  
Thermal Performance ◽  
Temperate Climate ◽  
Second Phase ◽  
Analysis Tool ◽  
Urban Heat ◽  
Indoor Comfort ◽  
The Impact ◽  
Clay Tiles ◽  
Warm Temperate

A remarkable advantage of clay tiles roof coverings in hot climates is the realization of a ventilated air layer between them and the roofing underlay that allows a natural and forced convection through the tiles joints and the channel from eaves to ridge, thus cooling the roof materials. However recently, in many countries, regulatory developments on buildings energy efficiency or buildings sustainability certification protocols are increasingly encouraging the use of alternative strategies, with the aim of reducing the urban heat island (UHI) effect and the buildings’ cooling consumptions. Among them, the use of ‘cool’ materials for roof covering. These mandatory or voluntary measures de facto push the construction products market towards specific directions, risking penalizing traditional components such as clay tiles. This article reports the results of experimental and numerical activities carried out in order to extensively characterize the optical properties of clay tile materials and investigate their impact, also coupled with above sheathing ventilation, on the thermal performance of a ventilated roof under warm-temperate climate. In the first phase of the research, the main optical properties of over 30 different clay products have been experimentally characterized in order to get a clear and extensive picture of such properties for the materials spread in the market. In a second phase, starting from the thermal data collected on an experimental real-scale building, a dynamic energy analysis tool was calibrated and used to perform simulations by varying the optical properties of the roof covering thus assessing the impact on the roof temperatures, also in comparison to a clay tiles roof. The results underline that the use of the above sheathing ventilation obtained through clay tiles is an effective strategy to reduce roof temperatures, even if covering materials are not qualified as ‘cool’, thus impacting on both UHI and indoor comfort.

scholarly journals Evaluation of two earth–air heat exchangers efficiency of different pipe materials within a warm temperate climate

2020 ◽  
Vol 307 ◽  
pp. 01028
Author(s):  
Mohammed Cherif LEKHAL ◽  
Abderahmane Mejedoub MOKHTARI ◽  
Rafik BELARBI
Keyword(s):  
Energy Performance ◽  
Temperate Climate ◽  
Airflow Rate ◽  
Outlet Temperature ◽  
Pipe Material ◽  
Cooling Mode ◽  
The North ◽  
Heating And Cooling ◽  
Principal Factors ◽  
Warm Temperate

The Earth-Air Heat Exchanger (EAHE) system was used for many years for both primary heating and cooling applications, especially in the building sector. Its energy performance can be influenced by three principal factors: the EAHE pipe material, the airflow rate, the soil characteristics and the moisture content. The state of the art shows a divergence about the effect of the pipe material on the performance of the EAHE. The aim of this study is to provide an adequate response to this problematic based on experimental analysis. In this regard, we tested two EAHEX of different materials: PVC and Zinc. The comparative study was conducted under a warm temperate climate in the north of Algeria. The data analyses showed that the pipe material can significantly affect the EAHE performance during periods when the EAHE passes from heating to cooling mode. Furthermore, the air outlet temperature differences provided by EAHE Zinc and those of PVC up to about 7.5°C.

scholarly journals Technical Note: Comparing and ranking soil drought indices performance over Europe, through remote-sensing of vegetation

2010 ◽  
Vol 14 (2) ◽  
pp. 271-277 ◽  
Author(s):  
E. Peled ◽  
E. Dutra ◽  
P. Viterbo ◽  
A. Angert
Keyword(s):  
Soil Moisture ◽  
Drought Index ◽  
Technical Note ◽  
Temperate Climate ◽  
Drought Indices ◽  
Soil Drought ◽  
The Past ◽  
Analysis Technique ◽  
Global Soil ◽  
Warm Temperate

Abstract. In the past years there have been many attempts to produce and improve global soil-moisture datasets and drought indices. However, comparing and validating these various datasets is not straightforward. Here, interannual variations in drought indices are compared to interannual changes in vegetation, as captured by NDVI. By comparing the correlations of the different indices with NDVI we evaluated which drought index describes most realistically the actual changes in vegetation. Strong correlation between NDVI and the drought indices were found in areas that are classified as warm temperate climate with hot or warm dry summers. In these areas we ranked the PDSI, PSDI-SC, SPI3, and NSM indices, based on the interannual correlation with NDVI, and found that NSM outperformed the rest. Using this best performing index, and the ICA (Independent Component Analysis) technique, we analyzed the response of vegetation to temperature and soil-moisture stresses over Europe.

Tectono-sedimentary evolution of a fore-chain domain : example of the Habt and Sidi Mrayt basins, northwestern external Moroccan Rif ; stratigraphic precisions and tectonic modelling

2004 ◽  
Vol 175 (4) ◽  
pp. 383-397 ◽  
Author(s):  
Abdelali Zakir ◽  
Ahmed Chalouan ◽  
Hugues Feinberg
Keyword(s):  
Upper Cretaceous ◽  
Middle Miocene ◽  
Middle Eocene ◽  
Fault Propagation ◽  
Lower Eocene ◽  
Structural Trend ◽  
Sedimentary Evolution ◽  
Structural Relationships ◽  
Regional Tectonic ◽  
Ridge Structures

Abstract In this paper, a tecto-sedimentary evolution model of the northwestern external Rif zones (Morocco) is proposed. It is based on the study of structural relationships and the biostratigraphic and sedimentologic analysis of different Tertiary syn-tectonic units. This zone shows alternating foredeep basins and anticlinal ramps with a NNW-SSE structural trend and a vergence toward the WSW. The trend of turbiditic bodies and palaeocurrent directions (from the SSE to the NNW) are parallel to the regional tectonic strike. Sidi Mrayt and El Habt basins are filled with syn-tectonic middle Eocene to middle Miocene sediments; The Habt basin is subdivided in two sub-basins: Asilah-Larache and Rirha-Gzoula. The deposits are distributed in two separated turbiditic complex, each one including a stacking of turbiditic systems. The Rirha-Gzoula and Asilah-Larache sub-basins are located in front of two anticline ridge structures made up of Upper Cretaceous and Lower Eocene material; they are respectively Boujediane and Arbaa Ayacha anticlines. The distribution of turbiditic bodies, unconformities and structural relationships within the thrusts and folds system in the northwestern external Rif indicate the progression toward the external zones of fault-propagation folds and associated basins.

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