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Tytuł:
Correlation of Pleistocene deposits in the area between the Baltic and Black Sea, Central Europe
Autorzy:
Lindner, L.
Bogutsky, A.
Gozhik, P.
Marks, L.
Łanczont, M.
Wojtanowicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/2058933.pdf
Data publikacji:
2006
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Polska
Ukraine
Baltic Sea
Black Sea
Pleistocene
stratigraphic correlation
Opis:
The distribution, age and correlation of Pleistocene sediments (1.806–0.01 Ma) is presented for an about 1200 km long geologic cross-section that extends from the Baltic Sea to the Black Sea and crosses the eastern part of the Polish Vistula drainage basin, the Dniester and Upper Pripyat drainage basins of the Ukraine, and also parts of the Russian Kaliningrad District andMoldova. In the vicinity of Warsaw, the oldest Pleistocene deposits comprise preglacial fluvio-lacustrine sediments of the Otvockian (Eburonian) cooling and Celestynovian (Waalian) warming stages that equate in the south with the Berezan and Kryzhaniv horizons, composed of loessy clays, silts and red-brown palaeosol. Along the cross-section, deposits of 8 main glaciations correlate with a similar number of main loesses (Narevian–Ilyichivsk, Nidanian–Pryazovsk, Sanian 1–Sula, Sanian 2–Tiligul, Liviecian–Orel, Krznanian–Dnieper 1, Odranian–Dnieper 2–Tyasmyn, Vistulian–Valday) that are separated by 7 main intra-loess palaeosols that developed during the main interglacial periods (Augustovian–Shirokino, Małopolanian–Martonosha, Ferdynandovian–Lubny–Solotvin, Mazovian–Zavadivka–Sokal, Zbójnian–Potagaylivka, Lubavian–Lublinian–Kaydaky–Korshiv, Eemian–Pryluky–Horokhiv). The first three interglacials are megainterglacials, which possibly include cool intervals during which ice sheets did not advance beyond Scandinavia. All glaciations and loesses, as well as interglacials and palaeosols that are considered asmain climatostratigraphic units of the Pleistocene of Central Europe, are grouped into climatic cycles and megacycles that correlate with corresponding units of Western Europe.
Źródło:
Geological Quarterly; 2006, 50, 1; 195-210
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Relative sea level changes and development of the Hiiumaa Island during the Holocene
Autorzy:
Vassiljev, J.
Saarse, L.
Grudzinska, I.
Heinsalu, A.
Powiązania:
https://bibliotekanauki.pl/articles/2059662.pdf
Data publikacji:
2015
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Litorina Sea
Limnea Sea
lithology
diatoms
AMS 14C dates
Estonia
Opis:
Three sediment cores (Loopsoo, Tihu, Prassi) from Hiiumaa Island (Estonia) were investigated using diatoms, lithological proxies, magnetic susceptibility, geochronological dates and incorporated with the previously studied Kõivasoo site, aiming to reconstruct the development of the island and shoreline changes during the Litorina Sea and the Limnea Sea. The highest level of the Litorina Sea shoreline near Kõivasoo is at 27.6 m a.s.l., and it occurred during the Initial Litorina Sea. Within the Litorina Sea transgression, 7800 cal yr BP, relative sea level reached 24.9 m a.s.l. at Kõivasoo, 24.1 m a.s.l. at Loopsoo, 23.6 m a.s.l. at Tihu, and 21.5 m a.s.l. at Prassi. Kõivasoo became isolated from the sea about 8500 cal yr BP, Loopsoo between 7100 and 6800 cal yr BP, Tihu around 4800 cal yr BP, and Prassi about 2500 cal yr BP. Presently gained data from Hiiumaa Island confirm that the Litorina Sea regressed consistently during the last 8000 years due to progressively declining isostatic rebound. The present study is also illustrated by 3-dimensional palaeogeographic maps of the Hiiumaa Island development.
Źródło:
Geological Quarterly; 2015, 59, 3; 517--530
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Groundwater flow conditions in the coastal bedrock area of the Gulf of Finland
Autorzy:
Mälkki, E.
