scholarly journals Holocene development of the Arresø area, north-east Sjælland, Denmark.

2017 ◽  
Vol 65 ◽  
pp. 25-35
Author(s):  
Ole Bennike ◽  
Pernille Pantmann ◽  
Esben Aarsleff
Keyword(s):  
Fresh Water ◽  
Brackish Water ◽  
Water Phase ◽  
Ostrea Edulis ◽  
Land Area ◽  
Marine Fauna ◽  
North East ◽  
Acidic Waters ◽  
Area North ◽  
Alkaline Waters

The Arresø area in north-east Sjælland, Denmark, was deglaciated about 18,000 to 16,000 years ago. In the Holocene it was probably a land area until it was transgressed by the sea c. 8500 years BP. During a first marine phase the area housed a species-rich marine fauna that included the oyster Ostrea edulis, the salinity and water temperatures were higher than at present, and there was a wide connection to the Kattegat sea. At about 6500 years BP there was a short-lived lake or brackish-water phase, but marine conditions were soon re-established with a fauna less diverse than before, and both salinity and water temperatures decreased. The present lake Arresø became isolated from the sea about 2500 years BP. The transition from brackish water to fresh water was rapid; the lake developed from shallow alkaline waters to deeper more acidic waters and finally to eutrophic waters.

scholarly journals Transitional fishery: a new resource for global nutritional food and medicinal security

2021 ◽  
Vol 10 (1) ◽  
pp. 26-31
Author(s):  
RC Yadav
Keyword(s):  
Fresh Water ◽  
Brackish Water ◽  
Scientific Management ◽  
Aquatic Birds ◽  
Water Stream ◽  
Study Objective ◽  
Marine Fishery ◽  
North East ◽  
Bird Droppings ◽  
Biological Nitrogen

Sea and river junctions form lagoon, sites become largely marshy land with fresh water at upper approaching river reach and brackish water towards sea. Such bays are plentiful in numbers and visited by aquatic birds during the winter seasons. Previous studies established vast possibility of harvesting biological nitrogen (N) and phosphorus (P) through aquatic bird droppings viz Guano. The vast sizes and number of such sites have huge potential for fishery with differing in quality characters which is termed as transitional fishery in the present study. Objective of the present study was to bring impetus in this new category of fishery with scientific management so as to make the venture highly efficient and responsive, and enable harnessing plentiful benefits of nutritional food and medicinal security. The transitional fishery was considered as ecosystems and various networks of ecology of land, vegetation, fish and aquatic birds were brought in a band for managing it in new pattern. Ecological lessons were hypothesized and validated by results on fishery on lagoons available in literatures. First innovative lesson was that fish adopt site in North East direction of fresh water stream, as also corroborated by honey bee comb sites on N-E side of any circular water tank’s supporting posts. The second innovative fact was to transformed terrestrial land as sites for growing highly palatable nitrogen rich organic feed for fishery. Thus, colonization and feeding become conclusive approach, as supported by past researches, as guide to fishery scientist to move steps ahead in harnessing productivity of lagoons. Thus, fresh and marine brackish water transition zones become vast resources for countries to derive prosperity and employment generations. The innovative fishery feed will be usable for other types of fisheries ie fresh water fishery as well as marine fishery.

The Archaean Atâ intrusive complex (Atâ tonalite), north-east Disko Bugt, West Greenland

1999 ◽  
pp. 103-112
Author(s):  
Feiko Kalsbeek ◽  
Lilian Skjernaa
Keyword(s):  
Intrusive Complex ◽  
The South ◽  
Original Series ◽  
Early Proterozoic ◽  
West Greenland ◽  
North East ◽  
The North ◽  
Southern Border ◽  
Area North ◽  
Igneous Layering

