scholarly journals Carbonate sedimentation and effects of eutrophication observed at the Kališta subaquatic springs in Lake Ohrid (Macedonia)

2010 ◽  
Vol 7 (3) ◽  
pp. 4715-4747 ◽  
Author(s):  
M. Matter ◽  
F. S. Anselmetti ◽  
B. Jordanoska ◽  
B. Wagner ◽  
M. Wessels ◽  
...  
Keyword(s):  
Sediment Traps ◽  
Authigenic Carbonate ◽  
Sidescan Sonar ◽  
Carbonate Content ◽  
Carbonate Precipitation ◽  
Lake Ohrid ◽  
Radiocarbon Dates ◽  
North West ◽  
The North ◽  
Spring Area

Abstract. To date, little is known about the role of spring waters with respect to authigenic carbonate precipitation in the shallow lacustrine setting. Lake Ohrid, located in Southeastern Europe, is a large lake fed to over 50% by karstic springs of which half enter subaquatically and influence significantly its ecology and species distribution. In order to evaluate how sedimentological processes are influenced by such shallow-water springs, the Kališta subaquatic spring area in the north west of Lake Ohrid was investigated by a sidescan sonar survey and with sediment traps and three transects of gravity short cores. Results indicate that sedimentation in the spring area is dominated by authigenic carbonate precipitation. High sedimentation rates and evidences for bio-induced precipitation processes were observed in the water column and in the sediments. Two distinct stratigraphic units characterize the shallow subsurface, both composed of carbonate silts with high carbonate contents of up to 96%, but differing in color, carbonate content and diatom content. A chronological correlation of the cores by radiocarbon dates and 137Cs activities places the transition between the two stratigraphic units after ~1955 AD. At that time, coastal sedimentation changed drastically to significantly darker sediments with higher contents of organic matter and more abundant diatoms. This change coincides with the recent human impact of littoral eutrophication.

scholarly journals Carbonate sedimentation and effects of eutrophication observed at the Kališta subaquatic springs in Lake Ohrid (Macedonia)

2010 ◽  
Vol 7 (11) ◽  
pp. 3755-3767 ◽  
Author(s):  
M. Matter ◽  
F. S. Anselmetti ◽  
B. Jordanoska ◽  
B. Wagner ◽  
M. Wessels ◽  
...  
Keyword(s):  
Sediment Traps ◽  
Authigenic Carbonate ◽  
Sidescan Sonar ◽  
Carbonate Content ◽  
Carbonate Precipitation ◽  
Lake Ohrid ◽  
Radiocarbon Dates ◽  
North West ◽  
The North ◽  
Spring Area

Abstract. To date, little is known about the role of spring waters with respect to authigenic carbonate precipitation in a shallow lacustrine setting. Lake Ohrid, located in Southeastern Europe, is a large lake fed to over 50% by karstic springs of which half enter subaquatically and influence significantly its ecology and species distribution. In order to evaluate how sedimentological processes are influenced by such shallow-water springs, the Kališta subaquatic spring area in the north west of Lake Ohrid was investigated by a sidescan sonar survey and with sediment traps and three transects of gravity short cores. Results indicate that sedimentation in the spring area is dominated by authigenic carbonate precipitation. High sedimentation rates and evidences for bio-induced precipitation processes were observed in the water column and in the sediments. Two distinct stratigraphic units characterize the shallow subsurface, both composed of carbonate silts with high carbonate contents of up to 96%, but differing in color, carbonate content and diatom content. A chronological correlation of the cores by radiocarbon dates and 137Cs activities places the transition between the two stratigraphic units after ~1955 AD. At that time, coastal sedimentation changed drastically to significantly darker sediments with higher contents of organic matter and more abundant diatoms. This change coincides with the recent human impact of littoral eutrophication.

scholarly journals Modelling the Neolithic dispersal in northern Eurasia

2004 ◽  
Vol 31 ◽  
pp. 35-47 ◽  
Author(s):  
Pavel Dolukhanov ◽  
Anvar Shrukov
Keyword(s):  
Probability Distribution ◽  
Central Europe ◽  
East European Plain ◽  
Northern Eurasia ◽  
Radiocarbon Dates ◽  
North West ◽  
East European ◽  
The North ◽  
Rate Of Spread ◽  
Spatio Temporal

Comprehensieve lists of radiocarbon dates from key Early Neolithic sites in Central Europe belonging to the Linear pottery Ceramic Culture (LBK) and early pottery-bearing cultures in the East European Plain were analysed with the use of the x2 test. The dates from the LBK sites form a statistically homogeneous set, with a probability distribution similar to a single-date Gaussian curve. This implies the rate of expansion of the LBK in Central Europe being in excess of 4 km/yr. Early potter-bearing sites on the East European Plain exhibit a much broader probability distribution of dates, with a spatio-temporal trend directed from the south-east to the north-west. The rate of spread of pottery-making is in the order of 1 km/yr, i.e., comparable to the average expansion rate of the Neolithic in Western and Central Europe.

