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Tytuł:
Geochemical and tectonic characteristics of manganese mineralization in the Yozgat region, Turkey
Autorzy:
Öksüz, Nursel
Koçak, İsmail
Temiz, Uğur
Powiązania:
https://bibliotekanauki.pl/articles/2059613.pdf
Data publikacji:
2021
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
manganese
geochemistry
hydrogenetic
hydrothermal
Yozgat
Turkey
Opis:
North of the Central Anatolian Crystalline Complex and bordered by the İzmir–Ankara–Erzincan Suture Zone, mineralization occurs within ophiolites known as Anatolian Ophiolite Complex. The mineralization is present within banded, laminated and lenticular radiolarites which are intensely fractured and folded. It is distributed around Derbent, Baltasarilar, Cihanpasa, Buyukmahal, Eymir and Kadisehri where pyrolusite, psilomelane, manganite and braunite comprise the main paragenesis and jacobsite, magnetite, limonite and goethite are minor phases. The negative Eu anomaly suggests that the hydrothermal source was distant from the mineralization area or was mixed with seawater. All samples from the Cihanpasa and Buyukmahal areas have a negative Ce anomaly and resemble low-temperature hydrothermal mineral deposits. Samples from other locations (Derbent, Baltasarilar, Cihanpasa, Eymir, Buyukmahal, Tarhana) are characterized by both negative and positive Ce anomalies. From this it can be inferred that both hydrothermal and hydrogenetic processes were active in mineralization. High Ba contents and a LREE-enriched pattern together with negative Ce anomalies and trace element distributions indicate that the mineralization in the area was derived from a primary hydrothermal source. In addition, diagenetic and epigenetic processes may also have played an important role in the manganese mineralization.
Źródło:
Geological Quarterly; 2021, 65, 2; 65: 31
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Environmental stress in the northern Tethys during the Paleogene : a review of foraminiferal and geochemical records from the Polish Outer Carpathians
Autorzy:
Olszewska, B.
Szydło, A.
Powiązania:
https://bibliotekanauki.pl/articles/2060601.pdf
Data publikacji:
2017
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Outer Carpathians
Polska
Paleogene
foraminifera
geochemistry
Opis:
During the Paleogene, the area of the northern Tethys was controlled by a turbidity system stimulated by diastrophic and geodynamic processes. These factors contributed to the dispersion and rapid oxygenation of organic debris. Its accumulation was a consequence of stagnant bottom water conditions that periodically occurred in the basin. In these periods, intense decomposition intensified by hydrothermal and diagenetic processes was associated with oxygen consumption and the release of greenhouse gases, which led to hypoxia and acidification. These phenomena intensified by thermal and density stratification had a major impact on the structure, evolution and distribution of biota. Stress associated with rapidly changing conditions induced by sedimentary process and upwelling resulted in the dominance of forms that colonized most sediments (Glomospira, Ammodiscus, Recurvoides, Rzehakina) and surface waters (Guembelitria, Chiloguembelina, Globanomalina, Globigerina, Cassigerinella, Catapsydrax). At the time, foraminifera were limited to low-diversified eutrophic assemblages or were mainly replaced by siliceous phytoplankton (radiolarians and diatoms). Geochemical data confirm that environmental crises in the Paleogene basin took place under changing thermal conditions that reflect global events (KTBE, PTME, EEOC and TTE). Thermal stress favouring the formation of certain minerals or rocks occasionally occurred during the Paleocene to Eocene (siderite, phosphates) and dominated in the Early Oligocene (silica).
