Ferroan Dolomitization by Seawater Interaction with Mafic Igneous Dikes and Carbonate Host Rock at the Latemar Platform, Dolomites, Italy: Numerical Modeling of Spatial, Temporal, and Temperature Data

Numerous publications address the petrogenesis of the partially dolomitized Latemar carbonate platform, Italy. A common factor is interpretation of geochemical data in terms of heating via regional igneous activity that provided kinetically favorable conditions for replacement dolomitization. New field, petrographic, XRD, and geochemical data demonstrate a spatial, temporal, and geochemical link between replacement dolomite and local mafic igneous dikes that pervasively intrude the platform. Dikes are dominated by strongly altered plagioclase and clinopyroxene. Significantly, where ferroan dolomite is present, it borders dikes. We hypothesize that seawater interacted with mafic minerals, causing Fe enrichment in the fluid that subsequently participated in dolomitization. This hypothesis was tested numerically through thermodynamic (MELTS, Arxim-GEM) and reactive flow (Arxim-LMA) simulations. Results confirm that seawater becomes Fe-enriched during interaction with clinopyroxene (diopside-hedenbergite) and plagioclase (anorthite-albite-orthoclase) solid solutions. Reaction of modified seawater with limestone causes ferroan and nonferroan replacement dolomitization. Dolomite quantities are strongly influenced by temperature. At 40 to 80°C, ferroan dolomite proportions decrease with increasing temperature, indicating that Latemar dolomitization likely occurred at lower temperatures. This relationship between igneous dikes and dolomitization may have general significance due to the widespread association of carbonates with rifting-related igneous environments.

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Neotethyan evolution of eastern Greece (Pagondas Mélange, Evia island) inferred from radiolarian biostratigraphy and the geochemistry of associated extrusive rocks

Geological Magazine ◽

10.1017/s0016756801005337 ◽

2001 ◽

Vol 138 (3) ◽

pp. 345-363 ◽

Cited By ~ 36

Author(s):

TANIEL DANELIAN ◽

ALASTAIR H. F. ROBERTSON

Keyword(s):

Shallow Water ◽

Carbonate Platform ◽

Ocean Basin ◽

Passive Margin ◽

Late Triassic ◽

Geochemical Data ◽

Chemical Compositions ◽

Similar Chemical ◽

Thrust Sheets ◽

Age Range

This paper presents new radiolarian biostratigraphic and igneous/metamorphic geochemical data for a Mesozoic volcanic–sedimentary mélange on the island of Evia (Euboea or Evvoia), eastern Greece. This mélange includes dismembered thrust sheets and blocks of radiolarian chert and basalt. Biostratigraphic age data show that radiolarites interbedded with basalt-derived, coarse clastic sediments near the base of a coherent succession were deposited in Middle and Late Triassic time (Late Ladinian–Carnian, Norian?). Geochemical evidence shows that associated extrusive rocks, of inferred Triassic age, range from ‘enriched’ alkaline basalts, to ‘transitional’ basalts, and more ‘depleted’ mid-ocean ridge-type basalts. Amphibolite facies meta-basalts from the metamorphic sole of the over-riding Evia ophiolite exhibit similar chemical compositions. Both the basalts and the meta-basalts commonly show an apparent subduction-related influence (e.g. relative Nb depletion) that may have been inherited from a previous subduction event in the region. The basalts are interpreted to have erupted during Middle–Late Triassic time (Late Ladinian–Carnian), related to initial opening of a Neotethyan ocean basin adjacent to a rifted continental margin. Radiolarites located stratigraphically higher in the coherent succession studied are dated as Middle Jurassic (Late Bathonian–Early Callovian). Similar-aged radiolarites are depositionally associated with ophiolitic rocks (including boninites), in some other areas of Greece and Albania. During initial ocean basin closure (Bajocian–Bathonian) the adjacent shallow-water carbonate platform (Pelagonian zone) disintegrated to form basins in which siliceous sediments were deposited and highs on which shallow-water carbonates continued to accumulate. This facies differentiation is seen as a response to crustal flexure as the Neotethyan ocean began to close. The over-riding Pagondas Mélange and other similar units in the region are interpreted as accretionary prisms related to subduction of Neotethyan oceanic crust in Middle–Late Jurassic time. These mélanges were emplaced, probably diachronously during Oxfordian–Kimmeridgian time, when the passive margin collapsed, creating a foredeep ahead of advancing thrust sheets of mélange and ophiolites.

