scholarly journals Petrographical and Geochemical Characteristics of Magmatic Rocks in the Northwestern Siberian Traps Province, Kulyumber River Valley. Part II: Rocks of the Kulyumber Site

Minerals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 415
Author(s):  
Nadezhda Krivolutskaya ◽  
Boris Belyatsky ◽  
Bronislav Gongalsky ◽  
Alexander Dolgal ◽  
Andrey Lapkovsky ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Element Distribution ◽  
River Valley ◽  
Geochemical Data ◽  
Trace Element Distribution ◽  
Mafic Rocks ◽  
Inductively Coupled ◽  
Magmatic Rocks ◽  
Magma Sources ◽  
Siberian Trap

The origin of the Siberian trap province is under discussion even though numerous models of its formation have been created over the last three decades. This situation is mainly due to lack of modern geochemical data on magmatic rocks around the province. These data are a very important tool to reconstruct of magmatic evolution within the province in time and space and to understand a mechanism of province formation. Geochemical study has only been carried out so far for the Norilsk and Meimecha–Kotuy areas. For the first time, we have studied the geochemical and mineralogical characteristics of magmatic rocks at the Kulyumber river valley located 150 km to south from the Norilsk ore district, in the junction of the Tunguska syneclise and Norilsk–Igarka zone. It comprises three sites, i.e., Khalil, Kaya, and Kulyumber. The geochemical data on the magmatic rocks of the Khalil and Kaya sites were published earlier (Part I). This article (Part II) regards geochemical and mineralogical data on igneous rocks at the Kulyumber site. Seventeen intrusive bodies (41 samples) and six samples of sedimentary rocks were studied by X-ray fluorescence (XRF) and inductively coupled plasma mass spectrometry (ICP-MS). Isotopes analyses (Sr, Nd, Pb) were conducted for 12 samples. These data were compared with data for intrusions of the Norilsk area, the Dzhaltulsky massif, Kureyka river, and intrusions in Angara river valley published earlier. The whole list of analyses includes 102 items. Three groups of intrusive rocks were recognized: (1) Mafic rocks with elevated K2O without negative Ta-Nb and Pb-positive anomalies, with (Gd/Yb)n = 2.0 and εNd = −1.0; attributed to a new Kulyumbinsky complex; (2) subalkaline rocks with elevated SiO2,TiO2, P2O5, and K2O with small negative Ta-Nb and positive Pb anomalies and (Gd/Yb)n = 1.8, εNd = −3.8; Ergalakhsky complex; and (3) mafic rocks with strong Ta-Nb and Pb anomalies and (Gd/Yb)n = 1.2–1.4, εNd = +0.4–+2.2. The third group is rather nonhomogeneous and includes intrusions of the Norilsk, Kuryesky, Katangsky, Ogonersky, and Daldykansky complexes differing in MgO content and trace element distribution (values of Ta-Nb, Pb, and Sr anomalies). Three groups of intrusive bodies had different magma sources and different condition of crystallization reflecting their origin in rift and platform regimes.

scholarly journals Zircon age of vaugnerite intrusives from the Central and Southern Vosges crystalline massif (E France): contribution to the geodynamics of the European Variscan belt

2020 ◽  
Vol 191 ◽  
pp. 26
Author(s):  
François Guillot ◽  
Olivier Averbuch ◽  
Michel Dubois ◽  
Cyril Durand ◽  
Pierre Lanari ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Granite Gneiss ◽  
Upper Ordovician ◽  
Inductively Coupled ◽  
Sedimentary Sequences ◽  
Magmatic Rocks ◽  
Continental Block ◽  
Plasma Mass Spectrometry ◽  
Granite Complex ◽  
Subduction System