Źródło:
Geological Quarterly; 2017, 61, 3; 682--695
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Geochemistry of shales of the Qadir Member (Nayband Formation, Upper Triassic), East Central Iran (Tabas Block) : implications for provenance and palaeogeography
Autorzy:
Zamaniyan, Ehsan
Khanehbad, Mohammad
Moussavi-Harami, Reza
Mahboubi, Asadollah
Powiązania:
https://bibliotekanauki.pl/articles/2058574.pdf
Data publikacji:
2019
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Triassic
Nayband Formation
Tabas
provenance
geochemistry
Opis:
The Upper Triassic shale of the Qadir Member of the Nayband Formation, East Central Iran has been analysed geochemically to evaluate provenance and palaeogeography. The Qadir Member in the Parvadeh Coal Mine section is 450 metres thick, and includes sandstone, shale, coal, siltstone, and fossiliferous limestone. XRD analysis of shale samples from the Qadir Member largely indicated the presence of illite and chlorite, with small amounts of kaolinite and montmorillonite. On binary and triangular diagrams the data suggests an intermediate igneous source rock for these shales. Plotting the geochemical data on binary diagrams also indicates the tectonic setting of an active continental margin, perhaps reflecting the Early Cimmerian tectonic event with Neothetys subduction under the Iran Plate, and collision of the Iran Plate with Turan during the Late Triassic. The Chemical Index of Alteration (CIA) and Plagioclase Index of Alteration (PIA) values for shale from the Qadir Member of Nayband Formation vary from 74.04 to 80.54 (average 78.02) and 84.31 to 91.85 (average 87.81), respectively, indicating moderate to high chemical alteration in the source area and suggesting a semi-humid climate during deposition. The geochemical data and palaeogeographical models indicate that the Qadir Member shale was deposited on an active margin in a shoreline to transitional-marine setting.
Źródło:
Geological Quarterly; 2019, 63, 3; 603--618
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Timing of ore mineralization using ore mineralogy and U-Pb dating, Iron Oxide Copper Gold Sin Quyen deposit, North Vietnam
Autorzy:
Pieczonka, Jadwiga
Nguyen, Chau Dinh
Piestrzyński, Adam
Le, Phon Khanh
Powiązania:
https://bibliotekanauki.pl/articles/2058646.pdf
Data publikacji:
2019
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
IOCG deposit
uraninite dating
mineral stages
geochemistry
Opis:
Magnetite, pyrite, pyrrhotite, chalcopyrite and sphalerite are the major minerals identified in the deposit, while ilmenite, marcasite, tennantite, cubanite, arsenopyrite, galena, allanite, chevkinite, apatite, Bi-native, bismuthinite, electrum, native gold, and tellurides are the minor ones in the Iron Oxide Copper Gold (IOCG) Sin Quyen deposit. The REEs are hosted mostly by allanite, and the minor minerals by chevkinite, monazite, apatite and uraninite. Based on chemical analyses and Raman spectroscopy, two varieties of allanite have been documented: (1) with lower total REE contents of 13-19 wt.%, and (2) with higher contents of 20-23 wt.%. Uraninite from copper-iron massive ores is inhomogeneous in both optical properties and chemical composition. The concentrations of uranium and total rare earth element oxides (REOs) in the paragenetically earlier uraninite are 84.55-85.96% and 1.9-8.0% on average, respectively, whereas in paragenetically later uraninite, the U and ΣREE2O3 concentrations are 96.2-96.7% and 1.3-2.7% on average respectively. The thorium concentration in both the early and late uraninites is very low (0.21-0.22% and 0.2 % on average). These are the highest REE concentrations as compared with the known concentrations of these elements in uraninite. Electron microprobe “chemical” dating of the uraninite yielded an age of 500 ±33 Ma (n = 35) for the paragenetically early uraninite, and an age of 73 ±15 Ma (n = 6) for the paragenetically later ones. The minerals of the older age, which is interpreted as the primary ore mineralization stage, correspond in age with a range of deposits along the East Gondwana margin. The measured δ34S of sulphide minerals from -2.78 to +8.65‰ suggests hydrothermal origin of fluid that was responsible for transportation and crystallization.
Źródło:
Geological Quarterly; 2019, 63, 4; 861--874
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Strontium isotope ratios and REE geochemistry in the Suwałki anorthosites, NE Poland
Autorzy:
Wiszniewska, J.
