scholarly journals The Eemian/Early Vistulian development of the Solniki paleolake (north-eastern Poland) as shown by subfossil Cladocera

2016 ◽  
Vol 7 (2) ◽  
Author(s):  
Monika Magdalena Niska
Keyword(s):  
Water Temperature ◽  
Water Level ◽  
Subfossil Cladocera ◽  
Climate Fluctuations ◽  
State Of Water ◽  
North Eastern ◽  
Alona Affinis ◽  
Geological Map ◽  
Abundance And Diversity ◽  
Eemian Interglacial

<p>This work presents results of a paleolimnological study focussed on subfossil Cladocera analysis and on different aspects of the evolution of the Solniki paleolake during the Eemian/Early Vistulian period. The study aimed at the reconstruction of the long-term dynamics of this paleoecosystem and at defining the conditions (<em>e.g</em>., water level, trophic status and water temperature) of the ancient lake. Paleolacustrine deposits of ca. 10 m thickness were discovered at Solniki during cartographic works for the Trześcianka sheet of the Detailed Geological Map of Poland. This archives recorded one full-interglacial sequence (Eemian Interglacial), one interstadial warming (Brørup) and two stadial coolings (Herning and Rederstall) stages, which were confirmed by palynological analyses. The subfossil Cladocera fauna from the Solniki paleolake consisted in 17 species belonging to the families Bosminidae, Chydoridae, Sididae and Daphniidae. Littoral species were dominant (52%), the most frequent of which were <em>Alona affinis</em> and <em>Camptocercus rectirostris</em>. The most abundance pelagic species were <em>Eubosmina coregoni</em> and <em>Bosmina longirostris</em>. The sediment species composition was quite similar to that of contemporary Central European lakes. The early and the late stages of Eemian Interglacial were likely the most favourable periods for the Cladocera development in the paleolake, in relation to higher water level, moderate water temperature and the mesotrophic state of water. A further ecologically favourable period was the Brørup Interstadial. The highest species richness, abundance, and diversity during the whole paleolake existence were recorded during these three periods. Surprisingly, the middle of the Middle Eemian Interglacial climate optimum appeared as an unfavourable period for the Cladocera growth as it was associated with decreasing water level and pronounced climate fluctuations. This sequence was also recorded by other studies of Eemian lakes in Central Europe.</p>

Explanatory notes to the Geological map of Greenland, 1:500 000, Humboldt Gletscher, Sheet 6

2004 ◽  
pp. 1-48
Author(s):  
Peter R. Dawes
Keyword(s):  
Coarse Grained ◽  
Mobile Belt ◽  
Nares Strait ◽  
General Terms ◽  
Mineral Occurrence ◽  
North Eastern ◽  
Copper Gold ◽  
High Grade Metamorphism ◽  
Geological Map ◽  
Map Series

NOTE: This Map Description was published in a former series of GEUS Bulletin. Please use the original series name when citing this series, for example: Dawes, P. R. (2004). Explanatory notes to the Geological map of Greenland, 1:500 000, Humboldt Gletscher, Sheet 6. Geological Survey of Denmark and Greenland Map Series 1, 48 pp. + map. https://doi.org/10.34194/geusm.v1.4615  _______________ These explanatory notes cover the map region bounded by latitudes 78°N and 81°N and longitudes 56°W and 74°W, with geology shown on the land areas between Nares Strait - the seaway between Greenland and Ellesmere Island, Canada - and the Inland Ice. The bedrock geology is composed of Precambrian and Lower Palaeozoic provinces that continue across Nares Strait into Canada. Map units and mineral occurrences are described in general terms and are proceeded by sections on physical environment, logistics, data sources and geoscientific research. The notes are aimed at the practical user and a guide for further reading. The bedrock is composed of three provinces separated by unconformities, each representing a hiatus of c. 500 Ma during which basic dykes were emplaced. The Palaeoproterozoic Inglefield mobile belt, forming the crystalline shield, is an E-W-trending belt of deposition and orogeny characterised by polyphase magmatism, deformation and high-grade metamorphism. Clastic deposition, with magmatism at c. 1985 Ma, are the oldest events recorded, followed by the accumulation of the Etah Group (carbonate, pelitic and psammitic sediments with supposedly coeval mafic and ultramafic rocks) between 1980 and 1950 Ma ago. These rocks were intruded 1950 to 1915 Ma ago by the Etah meta-igneous complex, that records polyphase plutonism (intermediate to felsic, with some basic and magnetite-rich rocks), followed by deformation and partial melting producing granites 1785 to 1740 Ma ago. The Mesoproterozoic Thule Basin, defined by the unmetamorphosed and little deformed Thule Supergroup, records sedimentation and basaltic volcanism at least as old as 1270 Ma. The faulted, north-eastern basin margin shown on the map preserves the passage from the basinal sequence to a relatively thin platform succession invaded by basic sills. The Palaeozoic Franklinian Basin is represented by a homoclinal Cambrian to Silurian shelf carbonate succession and a major Silurian reef complex, with coeval siliciclastic slope deposits. The map region includes the classical area for Franklinian stratigraphy, now composed of 29 formations and four groups - Ryder Gletscher, Morris Bugt, Washington Land and Peary Land Groups. The only younger units preserved in the map region are widespread Quaternary deposits, an isolated outcrop of coarse-grained fluvial deposits (Bjørnehiet Formation) and non-carbonised wood erratics of Neogene age. Five mineral occurrence types are shown on the map: in lithologies of the Inglefield mobile belt, sulphide-graphite rust zones, a magnetite deposit and copper-gold mineralisation and in the Franklinian Basin, commercially drilled, zinc-lead-silver and zinc-lead-barium mineralisations. The basic ingredients of a petroleum model exist in the Franklinian Basin but prospectivity is low.