To provide a better picture of the active geodynamics along the Variscan suture zones during the late collisional stage (particularly regarding the evolution of the orogenic system towards HT conditions), we focused here on vaugnerites, which consist of mafic ultra-potassic magmatic rocks, intrusive into the granite-gneiss sequences of the Variscan Vosges crystalline massif. Those rocks, though subordinate in volume, are frequently associated with late-collisional granites. In the Central-Southern Vosges, they appear either as (1) pluton margin of the Southern Vosges Ballons granite complex or (2) composite dykes intrusive into migmatite and metamorphic sequences classically referred to as granite-gneiss unit (Central Vosges). Both types correspond to melanocratic rocks with prominent, Mg-rich, biotite and hornblende (20–40% vol., 64 < mg# < 78), two-feldspar and quartz. Those Vosges vaugnerites display geochemical signatures characteristic of ultra-potassic mafic to intermediate, metaluminous to slightly peraluminous rocks. Zircon U-Pb ages were obtained by Laser Ablation Inductively Coupled Plasma Mass Spectrometry. Zircon grains were extracted from a sillimanite-bearing gneiss from the granite-gneiss unit hosting the Central Vosges vaugnerites. They yielded an age at 451 ± 9 Ma, indicating a pre-Variscan Upper Ordovician protolith for the host sequence. Zircon from the four vaugnerite intrusives display U-Pb ages (± 2σ) of 340 ± 2.5 Ma (Ballons), 340 ± 25 Ma, 340 ± 7 Ma and 336 ± 10 Ma (Central Vosges). Synchronous within uncertainty, vaugnerite age data suggest a relatively early emplacement during the Late Variscan collisional history (i.e. Middle Visean times). These results are in line with previously published ages from the Southern Vosges volcano-sedimentary sequences (Oderen-Markstein) and the nearby ultra-potassic granite complexes from the Central and Southern Vosges (Ballons, Crêtes) thereby arguing for a magmatic event of regional significance. Recent petrological studies on vaugnerites suggest that they derive from partial melting of a metasomatized mantle contaminated to some different degrees by elements of continental crust. We propose here that the major ultra-potassic magmatic pulse at 340–335 Ma is a consequence of a significant change into the dynamics of the Rhenohercynian subduction system below the Central-Southern Vosges. In the light of recent thermo-mechanical modelling experiments on mature continental collision, magmatism could result from a syn-collisional lithospheric delamination mechanism involving (1) first, continental subduction evolving towards (2) the underthrusting of the Avalonian continental margin lower crust and (3) the initiation of lithospheric delamination within the supra-subduction retro-wedge (Saxothuringian-Moldanubian continental block). This delamination would drive the emplacement of an asthenospheric upwelling, initially localized along the Variscan suture zones, and gradually propagating towards the southern front of the belt during the Late Carboniferous, as the delamination front migrated at the base of the crust.

scholarly journals Trace-Element Distribution on Sulfide Mineralization in Trento Province, NE Italy

Minerals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 736
Author(s):  
Gianluca Bianchini ◽  
Claudio Natali ◽  
Paolo Ferretti ◽  
Lara Casagrande ◽  
Manuel Conedera ◽  
...  
Keyword(s):  
Trace Element ◽  
Middle Ages ◽  
Inductively Coupled Plasma ◽  
Analytical Data ◽  
Element Distribution ◽  
Trace Element Distribution ◽  
Sulfide Mineralization ◽  
High Concentration ◽  
Thin Sections ◽  
Local Soil

Sulfide mineralization in the province of Trento (northeastern Italy) includes various mineral assemblages that are often silver-rich and have been exploited in different phases from the Middle Ages until the 20th century. This study investigates mineralized rocks from three historically important sites (Calisio mount, Erdemolo lake, and the locality of Cinque Valli), providing new analytical data (Inductively Coupled Plasma-Mass Spectrometry on bulk rocks, and Scanning Electron Microscopy on thin sections) that demonstrate that parageneses do not only include galena, chalcopyrite, and sphalerite but also accessory minerals, such as tetrahedrite, tennantite, acanthite, and sulfosalts (matildite/polybasite). This explains the high content of As (up to 278 ppm), Bi (up to 176 ppm), and Sb (up to 691 ppm) that are associated with Pb–Cu–Zn mineralization. Notably, trace-element ratios indicate that, although closely associated from a geographical point of view, the studied sites are not genetically related and have to be referred to in distinct mineralization events, possibly induced by three diverse magmatic and hydrothermal phases that occurred in the Variscan post-orogenic setting. Besides geological and petrogenetic reconstruction, the new data outline potential geochemical risks, as they reveal a high concentration of elements characterized by marked toxicity that can be transferred into the local soil and water. Therefore, future studies should be devoted to better investigating the metal distribution in the surroundings of ancient mining sites and their geochemical behavior during the weathering processes.

