Permian lamprophyres from the Western Carpathians: a review

2021 ◽  
pp. SP513-2020-237
Author(s):  
Ján Spišiak ◽  
Lucia Vetráková ◽  
David Chew ◽  
Štefan Ferenc ◽  
Viera Šimonová ◽  
...  
Keyword(s):  
Hydrothermal Fluid ◽  
Mineralogical Composition ◽  
Western Carpathians ◽  
Crustal Material ◽  
Calc Alkaline ◽  
Geochemical Composition ◽  
Nd Isotope ◽  
Icp Ms ◽  
Compositional Variations ◽  
Alkaline Lamprophyres

AbstractCalc-alkaline lamprophyres from the Western Carpathians occur as dykes and sills in the crystalline complexes (predominantly granites and gneisses) of the Tatric Unit. Some of the lamprophyre dykes have been strongly overprinted by tectonism and hydrothermal fluid ingress. They have a similar mineralogical composition, and they are comprised of clinopyroxene, amphibole, biotite and plagioclase. Based on their modal composition, they can be classified as spessartites and kersantites, and based on their geochemical composition, most of them are of calc-alkali type. Lamprophyres from individual core complexes (e.g. the Malá Fatra Mountains and Nízke Tatry Mountains) exhibit variable Nb, Ta and Sr–Nd isotope signatures. These differences are probably due to compositional variations in the mantle source and/or the lower crust at the site of lamprophyre melt generation, or variable incorporation of crustal material. The age of the lamprophyres is Permian (c. 265 Ma) based on U–Pb LA-ICP-MS dating of apatite micro-phenocrysts.

scholarly journals Petrology and dating of the Permian lamprophyres from the Malá Fatra Mts. (Western Carpathians, Slovakia)

2018 ◽  
Vol 69 (5) ◽  
pp. 453-466 ◽  
Author(s):  
Ján Spišiak ◽  
Lucia Vetráková ◽  
David Chew ◽  
Štefan Ferenc ◽  
Tomáš Mikuš ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Granitic Rocks ◽  
Western Carpathians ◽  
Magma Ascent ◽  
Crustal Material ◽  
Calc Alkaline ◽  
Nd Isotopes ◽  
Granitoid Rocks ◽  
Alkaline Lamprophyres

Abstract Calc–alkaline lamprophyres are known from several localities in the Malá Fatra Mountains. They form dykes (0.5–3 m) of varying degree of alteration that have intruded the surrounding granitoid rocks which are often incorporated xenoliths. Clinopyroxenes (diopside to augite), amphiboles (kaersutitic), biotites (annite) and plagioclases are major primary minerals of the dykes, accessory minerals include apatite, ilmenite, rutile, pyrite, chalcopyrite, and pyrrhotite. Apatite has a relatively low F, but increased Cl content compared to typical apatite from lamprophyres or magmatic apatite from granitic rocks in the Western Carpathians. The chemical composition of the lamprophyres indicates their calc–alkaline character, but affinity to alkaline lamprophyres is suggested by the Ti enrichment in clinopyroxene, amphibole and biotite. According to modal classification of the minerals, the studied rocks correspond to spessartite. The differences in the chemical composition of the rocks (including Sr and Nd isotopes) probably result from the contamination of primary magma by crustal material during magma ascent. The age of the lamprophyres, based on U/Pb dating in apatite, is 263.4 ± 2.6 Ma.

Carbonate and chert genesis in the 3.35 Ga old Strelley Pool Formation (Australia): Insights from trace metals and Sm/Nd dating

2020 ◽  
Author(s):  
Sebastian Viehmann ◽  
Simon V. Hohl ◽  
Nathalie Tepe ◽  
Martin Van Kranendonk ◽  
Joachim Reitner ◽  
...  
Keyword(s):  
Regression Line ◽  
Seawater Chemistry ◽  
Geochemical Composition ◽  
Nd Isotope ◽  
Black And White ◽  
Microbial Structures ◽  
Icp Ms ◽  
Authigenic Mineral ◽  
Isotope System ◽  
Pool Formation