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Kalsbeek, F., & Skjernaa, L. (1999). The Archaean Atâ intrusive complex (Atâ tonalite), north-east Disko Bugt, West Greenland. Geology of Greenland Survey Bulletin, 181, 103-112. https://doi.org/10.34194/ggub.v181.5118 _______________ The 2800 Ma Atâ intrusive complex (elsewhere referred to as ‘Atâ granite’ or ‘Atâ tonalite’), which occupies an area of c. 400 km2 in the area north-east of Disko Bugt, was emplaced into grey migmatitic gneisses and supracrustal rocks. At its southern border the Atâ complex is cut by younger granites. The complex is divided by a belt of supracrustal rocks into a western, mainly tonalitic part, and an eastern part consisting mainly of granodiorite and trondhjemite. The ‘eastern complex’ is a classical pluton. It is little deformed in its central part, displaying well-preserved igneous layering and local orbicular textures. Near its intrusive contact with the overlying supracrustal rocks the rocks become foliated, with foliation parallel to the contact. The Atâ intrusive complex has escaped much of the later Archaean and early Proterozoic deformation and metamorphism that characterises the gneisses to the north and to the south; it belongs to the best-preserved Archaean tonalite-trondhjemite-granodiorite intrusions in Greenland.

Stratigraphy, structure and geochemistry of Archaean supracrustal rocks from Oqaatsut and Naajaat Qaqqaat, north-east Disko Bugt, West Greenland

1999 ◽  
pp. 65-78
Author(s):  
Henrik Rasmussen ◽  
Lars Frimodt Pedersen
Keyword(s):  
Tectonic Setting ◽  
Trace Element Geochemistry ◽  
Element Geochemistry ◽  
West Greenland ◽  
North West ◽  
North East ◽  
Metavolcanic Rocks ◽  
Arc Setting ◽  
Area North ◽  
Back Arc

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Rasmussen, H., & Frimodt Pedersen, L. (1999). Stratigraphy, structure and geochemistry of Archaean supracrustal rocks from Oqaatsut and Naajaat Qaqqaat, north-east Disko Bugt, West Greenland. Geology of Greenland Survey Bulletin, 181, 65-78. https://doi.org/10.34194/ggub.v181.5114 _______________ Two Archaean supracrustal sequences in the area north-east of Disko Bugt, c. 1950 and c. 800 m in thickness, are dominated by pelitic and semipelitic mica schists, interlayered with basic metavolcanic rocks. A polymict conglomerate occurs locally at the base of one of the sequences. One of the supracrustal sequences has undergone four phases of deformation; the other three phases. In both sequences an early phase, now represented by isoclinal folds, was followed by north-west-directed thrusting. A penetrative deformation represented by upright to steeply inclined folds is only recognised in one of the sequences. Steep, brittle N–S and NW–SE striking faults transect all rock units including late stage dolerites and lamprophyres. Investigation of major- and trace-element geochemistry based on discrimination diagrams for tectonic setting suggests that both metasediments and metavolcanic rocks were deposited in an environment similar to a modern back-arc setting.

scholarly journals Content of inorganic solutes in lettuce grown with brackish water in different hydroponic systems

2017 ◽  
Vol 21 (3) ◽  
pp. 150-155 ◽  
Author(s):  
Alide M. W. Cova ◽  
Fabio T. O. de Freitas ◽  
Paula C. Viana ◽  
Maria R. S. Rafael ◽  
André D. de Azevedo Neto ◽  
...  
Keyword(s):  
Fresh Water ◽  
Nutrient Solution ◽  
Brackish Water ◽  
Dry Matter ◽  
Dry Matter Production ◽  
Matter Production ◽  
Water Plant ◽  
Hydroponic Systems ◽  
Inorganic Solutes

ABSTRACT The objective of this study was to evaluate the growth and accumulation of ions in lettuce grown in different hydroponic systems and recirculation frequencies. The experimental design was randomized blocks with 8 treatments and 4 replicates. The evaluated hydroponic systems were Nutrient Flow Technique (NFT) and an adapted Deep Flow Technique (DFT), the latter with recirculation frequencies of 0.25, 2 and 4 h. Both systems used fresh water and brackish water. Plant growth, accumulation of inorganic solutes (Na+, K+, Cl- and NO3-) and the correlation between dry matter production and Na+/K+ and Cl-/NO3- were evaluated. The salinity of the water used to prepare the nutrient solution caused decrease in growth and K+ and NO3- levels, and increased contents of Na+ and Cl- in the plants. When using fresh water the highest dry matter production was obtained in the NFT system. In case of brackish water the adapted DFT system increased the production, in relation to NFT system (at same recirculation frequency: 0.25 h). It was found that the choice of the type of hydroponic system and recirculation interval for the cultivation of lettuce depends on the quality of the water used to prepare the nutrient solution.

