scholarly journals Anomalous radioactivity level and high concentrations of heavy minerals in Lemme area, South-West Estonia

Baltica ◽  
2014 ◽  
Vol 27 (2) ◽  
pp. 93-104 ◽  
Author(s):  
Anto Raukas ◽  
Rein Koch ◽  
Krista Jüriado ◽  
Johanna-Iisebel Järvelill
Keyword(s):  
Heavy Mineral ◽  
Heavy Minerals ◽  
Radiocarbon Dates ◽  
Radioactivity Level ◽  
Near Shore ◽  
Buried Soil ◽  
High Concentrations ◽  
The 1960S ◽  
The Baltic ◽  
Mineral Concentrations

Abstract As early as in the 1960s, extensive heavy-mineral concentrations containing zircon, monazite, and xenotime were discovered in the Lemme region of south-western Estonia. These concentrations contribute to the elevated radioactivity levels of the enclosing sediments. The near shore sands of the Litorina Sea contain up to 10-cm-thick interlayers with a heavy mineral content of up to 80%. These anomalous layers were formed during the transgressive phase and result from a complicated cross- and alongshore migration of sedimentary material, derived mainly from local Devonian bedrock. Radioactivity level in the study area is higher relative to the majority of the Devonian plateau. The Lemmeoja buried soil has 13 radiocarbon dates in an area of renewed interest for the investigation of the Baltic Sea history.

Heavy minerals in stream sediments from Churchill Falls, Labrador—an aid in bedrock mapping

1980 ◽  
Vol 17 (2) ◽  
pp. 244-253
Author(s):  
John Edward Callahan
Keyword(s):  
Frequency Distribution ◽  
Mineral Content ◽  
Regional Metamorphism ◽  
Stream Sediments ◽  
Heavy Mineral ◽  
Heavy Minerals ◽  
Sediment Samples ◽  
Fluvial Deposits ◽  
Geologic Map ◽  
High Concentrations

Stream sediments from a 13 000 km2 previously glaciated area in central Labrador near Churchill Falls were examined for their heavy mineral content. The minus 0.25 mm (60 mesh) nonmagnetic heavy mineral fraction from 846 stream sediment samples consists mainly of magnetite, ilmenite. garnet, hornblende, epidote and minor clinopyroxene, orthopyroxene. kyanite. sillimanite, biotite. apatite, and zircon. Changes in the frequency distribution of epidote, hornblende, garnet, and sillimanite in the stream sediments correspond well with those reported in previously mapped underlying bedrock lithologies. The occurrence of kyanite and sillimanite, high concentrations of garnet and opaques (mainly ilmenite), and lower concentrations of hornblende and epidote were used to determine grades of regional metamorphism, resulting in revision of the geologic map of this area. Heavy minerals in glacial drift or fluvial deposits may be useful as an aid in mapping in glaciated areas.

scholarly journals THE IMPACT OF SEASONAL CHANGES ON HEAVY MINERALS CONCENTRATION FROM A PART OF EAST COAST OF INDIA

2020 ◽  
Vol 5 (1) ◽  
pp. 12-21
Author(s):  
Ali Mohammad ◽  
E.N. Dhanamjayarao
Keyword(s):  
Seasonal Changes ◽  
East Coast ◽  
Heavy Mineral ◽  
Heavy Minerals ◽  
Sediment Characteristics ◽  
Seasonal Fluctuations ◽  
Post Monsoon ◽  
Seasonal Circulation ◽  
Mineral Concentrations ◽  
The Impact

Pre and post monsoonal changes in the environment have led to a noticeable variation in sediment characteristics, heavy mineral concentrations and their distribution. The current study aimed to find out the effect of seasonal fluctuations on the concentration of heavy minerals along the coast and the variations in sediment textures and distribution. The study has revealed the effect of seasons on the sediments supply and its distribution along coast in the study area. The total heavy minerals concentrations are more in post monsoon than in pre monsoon and the concentration also increases from south to north in parts of the study area because of seasonal circulation of currents from south to north along the shore. The micro textural study of the heavy mineral grains from different locations in the study area revealed the mechanical and chemical erosions on the grain surfaces.