<p>Stromatolites are laminated, presumably microbial structures, consisting largely of an authigenic precipitate, thus, providing potential geochemical archives of early Earth aqueous environments and their habitability. In this study, we report trace element and Sm/Nd isotope data from Palaeoarchean stromatolites and adjacent cherts of the Strelley Pool Formation (NW Australia), obtained by ICP-MS and TIMS, to test their reliability as archives for palaeo-environmental reconstruction and to understand authigenic mineral formation.</p><p>Stromatolitic carbonates plot together with the stratigraphically underlying Marble Bar cherts on a linear Sm-Nd regression line yielding an age of 3253 ±320 Ma.. In contrast, associated crystal-fan carbonates yield 2718 ±220 Ma, suggesting that their Sm-Nd isotope system was altered after deposition. Geochronological information via Sm-Nd dating of black and white cherts is limited, probably due to a reset of the isotope system during an unknown Paleoproterozoic or younger alteration event.</p><p>Carbonates, as well as white cherts, show shale-normalized rare earth element and yttrium patterns (REY<sub>SN</sub>; except for redox-sensitive Ce and Eu) parallel to those of modern seawater, indicating a seawater-derived origin. Positive Eu<sub>SN</sub> anomalies (2.1 - 2.4), combined with heterogeneous ɛNd<sub>3.35Ga</sub> values (-3.2 to +5.8) within alternating stromatolite laminae, support that seawater chemistry was variably affected by both continental weathering and high-temperature hydrothermal fluids contributing elements of both young mafic or older felsic rocks. In contrast, black cherts show non-seawater like REY<sub>SN</sub> patterns and significant amounts of elements leached from the surrounding rocks, masking the pristine geochemical composition of ancient seawater. In conclusion, Archaean stromatolites indeed preserve pristine authigenic phases at the mm-scale that contain signatures representative of the water chemistry prevailing in the depositional environment.</p>

scholarly journals Komparasi Geokimia Batuan Gunung Api Kuarter dan Tersier di Tepian Selatan Lampung

EKSPLORIUM ◽  
2020 ◽  
Vol 41 (2) ◽  
pp. 101
Author(s):  
Ronaldo Irzon
Keyword(s):  
Volcanic Rocks ◽  
Crustal Contamination ◽  
Silica Content ◽  
Formation Processes ◽  
Calc Alkaline ◽  
Geochemical Composition ◽  
Eu Anomaly ◽  
Icp Ms ◽  
West Sumatra ◽  
Quaternary Volcanic Rock

ABSTRAK Keterdapatan batuan gunung api di Sumatra diakibatkan oleh penunjaman Lempeng Samudra India-Australia ke bawah Lempeng West Sumatra sejak Eosen. Tanggamus adalah kabupaten di ujung selatan Lampung dengan keterdapatan beberapa unit batuan gunung api berumur Tersier maupun Kuarter. Studi ini bertujuan untuk membandingkan komposisi geokimia batuan gunung api Tersier Formasi Hulusimpang dengan batuan gunung api Kuarter Gunung Tanggamus. Perangkat XRF dan ICP-MS dimanfaatkan untuk mengetahui kadar oksida utama, unsur jejak, dan unsur tanah jarang pada penelitian ini. Berdasarkan karakter geokimia, sampel dari Formasi Hulusimpang adalah batuan gunung api kalk-alkali, metalumina hingga peralumina, dan dalam rentang trakiandesit basaltik hingga riolit. Sampel batuan gunung api berumur Kuarter berada pada rentang kadar silika yang lebih sempit dan cenderung metalumina. Studi ini membuktikan bahwa kedua kelompok batuan berasal dari magma yang sama, tetapi dengan kontaminasi kerak selama diferensiasi. Proses pembentukan yang berbeda pada kedua kelompok batuan diperjelas oleh derajat kemiringan kurva diagram laba-laba UTJ dan jenis anomali Eu.ABSTRACT The presence of volcanic rocks in Sumatra is due to the subduction of the Indian-Australian Ocean Plate under the West Sumatra Plate since the Eocene. Tanggamus Regency situated at the southern edge of Lampung with the occurrence of several Tertiary and Quaternary volcanic rock units. The aim of this study is to compare the geochemical composition of Tertiary volcanic rocks from the Hulusimpang Formation and Quaternary volcanic rocks from Mount Tanggamus in the Tanggamus Regency. XRF and ICP-MS devices were used to determine the compositions of major oxides, trace elements, and rare earth elements in this study. Based on geochemical characters, samples from the Hulusimpang Formation are calc-alkaline volcanic rocks, metaluminous to peraluminous, and in the basaltic trachyandesite to rhyolite ranges. Quaternary samples are in a narrower range of silica content and tend to be metaluminous. This study proves that the two rock groups originate from the same magma but with crustal contamination during differentiation. The two volcanic should experience through different formation processes based on the slope of the heavy-REE and the type of Eu anomaly.

scholarly journals Petrography, geochemistry, and geochronology of the Sc-enriched Kiviniemi ferrodiorite intrusion, eastern Finland

