Redskin Granite: a rare-metal-rich Precambrian pluton, Colorado, USA

1980 ◽  
Vol 43 (332) ◽  
pp. 959-966 ◽  
Author(s):  
G. A. Desborough ◽  
S. D. Ludington ◽  
W. N. Sharp
Keyword(s):  
Trace Elements ◽  
Crystallization Temperature ◽  
Rare Metal ◽  
Volatile Elements ◽  
Accessory Minerals ◽  
Primary Mineral ◽  
Dioctahedral Mica ◽  
High Silica ◽  
High Concentrations ◽  
High Degree

SummaryThe Precambrian Redskin stock is a high-silica alkalic granite that forms a late pluton related to the 1000 Ma-old Pikes Peak batholith. Zircon, fluorite, fluocerite, ilmenorutile, columbite, biotite, magnetite, and hematite are the most abundant accessory minerals. Thorite, monazite, and xenotime are sparse, and cassiterite and topaz very rare. The principal residences of Sn, Nb, and Ta are ilmenorutile and columbite. The occurrence of cassiterite intergrown with biotite and columbite and the high contents of Nb and Ta in cassiterite are evidence that cassiterite is also a primary mineral. The high concentrations of certain trace elements indicate a high degree of fractionation of magma prior to emplacement of the Redskin Granite. An extremely low crystallization temperature for the granite is indicated by the compositions of albite and K-feldspars, the presence of Fe-rich dioctahedral mica, the absence of Ti in magnetite, and the low content of Ti in biotite. This low crystallization temperature seems due largely to the high concentrations of F, Rb, and other volatile elements in the magma.

scholarly journals Proteolytic enzyme arbitrated antagonization of helminthiasis by Cinnamomum cappara leaf extract in Pheretima posthuma

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Kayeen Vadakkan ◽  
Meena K Cheruvathur ◽  
Anu S Chulliparambil ◽  
Famy Francis ◽  
Anu P Abimannue
Keyword(s):  
Leaf Extract ◽  
Anthelmintic Activity ◽  
Enzymatic Action ◽  
Local Areas ◽  
Hyperbolic Relation ◽  
Proteolytic Action ◽  
High Concentrations ◽  
High Degree ◽  
Morphological And Molecular Characterization ◽  
Burk Plot

Abstract Background There have been several studies carried out to irradiate Helminthiasis however very little research have been carried out where in the enzymatic activity of plants are exploited to antagonize infections. Here we are analyzing the anthelmintic activity of Cinnamomum cappara leaf extract against Pheretima posthuma complimented by proteolytic action. Results The fresh leaves of Cinnamomum cappara was collected from local areas of Thrissur during December 2019. Plants were identified and authenticated by morphological and molecular characterization. The enzymatic action was analyzed by plotting Lineweaver–Burk plot which suggested that the extract possess the Km 185.77 μM for casein as substrate and obeyed Michaelis–Menten kinetics with typical hyperbolic relation with enzyme and increasing concentration of substrate. The effect of extract upon study subject was in directly proportional with concentration of antagonist where higher activities were obtained in high concentrations. The anatomical and histological studies suggested that the activity of extract was due to the degradation of muscular bundle of subject that resulted in the leakage of ceolomic fluid. Conclusions Cinnamomum cappara leaf extract possessed high degree of protease intervened anthelmintic activity against Pheretima posthuma. As the study subject show immense morphological and physiological resemblance with all other helminthic parasites, this results shall be adopted to further clinical and pharmacological applications.

Hydrochemistry and carbonate sediment characterisation of Bacalar Lagoon, Mexican Caribbean

2019 ◽  
Vol 70 (3) ◽  
pp. 382 ◽  
Author(s):  
Nidia I. Tobón Velázquez ◽  
Mario Rebolledo Vieyra ◽  
Adina Paytan ◽  
Kyle H. Broach ◽  
Laura M. Hernández Terrones
Keyword(s):  
Trace Elements ◽  
Water Column ◽  
Saturation Index ◽  
Major Elements ◽  
Anthropogenic Sources ◽  
Pollution Indices ◽  
Mexican Caribbean ◽  
High Concentrations ◽  
Geochemical Analyses ◽  
Changes Over Time