scholarly journals Responses of Benthic Macroinvertebrate Communities of Two Tropical, High-Mountain Lakes to Climate Change and Deacidification

Diversity ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 243
Author(s):  
Javier Alcocer ◽  
Luis A. Oseguera ◽  
Diana Ibarra-Morales ◽  
Elva Escobar ◽  
Lucero García-Cid
Keyword(s):  
Climate Change ◽  
Species Richness ◽  
Water Temperature ◽  
Water Level ◽  
Environmental Changes ◽  
Mountain Lakes ◽  
High Mountain ◽  
Macroinvertebrate Communities ◽  
High Mountain Lakes ◽  
La Luna

High-mountain lakes are among the most comparable ecosystems globally and recognized sentinels of global change. The present study pursued to identify how the benthic macroinvertebrates (BMI) communities of two tropical, high mountain lakes, El Sol and La Luna, Central Mexico, have been affected by global/regional environmental pressures. We compared the environmental characteristics and the BMI communities between 2000–2001 and 2017–2018. We identified three principal environmental changes (the air and water temperature increased, the lakes’ water level declined, and the pH augmented and became more variable), and four principal ecological changes in the BMI communities [a species richness reduction (7 to 4), a composition change, and a dominant species replacement all of them in Lake El Sol, a species richness increase (2 to 4) in Lake La Luna, and a drastic reduction in density (38% and 90%) and biomass (92%) in both lakes]. The air and water temperature increased 0.5 °C, and lakes water level declined 1.5 m, all suggesting an outcome of climate change. Contrarily to the expected acidification associated with acid precipitation, both lakes deacidified, and the annual pH fluctuation augmented. The causes of the deacidification and the deleterious impacts on the BMI communities remained to be identified.

Changing food habits of Macquarie perch, Macquaria australasica Cuvier (Pisces : Percichthyidae), during the initial filling phase of Lake Dartmouth, Victoria

1986 ◽  
Vol 37 (5) ◽  
pp. 647 ◽  
Author(s):  
PL Cadwallader ◽  
J Douglas
Keyword(s):  
Water Level ◽  
Food Supply ◽  
Food Habits ◽  
North Eastern ◽  
Riverine Habitat ◽  
Filling Phase

The composition of the diet of Macquarie perch changed markedly during the various stages of rising and falling water-level during the initial filling phase of Lake Dartmouth, an impoundment formed by the construction of Dartmouth Dam on the Mitta Mitta River in north-eastern Victoria. Macquarie perch fed on typical river-dwelling organisms from inflowing rivers, on terrestrial organisms that became displaced as the water-level rose, and on typical still-water or sluggish-water organisms, which were extremely abundant in the newly created lake. The relative proportions of several of these food types in the diet varied depending on whether the water-level was rising or falling. Macquarie perch appear to have adapted well to the changing food supply in the lake, and have included in their diet several food types that they would not normally have encountered in their natural riverine habitat.

scholarly journals Is hydrotectonics influencing the thermal spring in Eisensteinhöhle (Bad Fischau, Lower Austria)?