2020 ◽  
Vol 55 (8) ◽  
pp. 1561-1580
Author(s):  
Tapio Halkoaho ◽  
Marjaana Ahven ◽  
O. Tapani Rämö ◽  
Janne Hokka ◽  
Hannu Huhma
Keyword(s):  
Potassium Feldspar ◽  
Crustal Material ◽  
Magmatic Evolution ◽  
Nd Isotope ◽  
Mafic Intrusion ◽  
Mafic Intrusions ◽  
Rock Types ◽  
Icp Ms ◽  
Corona Formation ◽  
Granitoid Complex

Abstract The Kiviniemi mafic intrusion, near the eastern margin of the Paleoproterozoic Central Finland Granitoid Complex, is both spatially and temporally associated with post-kinematic Fe-Ti-P-enriched Svecofennian orogenic mafic magmatism. The main rock types in this small (~ 15 ha) intrusion are garnet-bearing fayalite ferrodiorite, leucoferrodiorite, ferromonzodiorite, and pyroxene diorite. The garnet-bearing fayalite ferrodiorite and leucoferrodiorite contain 50–281 ppm Sc, 275–5600 ppm Zr, and 58–189 ppm Y (n = 42), delineating a mineralized deposit some 2.5 ha in extent. Overall, these rocks show an evolved (iron-enriched) tholeiitic character; low values of Ni (< 20–40 ppm), Cr (< 20 ppm), and Cu (< 20–80 ppm); and high contents of Zn (213–700 ppm). The rock-forming minerals in the ferrodioritic rocks are (ferro)hedenbergite, plagioclase (~ An40), ferropargasite and ferroedenite, almandine garnet, and fayalite (Fo1–4). Accessory minerals include zircon, ilmenite, fluorapatite, biotite, pyrite, pyrrhotite, potassium feldspar, grunerite, and clinoferrosilite. Some relict cumulate textures have been preserved, but primary magmatic features have largely been overprinted by strong recrystallization and corona formation. The main carriers of Sc are amphibole, clinopyroxene, and apatite. The remarkably strong enrichment of Sc in ferromagnesian silicates and apatite, rather than in specific Sc-minerals, implies magmatic enrichment. Post-kinematic mafic intrusions in central Finland constitute a bimodal association with co-existing granitoid counterparts. The Kiviniemi mafic intrusion is associated with a coarse megacrystic granite and the two rock type display mingled contacts, indicative of contemporaneity of the two magmas. This conclusion is in accord with the coincident U-Pb zircon ages for the ferrodiorite, at 1857 ± 2 Ma (multigrain ID-TIMS) and the megacrystic granite, at 1860 ± 7 Ma (single-crystal LA-MC-ICP-MS). The initial εNd value of the ferrodiorite and the granite are + 0.1 and − 2.5, respectively. These Nd isotope compositions probably reflect a chondritic mantle source for the ferrodiorite and suggest incorporation of some Archaean crustal material into the granite in the course of magmatic evolution. The resource estimation calculated for Kiviniemi intrusion by using 40 g/t Sc cut off value is 13.4 Mt of rock with an average grade of 162.7 g/t scandium, 1726 g/t zirconium, and 81 g/t yttrium.

Distribution of Mercury in Lake St. Clair and the St. Clair River Sediments

1989 ◽  
Vol 24 (1) ◽  
pp. 1-22 ◽  
Author(s):  
Alena Mudroch ◽  
K. Hill
Keyword(s):  
Organic Matter ◽  
Sediment Cores ◽  
River Sediments ◽  
Size Fraction ◽  
Mineralogical Composition ◽  
Recent Sediment ◽  
Geochemical Composition ◽  
Visual Appearance ◽  
Decaying Wood ◽  
Relationship Of

Abstract Sediment cores were collected in Lake St. Clair in 1985 and in the St. Clair River in 1986 to investigate the horizontal and vertical distribution and association of Hg in the sediments. A layer of recent sediment up to about 35 cm thick was differentiated by the geochemical composition and visual appearance from the underlying glacial-lacustrine deposits. The concentration of Hg in the surficial sediments in Lake St. Clair was lower in 1985 (&lt;0.025 to 1.200 µg/g) than that found in 1974 (&lt;0.20 to 3.00 µg/g). Up to 8.30 µg/g of Hg were found in the sediments collected from the nearshore area at Sarnia, Ontario, in the St. Clair River in 1986. The concentrations of Hg ranged from 5.05 to 16.00 µg/g in different sand-sized fractions (0.063 to 0.350 mm) of the sediment. The concentration of Hg was 17.80 µg/g in the silt-clay size fraction (&lt;0.063 mm). No relationship was found between the concentration of organic matter and Hg, and the concentration of silica and Hg in the St. Clair River sediments. The results indicated a relationship of Hg with particles of different mineralogical composition. Up to 3.72 µg/g Hg was found in the surface sediment in Chenal Ecarte. The greatest concentration of Hg (13.15 µg/g) existed in the 0.350 mm particle size fraction, which consisted mainly of small pieces of decaying wood. A good relationship was found between the concentration of Hg and organic matter in the sediment at this area.