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Tauride Carbonate Platform Bauxite Deposits (Turkey) as an Alternative Source for Gallium

10.5194/egusphere-egu21-11122 ◽

2021 ◽

Author(s):

Hatice Nur Bayram ◽

Ali Erdem Bakkalbasi ◽

Zeynep Doner ◽

Ali Tugcan Unluer ◽

Huseyın Kocaturk ◽

...

Keyword(s):

Rare Earth ◽

Rare Earth Elements ◽

Carbonate Rocks ◽

Carbonate Platform ◽

Primary Source ◽

Geochemical Data ◽

Strong Positive Correlation ◽

Alternative Source ◽

Positive Correlation ◽

Bayer Liquor

Mediterranean type karstic bauxite deposits are considered as the primary source for aluminum (Al) production in Europe. During the Al production, Gallium (Ga) is extracted from the so called Bayer-liquor during the processing of bauxite to alumina. Ga, a rare metal, is widely used in modern chemistry and electronic industry. During the past decades, the worldwide demand for Ga has been continuously increasing. In Turkey, karstic bauxite deposits are generally found with shallow marine carbonate rocks which were deposited during Mesozoic period and located in Tauride Carbonate platform. Most of these karstic bauxite deposits can be hosted considerable Ga enrichments, with other immobile elements such as rare earth elements (REE), titanium (Ti), lithium (Li), and iron (Fe). This work focuses on the revealing of the potential Ga enrichments in bauxides from different deposits of Turkey (Morta&#351;-Do&#287;ankuzu, Konya; K&#252;&#231;&#252;kkora&#351;, Karaman; Ac&#305;elma-Yo&#287;unoluk, Kahramanmara&#351; bauxite deposits). Geochemical data of major and trace elements of studied bauxite deposits show that these deposits have significant Ga enrichments (up to 72.6 ppm), as well as the REE (up to 580 ppm), Ti (up to 1.8%), and Li (up to 428 ppm) enrichments. In addition, the Ga enrichments show strong positive correlation with heavy rare earth elements (HREE) and moderate positive correlation with Al, Fe, Ti, Li and Sn elements. In this context, it can be concluded that the most probable source for Ga is rock forming aluminosilicates of the source rock due to the substitution with Al3+ and Fe3+. During weathering process Ga exhibiting immobile behavior much like Al and Fe. Gallium is than incorporated into Al-bearing phases and thus enriched in the bauxite. Presence of Li content can be also interpreted as a contribution from micaceous source such as meta-carbonate rocks of Tauride platform. Moreover, geochemical association between Ga, Ti, Li, tin (Sn) and HREE can be explained by the redox and pH conditions causing other ions seperated from shallow environments.

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Study on Geochemical Characteristics of the Sb Polymetallic District in Da Zhuang of Kai Yuan County in Yunnan Province

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.807-809.2184 ◽

2013 ◽

Vol 807-809 ◽

pp. 2184-2187

Author(s):

Jiao Jiao Chen ◽

Ying Shu Li ◽

Yi Ke Zhang ◽

Da Qing He ◽

Dong Ming Yang

Keyword(s):

Yunnan Province ◽

Mineral Resources ◽

Mining Area ◽

Geochemical Characteristics ◽

Geochemical Data ◽

Geological Investigation ◽

Ore Deposit ◽

Structure Characteristics ◽

Yunnan Area ◽

Favorable Conditions

Southeast Yunnan Area is an Important Nonferrous Metals Mineral Resources Base in Yunnan Province, with Good Metallogenic Conditions. the Structure Characteristics of Kai Yuan Da Zhuang Mining Area is more Complex, with Favorable Conditions for Mineralization. Based on Detailed Geological Investigation, Combined with the Geochemical Data and Geological Setting, Deposit Features of Da Zhuang Antimony Ore Deposit and Summarizes Geochemical Characteristics, that is to Study the Genesis of this Deposit and is to Predict the Mining Ore.

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Subsurface Temperature Properties for Three Types of Permeable Pavements in Cold Weather Climates and Implications for Deicer Reduction

Water ◽

10.3390/w13243513 ◽

2021 ◽

Vol 13 (24) ◽

pp. 3513

Author(s):

Mari E. Danz ◽

Nicolas H. Buer ◽

William R. Selbig

Keyword(s):

Stormwater Management ◽

Temperature Data ◽

Cold Weather ◽

Management Tool ◽

Temperature Profiles ◽

Permeable Pavement ◽

Urban Stormwater Management ◽

Air Temperatures ◽

Favorable Conditions ◽

Winter Rain

Permeable pavement has been shown to be an effective urban stormwater management tool although much is still unknown about freeze-thaw responses and the implications for deicer reduction in cold weather climates. Temperature data from the subsurface of three permeable pavement types—interlocking concrete pavers (PICP), concrete (PC), and asphalt (PA)—were collected over a seven-year period and evaluated. Temperature profiles of all pavements indicate favorable conditions to allow infiltration during winter rain and melting events, with subsurface temperatures remaining above freezing even when air temperatures were below freezing. Data show that PICP surpassed PC and PA with fewer days below freezing, higher temperatures on melt days, slower freeze and faster thaw times, and less penetration of freezing temperatures at depth.