Powiązania:
https://bibliotekanauki.pl/articles/2059431.pdf
Data publikacji:
2000
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Suwałki Anorthosite Massif
strontium ratio
REE geochemistry
Opis:
Strontium isotope ratios for 14 samples of anorthositic rocks in the Suwałki Anorthosite Massif (SAM) range from 0.704875 to 0.705772. The same isotopic ratios calculated for 1.5 Ga (the U-Pb zircon age of the rapakivi-like granites from adjacent Mazury Complex) range from 0.704583 to 0.705483. The corresponding eSr1500 values for the same rocks range from 25.5 to 39.0. The pronounced Eu anomaly which characterises the REE distribution in the anorthosite plagioclase is consistent with early crystallization from basic magma.
Źródło:
Geological Quarterly; 2000, 44, 2; 183-186
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Petrographic and geochemical study of the Maastrichtian Ajali Sandstone, North Central Nigeria
Autorzy:
Ogala, J. E.
Olobaniyi, S. B.
Omo-Irabor, O. O.
Adaikpoh, E. O.
Powiązania:
https://bibliotekanauki.pl/articles/2059843.pdf
Data publikacji:
2015
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
petrography
geochemistry
Ajali Sandstone
provenance
tectonic setting
Opis:
he Upper Cretaceous Ajali Sandstone is an extensive stratigraphic unit of the Anambra Basin in southern Nigeria. It consists of friable, white cross-bedded sandstones exhibiting a fining upward sequence. Structures such as bioturbation, planar and herringbone cross beds indicate variability in depositional environment ranging from fluviatile to deltaic. Petrographic and geochemical compositions (major and trace elements) of these sandstones have been investigated to determine their provenance, tectonic setting and weathering conditions. Fifteen sandstone samples examined are rich in quartz but poor in feldspar and lithic fragments. Texturally, the framework grains of the sandstones are fine- to medium-grained, sub-angular to sub-rounded, moderately sorted to poorly sorted, positively skewed and leptokurtic. The sandstones are texturally immature as depicted by their sub-angular edges of grains, but mineralogically mature in terms of high percentage of quartz. The high chemical index of alteration (CIA) values (71.0–99.2%) for these sandstones suggests that they were derived from highly weathered rocks in the source area. The composition of the major oxides in the sandstones revealed that SiO2 (49.1–99.7%), Al2O3 (0.2–30.3%), Fe2O3 (0.4–1.8%) and TiO2 (0.06–3.2%) were the most abundant elements in all sandstone samples indicating a high detrital quartz and clay mineral content. The Al2O3/TiO2 ratios (1.47 to 12.48), Ti/Zr (6.48–18.63) and Zr/Cr (2.24–22.36) suggest that the sandstones were derived from variable basement complex rocks, including some contribution from mafic or ultramafic components. Inferences from the plots of K2O/Na2O versus SiO2 indicated a passive margin tectonic setting for the sandstones. The high loading of CaO and Na2O in more than 50% of the samples is indicative of terrigenous input, mainly in the form of carbonates and silicates. These results are generally consistent with a derivation of the sandstones from adjacent igneous and metamorphic basement complexes (Cameroon–Adamawa highlands and Oban Massif) while the extensive and blanket-like geometry of the Ajali Sandstone is indicative of an excellent reservoir for groundwater in the Anambra Basin.
Źródło:
Geological Quarterly; 2015, 59, 1; 79--90
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Depositional redox conditions of the Grybów Succession (Oligocene, Polish Carpathians) in the light of petrological and geochemical indices
Autorzy:
Wójcik-Tabol, P.