Origin of the Ordovician Mansehra granite in the NW Himalaya, Pakistan: constraints from Sr–Nd isotopic data, zircon U–Pb age and Hf isotopes

2018 ◽  
Vol 481 (1) ◽  
pp. 277-298 ◽  
Author(s):  
Masatsugu Ogasawara ◽  
Mayuko Fukuyama ◽  
Rehanul Haq Siddiqui ◽  
Ye Zhao
Keyword(s):  
Granitic Magma ◽  
Geochemical Data ◽  
Large Contribution ◽  
Crustal Material ◽  
Sr Isotope ◽  
Nw Himalaya ◽  
Nd Isotope ◽  
Isotope Data ◽  
Late Neoproterozoic ◽  
T Values

AbstractThe Mansehra granite in the NW Himalaya is a typical Lesser Himalayan granite. We present here new whole-rock geochemistry, Rb–Sr and Sm–Nd isotope data, together with zircon U–Pb ages and Hf isotope data, for the Mansehra granite. Geochemical data for the granite show typical S-type characteristics. Zircon U–Pb dating yields 206Pb/238U crystallization ages of 483–476 Ma. The zircon grains contain abundant inherited cores and some of these show a clear detrital origin. The 206Pb/238U ages of the inherited cores in the granite cluster in the ranges 889–664, 1862–1595 and 2029 Ma. An age of 664 Ma is considered to be the maximum age of the sedimentary protoliths. Thus the Late Neoproterozoic to Cambrian sedimentary rocks must be the protolith of the Mansehra granitic magma. The initial Sr isotope ratios are high, ranging from 0.7324 to 0.7444, whereas the εNd(t) values range from −9.2 to −8.6, which strongly suggests a large contribution of old crustal material to the protoliths. The two-stage Nd model ages and zircon Hf model ages are Paleoproterozoic, indicating that the protolith sediments were derived from Paleoproterozoic crustal components.

Age and Sources of Metasandstone of the Chiney Subgroup (Udokan Group, Aldan Shield): Results of U–Th–Pb Geochronological (LA–ICP–MS) and Nd Isotope Study

2018 ◽  
Vol 482 (1) ◽  
pp. 1138-1141 ◽  
Author(s):  
V. P. Kovach ◽  
A. B. Kotov ◽  
D. P. Gladkochub ◽  
E. V. Tolmacheva ◽  
S. D. Velikoslavinsky ◽  
...  
Keyword(s):  
Aldan Shield ◽  
Nd Isotope ◽  
Icp Ms ◽  
Isotope Study

Geochemistry and Sr–Nd isotopic composition of Eocene lamphrophyre dykes, southeastern British Columbia

2003 ◽  
Vol 40 (6) ◽  
pp. 853-864 ◽  
Author(s):  
J H Sevigny ◽  
R J Thériault
Keyword(s):  
British Columbia ◽  
Limited Range ◽  
Calc Alkaline ◽  
Lithospheric Thinning ◽  
Enriched Mantle ◽  
Mantle Enrichment ◽  
Mantle Reservoir ◽  
Geochemical Analyses ◽  
Alkaline Lamprophyres

Mineral compositions, geochemical analyses, and Sr–Nd isotopic compositions are reported for alkaline and calc-alkaline lamprophyres collected along the southern margin of the Valhalla Complex, southeastern British Columbia. The lamprophyres were emplaced during Eocene extension and lithospheric thinning associated with tectonic denudation of the Valhalla Complex. SiO2 contents range from 44.4–51.6 wt.%, K2O from 1.3–3.7 wt.%, and volatile contents (H2O + CO2 + SO3) from 0.8–4.6 wt.%. MgO and Cr contents are 9.5–7.6 wt.% and 540–130 ppm, respectively, for samples with Mg#s between 0.69 and 0.65. Chrondrite-normalized rare-earth element patterns are strongly fractionated with Cen = 120–375 and Ybn = 8.4–12.7. Alkaline lamprophyres contain biotite ± kaersutite ± calcic plagioclase and exhibit a limited range in initial 87Sr/86Sr (0.7051–0.7057), initial εNd (–3.7 to –4.3), and TDM (766–796 Ma). Calc-alkaline lamprophyres contain F-rich phlogopite and sodic plagioclase, and exhibit a wider range in initial 87Sr/86Sr (0.7064–0.7090), initial εNd (–6.3 to –11.9), and TDM (917–1,614 Ma). Alkaline lamprophyres are interpreted as uncontaminated melts derived from a long-term, volatile, and incompatible element-enriched mantle reservoir. Mantle enrichment coincided with continental rifting of western North America (ca. 760 Ma). The enriched mantle reservoir remained isolated for ~700 Ma. Lamprophyres were generated by partial melting of the mantle reservoir in response to adiabatic decompression and lithospheric thinning during Eocene extension.