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Tumor-derived hyaluronan induces formation of immunosuppressive macrophages through transient early activation of monocytes

Blood ◽

10.1182/blood-2007-01-068031 ◽

2007 ◽

Vol 110 (2) ◽

pp. 587-595 ◽

Cited By ~ 152

Author(s):

Dong-Ming Kuang ◽

Yan Wu ◽

Nini Chen ◽

Jiasen Cheng ◽

Shi-Mei Zhuang ◽

...

Keyword(s):

Tumor Cells ◽

Common Factor ◽

Human Tumor ◽

Blood Monocytes ◽

Activation Patterns ◽

Tumor Microenvironments ◽

Proinflammatory Responses ◽

Favorable Conditions ◽

Hyaluronan Synthase 2 ◽

Culture Supernatants

Abstract Macrophages (Mφ) in most solid tumors exhibit a distinct immunosuppressive phenotype, but the mechanisms that allow tumor microenvironments to “educate” Mφ are incompletely understood. Here, we report that culture supernatants (TSNs) from several types of tumor cell lines can drive monocytes to become immunosuppressive Mφ. Kinetic experiments revealed that soon after exposure to these TSNs, monocytes began to provoke transient proinflammatory responses and then became refractory to subsequent stimulation. Other TSNs that failed to cause such temporary preactivation did not alter Mφ polarization. Consistent with these results, we observed that the monocytes/Mφ in different areas of human tumor samples exhibited distinct activation patterns. Moreover, we found that hyaluronan fragments constitute a common factor produced by various tumors to induce the formation of immunosuppressive Mφ, and also that upregulation of hyaluronan synthase-2 in tumor cells is correlated with the ability of the cells to cause Mφ dysfunction. These results indicate that soluble factors derived from tumor cells, including hyaluronan fragments, co-opt the normal development of Mφ to dynamically educate the recruited blood monocytes in different niches of a tumor. The malignant cells can thereby avoid initiation of potentially dangerous Mφ functions and create favorable conditions for tumor progression.

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40Ar/39Ar Geochronology and New Mineralogical and Geochemical Data from Lamprophyres of Chompolo Field (South Yakutia, Russia)

Minerals ◽

10.3390/min10100886 ◽

2020 ◽

Vol 10 (10) ◽

pp. 886

Author(s):

Evgeny I. Nikolenko ◽

Konstantin V. Lobov ◽

Alexey M. Agashev ◽

Nikolay S. Tychkov ◽

Maria V. Chervyakovskaya ◽

...

Keyword(s):

Siberian Craton ◽

Lithospheric Mantle ◽

Aldan Shield ◽

Geochemical Data ◽

Alkaline Magmatism ◽

Mantle Minerals ◽

Tectonic Events ◽

Igneous Activity ◽

Lithospheric Mantle Source ◽

Garnet Lherzolites

The alkaline igneous rocks of the Chompolo field (Aldan shield, Siberian craton), previously defined as kimberlites or lamproites, are more correctly classified as low-Ti lamprophyres. The emplacement age of the Ogonek pipe (137.8 ± 1.2 Ma) and the Aldanskaya dike (157.0 ± 1.6 Ma) was obtained using 40Ar/39Ar K-richterite dating. The Chompolo rocks contain abundant xenocrysts of mantle minerals (chromium-rich pyropic garnets, Cr-diopsides, spinels, etc.). The composition of the mantle xenocrysts indicates the predominance of spinel and garnet–spinel lherzolites, while the presence of garnet lherzolites, dunites, harzburgites, and eclogites is minor. The Chompolo rocks are characterized by large-ion lithophile element (LILE) and Light Rare Earth Element (LREE) enrichments, and high field strength element (HFSE) depletions. The rocks of the Ogonek pipe have radiogenic Sr (87Sr/86Sr (t) = 0.70775 and 0.70954), and highly unradiogenic εNd(t) (−20.03 and −20.44) isotopic composition. The trace element and isotopic characteristics of the Chompolo rocks are indicative of the involvement of subducted materials in their ancient enriched lithospheric mantle source. The Chompolo rocks were formed at the stage when the Mesozoic igneous activity was triggered by global tectonic events. The Chompolo field of alkaline magmatism is one of the few available geological objects, which provides the opportunity to investigate the subcontinental lithospheric mantle beneath the south part of the Siberian craton.