Powiązania:
https://bibliotekanauki.pl/articles/2059988.pdf
Data publikacji:
2015
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Paratethys
Oligocene
Grybów Succession
geochemistry
organic matter
Opis:
This study details the petrology and chemistry of the Oligocene succession of the Grybów Nappe in its stratotype-locality in the Grybów tectonic window (Polish Carpathians). The section studied is composed of the Sub-Grybów Beds, the Grybów Marl Formation (GMF), and the Cergowa Beds, representing the middle to upper part of the Oligocene succession. The rocks studied consist of quartz, calcite, Na-plagioclase, muscovite and clay minerals (illite-smectite with 25–30% of smectite and kaolinite). Additionally, hematite occurs in the GMF and chlorite in the Cergowa Beds, respectively. The macerals assemblage of the GMF is dominated by landplant-derived compounds of liptinite, associated with minor amounts of vitrinite representing type II kerogen. The total organic carbon (TOC) content is between 0.45 and 6.16 wt.%. The δ13Corg values of the GMF vary between –27.1 and –27.9‰. The values of both carbon and oxygen isotopic ratios of carbonates range for δ13C from –1.1 to –4.3‰ VPDB, and for O from –1.5 to –4.8‰ VPDB. The concentrations of Co, U, Ni, As, and Mo are higher in the GMF than in the adjacent strata and positively correlate with TOC and S. Values of the TOC/S and V/V+Ni ratios are 0.7 to 3.5 and 0.67 to 0.78, respectively, and indicate anoxic conditions. The ratios of U/Th and V/Cr (0.3–2.2, 1.18–3.18, respectively) suggest the change of oxic conditions to reducing conditions occurred during the GMF deposition. This change could have been preceded by a plankton bloom, initiated by a nutrient-rich freshwater inflow that is inferred from the decrease of the δ13Ccarb values and the terrestrial detritus supply. Thermal alteration of the Grybów Succession is concluded on the basis of smectite illitisation and low δ18O values.
Źródło:
Geological Quarterly; 2015, 59, 4; 603--614
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Geochemistry and geochronology of the Jawornik granitoids, Orlica–Śnieżnik Dome, Sudetes, Poland
Autorzy:
Białek, Dawid
Powiązania:
https://bibliotekanauki.pl/articles/2060123.pdf
Data publikacji:
2020
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Jawornik granitoids
geochemistry
geochronology
Sudetes
Variscan
granitoids
Opis:
The Jawornik granitoids intrude, in vein-like form, a sequence of a polymetamorphic metavolcanic and metapelitic rocks of the Orlica-Śnieżnik Dome, Sudetes, Poland. This paper provides whole-rock geochemical data, sensitive high-resolution ion microprobe (SHRIMP) U-Pb zircon geochronological data as well as 40Ar-39Ar age determinations to constrain the genetic and temporal relationships of the different rock types forming these veins. Based on macroscopically visible features of the granitoids and their relationship with tectonic structures visible in the country rocks, four varieties of the Jawornik granitoids have been distinguished: amphibole- and biotite-bearing granites (HBG), biotite-bearing granites (BG), biotite- and muscovite-bearing granites (BMG) and muscovite-bearlng granites (MG). The Jawornik granitoids as a whole show a limited but significant variation in major element chemical composition, with SiO2 ranging from 65 to 76 wt.% (average 69.16 wt.%, n = 24). They are subalkalic, peraluminous and calc-alkaline [average A/CNK = 1.07, average (Na2O + K2O) = 7.75, average (Fe2O3t/(Fe2O3t + MgO) = 0.59]. Close inspection of their geochemical parameters showed that the samples investigated can be subdivided into two groups. The first group, the HBG, BG, and BMG varieties, comprising most of the granitoids in the Złoty Stok-Skrzynka Tectonic Zone, were formed by melting of greywackes or/and amphibolites. The MG, belonging to the second group, were formed by partial melting of a more felsic source. The HBG yielded a zircon U-Pb age of 351 ±1.3 Ma and well-defined Ar-399Ar plateau ages for hornblende (351.1 ±3.9 Ma) and coexisting biotite (349.6 ±3.8 Ma), indicating probably the oldest magmatic event in this region. Zircons from the MG, the youngest rock variety on the basis of their relationship with the tectonic structures in the host rocks yielded a U-Pb age of 336.3 ±2.4 Ma, though based on three points only. The biotites and muscovites from the BMG have Ar-39Ar plateau ages of 344.1 ±4.7 Ma and 344.6 ±3.8 Ma, respectively. These data, in combination with already published isotopic ages, suggest that the Jawornik granitoids intruded host rocks of the Orlica-Śnieżnik Dome in three stages, at ~350, ~344 and ~335 Ma.
Źródło:
Geological Quarterly; 2020, 64, 4; 942--957
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Geochemical composition of Vistulian loess and micromorphology of interstadial palaeosols at the Kolodiiv site (East Carpathian Foreland, Ukraine
Autorzy:
Łącka, B.