Powiązania:
https://bibliotekanauki.pl/articles/2058880.pdf
Data publikacji:
2003
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
groundwater
bedrock
groundwater discharge
Baltic Sea
Opis:
The coastal area and archipelago of the Gulf of Finland mostly comprises bedrock terrain with a generally thin soil cover and represents a distinct hydrogeological regime. The bulk of the bedrock area consists of relatively unbroken blocks with small, hydraulically uniform systems. The direct groundwater flow from the blocks to the sea is restricted to the blocks bordering the sea. The blocks are crossed by faults and fractures, which locally form long broken zones inside the rock mass. A single fault can catch water from several blocks and also from the soil cover. Most groundwater in the coastal strip flows to the sea through the bedrock fault zones, which are thought to represent the most favourable flow conditions. The dimensions of hydraulically uniform horizons, hydraulic conductivities and hydraulic gradients of the fault zones are poorly known. The estimated groundwater flow distance from the land to the sea in the faults reaches 8–10 km, thought the average distance may only be around 2 km. In the block areas the flow distance is even shorter, down to about one kilometre. On the whole, the amount of groundwater discharging directly to the sea from this regime (excluding overlying sand and gravel deposits), which has a surface area of around 2100 km2, is approximately 4 m3 s–1. This is a third of the total direct discharge to the sea in the coastal areas of Finland.
Źródło:
Geological Quarterly; 2003, 47, 3; 299-306
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The history of the Yoldia Sea in Northern Estonia: palaeoenvironmental conditions and climatic oscillations
Autorzy:
Heinsalu, A.
Veski, S.
Powiązania:
https://bibliotekanauki.pl/articles/2059524.pdf
Data publikacji:
2007
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Estonia
Yoldia Sea
palaeoenvironment
diatoms
pollen analysis
Opis:
Late glacial and Early Holocene sediment sequences from North ern Estonia were investigated using diatom and pollen analysis and the accelerator mass spectrometry (AMS) 14C dating. The results of diatom analysis indicate that fresh water conditions prevailed during the initial and final phases of the Yoldia Sea in the investigated area. A near-bottom saline water current that penetrated into the Baltic Sea Basin during the brackish phase of the Yoldia Sea spread into the Gulf of Finland at ca. 11 300-11 200 calendar years BP. Coastal upwelling probably caused mixing of the water column and the circulation of brackish water up to the surface incertain near-shore areas in the Gulf of Finland. A slight change in the pollen composition may suggest deterioration in the climate and can be correlated to the Preboreal Oscillation. AMS 14C dates on aquatic plant macrofossils suggest a reservoir ef fect more than 1000 year for the brackish phase of the Yoldia Sea.
Źródło:
Geological Quarterly; 2007, 51, 3; 295-306
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Geohazard assessment of the coastal zone : the case of the southern Baltic Sea
Autorzy:
Uścinowicz, Grzegorz
Szarafin, Tomasz
Pączek, Urszula
Lidzbarski, Mirosław
Tarnawska, Ewa
Powiązania:
https://bibliotekanauki.pl/articles/2058861.pdf
Data publikacji:
2021
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
coastal measurements
northern Poland
land-sea interaction
Opis:
Research by the Polish Geological Survey has been carried out along the southern Baltic coastal zone over a distance of 38 km. The Baltic Sea is classified as non-tidal, and its southern coasts are built entirely of weakly lithified sedimentary rocks. These deposits form three main types of coast, namely cliffs, barriers and alluvial coasts (wetlands), with the research focusing on the first two. Methods including remote sensing, mapping (geological, hydrogeological), offshore survey (bathymetric and geophysical measurements), laboratory analyses and modelling revealed a number of natural hazards. These are, respectively: (1) permanently occurring hazards, causing material damage such as: landslides, coastal erosion and seabed erosion; (2) incidental hazards such as dune breakage and storm surge overflow and (3) hypothetical threats that may occur in the future, such as hydrogeohazards defined here as flooding resulting from groundwater level rise or more rarely, earthquake threats.
Źródło:
Geological Quarterly; 2021, 65, 1; 5
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Probable root structures and associated trace fossils from the Lower Pleistocene calcarenites of Favignana Island, southern Italy : dilemmas of interpretation
Autorzy:
Uchman, A.