2019 ◽  
Vol 112 (2) ◽  
pp. 166-181
Author(s):  
Jonas Hardege ◽  
Lukas Plan ◽  
Gerhard Winkler ◽  
Bernhard Grasemann ◽  
Ivo Baroň
Keyword(s):  
Water Temperature ◽  
Water Level ◽  
Pumping Test ◽  
Normal Faults ◽  
Central Basin ◽  
Sandy Bottom ◽  
Vienna Basin ◽  
High Resolution Data ◽  
Western Margin ◽  
Groundwater Levels

AbstractEisensteinhöhle is a 2 km long crevice cave that is significantly overprinted by hydrothermal karst processes. It was opened during quarrying in the Fischauer Vorberge, at the western margin of the Vienna Basin. This pull-apart basin cuts the eastern foothills of the Alps and is formed by a major NE-SW striking, sinistral transform fault. The western margin consists of NNE-SSW striking normal faults creating paths for thermal water to rise from the central basin. The deepest part of the cave, 73 m below the entrance, hosts a pond with 14.6 ±0.2 °C warm water that occasionally acts as a spring. The water level and temperature fluctuate and at a certain level, water visibly discharges into a nearby narrow fissure. As sporadic observations of the water level since 1992 gave no obvious connection to precipitation events, the connection to an aquifer and the origin of the water remained unknown. A pumping test, conducted on 13/7/2016, yielded a volume of the spring/pool of about 2.8 m3 that is fed by a very small inlet at the sandy bottom. At the time of the pumping test, the discharge was only 4.5 l/h but during previous overflow events, discharge values of up to 289 l/h were recorded.Water temperature and hydrochemistry hint towards a mixture of an old thermal component and a young meteoric component. During continuous monitoring of water level and temperature from October 2015 until November 2018, the water level was almost stable with few periods of high level (almost at overflow) that lasted for about 3 to 4 weeks each. The water temperature increased during most high stands and is positively correlated with the water level. Correlation of the high-resolution data on water level and temperature fluctuations with precipitation measurements at the nearest meteorological stations show a relation of water level to certain rainfall events and the sporadically taken long time records show a correlation with annual precipitation sums. Long-term observations also indicate a connection to groundwater levels in the Vienna Basin with a delay of about 8 weeks in Bad Fischau. In July 2017, the water level dropped suddenly and then recovered simultaneously in the time of several weak earthquakes in the vicinity. The data suggest that the spring in Eisensteinhöhle is influenced by precipitation. For one seismic event, there is a correlation with unusual water level changes at Eisensteinhöhle, but the rareness of earthquakes demands for a longer time series to confirm this observation.

scholarly journals Karst hydrogeology of Lamprechtsofen (Leoganger Steinberge, Salzburg)

2019 ◽  
Vol 112 (1) ◽  
pp. 50-61 ◽  
Author(s):  
Katharina Gröbner ◽  
Wolfgang Gadermayr ◽  
Giorgio Höfer-Öllinger ◽  
Harald Huemer ◽  
Christoph Spötl
Keyword(s):  
Electrical Conductivity ◽  
Water Temperature ◽  
Water Level ◽  
Stream Water ◽  
Tracer Tests ◽  
Karst Water ◽  
Stream Flows ◽  
Surface Precipitation ◽  
Mineralized Water ◽  
Show Cave

AbstractThe Leoganger Steinberge are a heavily karstified massif largely composed of Dachstein dolomite and limestone hosting the deepest through-trip cave in the world, Lamprechtsofen, whose frontal parts are developed as a show cave. Many parts of this 60 km-long and 1724 m-deep system are hydrologically active. 1.5 km behind the lower cave entrance Grüntopf stream and Kneippklamm stream merge to form the main cave stream. Another underground stream, Stainerhallen stream, flows through the eponymous hall of the show cave. Since 2007 water temperature, electrical conductivity and water level have been monitored in the Grüntopf and Kneippklamm stream. Water temperature and water level in the Stainerhallen and main cave stream have been measured since 2016.The long-term dataset (2013–2017) shows that the water temperature of the cave streams (Grüntopf stream: 3.7–5.2°C; Kneippklamm stream: 5.1–5.9°C) is largely invariant, but the electrical conductivity varies strongly (Grüntopf stream: 107–210 µS/cm; Kneippklamm stream: 131–248 µS/cm) in response to snowmelt and precipitation events. The event water of the Kneippklamm stream is characterized by a low electrical conductivity and is then followed by slightly warmer and higher mineralized water derived from the phreatic zone. This dual flow pattern also explains the asymmetrical changes of the water level during snowmelt: the fast event water flows directly through vadose pathways to the measurement site, whereas the hydraulic (phreatic) response is delayed. The Grüntopf stream reacts to precipitation and snowmelt events by changes in the karst-water table, which can be explained by a piston flow-model. The Kneippklamm stream reveals evidence of a lifter system.The altitude of the catchments was calculated using δ18O values of water samples from the underground streams and from surface precipitation. The Grüntopf stream shows the highest mean catchment (2280 m a.s.l.), which is in agreement with its daily fluctuations of the water level until August caused by long-lasting snowmelt. The Stainerhallen stream has the lowest catchment (average 1400 m a.s.l.). The catchments of the other two streams are at intermediate elevations (1770–1920 m a.s.l.). The integration of the catchment analyses and observations from tracer tests conducted in the 1970s showed that the latter reflected only one aspect of the karst water regime in this massif. During times of high recharge the water level rises, new flow paths are activated and the karst watershed shifts.