scholarly journals SEDIMENT DISTRIBUTION AND ITS RELATIONS TO CIRCULATION PATTERNS IN BOLINAS BAY, CALIFORNIA

1970 ◽  
Vol 1 (12) ◽  
pp. 86
Author(s):  
P. Wilde ◽  
T. Yancey
Keyword(s):  
Grain Size ◽  
San Francisco ◽  
Heavy Mineral ◽  
Heavy Minerals ◽  
Statistical Parameters ◽  
Sediment Distribution ◽  
Primary Mode ◽  
Marine Samples ◽  
Long Term Study ◽  
High Concentrations

Grain size and heavy mineral analyses of 6 cliff, 12 beach, and 44 marine sediment and rock samples from Bolmas Bay and its surrounding drainage area were done as part of a long term study of sediment transport on the continental shelf off Central California Sediments in the bay are predominately very fine sands Some samples, particularly adjacent to Duxbury Reef on the west, have a coarse sand to pebble component The primary mode of the marine samples is in the range 088 to 125 mm, whereas, the primary mode for beach material is from 175 to 25 mm The range of median diameters of the marine samples is from 07 to 14 mm The median diameters show a trend of decreasing grain size seaward parallel to the depth contours except opposite the entrance to Bolmas Lagoon where a tongue of relatively coarser material cuts across the depth contours The range of other statistical parameters are (1) sorting coefficient 1 10 to 1 41, (2) skewness 0 83 to 1 18, and (3) kurtosis 0 15 to 0 32 Our sediment studies indicate (1) The heavy mineral assemblage is predominantly green hornblende with secondary amounts of hypersthene and augite Glaucophane and jadeite occur in locally high concentrations near shore (2) The pattern of distribution of the heavy minerals shows (a) a tongue of high concentrations of minerals with a granitic source extending northwest from the San Francisco Bar, (b) flanked on the north and northeast by increasing landward concentrations of Franciscan metamorphic minerals (3) The major source of heavy minerals is the San Francisco Bar Secondary contributions come from Bolmas Lagoon and the adjacent cliffs (4) The circulation in the Bay is primarily counterclockwise, produced by a combination of wave refraction around Duxbury Reef and the tidal Coast Eddy Current The tidal influence, however, of Bolmas Lagoon is restricted to about one mile from the lagoon mouth.

Quaternary sedimentation and marine placers along the North Shore, Gulf of St. Lawrence

1993 ◽  
Vol 30 (3) ◽  
pp. 553-574 ◽  
Author(s):  
Frances J. Hein ◽  
James P. M. Syvitski ◽  
Lynda A. Dredge ◽  
Bernard F. Long
Keyword(s):  
Current System ◽  
Heavy Mineral ◽  
Heavy Minerals ◽  
Coarse Grained ◽  
Mineral Concentration ◽  
Lawrence Estuary ◽  
North Shore ◽  
The North ◽  
Late Wisconsinan ◽  
Mineral Concentrations

Offshore areas, along the North Shore of the St. Lawrence Estuary, have major lithostratigraphic and seismostratigraphic units that relate to the advance or retreat of the Late Wisconsinan Ice Sheet, subsequent marine transgression or regression, and reworking of postglacial deposits. Glacial diamicton and glaciomarine units (acoustic units 1 and 2) were emplaced between >18 and 14.5 ka, by basal meltout or ice-marginal sedimentation; they reflect ice-proximal sedimentation associated with ice-terminal stillstands. Deep-water muds (acoustic unit 3) represent ice-distal accumulation of glaciomarine sediment from glaciofluvial plumes between 13.5 and 11 ka. After this time exceptionally thick nearshore coarse-grained deltaic and estuarine successions (acoustic unit 4) were deposited. The uppermost postglacial sediment (acoustic unit 5) forms the seabed and reflects a reworking phase concomitant with a lowering sea level and ablating Late Wisconsinan ice sheets.Glacioisostatic rebound, which occurred about 23 ka to the present, uplifted glacial and marine deposits and resulted in extensive reworking and production of modern placers. Heavy-mineral concentrations vary as follows: terrestrial tills, 9–20%; modem storm-berm and delta top deposits, 43–60%; delta slope deposits, 25–55%; and deep (170+ m) offshore sediments, 0–2%. Three stages occurred in marine placer formation: (1) 6700 BP, fluvial discharge was high, and fluvial-dominated deltas were built; marine limit was 30 m asl, with progradation of deltas and delivery of sediments with at most 2% heavy minerals; (2) 5200 BP, fluvial discharge was reduced; marine limit was 15 m asl, deltaic sediments were reworked, increasing heavy mineral concentration to 2–8%; (3) 2800 BP, fluvial input was greatly reduced, waves and tides were more influential, a strong littoral current system developed, causing significant reworking of nearshore sediments, heavy mineral concentrations increased, with values exceeding 20% locally. Mass budget calculations show that the second-cycle reworked sediment (acoustic unit 5) is a potential economic target (1 km3, or 1700 Mt). If 7% (using atomic weights) of this target sediment is ilmenite (FeTiO3). then 27 Mt of titanium may be available.