Ślączka, A.
Renda, P.
Powiązania:
https://bibliotekanauki.pl/articles/2060614.pdf
Data publikacji:
2012
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
ichnology
root structures
burrows
carbonates
Quaternary
Mediterranean Sea
Opis:
Two types of large, branched structures from the Lower Pleistocene (Calabrian) high-energy calcarenites of Favignana Island are described: Faviradixus robustus gen. et sp. nov. and Egadiradixus rectibrachiatus gen. et sp. nov. They may be interpreted as root structures of large plants, trees and trees or shrubs, respectively. The former taxon co-occurs with the marine animal trace fossils Ophiomorpha nodosa, Ophiomorpha isp., Thalassinoides isp. and Beaconites isp. The interpretation as root structures although tentative is probable and can be related to short emergence episodes for the formation of E. rectibrachiatus or to longer emergence, responsible for the discontinuity at the base of the overlying Tyrrhenian deposits, for F. robustus. Calcified root mats of smaller plants associated with the Tyrrhenian or younger emergence surfaces are common.
Źródło:
Geological Quarterly; 2012, 56, 4; 745--756
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hydrocarbon and aqueous inclusions in minerals: a review of analyses and interpretations for Paleozoic rocks in Poland
Autorzy:
Jarmołowicz-Szulc, Katarzyna
Powiązania:
https://bibliotekanauki.pl/articles/2058676.pdf
Data publikacji:
2021
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
fluid inclusions
hydrocarbons
Paleozoic
Baltic Sea
Polish Lowlands
Opis:
Two decades of microthermometric studies of fluid inclusions within cements of Paleozoic sedimentary rocks in Poland are reviewed. The inclusions contain palaeofluids of variable composition: aqueous, brine, and hydrocarbon. They may be primary and/or secondary in origin and have one, two or more phases. They display visual fluorescence in blue, sometimes yellow to red (oil) or dull blue (one phase, methane) colours, or do not fluoresce at all. Based on the fluorescence characteristics in ultraviolet light, the inclusions' hydrocarbons infill character may be estimated. The homogenization temperatures, which correspond to the minimum estimate of the trapping temperatures in the minerals, show variability in respect to the geological history of the area studied. They point to different geological stages in relation to the basin's burial evolution. Microthermometric analyses enable wider interpretation due to the combination of studies of both hydrocarbon and aqueous inclusions. The presence of oil and/or gas in inclusions is proof of the occurrence and/or migration of oil and gas in the rocks of a region.
Źródło:
Geological Quarterly; 2021, 65, 4; 158--176
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mercury and methylmercury in Baltic Sea sediments, and Polish and Lithuanian soils
Autorzy:
Ignatavičius, Gytautas
Unsal, Murat H.
Busher, Peter E.
Wołkowicz, Stanisław
Satkūnas, Jonas
Valskys, Vaidotas
Powiązania:
https://bibliotekanauki.pl/articles/2201219.pdf
Data publikacji:
2022
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
mercury
methylmercury
soil
sediment
Lithuania
Polska
Baltic Sea
Opis:
We review the current environmental pollution by mercury in the soils of Poland and Lithuania and in the sediments of the Baltic Sea. Mercury is documented to have many negative impacts on the environment as a toxic trace element. In many different chemical forms, it is being released into the environment by both geogenic and anthropogenic activities, with most being released from anthropogenic sources. Methylmercury is considered one of the most toxic forms found in the environment. Mercury levels in sediment and various point sources increased after World War II in the Baltic Sea, which was used as a dumpsite. Previous studies show noticeable differences in total mercury in the Baltic Sea. In the Warta and Odra rivers in Poland, mercury levels are also higher than the background value, though recent findings suggest that river sediments are not the main source of mercury to marine sediments. Concentrations in soils in Poland and Lithuania were below the level of limit values (1 and 1.5 mg/kg-1 respectively), but Upper Silesia showed concentrations (up to 4.01 mg · kg-1) above the limit values. Furthermore, between 1992 and 2006, mercury levels in Wroc³aw dropped dramatically. The dominant trees in the area can affect mercury accumulation. No data were available for comparison with the soils in Estonia and Latvia.