Mapping Magmatic and Hydrothermal Processes from Routine Exploration Geochemical Analyses

2020 ◽  
Vol 115 (3) ◽  
pp. 489-503 ◽  
Author(s):  
Scott Halley
Keyword(s):  
Inductively Coupled Plasma ◽  
Mining Industry ◽  
Analysis Data ◽  
Ore Deposits ◽  
Mineral Deposits ◽  
Geochemical Data ◽  
High Quality ◽  
Inductively Coupled ◽  
Hydrothermal Processes ◽  
Geochemical Analyses

Abstract Analytical methods used by commercial assay laboratories have improved enormously in recent years. Inductively coupled plasma-atomic emission spectroscopy and inductively coupled plasma-mass spectrometry methods now report analyses for half of the periodic table with exceptional detection limits and precision. It is becoming commonplace for mining companies to use such methods routinely for the analysis of drill samples throughout mineral deposits. Improvements in software and computing power now allow rapid interrogation of upward of 100,000 assay samples. Geochemical analyses are quantitative, are independent of observer bias, and can form the basis for robust geologic and mineralogical models of mineral deposits, as well as shed light on scientific questions. In particular, consistently collected, high-quality geochemical analyses can significantly improve and systematize logging of lithological and hydrothermal alteration mineralogic changes within drill core. In addition, abundant, high-quality geochemical data provide insights into magmatic and hydrothermal processes that were previously difficult to recognize and that have obvious applications to mineral exploration and improved genetic models of ore deposits. This paper describes a workflow that mining industry geologists can apply to their multielement analysis data to extract more information about magma compositions and gangue mineralogy.

A geochemical record of late Holocene palaeoenvironmental changes at King George Island (maritime Antarctica)

2011 ◽  
Vol 23 (3) ◽  
pp. 255-267 ◽  
Author(s):  
Patrick Monien ◽  
Bernhard Schnetger ◽  
Hans-Jürgen Brumsack ◽  
H. Christian Hass ◽  
Gerhard Kuhn
Keyword(s):  
Inductively Coupled Plasma ◽  
Chemical Weathering ◽  
Radiometric Dating ◽  
Ice Age ◽  
Geochemical Data ◽  
King George Island ◽  
Overlying Water ◽  
Inductively Coupled ◽  
Bulk Parameters ◽  
Maxwell Bay

AbstractDuring RV Polarstern cruise ANT-XXIII/4 in 2006, a gravity core (PS 69/335-2) and a giant box core (PS 69/335-1) were retrieved from Maxwell Bay off King George Island (KGI). Comprehensive geochemical (bulk parameters, quantitative XRF, Inductively Coupled Plasma Mass Spectrometry) and radiometric dating analyses (14C, 210Pb) were performed on both cores. A comparison with geochemical data from local bedrock demonstrates a mostly detrital origin for the sediments, but also points to an overprint from changing bioproductivity in the overlying water column in addition to early diagenetic processes. Furthermore, ten tephra layers that were most probably derived from volcanic activity on Deception Island were identified. Variations in the vertical distribution of selected elements in Maxwell Bay sediments further indicate a shift in source rock provenance as a result of changing glacier extents during the past c. 1750 years that may be linked to the Little Ice Age and the Medieval Warm Period. Whereas no evidence for a significant increase in chemical weathering rates was found, 210Pb data revealed that mass accumulation rates in Maxwell Bay have almost tripled since the 1940s (0.66 g cm-2 yr-1 in ad 2006), which is probably linked to rapid glacier retreat in this region due to recent warming.

scholarly journals Rare Earth Elements Assessment in the Granitoids of Part of Southwestern Nigeria

2020 ◽  
Vol 1 (5) ◽  
Author(s):  
Victoria B. Omotunde ◽  
Akinade S. Olatunji ◽  
Maryam O. Abdus-Salam
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Inductively Coupled Plasma ◽  
Granite Gneiss ◽  
Biotite Granite ◽  
Geochemical Data ◽  
Southwestern Nigeria ◽  
Lithological Mapping ◽  
Inductively Coupled ◽  
Gneiss Granite