The aim of the study is to determine the distribution of trace and major elements in the water and in the sediments of the south part of the Bacalar Lagoon and to identify the sources of the trace elements and their changes over time. The western part of the lagoon water column is characterised by high concentrations of Ca2+, HCO3– and Sr2+, derived from groundwater input. In contrast, the eastern part of the lagoon is characterised by high concentrations of Mg2+, Na+ and Cl–. The lagoon is not affected by present-day seawater intrusion. Water column and sediment geochemical analyses performed in Bacalar Lagoon show clear spatial distribution of different parameters. The saturation index of the water column indicates three main groups: (1) a zone oversaturated with regard to aragonite, calcite and dolomite; (2) an undersaturated area where all three minerals are dissolving; and (3) an area with calcite equilibrium and undersaturation with regard to the other minerals. Herein we present the first measurements of trace element (Ba2+, Mn2+, K+, Ni2+, Zn2+) concentrations in carbonates obtained from sediments in Bacalar Lagoon. In order to evaluate whether the trace elements are derived from natural or anthropogenic sources, four pollution indices were calculated. The results confirmed that Bacalar Lagoon sediments are not contaminated with Ni2+, K+, Mn2+ and Ba2+, and that the Zn2+ seems to have a predominantly anthropogenic origin.

The Projectile of the Lappajärvi Impact Crater

1980 ◽  
Vol 35 (2) ◽  
pp. 197-203 ◽  
Author(s):  
Elke Göbel ◽  
Uwe Reimold ◽  
Hildegard Baddenhausen ◽  
Herbert Palme
Keyword(s):  
Impact Crater ◽  
Carbonaceous Chondrite ◽  
Volatile Elements ◽  
Rich Phase ◽  
Impact Melt ◽  
Siderophile Elements ◽  
High Concentrations ◽  
Impact Melts

Abstract Two impact melt samples from the Lappajärvi crater (Scandinavia) are highly enriched in siderophile elements, such as Ir, Re, and Os. This indicates the presence of a meteoritic component. The simultaneous enrichments of Ni, Co, Cr, and Se suggest a chondritic projectile. Because of the relatively large indigenous contributions to Ni, Co, and Cr, it is not possible to distinguish between a normal and a carbonaceous chondrite. The high concentrations of relatively volatile elements could point towards a volatile-rich projectile.The two melt samples have high Re/Ir ratios compared to chondritic ratios. Enrichment of Re relative to Ir is very unusual in terrestrial impact melts. Loss of Re, because of volatilisation under oxidizing conditions or by weathering is frequently observed.The high Re/Ir ratios and the high abundances of relatively volatile elements either indicate the presence of a volatile rich phase or they characterize a type of meteorite, which has not been sampled. Some lunar highland rocks have a pattern of meteoritic elements rather similar to that observed for the Lappajärvi meteorite.The Lappajärvi crater is, after Rocheehouart, the second European crater where a significant amount of meteoritic component has been found.A melt sample from the Lake St. Martin crater (Manitoba), did not show any enrichment in meteoritic elements.

The isolation of nucleic acids from woody tissue using dimethyl sulfoxide

1972 ◽  
Vol 50 (5) ◽  
pp. 1085-1090 ◽  
Author(s):  
L. V. Gusta ◽  
V. C. Runeckles
Keyword(s):  
Nucleic Acids ◽  
Experimental Evidence ◽  
Dimethyl Sulfoxide ◽  
Ribonuclease Activity ◽  
Woody Tissue ◽  
Bark Tissue ◽  
High Concentrations ◽  
High Degree

A procedure is described for the isolation of nucleic acids from apple bark tissue using dimethyl sulfoxide. Nucleic acids isolated by this method are high in yield, and exhibit a high degree of purity as evidenced by their spectra. Experimental evidence is given to show that extraction of the tissue with dimethyl sulfoxide before the extraction of nucleic acids removes protein and pigments. Little or no ribonuclease activity could be detected in apple bark tissue after extraction with dimethyl sulfoxide. Ribonuclease activity was shown to be strongly inhibited by high concentrations of dimethyl sulfoxide.