scholarly journals Prospects and limitations of heavy mineral analyses to discriminate preglacial/glacial transitions in Pleistocene sedimentary successions

Geologos ◽  
2018 ◽  
Vol 24 (2) ◽  
pp. 151-162
Author(s):  
Tomasz Zieliński
Keyword(s):  
Geological Structure ◽  
Heavy Mineral ◽  
Heavy Minerals ◽  
Early Pleistocene ◽  
Middle Pleistocene ◽  
Mineral Associations ◽  
Scandinavian Ice Sheet ◽  
Middle Pleistocene Transition ◽  
The Baltic ◽  
Heavy Mineral Analysis

Abstract The present study revolves around the identification of the stratigraphical boundary between Pleistocene formations that formed prior to the first advance of the Scandinavian ice sheet (Early Pleistocene, i.e., the so-called preglacial) and the overlying, glacially derived deposits (Middle Pleistocene). In particular, it focuses on variation in heavy mineral assemblages, which are an important tool for stratigraphers. The Neogene basement, described here, was most often the source of material that was redeposited by Early Pleistocene rivers. The geological structure and Early Pleistocene palaeogeographical scenarios for various Polish regions are discussed. Moreover, comparisons with other European preglacial formations are carried out. The mineral spectrum of Lower Pleistocene deposits is largely dependent of rocks of the Neogene and Mesozoic basement. If the incision of ancient catchments was into terrigenous rocks, the stratigraphical boundary between preglacial and glacial formations is easily determined with the help of a heavy mineral analysis. As a rule, this coincides with a noticeable change from resistant to non-resistant mineral associations. Such cases are noted for successions in central Poland and eastern England. On the other hand, outcrops of igneous or metamorphic rocks exist within preglacial river catchments in most parts of Europe. They were the local sources of non-resistant heavy minerals long before their glacial supply from the Baltic Shield. In these cases, mineralogical analysis fails in the search for the Early/Middle Pleistocene transition.

Qualitative Petrographic Interpretation of Potsdam Sandstone (Cambrian), Southwestern Quebec

1971 ◽  
Vol 8 (8) ◽  
pp. 853-882 ◽  
Author(s):  
D. W. Lewis
Keyword(s):  
Heavy Mineral ◽  
Heavy Minerals ◽  
Coarse Grains ◽  
Mineral Concentrations ◽  
Petrographic Study

The Cambrian Potsdam Group in southwestern Quebec comprises the quartzo-feldspathic Covey Hill Formation (up to 2000 ft (610 m) thick), and the unconformably overlying and overlapping Chateauguay Formation, which is subdivided into the lower Cairnside Member (up to 500 ft (152 m) thick) of pure quartz sandstone and the Upper Theresa Member of interlayered quartz sandstone and dolostone. Petrographic study concentrated on Covey Hill and Cairnside lithologies from three deep cores near Montreal. Traditional interpretation of Potsdam Sandstone as a pure quartz blanket deposited by transgressing seas applies only to the Cairnside Member.The Covey Hill Formation comprises subround-round sands, sparse rounded gravels, scattered penecontemporaneous clay clasts, and rare thin mud layers. Juxtaposition of well and poorly sorted laminations of different sand sizes, mica-clay, and heavy mineral concentrations, attests fluctuating depositional energies. Presence of silt-free clayey matrix and scattered coarse grains set amongst much finer sands attests marked predepositional eolian activity. Composition of quartz, fresh and partly weathered K-feldspar, micas, and stable heavy minerals is inferred to reflect a prolonged predepositional history during which unstable minerals were destroyed. Hematitization of biotite flakes, and other diagenetic modifications, are inferred to result from pedogenesis in an alluvial environment of deposition.

scholarly journals The Influence of Manganese on Growth Processes of Hordeum L. (Poaceae) Seedlings

Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1009
Author(s):  
Kirill Tkachenko ◽  
Irina Kosareva ◽  
Marina Frontasyeva
Keyword(s):  
Plant Genetic Resources ◽  
Acid Resistance ◽  
Normal Growth ◽  
Wide Distribution ◽  
Acidic Soils ◽  
Baltic Countries ◽  
High Concentrations ◽  
Northern Territories ◽  
Cis Countries ◽  
The Baltic

Manganese, as one of the xenobionts, belongs to the group of heavy metals, which, in high concentrations, can negatively affect the development of plants. In small concentrations, it is necessary for plants for normal growth and development. It is present in soils and is available to plants to varying degrees. In acidic soils, it often acts as a toxic element, and plants do not develop well and can even die. Screening major crops for manganese tolerance is essential. Based on the analysis of the collection of barley (Hordeum L., Poaceae), the N.I. Vavilov All-Russian Institute of Plant Genetic Resources (VIR) presented data that manganese-tolerant varieties and samples are concentrated in western and northern countries with a wide distribution of soils with low pH levels and high contents of mobile manganese. It follows from the diagnostic results that the maximum number of barley genotypes resistant to manganese is concentrated in Sweden, Finland, the northwestern and northern regions of the CIS countries, and the Russian Federation. In most cases, the samples tolerant to Al showed resistance to Mn as well, which is of great interest for further study of the mechanisms of plant resistance to these stressors. As a rule, samples from the northern territories—zones of distribution of acidic soils—were highly resistant. In this case, the role of the species belonging to the sample was leveled out. The highlighted areas (Scandinavia (Finland, Sweden), northern and northwestern regions of Russia, Belarus, and the Baltic countries) are sources of germplasm valuable for selection for acid resistance of barley.

scholarly journals A Lateglacial palaeosol cover in the Altdarss area, southern Baltic Sea coast (northeast Germany): investigations on pedology, geochronology and botany

2006 ◽  
Vol 85 (3) ◽  
pp. 197-220 ◽  
Author(s):  
K. Kaiser ◽  
A. Barthelmes ◽  
S. Czakó Pap ◽  
A. Hilgers ◽  
W. Janke ◽  
...  
Keyword(s):  
Soil Cover ◽  
Younger Dryas ◽  
Soil Surface ◽  
Vegetation Pattern ◽  
Buried Soils ◽  
Radiocarbon Dates ◽  
Buried Soil ◽  
Nw Europe ◽  
Aeolian Sands ◽  
Sea Coast

AbstractA new site with Lateglacial palaeosols covered by 0.8 - 2.4 m thick aeolian sands is presented. The buried soils were subjected to multidisciplinary analyses (pedology, micromorphology, geochronology, dendrology, palynology, macrofossils). The buried soil cover comprises a catena from relatively dry (’Nano’-Podzol, Arenosol) via moist (Histic Gleysol, Gleysol) to wet conditions (Histosol). Dry soils are similar to the so-called Usselo soil, as described from sites in NW Europe and central Poland. The buried soil surface covers ca. 3.4 km2. Pollen analyses date this surface into the late Allerød. Due to a possible contamination by younger carbon, radiocarbon dates are too young. OSL dates indicate that the covering by aeolian sands most probably occurred during the Younger Dryas. Botanical analyses enables the reconstruction of a vegetation pattern typical for the late Allerød. Large wooden remains of pine and birch were recorded.

Radiocarbon dates from Fazzan, southern Libya

2002 ◽  
Vol 33 ◽  
pp. 9-19 ◽  
Author(s):  
David Mattingly ◽  
David Edwards ◽  
John Dore
Keyword(s):  
Radiocarbon Dating ◽  
Short Paper ◽  
Important Conclusion ◽  
Historic Period ◽  
Radiocarbon Dates ◽  
Full List ◽  
Ams Dating ◽  
The 1960S ◽  
Early Islamic

AbstractThis short paper presents a full list of the currently available radiocarbon dates from the work of Charles Daniels in the 1960s-1970s and the Fazzan Project (1997-2001). The dates can be grouped into several categories, by site or area, and demonstrate the potential of radiocarbon dating being applied to historic-period archaeology in the Sahara. This complements earlier Italian work on later prehistory. One of the most important conclusions to emerge is that the construction of castle-like buildings in Fazzan began within the Garamantian period and that some of the numerous well-preserved mudbrick fortified sites are thus rather earlier than has previously been envisaged. A second important conclusion is that the use of AMS dating can help to identify and confirm activity of the post-Garamantian and early Islamic phases, which has hitherto been elusive.

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