The Rare Earth Elements (REE) composition of granitoids in and around Ila-Orangun area Southwestern Nigeria was assessed in order to ascertain their potential for possible exploitation. Detailed lithological mapping of the area was undertaken followed by whole rock geochemical analysis of representative samples of the granitoids using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) technique. Petrographic study of the samples was carried out as well as the interpretation of the geochemical data using diverse geochemical discrimination plots. The rock units mapped were biotite granite gneiss, granite gneiss and hornblende biotite granite. Biotite hornblende gneiss, quartzite, talc-chlorite-tremolite-schist, mica schist and pegmatites were the surrounding country rocks. The REE concentrations (in ppm) revealed higher concentrations of the light REEs compared to the heavy REEs. The fractionation ratio, (La/Yb)N ranged from 4.35-15.04 (granite gneiss) and 13.78-18.48 (hornblende biotite granite) indicating enrichment in LREEs over the HREEs. The spider plot for the REEs also showed that the granitoids are LREE-enriched and HREE-depleted suggesting fractional crystallisation and a distinct negative Eu anomaly indicating plagioclase fractionation. Enrichment plot also revealed that the REEs in the granitoids are significantly enriched. Comparison with other areas showed that the granitoids of the study area especially the hornblende biotite granite has higher concentrations of REEs and may be a possible pointer of REE mineralisation.

scholarly journals RECONNAISSANCE SURVEY OF TRACE ELEMENT CONCENTRATIONS IN PROMINENT CROPS OF CALIFORNIA'S SAN JOAQUIN VALLEY

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 664g-664
Author(s):  
S.R. Grattan ◽  
R.O. Miller ◽  
J.P. Mitchell
Keyword(s):  
Trace Element ◽  
Element Distribution ◽  
Soil Sampling ◽  
San Joaquin Valley ◽  
Trace Element Distribution ◽  
Tissue Concentrations ◽  
Inductively Coupled ◽  
Element Concentrations ◽  
Reconnaissance Survey ◽  
Wide Range

Since the discovery of elevated concentrations of selenium in the water, sediments, and biota at the Kesterson Wildlife Refuge, several studies regarding trace element distribution in the San Joaquin Valley and their potential environmental impacts have been initialed. We conducted a reconnaissance investigation to assess the concentration of boron, selenium, arsenic, molybdenum, uranium and vanadium using inductively coupled mass spectroscopy in prominent vegetation in the San Joaquin Valley. Five regions representing a range of geochemical environments with known differences in trace element concentrations in their soils or shallow ground water were selected for plant and soil sampling. Concentrations of boron, selenium arsenic, molybdenum, uranium, and vanadium in soil and tissue will be presented for these geographic areas for alfalfa, almonds, cotton, garlic, grapes, onions, tomatoes, and wheat. Interpretations of the wide range of trace element tissue concentrations that have been found will be discussed.

scholarly journals Element Segregation and Electrical Properties of PMN-32PT Grown Using the Bridgman Method

Crystals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 98 ◽  
Author(s):  
Sijia Wang ◽  
Zengzhe Xi ◽  
Pinyang Fang ◽  
Xiaojuan Li ◽  
Wei Long ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Inductively Coupled Plasma ◽  
Axial Direction ◽  
Element Distribution ◽  
Nominal Composition ◽  
X Ray Diffraction ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Plasma Mass Spectrometry ◽  
Element Segregation

A single crystal with nominal composition Pb(Mg1/3Nb2/3)O3-32PbTiO3 (PMN-32PT) was grown by the Bridgman technique. Crystal orientation was determined using the rotating orientation X-ray diffraction (RO-XRD). Element distribution was measured along different directions using inductively coupled plasma-mass spectrometry (ICP-MS). The effect of the element segregation along axial and radial directions on the electrical properties of the PMN-32PT crystal was investigated. It is indicated that the electrical properties of the samples along the axial direction were strongly dependent on the PT (PbTiO3) content. With the increase of the PT content, the piezoelectric coefficient and remnant polarization were improved. Differently, the electrical properties of the samples along the radial direction were mainly determined by the ratio of the Nb and Mg. The reasons for the element segregation and electrical properties varied with the composition were discussed.

scholarly journals Petrographical and Mineralogical Characteristics of Magmatic Rocks in the Northwestern Siberian Traps Province, Kulyumber River Valley. Part I: Rocks of the Khalil and Kaya Sites