Łanczont, M.
Madeyska, T.
Boguckyj, A.
Powiązania:
https://bibliotekanauki.pl/articles/2059503.pdf
Data publikacji:
2007
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Ukraine
Late Pleistocene
palaeosols
loess
micromorphology
geochemistry
Opis:
This paper summarizes geochemical and palaeopedological investigations of the Upper Pleistocene loess-palaeosol sequences at the Kolodiiv site. The Kolodiiv 2, 3 and 5 profiles were selected for this study. The Kolodiiv 2 profile contains loesses, interglacial (Eemian) and interstadial (Vistulian) palaeosols. A set of Early Vistulian soils over lying Eemian gyttja and peat is exposed in the Kolodiiv 3 and 5 profiles. The mineral composition of the 50-2 mm silt fraction was analysed using non-oriented powder samples by means of X-ray dif - fraction. The total concentrations of nine major (Si, Ti, Al, Fe, Mn, Mg, Ca, K and Na) and nine trace elements (Zn, Pb, Ni, Rb, Cr, Sr, Ba, Co, V) as well as the humus content and loss on ignition were measured. The major elements concentrations in mineral deposits from the Kolodiiv 2 loess-palaeosol sequence indicate that the loess particles were derived from poorly weathered source rocks that have under - gone at least one sedimentary cycle. Climatic conditions have strongly in fluenced the mobilization and accumulation of elements in the palaeosol horizons due to the changes in the intensity of weathering and pedogenic processes. For the micromorphological study, ten samples from the Kolodiiv 3 and 5 profiles were used. Thin sections representing the Kolodiiv and Dubno set of palaeosols from Early Vistulian and Middle Pleniglacial show, be sides palaeopedologic characteristics, significant evidence of redeposition of sediments and soils.
Źródło:
Geological Quarterly; 2007, 51, 2; 127-146
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Geochemistry of siliciclastic rocks from the Shemshak Group (Upper Triassic-Middle Jurassic), northeastern Alborz, northern Iran : implications for palaeoweathering, provenance, and tectonic setting
Autorzy:
Taheri, A.
Jafarzadeh, M.
Armstrong-Altrin, J. S.
Mirbagheri, S. R.
Powiązania:
https://bibliotekanauki.pl/articles/2060454.pdf
Data publikacji:
2018
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Shemshak Group
geochemistry
provenance
palaeoweathering
tectonic setting
Neotethys
Opis:
Combined petrographic and geochemical data of the siliciclastic sedimentary rocks from the Shemshak Group in the northeastern Alborz Mountains, north of Iran are described, together with their implications for palaeoweathering, their provenance, and tectonic setting. Based on field observations and modal composition, the sandstones are classified as litharenites. The chemical index of alteration (CIA) indicated that the source terrains underwent a moderate intensity of chemical weathering. The index of chemical variation (ICV) values indicated that the Shemshak Group rocks were immature and related to a source area with an active tectonic regime. Major, trace and rare earth element (REE) data suggested the domination of mixed sedimentary (recycled) and igneous rocks in the source area of the Shemshak Group. Petrographic and geochemical characteristics of Shemshak Group rocks suggest an active continental margin (ACM), which corresponds to the collision of the Iran plate with the Turan plate.