Źródło:
Geological Quarterly; 2022, 66, 3; art. no. 22
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ordovician seawater composition : evidence from fluid inclusions in halite
Autorzy:
Meng, F.
Zhang, Y.
Galamay, A. R.
Bukowski, K.
Ni, P.
Xing, E.
Ji, L.
Powiązania:
https://bibliotekanauki.pl/articles/2059770.pdf
Data publikacji:
2018
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Ordovician
fluid inclusions
halite
seawater composition
calcite sea
Opis:
Fluid inclusions in halite can directly record the major composition of evaporated seawater; however, Ordovician halite is very rare. The Ordovician is a key time during the evolution history because profound changes occurred in the planet’s ecosystems. Marine life was characterized by a major diversification, the Great Ordovician Biodiversification Event and the Late Ordovician Mass Extinction, the first of the “big five” mass extinctions. However, so far there is no data on the Ordovician seawater. Data from the Ordovician-Silurian boundary were available only. In this study, we report the major compositions from Middle Ordovician halite in China to give the exact composition of Ordovician seawater. The basic ion composition (K+, Mg2+, Ca2+, and SO42-) of inclusion brines was established with the use of ultramicrochemical analysis. The data on the chemical composition of the brines in the primary inclusions indicated that the brines were of Na-K-Mg-Ca-Cl (Ca-rich) type, and cover a huge gap in the evolution of seawater chemistry. The chemical composition of the primary inclusion brine in halite confirmed the earlier results for the Cambrian and Silurian halite originating from other salt basins and the previous speculation of “calcite sea” during the Ordovician, indicating a higher potassium content in the Lower Paleozoic seawater than in the seawater of other periods of the Phanerozoic.
Źródło:
Geological Quarterly; 2018, 62, 2; 344--352
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The lower reaches of the Nemunas River at the end of the Last (Weichselian) Glacial and beginning of the Holocene
Autorzy:
Bitinas, A.
Druzhinina, O.
Damušytė, A.
Napreenko-Dorokhova, T.
Guobytė, R.
Mažeika, J.
Powiązania:
https://bibliotekanauki.pl/articles/2060341.pdf
Data publikacji:
2017
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Baltic Sea
Nemunas Delta
Ancylus Lake
palaeogeography
hydrography
archaeology
Opis:
The Russian–Lithuanian cross-border area around the Nemunas and Šešupė rivers confluence is a key area for solving palaeogeographic issues important for this region: when the Nemunas Delta started to form, why the essential changes of hydrographic network occurred, and so on. The results of conventional radiocarbon (14C) dating and pollen analysis in the present dry valley between the Šešupė River and the Įrutis River as well as the results of former studies at the Riadino-5 archaeological site suggest that the essential changes in the Nemunas River hydrographic system occurred before 9.5 ka, most likely in Preboreal time, when the Nemunas River cut through the Vilkiškė Marginal Ridge and started to flow directly to the west from this ridge into one of the former basins of the Baltic Sea – to the Yoldia Sea, or to the Ancylus Lake. A new divide was formed between the Šešupė and Įsrutis rivers, and the basins of the Nemunas and Prieglius rivers (formerly a single hydrographic system) became two independent drainage basins of the Baltic Sea. The present Nemunas Delta formation started after the Litorina Sea transgression when the Nemunas River mouth moved from a Baltic Sea nearshore position to close to the western margin of the Vilkiškės Marginal Ridge. A set of palaeogeographic reconstructions of the Nemunas and Šešupė rivers confluence area for different periods of the very end of the Last (Weichselian) Glacial and the beginning of the Holocene have been constructed.
Źródło:
Geological Quarterly; 2017, 61, 1; 156--165
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Outline of the lithology and depositional features of the lower Paleozoic strata in the Polish part of the Baltic region
Autorzy:
Podhalaska, T.
Modliski, Z.