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Five decades of shrinkage of July 1st glacier, Qilian Shan, China

Journal of Glaciology ◽

10.3189/172756506781828836 ◽

2006 ◽

Vol 52 (176) ◽

pp. 11-16 ◽

Cited By ~ 24

Author(s):

Akiko Sakai ◽

Koji Fujita ◽

Keqin Duan ◽

Jianchen Pu ◽

Masayoshi Nakawo ◽

...

Keyword(s):

Surface Melting ◽

Temperature Data ◽

Surface Elevation ◽

Surface Velocity ◽

Ice Thickness ◽

Glacier Shrinkage ◽

The Past ◽

Glacier Ice ◽

Elevation Changes ◽

Increasing Temperature

AbstractA survey of July 1st glacier, Qilian Shan, China, was carried out in 2002. Previously, the glacier’s boundary had been recorded in 1956, and further research had been carried out in the mid- 1970s and 1980s. Our survey reveals that area shrinkage and surface lowering have accelerated in the past 15 years. Surface elevation changes can result from changes in accumulation, surface melting and emergence velocity. The contributions of these elements to surface lowering are evaluated at the lower part of the glacier from observations of surface velocity, ice thickness and precipitation, and from temperature data near the glacier. Apart from the effect of glacier ice redistribution, our analysis reveals quantitatively that the recent accelerated glacier shrinkage has been caused by increasing temperature. Furthermore, it is established that meltwater discharge from the glacier in the past 17 years has increased due to glacier shrinkage, by about 50% over that from 1975 to 1985.

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Quantitative Model of the Formation Mechanism of the Rollfront Uranium Deposits

Eurasian Chemico-Technological Journal ◽

10.18321/ectj724 ◽

2018 ◽

Vol 20 (3) ◽

pp. 213

Author(s):

D.Y. Aizhulov ◽

N.M. Shayakhmetov ◽

A. Kaltayev

Keyword(s):

Reactive Transport ◽

Redox Reactions ◽

Reaction Rates ◽

Quantitative Model ◽

Production Costs ◽

Reactive Flow ◽

Uranium Deposits ◽

Geological Processes ◽

Exploration And Production ◽

Favorable Conditions

The rollfront type deposits are crescent shaped accumulation of mineralization including uranium, selenium, molybdenum in reduced permeable sandstones. It generally forms within a geochemical barrier between mostly reduced and predominantly oxidized environments. Redox reactions between oxidant and reductant creates favorable conditions for uranium precipitation, while constant flow of oxidant continuously dissolves uranium minerals thereby creating a reactive transport. Several previous works had either focused on the characteristics of the rollfront type deposits, or on the description of chemical and geological processes involved in their genesis. Based on these previous works, authors aimed to mimic laboratory experiments numerically by reactive flow and numerical simulation. Data from one particular experiment was used to determine reaction rates between reactants to produce a model of reactive transport and chemical processes involved in the formation of rollfront type deposits. The resulting model was used to identify the causes of crescent like formations and to determine main mechanisms influencing rollfront evolution. A better understanding and simulation of the mechanism involved in the formation of rollfront type deposits and their properties would contribute to decreased exploration and production costs of commodities trapped within such accumulations. The results of this work can be used to model other deposits formed through infiltration and subsequent precipitation of various minerals at the redox interface.

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Late Palaeozoic extensional volcanism along the northern margin of Gondwana in southern Turkey: implications for Palaeotethyan development

International Journal of Earth Sciences ◽

10.1007/s00531-021-02051-7 ◽

2021 ◽

Author(s):

Alastair H. F. Robertson ◽

Osman Parlak ◽

Timur Ustaömer

Keyword(s):