Minerals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 409 ◽  
Author(s):  
Nadezhda Krivolutskaya ◽  
Boris Belyatsky ◽  
Bronislav Gongalsky ◽  
Alexander Dolgal ◽  
Andrey Lapkovsky ◽  
...  
Keyword(s):  
River Valley ◽  
Geochemical Data ◽  
Magmatic Evolution ◽  
Siberian Traps ◽  
Magmatic Rocks ◽  
Real Model ◽  
Mineralogical Characteristics ◽  
Intrusive Rocks ◽  
First Time ◽  
Good Agreement

The origin of the Siberian Traps province has been under discussion for the last three decades. Up to now, there is no real model of its formation in a good agreement with geological data on the magmatic evolution at P–T boundary in Eastern Siberia. Modern geochemical data on magmatic rocks around the province is a key to reconstructing magmatic development in time and space. Such data have been obtained for the Norilsk and Meimecha–Kotuy and not for other parts of the Siberian province. For the first time, we studied the geochemistry and mineralogy of magmatic rocks at the Kulyumber river valley, located in the intersection of the Tunguska syneclise and Norilsk–Igarka zone in the NW Siberian platform. In this article, we present data from the Khalil and Kaya sites of this area belonging to the Syverminsky, Gudchikhinsky, Khakanchansky and Nadezhdinsky formations. Their mineralogical and geochemical features (including Sr, Nd and Pb isotope data) are similar to the same formations in the Norilsk area, while the rocks belonging to the Gudchikhinsky formation show differences. The Syverminsky tuffs are also described for the first time. The intrusive rocks are attributed to four intrusive complexes, i.e., Ergalakhsky, Kureysky, Katangsky and Norilsk. The Ergalakhsky complex comprises trachydolerites similar to the trachydolerites of the Norilsk area. The rocks of the Norilsk complex at the Khalil site differ from the rocks of the same complex at the Norilsk area by the (U/Nb)n = 1.8, (La/Yb)n = 2.1 in comparison with 3.7 and 2.3 of the rocks of the Norilsk 1 intrusion. The intrusions of the Kureysky complex are more differentiated than those of the Katangsky intrusions but show comparable TiO2 and trace elements distribution. Thus, the magmatism of the Kulyumber area is characterized by features matching those of the Tunguska syneclise and Norilsk area, i.e., suggesting rift and platform regimes.

Petrogenesis of early Permian granitic dykes in the Wulanhuduge area, central Inner Mongolia, North China: constraints from geochronology, geochemistry, and Sr–Nd–Pb isotopes

2020 ◽  
Vol 57 (6) ◽  
pp. 747-764 ◽  
Author(s):  
Xiang-xin Zhang ◽  
Yong-feng Gao ◽  
Shi-he Lei
Keyword(s):  
Inner Mongolia ◽  
Inductively Coupled Plasma ◽  
North China ◽  
Granite Porphyry ◽  
Pb Isotopes ◽  
Geochemical Data ◽  
Early Permian ◽  
Inductively Coupled ◽  
Slab Breakoff ◽  
End Stage

Early Permian granitic dykes are well developed in the Wulanhuduge area, central Inner Mongolia, North China. In this study, we investigated the petrography, geochronology, and whole-rock geochemistry of the granite porphyry dykes in the Wulanhuduge area. Laser ablation inductively coupled plasma mass spectrometry zircon U–Pb dating yielded 206Pb/238U ages of 289–288 Ma for these granite porphyry dykes, indicating they were emplaced in the early Permian. These granitic dykes are high in silica and alkali contents, and low in total Fe2O3, MgO, CaO, and P2O5 contents. They show enrichment in large-ion lithophile elements such as Rb, Ba, Th, U and K, and depletion in high field strength elements such as Nb, Ta, and Ti, typical of arc-like magma. Their Sr–Nd–Pb isotopic compositions indicate low initial 87Sr/86Sr ratios (0.70306–0.70564), positive εNd(t) values (+3.3 to +3.9), and radiogenic Pb isotopes with (206Pb/204Pb)i of 18.080–18.616, (207Pb/204Pb)i of 15.497–15.555, and (208Pb/204Pb)i of 37.713–38.175. These geochemical data, along with petrological characteristics, suggest that they belong to high K calc-alkaline I-type granites and were generated by the partial melting of the mafic rocks from the pre-existing juvenile arc crust in a post-subduction extensional setting caused by slab breakoff. Therefore, the emplacement of these granite porphyry dykes in the Wulanhuduge area may represent the end stage of the subduction–accretion process in central Inner Mongolia.

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