Sedimentary provinces of the fishing grounds of the North West Shelf of Australia: Grain-size frequency analysis of surficial sediments

1985 ◽  
Vol 36 (5) ◽  
pp. 671 ◽  
Author(s):  
RJ McLoughlin ◽  
PC Young
Keyword(s):  
Grain Size ◽  
Frequency Analysis ◽  
Fine Sand ◽  
Carbonate Content ◽  
North West ◽  
North East ◽  
The North ◽  
Size Frequency ◽  
Sediment Types ◽  
Shelf Slope

As part of a multidisciplinary study of the continental shelf of north-west Australia, 354 sediment samples were taken to describe the distribution of sedimentary provinces contained within the region. A grain-size frequency analysis and subsequent classification have revealed six principal sediment types roughly corresponding to an east-west and inshore-offshore distribution. The study area is characterized by coarse skeletal detritus in the south-west, with a transition to a significant accretionary carbonate component in the form of oolites, pellets and infilled biogenic particles in the north-east. Superimposed on this pattern is a decrease in grain size from shallow to deeper waters, culminating in carbonate muds on the shelf slope. Carbonate content of sediments is uniformly high, ranging from 60 to 100% of the total weight of all samples. Non-carbonate material is principally clay; however, small quantities (less than 1%) of fine sand-size angular quartz are present.

Excavation of Four Barrows, and a Middle Bronze Age Cremation Cemetery, at Heatherstone Grange, Bransgore, Hampshire

2018 ◽  
Vol 73 (1) ◽  
pp. 11-89
Author(s):  
Richard Massey ◽  
Elaine L. Morris
Keyword(s):  
Bronze Age ◽  
Iron Age ◽  
Early Bronze Age ◽  
The South ◽  
The West ◽  
Radiocarbon Dates ◽  
North West ◽  
The North ◽  
South West ◽  
Middle Bronze Age

Excavation at Heatherstone Grange, Bransgore, Hampshire, investigated features identified in a previous evaluation. Area A included ring ditches representing two barrows. Barrow 1.1 held 40 secondary pits, including 34 cremation-related deposits of Middle Bronze Age date, and Barrow 1.2 had five inserted pits, including three cremation graves, one of which dated to the earlier Bronze Age, and was found with an accessory cup. A number of pits, not all associated with cremation burials, contained well-preserved urns of the regional Deverel-Rimbury tradition and occasional sherds from similar vessels, which produced a closely-clustered range of eight radiocarbon dates centred around 1300 BC. Of ten pits in Area C, three were cremation graves, of which one was radiocarbon-dated to the Early Bronze Age and associated with a collared urn, while four contained only pyre debris. Barrow 1.3, in Area E, to the south, enclosed five pits, including one associated with a beaker vessel, and was surrounded by a timber circle. Area F, further to the south-west, included two pits of domestic character with charcoal-rich fills and the remains of pottery vessels, together with the probable remains of a ditched enclosure and two sets of paired postholes. Area H, located to the north-west of Area E, partly revealed a ring ditch (Barrow 1.4), which enclosed two pits with charcoal-rich fills, one with a single Late Bronze Age/Early Iron Age potsherd, and the other burnt and worked flint. A further undated pit was situated to the east of Barrow 1.4. The cremation cemetery inserted into Barrow 1.1 represents a substantial addition to the regional record of Middle Bronze Age cremation burials, and demonstrates important affinities with the contemporary cemeteries of the Stour Valley to the west, and sites on Cranborne Chase, to the north-west.

scholarly journals The Catacomb Cultures of the North-West Caspian Steppe: 14C Chronology, Reservoir Effect, and Paleodiet

Radiocarbon ◽  
2007 ◽  
Vol 49 (2) ◽  
pp. 713-726 ◽  
Author(s):  
N I Shishlina ◽  
J van der Plicht ◽  
R E M Hedges ◽  
E P Zazovskaya ◽  
V S Sevastyanov ◽  
...  
Keyword(s):  
Bronze Age ◽  
Stomach Contents ◽  
Bone Collagen ◽  
Stable Isotope Ratios ◽  
Radiocarbon Dates ◽  
Bone Material ◽  
Reservoir Effect ◽  
North West ◽  
The North ◽  
The Bronze Age