scholarly journals Petrogenetic and Compositional Features of Rare Metal Pan-African Post-Collisional Pegmatites of Southwestern Nigeria; A Status Review

2018 ◽  
Vol 7 (2) ◽  
pp. 166-187
Author(s):  
Abiola Oyebamiji ◽  
Adeniyi JohnPaul Adewumi ◽  
Tehseen Zafar ◽  
Adegbola Odebunmi ◽  
Philips Falae ◽  
...  
Keyword(s):  
Mineral Chemistry ◽  
Rare Metal ◽  
Border Zone ◽  
Chemical Compositions ◽  
Molten Material ◽  
Southwestern Nigeria ◽  
Pan African ◽  
Opening And Closing ◽  
High Degree ◽  
Rare Metal Pegmatite

Abstract This research reviews the geology, petrogenesis, compositional trends and geochronology of the rare-metal pegmatite of southwestern Nigeria. The source of these pegmatites is still presently debated which have been explained as either product of highly fractionated molten material or anatexis of the local crust. However, published works of past authors have been compiled to give a detailed understanding of the formation of the mineral deposits. The basement complex of southwestern Nigeria comprises of Precambrian rocks of amphibolite, the hornblende gneiss and the granite gneisses which were formed as a result of the opening and closing of the ensialic basin with significant, extensive subduction during the Pan-African orogeny. The pegmatites in this region have shown internal zoning and a high degree of evolution from the border zone to the core zone during the crystallization and solidification of the felsic granite to pegmatite melt. The rare-metal pegmatites have distinct chemical compositions and mineralogy, containing quartz, biotite, muscovite, microcline, garnet with localized tourmaline, tantalite and columbite. These pegmatites vary significantly by their bulk-rock and mineral chemistry which indicates a more peraluminous attribute and enrichments of lithophile elements of Rb, Cs, Ta and Ba. Previous K/Ar isotopic ages (502.8±13.0 Ma and 514.5±13.2 Ma) suggest that the pegmatites are related to the post-collisional phase of intensive metasomatism. Adopted from previous studies, a five-stage conceptual model of evolution which is widely accepted have been proposed for the origin of the pegmatites.

Trace elements in skin-contact clothes and migration to artificial sweat: Risk assessment of human dermal exposure

2016 ◽  
Vol 87 (6) ◽  
pp. 726-738 ◽  
Author(s):  
Joaquim Rovira ◽  
Martí Nadal ◽  
Marta Schuhmacher ◽  
José L Domingo
Keyword(s):  
Trace Elements ◽  
Health Risks ◽  
Hazard Quotient ◽  
Dermal Exposure ◽  
Environmental Scanning ◽  
Potential Health ◽  
Skin Contact ◽  
Artificial Sweat ◽  
High Concentrations ◽  
And Migration

The concentrations of a considerable number of trace elements (Ag, Al, As, B, Ba, Be, Bi, Cd, Co, Cr, Cu, Fe, Hg, Mg, Mn, Mo, Ni, Pb, Sb, Sc, Se, Sm, Sn, Sr, Ti, Tl, V and Zn) were determined in various skin-contact clothes (T-shirts, blouses, socks, baby pajamas and bodies) from the Catalan (Spain) market. In addition, migration experiments with artificial acidic sweat were conducted in order to establish the migration rates of these elements. High levels of Zn (186–5749 mg/kg) were found in zinc pyrithione labeled T-shirts, while high concentrations of Sb and Cr were found in polyester and black polyamide fabrics, respectively. An environmental scanning electron microscope (ESEM) confirmed the presence of Ag and Ti particles and aggregates in several clothing items. The use of the ESEM complemented the results of the elemental analysis and migration experiments. Dermal exposure to trace elements was subsequently calculated, and the human health risks were assessed. Antimony showed the highest mean hazard quotient (HQ = 0.4) for male and female adults wearing polyester clothes; for one of the examined items (polyester T-shirt) the HQ was even above the safety limit (HQ > 1). Exposure to Sb from polyester textile could mean potential health risks in subpopulation groups who frequently wear these clothes, and for long time periods. The migration experiments with artificial sweat showed to be essential for establishing the exposure to trace elements through cloth with direct contact with skin.