Źródło:
Geological Quarterly; 2018, 62, 3; 522--535
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Geochemistry and tectonic setting of the volcanic host rocks of VMS mineralisation in the Qezil Dash area, NW Iran : implications for prospecting of Cyprus-type VMS deposits in the Khoy ophiolite
Autorzy:
Imamalipour, Ali
Barak, Samaneh
Powiązania:
https://bibliotekanauki.pl/articles/2058590.pdf
Data publikacji:
2019
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
geochemistry
massive sulphide mineralisation
IAT
ophiolite
Khoy
Iran
Opis:
The uppermost part of the Khoy ophiolite includes submarine volcanic lavas. These rocks are found as two different types including basaltic pillow lavas and andesitic to andesitic basalt massive-sheet lavas known as the Qezil Dash unit. These last rocks host volcanogenic massive sulphide mineralisation (VMS). Concordant small lenticular massive sulphides associated with widespread stockworks, extensive wall rock alteration and simple mineralogical parageneses are characteristic of this mineralisation. The Qezil Dash lavas are characterized by HFSE depletion (such as in Nb, Zr, and Hf) and LILE enrichment, low Yb, Y and Ni contents and low Zr/Hf and Nb/Ta ratios. These rocks have low Ti contents and are of LKT type. These geochemical characteristics can be interpreted as indicating SSZ magmatism and suggesting that the Qezil Dash rocks belong to an early stage of island arc formation. Geochemically, this host rock is comparable with the Lasail unit, part of a volcanic sequence within the Oman ophiolite. In the Troodos and Oman ophiolites VMS mineralisation has occurred at the contacts of MOR-basalt and island arc tholeiite (IAT) lavas, so prospecting for VMS deposits in the Khoy area should be estabilished based on geochemical investigations of the volcanic rocks and recognition of their field boundaries.
Źródło:
Geological Quarterly; 2019, 63, 3; 435--448
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Geochemistry of Upper Cretaceous of the Bozeş Formation (Apuseni Mts., Romania) : provenance implications
Autorzy:
Zaharia, L.
Balc, R.
Stremţan, C. C.
Socaciu, A.
Powiązania:
https://bibliotekanauki.pl/articles/2059954.pdf
Data publikacji:
2016
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
geochemistry
provenance
Upper Cretaceous
Bozeş flysch
Apuseni Mountains
Opis:
A whole-rock geochemical study was carried out on sandstones from the Upper Cretaceous Bozeş Formation in the southeastern part of the Apuseni Mountains (Romania) in order to constrain their provenance and depositional setting. The geochemical results were compared and integrated with previously reported provenance indicators, such as framework composition and heavy mineral assemblages. The chemical composition is similar for all samples investigated, with limited ranges for both major oxides and trace elements. The sandstones are potassic (Na2O/K2O < 1) and can be classified mainly as arenites with a few greywackes. Their immature to relatively mature character is revealed by the SiO2/Al2O3 ratios, ranging between 3.90 and 11.25, as well as their high Sr/Rb ratios. The source rocks were affected by weak to moderate chemical alteration, as indicated by the specific index (CIA), with values between 47 and 71. The detrital material was influenced by a little hydraulic sorting during transportation, while post-depositional eftects were limited to K-metasomatism. Two major potential source types were identified based on the chemical composition of the samples studied: a felsic magmatic arc and a recycled, quartzose metasedimentary basement. Our data indicate that the depositional setting is likely to be on a convergent margin. The results are consistent with uplifted and exhumed Transylvanian basement as the major source area.
Źródło:
Geological Quarterly; 2016, 60, 3; 746--757
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Palaeogeographical significance of the Eemian biogenic sediments at Bór site (Warta River valley, Central Poland)
Autorzy:
Petera-Zganiacz, J.
Borówka, R.K.
Forysiak, J.
Miotk-Szpiganowicz, G.
Pawłowski, D.
Powiązania:
https://bibliotekanauki.pl/articles/2060307.pdf
Data publikacji:
2013
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
gyttja
palynology
cladocera
geochemistry
Warta River valley deposits
Opis:
An investigated area is located in the middle reach of the WartaRiver valley. During drillings in the Bór site organic deposits such as detritous calcareous gyttja and calcareous detritous gyttja has been documented in a depth between 14,9 and 16,6 m. The organic deposits are covered by mineral, mostly sandy deposits. The accumulation took place in the small lake formed as an abandoned channel. Palynological analysis led to conclusion that biogenic accumulation began at the end of Wartanian and took place at least to the Eemian Interglacial optimum. Results of palynological, Cladocera and geochemical analysis inform about water level changes and increasing of trophy status of the reservoir. Presence of Mesozoic substratum very close to the palaeolake bottom influenced significantly chemical features of the organic deposits. As Eemian organic deposits are uncommon in the Warta River valley, the Bór site seems important for palaeogeographical reconstructions of the Warta River valley during Eemian Interglacial.