Powiązania:
https://bibliotekanauki.pl/articles/2059058.pdf
Data publikacji:
2010
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Lower Paleozoic
northern Poland
Baltic Sea
lithostratigraphy
deposition
thickness
Opis:
Lower Paleozoic deposits have been noted in the western part of the Baltic Depression belonging to the Precambrian platform as well as in the Koszalin-Chojnice Zone that represents a hypothetical fragment of the Caledonian fold and thrust belt. Generally, the boundary between these regions is considered to run along faults belonging to the Teisseyre-Tornquist Zone. The deposits have been widely recognized in the East European Craton, and their entire lithological column has been drilled through in on- and offshore boreholes. New constructed lithofacies-thickness maps have updated the lithofacies diversity and thickness changes of the Ediacaran-lower Paleozoic deposits. The sedimentary infill of the Baltic Basin begins with deposits of the arnowiec Formation ascribed to the uppermost Ediacaran and lowermost Cambrian. The upper part of the Lower Cambrian comprises sandstones and mudstones and the Middle Cambrian is made of sandstones, mudstones and claystones. Upper Cambrian to Tremadocian strata are represented by dark bituminous shales. Arenigian to Ashgillian deposits are developed as thin calcareous-muddy deposits. Silurian strata represent a thick (over 3000 m) succession of siltstones and shales with subordinate calcareous intercalations in the upper part of the succession (Pridoli). In the Koszalin-Chojnice Zone only, fragments of tectonically disturbed Ordovician and Silurian shales and siltstones have been recognized.
Źródło:
Geological Quarterly; 2010, 54, 2; 109-121
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A multidisciplinary study on the palaeoenvironmental history of the Resko Przymorskie Lake spit during the Late Glacial and Holocene (the southern Baltic coast, NW Poland)
Autorzy:
Sydor, P.
Krzymińska, J.
Rzodkiewicz, M.
Kotrys, B.
Powiązania:
https://bibliotekanauki.pl/articles/2059656.pdf
Data publikacji:
2015
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
sedimentology
pollen
diatom
ostracods
molluscs
palaeogeography
Baltic Sea coast
Opis:
The paper presents the results of sedimentological and biostratigraphical analyses from the Resko Przymorskie Lake spit (NW Poland), supported by radiocarbon datings. The study has aimed to recognize the geological structure of the spit and its base and to recognize the palaeoenivronmental changes. Nine sedimentary series composing the Resko Przymorskie Lake spit have been distinguished (I–IX). The oldest sediments are the Vistulian Glaciation till (series I) and fluvioglacial sand and gravel (series II). In the Early Holocene, in the study area there was a river valley (series III) followed by a shallow water basin (series IV), which was replaced by a peat bog (series V). In the Atlantic (7.4 ka cal BP), the water level rose (Littorina transgression) and accumulation of lagoonal sediments started (series VI). Biostratigraphic analysis of deposits in series VI indicates a marine influence. In the Atlantic and Subboreal, the spit moved southwards and fine sand (series VII) was deposited on lagoonal gyttja and silt (series VI). In the western part of the study area, peat accumulated (series VIII), dated at 6.7 ka cal BP (Late Atlantic). The youngest series IX is composed of aeolian fine sand in white dunes that formed in the last 400 years.
Źródło:
Geological Quarterly; 2015, 59, 3; 531--550
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Review of Miocene shallow marine and lacustrine depositional environments in Northern Croatia
Autorzy:
Malvić, T.
Powiązania:
https://bibliotekanauki.pl/articles/2059402.pdf
Data publikacji:
2012
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Pannonian Sea
Pannonian Lakes
Paratethys
Miocene
alluvial fans
turbidites
Opis:
The Neogene and Quaternary depositional and structural characteristics of the southwestern Croatian Pannonian Basin System (CPBS) are unique within the Pannonian Basin System. Due to its position at the basin margin, the area was covered by shallow and partially isolated parts of the Pannonian Sea in the Badenian (Middle Miocene). Later, in the Pannonian and Pontian ages, the area contained several brackish lakes, the largest being Sava Lake and Drava Lake. Tectonic events, sedimentation and depositional mechanisms occurring during the Neogene in the CPBS have revealed that those areas can be considered as former shallow seas or lakes dominated by clastic sedimentation. Marine coarse-grained clastic sedimentation took place during the Badenian, with local sources of material and numerous alluvial fans developed during the first transtensional phase. In the Pannonian and Pontian (Late Miocene), sediments were deposited by turbidity currents from a single, distal material source located in the Eastern Alps during the second transtensional tectonic phase.