scholarly journals Petrogenesis and tectonic of the Urucum granitic suite, Rio Doce Valley (Minas Gerais - Brazil): an example of syn to late collisional peraluminous magmatism associated with high-angle transcurrent shear zone

2015 ◽  
Vol 45 (1) ◽  
pp. 127-141 ◽  
Author(s):  
Hermínio Arias Nalini Júnior ◽  
Rômulo Machado ◽  
Essaid Bilal
Keyword(s):  
Trace Elements ◽  
Solid State ◽  
Shear Zone ◽  
Saturation Index ◽  
Minas Gerais ◽  
High Angle ◽  
Accessory Minerals ◽  
Major Oxides ◽  
Minas Gerais State ◽  
Alumina Saturation Index

The Urucum suite (582 ± 2 Ma, zircon U-Pb age), situated in the Mid-Rio Doce Valley, eastern part of Minas Gerais State, is characterized by elongated, NW-SE and N-S trending granitic massifs associated with the Conselho Peña-Resplendor high-angle shear zone. It corresponds to a syn to late collisional magmatism that presents dominant solid-state foliation. Four facies are distinguished within the Urucum suite: (i) a porphyritic (Urucum); (ii) a medium- to coarse nequigranular (Palmital); (iii) a tourmaline-bearing; and (iv) a pegmatitic facies. These facies are peraluminous, with alumina saturation index varying from 0.98 to 1.38. SiO2 contents vary from 70.7 to 73.7 wt%, with K2O values ranging from 3.5 to 5.7 wt%, Na2O from 1.9 to 4.4 wt%, MgO from 0.6 to 1.2 wt%, and CaO from 0.3 to 0.9%. Harker-type diagrams show rather continuous trends from the less-evolved Urucum facies to the more evolved tourmaline-bearing and pegmatitic facies. The behavior of several major oxides and trace elements (Fe2O3, MgO, MnO, CaO, TiO2, Al2O3, K2O, Rb and Ba) reflects the role played by fractionation of ferromagnesian minerals, feldspars and accessory minerals. Initial Sr87/Sr86 ratios vary from 0.711 to 0.716, with εNd (580 Ma) values between -7.4 to -8.2, and Sm-Nd TDM model ages ranging from 2290 to 1840 Ma.

scholarly journals Magmatic and Postmagmatic Mineral Associations of the Malyutka Massif Rocks (Khudolazovkiy Complex of the South Urals)

2021 ◽  
Vol 20 (2) ◽  
pp. 99-109
Author(s):  
I.R. Rakhimov ◽  
Keyword(s):  
Chemical Composition ◽  
Crystallization Temperature ◽  
Equilibrium Temperature ◽  
South Urals ◽  
The South ◽  
Accessory Minerals ◽  
Rock Formation ◽  
Genetic Interpretation ◽  
Mineral Associations ◽  
Ore Minerals

The results of detailed mineralogical studies of the Malyutka massif altered rocks of the Khudolazovskiy differentiated complex are presented. The morphology and chemical composition of many rock-forming and accessory minerals are described. According to the study, the magmatic and post-magmatic (hydrothermal-metasomatic) stages of rock formation are distinguished. The problems associated with the genetic interpretation of a number of rock-forming and ore minerals are discussed. The conclusion about the polygenic nature of the formation of spinelids is made. The equilibrium temperature in the «Ti-magnetite–ilmenite» system (633–650 °C), as well as the crystallization temperature of chlorite, replacing phlogopite and hornblende (145–185 °C), were estimated.

scholarly journals Rhombic calcite microcrystals as a textural proxy for meteoric diagenesis

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Mohammed S. Hashim ◽  
Stephen E. Kaczmarek
Keyword(s):  
Trace Elements ◽  
Laboratory Experiments ◽  
Crystal Form ◽  
Geochemical Data ◽  
Carbonate Sediments ◽  
Geochemical Evidence ◽  
Meteoric Diagenesis ◽  
Low Degree ◽  
Rock Record ◽  
High Degree