scholarly journals Determination of diurnal water level fluctuations in headwaters

2016 ◽  
Vol 47 (4) ◽  
pp. 888-901 ◽  
Author(s):  
Marek Marciniak ◽  
Anna Szczucińska
Keyword(s):  
Water Temperature ◽  
Water Level ◽  
Air Temperature ◽  
Hyporheic Zone ◽  
Water Pressure ◽  
Water Levels ◽  
Water Level Fluctuations ◽  
Diurnal Changes ◽  
Atmospheric Conditions ◽  
Diurnal Fluctuations

The aim of this paper is to study diurnal fluctuations of the water level in streams draining headwaters and to identify the controlling factors. The fieldwork was carried out in the Gryżynka River catchment, western Poland. The water levels of three streams draining into the headwaters via a group of springs were monitored in the years 2011–2014. Changes in the water pressure and water temperature were recorded by automatic sensors – Schlumberger MiniDiver type. Simultaneously, Barodiver type sensors were used to record air temperature and atmospheric pressure, as it was necessary to adjust the data collected by the MiniDivers calculate the water level. The results showed that diurnal fluctuations in water level of the streams ranged from 2 to 4 cm (approximately 10% of total water depth) and were well correlated with the changes in evapotranspiration as well as air temperature. The observed water level fluctuations likely have resulted from processes occurring in the headwaters. Good correlation with atmospheric conditions indicates control by daily variations of the local climate. However, the relationship with water temperature suggests that fluctuations are also caused by changes in the temperature-dependent water viscosity and, consequently, by diurnal changes in the hydraulic conductivity of the hyporheic zone.

The Influence of Proximity of Plantation Edge on Diversity and Abundance of bird species in an exotic pine plantation in north-eastern New South Wales

1991 ◽  
Vol 18 (3) ◽  
pp. 299 ◽  
Author(s):  
GN Curry
Keyword(s):  
New South ◽  
Structural Characteristics ◽  
New South Wales ◽  
Bird Species ◽  
Native Forest ◽  
Feeding Guild ◽  
South Wales ◽  
North Eastern ◽  
Plantation Life ◽  
Abundance And Diversity

Data were collected in summer and winter in a 15-year-old plantation of Pinus taeda, at Clouds Creek, north-eastern New South Wales. In summer, diversity and abundance of bird species declined over a distance of 900 m into the plantation. However, in winter this progressive decline in bird densities was limited to within the first 200 m of the plantation periphery. At greater distances into the plantation, the floristic and structural characteristics of the vegetation (including windrows) were of more importance than the proximity of the plantation edge in accounting for variations in the abundance and diversity of birds. Food for insectivorous birds (the dominant feeding guild) is probably restricted in the plantation because few local species of invertebrates are likely to be adapted to living on exotic pines; invertebrate mobility as well as abundance is probably less in winter, so that fewer invertebrates enter the plantation from adjacent native forest. Windrows are an important habitat feature contributing to the diversity and abundance of birds within plantations, probably serving as 'corridors' through the alien habitat of exotic pines, thus enabling birds to range further into plantations. For approximately 40 per cent of the plantation life cycle, the influence of proximity of plantation edge on diversity and abundance of bird species is probably of limited importance, particularly in winter. Reducing plantation size in order to increase the diversity and abundance of bird species is not realistic, because plantations would have to be very small. Instead, emphasis should be placed on increasing the structural and floristic diversity of plantations by creating a broad range of successional stages throughout the plantation complex, by enhancing the habitat value of windrows, and by retaining native vegetation within and near plantations.