For the Bronze Age Catacomb cultures of the North-West Caspian steppe area in Russia, there is a conflict between the traditional relative archaeological chronology and the chronology based on radiocarbon dates. We show that this conflict can be explained largely by the fact that most dates have been obtained on human bone material and are subject to 14C reservoir effects. This was demonstrated by comparing paired 14C dates derived from human and terrestrial herbivore bone collagen. In addition, values of stable isotope ratios (δ13C and δ15N) and analysis of food remains from vessels and the stomach contents of buried individuals indicate that a large part of the diet of these cultures consisted of fish and mollusks, and we conclude that this is the source of the reservoir effect.

scholarly journals The results of investigations at the Trypillia settlement of Hordashivka II in Cherkassy region

Vita Antiqua ◽  
2021 ◽  
pp. 129-138
Author(s):  
V.O. Shumova ◽  
Keyword(s):  
The West ◽  
Radiocarbon Dates ◽  
North West ◽  
The North ◽  
Working Space ◽  
Painting Analysis ◽  
Settlement Size ◽  
The Village ◽  
Eastern Edge ◽  
Archaeological Excavations

Rescue archaeological excavations at the Trypillia settlement of Hordasivka-II (Zvenigorodka district, Cherkassy region) were started in 1996. This settlement is located at western bank of Hirs’kyy Tikych river, in 2.5 km to the west from the south-eastern edge of the village. It is placed on a part of plateau formed by the creek valley from the north and long cavin from the east. Visual observations indicate elliptic structure composed of a single row of dwellings. Settlement size did not exceed 3 ha. The rectangular-shaped Dwelling 1 excavated in Hordashivka (12.5 x 5.0 m) was oriented from north-west to southeast. It is reconstructed as a house with the lower storey’s floor covered by clay and massive ceiling of the lower storey (= floor of the upper storey). Most of the interior details were found on the floor of the lower storey. These are the fireplace, working space, elevations. Collection of finds is mostly represented by pottery (70% of the assemblage is referred to kitchen pottery and 30% of the assemblage is referred to table pottery). Part of the table pottery is decorated in black monochromic painting. Analysis of ceramics allows dating the settlement to Tripolye CII. Considering the relative and absolute chronology (radiocarbon dates obtained for Sharin III), this site may be dated to c. 3400 – 3200 BC. Materials from Hordashivka are “genetically” linked to post-Kosenovskaya group populations in the Southern Bug and Dnieper interfluve. This is traced by the specifics of the technology of vessels production and their decoration. It is important to admit ceramic influences from Sofievskaya group populations in the Middle Dnieper region. Settlements which are chronologically similar to Hordashivka II in the Southern Bug and Dnieper interfluve are not numerous. Later sites in this area are not known, while Trypillia traditions continued in other regions. Keywords: Hordasivka-II, Late Trypillia (C II), settlements, houses, reconstruction, ceramics, chronology.

scholarly journals Sosruco Rockshelter: revision of materials of the excavation by S.N. Zamiatnin and the Upper Horizons Radiocarbon Chronology

2021 ◽  
pp. 101-119
Author(s):  
Elena Leonova ◽  
Keyword(s):  
Iron Age ◽  
Faunal Remains ◽  
The Caucasus ◽  
Radiocarbon Dates ◽  
North West ◽  
The North ◽  
Three Samples ◽  
Late Upper Palaeolithic ◽  
Absolute Age ◽  
Radiocarbon Chronology

The new radiocarbon dates were obtained from samples of the collections from the excavations by S.N. Zamyatnin in 1955–1957 of the Sosruko Rockshelter in the Elbrus region. The Sosruko Rockshelter is a multi-layered site containing cultural horizons of the Iron Age, Mesolithic and Late Upper Palaeolithic. Clear stratigraphy of the Stone Age layers and representative collections were used to create periodization schemes of the development and change of the lithic industries of the late Pleistocene — early Holocene of the Caucasus. But the lack of radiocarbon dating did not allow determining their absolute age. Three samples of faunal remains of layers M1, M2 and M3 were analyzed. Obtained four radiocarbon AMS dates are in agreement not only with the sequence of deposits in the Rockshelter, but also with the data obtained for similar typological collections of the North-West Caucasus synchronous sites.