Źródło:
Geological Quarterly; 2012, 56, 3; 493--504
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Geochemical signatures of pervasive meteoric diagenesis of Early Miocene syn-rift carbonate platform, Red Sea, NW Saudi Arabia
Autorzy:
Al-Ramadan, K.
Powiązania:
https://bibliotekanauki.pl/articles/2060345.pdf
Data publikacji:
2017
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
meteoric diagenesis
carbonate
stable isotopes
trace elements
Red Sea
Miocene
Opis:
Different diagenetic environments have been recognized in the Early Miocene carbonate platform of Musayr Formation in the Red Sea rift area. Early marine diagenesis includes micritisation that occurs as thin envelope around skeletal and non-skeletal grains in low-energy mud dominated facies and isopachous fibrous calcite in high-energy grain-dominated facies. Pervasive meteoric water diagenesis resulted in cementation of the carbonates by coarse-crystalline blocky-drusy calcite and meniscus cements. Depletion of oxygen (avg. –9.08‰), carbon (avg. –1.6‰) isotopes and trace elements concentrations (avg. values of Fe: 1387 ppm; Mn: 1444 ppm; Sr: 419 ppm; Na: 1194 ppm) in conjunction with negative correlation between Mn2+ and oxygen isotope data suggest variable degrees of fluid-rock interactions and pervasive meteoric diagenesis. The formation of meteoric diagenesis in the Musayr Formation can be explained by two subsequent mechanisms: (1) the presence of meteoric lenses during the time of deposition might have been associated with active freshwater input from the hinterland (NE) due to fall in the relative sea level; (2) later uplift episode during Plio-Pleistocene may have also contributed to the pervasive meteoric diagenetic alterations of the carbonates of the Musayr Formation. The first mechanism is supported by the cement stratigraphy where the blocky-drusy cements postdate the meniscus cement. The latter mechanism seems to have more pronounced effect on the alteration of Musayr carbonate sequence by observing the occurence of late cements such as blocky calcite in most of the samples. The impact of meteoric diagenesis on the studied samples suggest that dissolution is less severe than cementation, hence the visible porosity is very low. Understanding the timing of meteoric diagenesis provides useful information about the reservoir quality distribution in syn-rift carbonate sequences.
Źródło:
Geological Quarterly; 2017, 61, 1; 239--250
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Geochemistry of surface sediments from the northwestern Gulf of Mexico : implications for provenance and heavy metal contamination
Autorzy:
Armstrong-Altrin, John S.
Botello, Alfonso V.
Villanueva, Susana F.
Soto, Luis A.
Powiązania:
https://bibliotekanauki.pl/articles/2058576.pdf
Data publikacji:
2019
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Tamaulipas
deep-sea sediments
enrichment factor
contamination
principle component analysis
Opis:
Thirty-five near-surface sediment samples were recovered from the continental shelf and upper slope regions of the north-western (NW) Gulf of Mexico. The geochemical data of the sediments recovered were examined to investigate the weathering intensity, provenance, palaeo-oxygenation condition, and level of heavy metal contamination. The sediments analysed showed a moderate to high intensity of chemical weathering. Major and trace element concentrations indicated a terrigenous origin, closely related to the weathering of rocks rich in aluminosilicates. The results of this study further revealed that major rivers, the Bravo and Soto La Marina, played an important role in delivering sediments to the study area. The concentration of transition trace elements such as Cr, Cu, Ni, and V revealed that the sediments were derived from intermediate rocks such as andesite. The V/Cr, Ni/Co, and Cu/Zn ratios in the sediments were <2, <5, and <1, respectively, suggesting a depositional process occurred under well-oxygenated conditions. Principle Component Analysis (PCA) did not show a significant difference in sediment texture between the continental shelf and slope areas. The enrichment factor (EF) and Geo-accumulation index (lgeo) values were <2 and <1, respectively, suggesting the absence of an anthropogenic input.
Źródło:
Geological Quarterly; 2019, 63, 3; 522--538
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł

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