Distributional and demographic consequences of Pleistocene climate fluctuations for a marine demersal fish in the north-eastern Atlantic

2009 ◽  
Vol 36 (6) ◽  
pp. 1138-1151 ◽  
Author(s):  
Maarten H. D. Larmuseau ◽  
Jeroen K. J. Van Houdt ◽  
Jef Guelinckx ◽  
Bart Hellemans ◽  
Filip A. M. Volckaert
Keyword(s):  
Demersal Fish ◽  
Climate Fluctuations ◽  
The North ◽  
Pleistocene Climate ◽  
North Eastern

Use by small mammals of a chronosequence of tropical rainforest revegetation

2014 ◽  
Vol 41 (3) ◽  
pp. 233 ◽  
Author(s):  
Tegan Whitehead ◽  
Miriam Goosem ◽  
Noel D. Preece
Keyword(s):  
Community Composition ◽  
Small Mammals ◽  
Small Mammal ◽  
Tropical Rainforest ◽  
Management Technique ◽  
Population Declines ◽  
North Eastern ◽  
Small Mammal Community ◽  
Mammal Community ◽  
Abundance And Diversity

Context The conversion of tropical rainforest to grazing pasture results in a drastic change in small-mammal community composition. Restoring the landscape through ecological revegetation is thus an increasingly important management technique to conserve rainforest mammals. Aims This study aimed to determine the habitat ages at which species of small mammals recolonised revegetated habitats on the southern Atherton Tablelands, north-eastern Queensland, Australia. We focussed on changes in rainforest mammal abundance and diversity with increasing habitat age. Methods Small-mammal trapping and mark–recapture techniques investigated mammal diversity, abundance and community composition within remnant rainforest, three age classes of ecological revegetation and abandoned grazing pasture. Key results Small-mammal community composition differed between remnant rainforest and abandoned grazing pasture. The pasture and 3-year old revegetated sites were similar in composition, both lacking rainforest small mammals. Six- and 7-year old revegetation plantings provided suboptimal habitat for both rainforest and grassland mammals, whereas 16- and 22-year old revegetated habitats were dominated by rainforest species, with some individuals being frequently recaptured. Conclusions As revegetated habitats aged, the small-mammal community composition transitioned from a grassland-like composition to a community dominated by rainforest species. Implications Although rainforest small mammals were very occasionally captured within the 6- and 7-year old habitats, revegetated plantings were not dominated by rainforest species until the habitat was 16 years old. This highlights the importance of commencing revegetation as early as possible to minimise future population declines and maximise the conservation of rainforest mammals.

The quaternary deposits of central Leicestershire

1968 ◽  
Vol 262 (1131) ◽  
pp. 459-509 ◽  
Keyword(s):  
Surface Expression ◽  
Normal Faults ◽  
Quaternary Deposits ◽  
River Terraces ◽  
North Eastern ◽  
Local Equivalent ◽  
Sand And Gravel ◽  
Weichselian Glaciation ◽  
Eemian Interglacial ◽  
North Western

A programme of mapping and augering has shown the glacial drifts of central Leicestershire to consist of a basal sand and gravel overlain by a complex succession of tills and interbedded waterlaid sediments. The tills display a transition from materials of predominantly north-western derivation to those of north-eastern derivation. Arguments are adduced by which the succession is correlated with that described by Shotton in Warwickshire, and it is concluded that the vast majority of the drifts belong to the Saalian glaciation. A widespread but discontinuous horizon of sand and gravel is believed to denote a temporary melt phase in the middle of the glaciation, while more limited beds of stoneless silt and clay betoken still-water sedimentation which, south of Leicester, is regarded as the local equivalent of the lacustrine Wolston clay of Warwickshire. Although the bedrock surface over most of central Leicestershire has a form consistent with an origin by normal stream erosion, there remain a number of areas where it is difficult to sustain such an interpretation. At Narborough excavations and augering have revealed virtually the full drift succession cut by a series of normal faults traceable over a distance of at least a mile. Near these faults there is evidence of an enclosed depression scored into bedrock and filled with water-laid drift. Although subsequent to the deposition of the drift, the faults have no surface expression at the present time, the structures being truncated by an early post-glacial erosion surface. Later phases in the post-glacial evolution of the Soar and Wreak valleys are associated with a suite of river terraces which, from their included fauna, span the period of the Eemian interglacial and the Weichselian glaciation.

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