NON-VOLATILE HYDROCARBON CHEMISTRY STUDIES AROUND A PRODUCTION PLATFORM ON AUSTRALIA'S NORTH WEST SHELF

1998 ◽  
Vol 38 (1) ◽  
pp. 626 ◽  
Author(s):  
K.A. Burns ◽  
S. Codi
Keyword(s):  
High Volume ◽  
Sediment Traps ◽  
Balance Model ◽  
Potential Zone ◽  
Operational Strategies ◽  
Volatile Hydrocarbon ◽  
North West ◽  
The North ◽  
Production Platform ◽  
Hydrocarbon Chemistry

In September 1994 and 1995, scientists from the Australian Institute of Marine Science (AIMS) and the Australian Geological Survey Organisation (AGSO) conducted surveys aboard the Research Vessel Lady Basten to determine the dispersion, fates and effects of Produced Formation Water (PFW) discharged from the Harriet A production platform near the Montebello Islands, on the North West Shelf of Australia. This report describes the non-volatile hydrocarbon chemistry studies.We measured the dispersion of the PFW into dissolved and particulate fractions of seawater using moored high volume water samplers, surface screen samplers and moored and drifting sediment traps. We studied bioaccumulation using transplanted oysters, and we measured dispersion into sediment with benthic grabs. Samples were analysed for total non-volatile hydrocarbons and individual hydrocarbon components using ultraviolet fluorescence spectroscopy (UVF), gas chromatography with flame ionisation detection (GC-FID), and GC with mass selective detection (GC/MS). The hydrocarbon concentrations were used to calculate vertical fluxes and the total concentrations of hydrocarbons in the various ecosystem compartments. A mass balance model was then used to calculate the rates of other important dispersion and degradation processes.We estimate the potential zone of biological impact in the water column extends to a distance of approximately 0.5 nmile (900 m). Concentrations of oil in sediments were too low to indicate potential toxicity. By the collaborative application of oceanographic and geochemical techniques to marine environmental problems, we endeavour to provide effective feedback to the oil industry to gauge the effectiveness of their operational strategies in minimising impact in these pristine regions.

scholarly journals Andesite and obsidian accessibility and distribution during the Holocene in north-west Santa Cruz province (south-central Patagonia), Argentina

2018 ◽  
Vol 5 (2) ◽  
Author(s):  
Mariana Sacchi ◽  
Damián Leandro Bozzuto ◽  
Ana Gabriela Guraieb ◽  
María Teresa Civalero ◽  
Nicolás Maveroff
Keyword(s):  
Raw Materials ◽  
Lake Basin ◽  
Santa Cruz ◽  
Radiocarbon Dates ◽  
North West ◽  
The North ◽  
South Central ◽  
Non Local ◽  
Bodies Of Water ◽  
Over Time

This paper discusses different aspects related to the andesite and obsidian availability and circulation routes in different moments of the occupation sequence in the Pueyrredón-Posadas-Salitroso (PPS) Lake Basin in the north, and the Burmeister-Belgrano (BB) Lake Basin to the south (north-west Santa Cruz province, Argentinian Patagonia). The distribution of raw materials - both in space and time - allows us to assert that potential regional circulation routes would have been affected differentially by the palaeolakes present from the Pleistocene up until the mid-Holocene. We are taking into account three sites: Cueva Milodón Norte 1 (CMN1), located in the northeast coast of the Pueyrredón Lake, Cerro de los Indios 1 (CI1) (central portion of the PPS Basin), and Cerro Casa de Piedra 7 (CCP7) (near to the Burmeister Lake). This investigation considers six periods, based on the calibrated ranges from 73 radiocarbon dates: 17 from CI1, 14 from CMN1, and 42 radiocarbon dates from CCP7. As a result of this analysis we can conclude that, in sites with a higher density of occupation such as CI1 and CCP7, the use of obsidian (non-local rock) and andesite or basalt did not vary over time. In the case of CMN1, access to the sources of these raw materials varied according to the presence of large bodies of water, although it does not seem to have influenced the procurement of these rocks.

SEM and TEM observations of sperm development in the testis of the freshwater fish Oreochromis mossambicus

1990 ◽  
Vol 48 (3) ◽  
pp. 58-59
Author(s):  
Daryl A. Cornish ◽  
George L. Smit
Keyword(s):  
Morphological Characteristics ◽  
Oreochromis Mossambicus ◽  
Breeding Cycle ◽  
Limited Information ◽  
North West ◽  
The North ◽  
Sem And Tem ◽  
Sperm Development ◽  
Ultrastructural Characteristics ◽  
The University

Oreochromis mossambicus is currently receiving much attention as a candidater species for aquaculture programs within Southern Africa. This has stimulated interest in its breeding cycle as well as the morphological characteristics of the gonads. Limited information is available on SEM and TEM observations of the male gonads. It is known that the testis of O. mossambicus is a paired, intra-abdominal structure of the lobular type, although further details of its characteristics are not known. Current investigations have shown that spermatids reach full maturity some two months after the female becomes gravid. Throughout the year, the testes contain spermatids at various stages of development although spermiogenesis appears to be maximal during November when spawning occurs. This paper describes the morphological and ultrastructural characteristics of the testes and spermatids.Specimens of this fish were collected at Syferkuil Dam, 8 km north- west of the University of the North over a twelve month period, sacrificed and the testes excised.

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