AbstractNumerous Phanerozoic limestones are comprised of diagenetic calcite microcrystals formed during mineralogical stabilization of metastable carbonate sediments. Previous laboratory experiments show that calcite microcrystals crystallizing under conditions similar to those that characterize meteoric diagenetic settings (impurity-free, low degree of supersaturation, high fluid:solid ratio) exhibit the rhombic form/morphology, whereas calcite microcrystals crystallizing under conditions similar to those that prevail in marine and marine burial diagenetic settings (impurity-rich, high degree of supersaturation, low fluid:solid ratio) exhibit non-rhombic forms. Based on these experimental observations, it is proposed here that rhombic calcite microcrystals form exclusively in meteoric environments. This hypothesis is tested using new and previously published textural and geochemical data from the rock record. These data show that the vast majority of Phanerozoic limestones characterized by rhombic microcrystals also exhibit petrographic and/or geochemical evidence (depleted δ13C, δ18O, and trace elements) indicative of meteoric diagenesis whereas non-rhombic forms are associated with marine burial conditions. By linking calcite microcrystal textures to specific diagenetic environments, our observations bring clarity to the conditions under which the various microcrystal textures form. Furthermore, the hypothesis that rhombic calcite microcrystals form exclusively in meteoric environments implies that this crystal form may be a useful textural proxy for meteoric diagenesis.

scholarly journals Evaluation of sediment contamination by trace elements and the zooplankton community analysis in area affected by gold exploration in Southeast (SE) of the Iron Quadrangle, Alto Rio Doce, (MG) Brazil

2013 ◽  
Vol 25 (2) ◽  
pp. 150-157
Author(s):  
Cláudia de Lima e Silva ◽  
Adivane Terezinha da Costa ◽  
Giovanni Guimarães Landa ◽  
Herton Fabrício Camargos Fonseca ◽  
Aléssio Silveira
Keyword(s):  
Trace Elements ◽  
Reference Values ◽  
Zooplankton Community ◽  
Reference Value ◽  
Community Analysis ◽  
Major And Trace Elements ◽  
Geochemical Composition ◽  
Gold Exploration ◽  
Local Reference ◽  
High Concentrations

AIM: The aim was to verify the geochemical composition of sediments samples (riverbed and bank) and the relationship of the following elements: Al, As, Cd. Cr, Cu, Fe, Mn, Ni and Zn with the zooplankton community. METHODS: Bank and riverbed sediments were collected in four sampling points along the studied area, in June/2010 (dry season) and March/2011 (rainy season). Three types of analysis were performed: granulometric, mineralogical (by X-Ray diffractometer) and geochemical (by ICPOES), where for the last two types, only a fraction of silt/clay (<0.062 mm) was used, and the results were compared with the following reference values: Local Reference Value (Costa et al., 2010), Quality Reference Values (São Paulo, 2005), PEC and TEC values (MacDonald et al., 2000). For identification of the zooplankton community, riverbed and bank samples were collected in polyethylene bottles, suspended with deionized water (bank sample only), stained with Rose Bengal and preserved in formalin at 4%. RESULTS: As concentrations at Col sampled point were 18 times greater than the Local Reference Value (3.84 mg.kg-1). Cd concentrations were greater than the values established by the QRV (<0.5 mg.kg-1) and PEC (4.98 mg.kg-1) in almost all the sampled points, regarding seasonality. The following zooplanktonic species were identified: Arcella costata (Ehrenberg, 1847), Arcella discoides (Ehrenberg, 1843), Arcella vulgaris (Ehrenberg, 1830), Centropyxis aculeata (Ehrenberg, 1838), Centropyxis ecornis (Ehrenberg, 1841), Difflugia sp., Difflugia acuminata (Ehrenberg, 1838), Euglypha laevis (Perty, 1849), Trynema enchelys (Ehrenberg, 1938), Asplanchna priodonta (Gosse, 1850), and Bedelloida, with, approximately 81% belonging to the Protozoa group. CONCLUSIONS: The studied area, with the exception of the Tripuí point, was found to be impacted by historical gold exploration in the region, as well as by the growing urbanization. Within the elements considered to be the most toxic to the biota, As and Cd violated all their reference values. In spite of high concentrations of major and trace elements encountered at downstream points, testacea species were identified, suggesting that this group has the capacity to adapt to adverse situations.

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