scholarly journals Technological study on the Gravity Processing of Manganese Ore

2019 ◽  
pp. 18-22
Author(s):  
Zagarzusem Ts ◽  
Baasanjav D ◽  
Sugir-Erdene N ◽  
Orgilbayar B ◽  
Sukhbat S ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Mineralogical Composition ◽  
Shaking Table ◽  
Petrographic Analysis ◽  
Manganese Ore ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Plasma Mass Spectrometry ◽  
Manganese Minerals ◽  
Technological Study

This study investigated the effectiveness of the gravity beneficiation method based on gravitation and centrifugal forces for manganese ore. Manganese ores from Unagad deposit, samples powders were analyzed for their element and mineralogical composition using inductively coupled plasma mass spectrometry (ICP-MS) and X-ray diffractometer (XRD). Mineralogy and petrographic analysis are presented the mineralogical compositions are hydro goethite, manganese minerals and magnetite, the gangue minerals are quartz, albite, orthoclase, microcline in manganese ore. Manganese mineral occurs white, improper shape particles, weak grained-aggregates associated in gangue minerals. The most important minerals consist of manganese minerals are hausmannite, pyrolusite, rhodochrosite, and manganosite. The composite of feed containing 17.31 % Mn and 36.3 % SiO2 was produced by a centrifugal concentrator in combination with the shaking table. In the experiment, a concentrate assaying 41.37% Mn was obtained from this composite with 11.9 % yields. In the next experiment, f80=0.074mm particle size feed ore was used in the MGS concentration test. A concentrate containing 38.33 % Mn with 26.57 % yields was produced in this experiment. The results showed that it is possible to obtain concentrate on the gravity processing of manganese ore that economically significant and meet standard requirements. Манганы хүдрийг гравитацийн аргаар баяжуулах технологийн судалгаа Хураангуй:  Энэхүү судалгааны ажлаар манганы хүдрийг хүндийн хүч болон төвөөс зугтах хүчний үйлчлэл дээр үндэслэн гравитацийн аргаар баяжуулах туршилт явуулав. Унагад ордын манганы хүдрийн дээжийн элементийн найрлагыг индукцийн холбоост плазмын масс спектрометр (ICP-MS), эрдсийн найрлагыг рентген дифрактометрийн аргаар тодорхойлсон. Минералоги, петрографийн шинжилгээгээр чулуулагт гидрогётит, манганы эрдсүүд, магнетит гэсэн хүдрийн эрдсүүд, кварц, альбит, ортоклаз, микроклин зэрэг хүдрийн бус эрдсүүд тодорхойлогдлоо. Хүдрийн бус эрдэс дотор манганы эрдэс нь цагаан өнгөтэй, зөв бус хэлбэртэй мөхлөгүүд мөн сул шигтгээлэг байдлаар тааралдаж байна. Манганы эрдсүүд нь гаусманит, пиролюзит, родохрозит, манганизит хэлбэрээр агуулагдсан байна. Манганы 17.31%, цахиурын ислийн 36.3% агуулгатай анхдагч хүдрийг төвөөс зугтах хүчний сепаратор болон ширээний хосолсон аргаар баяжуулахад баяжмалын агуулга Mn-41.37%, гарц 11.9% байв. Харин -0.074 мм фракцийн агуулга 80%-тай анхдагч хүдрийг хүндийн хүчний сепаратор (MGS)–аар баяжуулж, 38.33% -ийн манган агуулсан, 26.57% -ийн гарцтай баяжмал гарган авсан. Иймд манганы хүдрийг гравитацийн аргаар баяжуулахад стандартын шаардлага хангасан эдийн засгийн ач холбогдолтой бүтээгдэхүүн гарган авах боломжтойг тогтоов. Түлхүүр үг: Манганы хүдэр, хүндийн хүчний сепаратор, төвөөс зугтах хүчний сепаратор, рентген - дифрактометр.

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