Continental Margin ◽

Carbonate Platform ◽

Late Carboniferous ◽

Geochemical Data ◽

Low Grade ◽

Thrust Sheet ◽

The North ◽

Late Palaeozoic ◽

Granitic Magmatism ◽

North Gondwana

AbstractThe Late Palaeozoic–Early Mesozoic Tethyan development of the Eastern Mediterranean region remains debatable, especially in Turkey, where alternative northward and southward subduction hypotheses are proposed. Relevant to this debate, new whole-rock geochemical data are provided here for early Carboniferous (Late Tournaisian-Late Visean; c. 340–350 Ma) tuffaceous sedimentary rocks within the Çataloturan thrust sheet (Aladağ nappe), eastern Taurides. The tuffs accumulated from evolved alkaline volcanism, variably mixed with terrigenous and radiolarian-rich sediments. In addition, Late Palaeozoic meta-volcanic rocks, c. 150 km farther NE, within the Binboğa (= Malatya) metamorphics (a low-grade high-pressure unit), are indicative of a within-plate setting. An impersistent geochemical subduction signature in these volcanics may represent an inherited, rather than contemporaneous, subduction influence, mainly because of the absence of a continental margin arc or of arc-derived tuff. Both the Binboğa metamorphics and the Çataloturan thrust sheet (Aladağ nappe) restore generally to the north of the relatively autochthonous Tauride carbonate platform (Geyik Dağ), within the carbonate platform bordering north-Gondwana. The Çataloturan thrust sheet is interpreted, specifically, as a c. E–W, deep-water, volcanically active rift that progressively infilled. Regional geological evidence suggests that melange units (Konya Complex, Afyon zone), Teke Dere unit, Lycian nappes), and Chios–Karaburun melange, E Aegean) accreted to the north-Gondwana continental margin during the late Carboniferous; this was coupled with localised calc-alkaline granitic magmatism (Afyon zone of Anatolide crustal block). We propose an interpretation in which Late Devonian–Carboniferous alkaline intra-plate volcanism relates to extension/rifting along the north-Gondwana margin. In contrast, the melange accretion and granitic magmatism could relate to short-lived late Carboniferous southward subduction that accompanied the diachronous closure of Palaeotethys.

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One’s soil is another one’s regolith – let’s combine our efforts in investigating the critical zone

10.5194/egusphere-egu21-10474 ◽

2021 ◽

Author(s):

Carsten Laukamp ◽

Ian C. Lau

Keyword(s):

Remote Sensing ◽

Soil Properties ◽

Common Factor ◽

Critical Zone ◽

Earth Observation ◽

Environmental Data ◽

Geochemical Data ◽

Sensing Data ◽

Geochemical Survey ◽

Wide Range

Earth observation is invaluable for the agricultural sector as well as the critical metals sector, providing cost-effective, spatially comprehensive information about Earth&#8217;s surface composition from the regional to paddock/mine-scale. A wide range of remote sensing instruments are used to monitor soils, to give information on properties such as moisture and mineralogy. At the same time, remote sensing data facilitate the discovery and mining of mineral deposits, including iron ore, copper and other metals critical for the transition of the fossil fuel-based energy sector to a sustainable, renewable energy future. One common factor of these two sectors is that all Earth observation systems require calibration sites that help to ensure the data being collected is of high accuracy. Another common factor is that both sectors require ground validation of the remotely sensed data, producing a plethora of publicly available Earth surface data distributed across numerous web portals and platforms. Both sectors aim, ultimately, towards characterising the composition of the subsurface - which starts in both sectors at Earth&#8217;s surface and reaches to 10s or even 100s of metres below. This can be achieved by developing conceptual models that describe the weathering of bedrock in the soil/regolith. In mineral resource exploration, specific weathering-resistant minerals (e.g. talc) can be traced at Earth&#8217;s surface by means of Earth observation to characterise the type of bedrock through cover (i.e. beneath the soil/regolith). Another example is the mapping of differences in kaolin crystallinity at Earth&#8217;s surface and in the subsurface (e.g. drilling, trenches) to infer the distribution of in-situ versus transported regolith, which is of key importance for raw materials exploration. Remote sensing is also commonly used for collecting baseline environmental data prior to mining and for monitoring its impact on the environment during and after the process. In soil science, infrared spectral measurements have been conducted on soil samples in laboratories for estimation of soil properties, such as soil carbon, pH, EC. These estimations require a training library as well as standardised preparation of the samples and measurement technique. The ultimate goal is the accurate measurement of these soil properties using remote sensing, where complex variance of the nature of the materials and illumination conditions exists. &#160;This paper discusses opportunities for sharing facilities, data, workflows and methods for collecting, processing and interpreting remote and proximal multi- and hyperspectral sensing technologies. For this, publicly available mineralogical and geochemical data sets collected from the critical zone, such as in the frame of the National Geochemical Survey of Australia (NGSA; https://www.ga.gov.au/about/projects/resources/national-geochemical-survey) project and AuScope&#8217;s National Virtual Core Library Infrastructure Program (NVCL; https://www.auscope.org.au/nvcl), as well as publicly available Earth observation products, such as the Australian ASTER Geoscience Products, will be used to demonstrate the multidisciplinary applications of multi- and hyperspectral remote and proximal sensing data. For the benefit of meeting the United Nations&#8217; Sustainable Development Goals, agriculture, resources and environment sectors should overcome unnecessary competition and work hand in hand.

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