2. Communication relative to the Fresh-Water Limestone of Burdiehouse, near Edinburgh, belonging to the Carboniferous Group of Rocks

1845 ◽  
Vol 1 ◽  
pp. 33-35 ◽  
Author(s):  
Hibbert
Keyword(s):  
Fresh Water ◽  
Marine Origin ◽  
North East ◽  
South West ◽  
Water Origin ◽  
The Common ◽  
Firth Of Forth ◽  
Carboniferous Limestone

In his paper, the author explains that the limestone in question, which is confounded with the common carboniferous or mountain limestone of marine origin, is, in his opinion, of fresh-water origin.On an irregular line extending from Joppa on the coast of the Firth of Forth, in a south and south-west direction to the Pentland Hills, strata of mountain or carboniferous limestone crop out at intervals; and their marine origin is indicated by encrinites, the Productus, &c., and corallines. This limestone is developed with least interruption between Edmonstone and Muirhouse, where it is from twelve to twenty feet thick. At this part of the line may be seen fractures and elevations of the strata of limestone and superincumbent shale and sandstone, evidently occasioned by a sudden and violent uplifting force acting from north-east to south-west, and causing the uplifted strata to dip south-east at an angle of 25°. These uplifted beds, between Edmonstone and Muirhouse, and subsequently to Burdiehouse, form the strata which dip under the coalmeasures of Gilmerton, Loanhead, and other sites.

scholarly journals Pre-Nagssugtoqidian crustal evolution in West Greenland: geology, geochemistry and deformation of supracrustal and granitic rocks north-east of Kangaatsiaq

2006 ◽  
Vol 11 ◽  
pp. 33-52
Author(s):  
Jean-François Moyen ◽  
Gordon R. Watt
Keyword(s):  
Sedimentary Basin ◽  
Granulite Facies ◽  
Great Circle ◽  
Granitic Rocks ◽  
Early Event ◽  
Porphyritic Granite ◽  
The Core ◽  
North East ◽  
Greenstone Belts ◽  
Area North

The area north-east of Kangaatsiaq features polyphase grey orthogneisses, supracrustal rocks and Kangaatsiaq granite exposed within a WSW–ENE-trending synform. The supracrustal rocks are comprised of garnet-bearing metapelites, layered amphibolites and layered, likewise grey biotite paragneisses. Their association and geochemical compositions are consistent with a metamorphosed volcano-sedimentary basin (containing both tholeiitic and calc-alkali lavas) and is similar to other Archaean greenstone belts. The Kangaatsiaq granite forms a 15 × 3 km flat, subconcordant body of deformed, pink, porphyritic granite occupying the core of the supracrustal synform, and is demonstrably intrusive into the amphibolites. The granite displays a pronounced linear fabric (L or L > S). The post-granite deformation developed under lower amphibolite facies conditions (400 ± 50°C), and is characterised by a regular, NE–SW-trending subhorizontal lineation and an associated irregular foliation, whose poles define a great circle; together they are indicative of highly constrictional strain. The existence of a pre-granite event is attested by early isoclinal folds and a foliation within the amphibolites that is not present in the granite, and by the fact that the granite cuts earlier structures in the supracrustal rocks. This early event, preserved only in quartz-free lithologies, resulted in high-temperature fabrics being developed under upper amphibolite to granulite facies conditions.

XII.—The Brackish-water Lochs of North Uist

1937 ◽  
Vol 56 ◽  
pp. 169-195 ◽  
Author(s):  
A. T. Nicol
Keyword(s):  
Fresh Water ◽  
Brackish Water

About the year 1695 Martin Martin visited the Hebrides, and of the Island of North Uist he writes, “There is such a number of fresh water lakes here as can hardly be believed. … They are generally well stocked with trout and eels and some of them with salmon, and, which is yet more strange, cod, ling, mackerel, etc., are taken in these lakes into which they are brought by the spring tides.” This old reference suggested that the brackish-water fauna of the Hebrides might be of considerable interest and extent. Consequently I spent part of the summers of 1933 and 1935 in North Uist in order to study the fauna of the lochs and the conditions under which the animals were living.

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