Źródło:
Geological Quarterly; 2013, 57, 4; 687--700
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Chromian spinels from the Magura Unit (Western Carpathians, Eastern Slovakia) : their petrogenetic and palaeogeographic implications
Autorzy:
Bónová, K.
Špisiak, J.
Bóna, J.
Kováčik, M.
Powiązania:
https://bibliotekanauki.pl/articles/2060358.pdf
Data publikacji:
2017
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Western Carpathians
Magura Basin
provenance
detrital chromian spinel
geochemistry
Opis:
Detrital chromian spinels in sedimentary rocks provide much information concerning the tectonics of their parental ultrabasic rocks. Chromian spinels occurring in the Eocene to Oligocene depos its from the Magura Nappe were exam i ned to provide some constraints on the history of the Magura Basin. The Magura Nappe is a part of the Flysch Belt belonging to the External Western Carpathians. The Magura Nappe is separated by a narrow zone associated with the Pieniny Klippen Belt and is divided into three principal tectono-lithofacies units (from the S to N): the Krynica, Bystrica and Rača units. Cr-spinel is a common accessory mineral (2.3-5.9 vol% of heavy mineral spectra) in the siliciclastic rocks of the Rača and Krynica units. In terms of texture and chemical composition, two types of Cr-spinels were recognized: unaltered and altered. Unaltered spinels were found to contain silicate inclusions such as chromio-pargasite, enstatite, diopside, pargasite, plagioclase and olivine (forsterite). The chromian spinels show wide variations in compositional parameters such as Cr# (0.3-0.7), Mg# (0.3-0.7), TiO2 (<0.03-1.9 wt.%) and Fe2+/Fe3+ (2.5-13) whereas the differences between the Rača and Krynica units are in- significant. These parameters suggest a peridotitic and volcanic origin of the spinels, respectively. The ophiolite source consisting of harzburgitic mantle peridotites was developed mainly in a supra-subduction zone setting; volcanic spinels indicate an origin in mid-ocean ridge basalts, back-arc basin basalts and sporadically in ocean-island basalts. Concerning their geochem i cal features, we propose that during the Eocene to Early Oligocene, the ophiolitic detritus in the eastern part of the Magura Basin deposits may have been derived from a source area located in the Fore-Marmarosh Suture Zone (Eastern Carpathians) that is considered an equivalent of the Black Flysch and Ceahlau units. Some Cr-spinels found in the Eocene sedimentary successions may have resedimented from older Late Cretaceous-Paleocene formations of the Magura Unit, which are considered as reworked sedimentary material from the Pieniny Klippen Belt.
Źródło:
Geological Quarterly; 2017, 61, 1; 3--18
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The relationship between the chemical composition and lithology of Late Glacial and Holocene biogenic deposits of the Żabieniec mire (Central Poland)
Autorzy:
Okupny, Daniel
Borówka, Ryszard Krzysztof
Forysiak, Jacek
Twardy, Juliusz
Kloss, Marek
Żurek, Sławomir
Powiązania:
https://bibliotekanauki.pl/articles/2058726.pdf
Data publikacji:
2021
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
kettle hole
limnogenic mire
geochemistry
macrofossils
denudation
Central Poland
Opis:
Geochemical and plant macrofossil analyses of the Żabieniec mire deposits and the palaeoenvironmental changes they record of the past several thousand years constitute an important source for palaeogeographical reconstruction of the Polish Lowland. We describe the phases of the basin’s development from the final part of the Plenivistulian (MIS2), through the Late Glacial and the entire Holocene, encompassing changes determined by both regional and global factors in the surrounding environment, and habitat transformations in the limnogenic mire. The kettle-hole infill of the Żabieniec mire is the only documented example in Central Poland of a succession of biogenic deposits exceeding 10 m in thickness in such a setting. Deposition initially took place in a lake environment, which led to a shallowing of the lake that persisted until the end of the Mesoholocene.
Źródło:
Geological Quarterly; 2021, 65, 1; 11
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 43

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