scholarly journals New View on the Genesis of the Bashuihe Pluton, Laoshan Granites, China: Indications from Fluid Inclusions and H–O Isotopes

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Huimin Liu ◽  
Zhaojun Song ◽  
Hongbo Yan ◽  
Wenyu Wang ◽  
Xinru Wang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Isotope Analysis ◽  
Hydrothermal Solution ◽  
Hydrothermal Activity ◽  
Salinity Range ◽  
Element Analysis ◽  
O Isotopes ◽  
Alkali Granites ◽  
Hydrogen And Oxygen Isotope ◽  
Host Rocks

Oval caves have recently been discovered in the Bashuihe granite pluton of Laoshan Mountain, China. Oval caves typically occur in alkaline granites. This study conducted microthermometry and stable isotope analysis of quartz inclusions from oval caves and host rocks from the Bashuihe pluton to reconstruct the diagenetic evolutionary history of the Laoshan area. The temperature measurement results indicated a homogenisation temperature range from 162.5 to 261.6°C (mean 203.9°C), a salinity range of 2.1–8.3 wt% (mean 5.07 wt%), and a density range of 0.8–0.98 g/cm3 (mean 0.90 g/cm3), indicating a low-temperature, low-salinity, and low-density fluid. The emplacement depth ranged from 2.73 km to 4.43 km, indicating medium-shallow granite. A hydrogen and oxygen isotope analysis ( δ D = − 83.58 – − 67.17 , δ 18 O H 2 O = 0.83 – 0.39 ) revealed that the diagenetic fluids of the Bashuihe pluton represented a mixed hydrothermal solution composed of meteoric water and magmatic water. The results of a whole rock, H–O isotopes, rare earth element, and high field strength element analysis on the Laoshan alkali granites suggest significant hydrothermal activity in the late stage of magmatism. Primary oval caves in the Bashuihe pluton most likely evolved in the following sequence: fluid was enriched in the late diagenetic stage, diagenetic minerals crystallised under low temperature and pressure conditions, the crystallisation rate accelerated, and the magma condensed rapidly. Moreover, the increase in magma fluid enabled the movement and convergence of fluid. The accumulated fluid and volatiles occupied more space, and rapid magma condensation trapped the accumulated fluid and volatiles in the pluton, forming the oval granite cave. This research provides a crucial theoretical reference for the development and utilisation of underground space and engineering buildings in granite regions.

scholarly journals Analysis of the Ordovician Carbonate Hydrothermal Process in Tadong Area, Xinjiang, China

2019 ◽  
Vol 23 (2) ◽  
pp. 127-132
Author(s):  
Wancang Tan ◽  
Yuanlin Meng ◽  
Zihui Feng ◽  
Qi'an Meng ◽  
Qiang Li ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Hydrothermal Process ◽  
Isotope Analysis ◽  
Hydrothermal Activity ◽  
Geochemical Characteristics ◽  
Element Analysis ◽  
Oil And Gas Exploration ◽  
Eu Anomaly ◽  
Fe Content ◽  
Carbon And Oxygen Isotope

Hydrothermal activity played an important part in the formation of the Ordovician dolostone reservoirs in Tadong area (eastern Tarim Basin). By applying the technologies of thin rock section microscopic identification, cathodoluminescence analysis, carbon and oxygen isotope analysis, trace element, rare earth element analysis, among others, the mineralogical characteristics and geochemical characteristics of the hydrothermal process are studied. It can have seen that the Ordovician hydrothermal process has represented by dolomite in various forms in the aspect of petrology and mineralogy. It is mainly composed of medium-megacryst crystalline dirty dolomite and powder-megacryst crystalline cleaner dolomite. The geochemical characteristics are the hydrothermal origin, medium-megacryst crystalline dirty dolomite with lower δ18O value, high Mn-Fe content, and positive Eu anomaly. The powder-megacryst crystalline has cleaner dolomite, with higher δ18O value, the Mn content low, and the negative Eu anomaly. Provide a reference for the Ordovician carbonate in Tadong area oil and gas exploration in the study.

Petrographic and isotopic studies of the altered acid volcanics of the Tolfa-Cerite area, Italy: the genesis of the clays

Clay Minerals ◽  
1977 ◽  
Vol 12 (2) ◽  
pp. 147-162 ◽  
Author(s):  
G. Lombardi ◽  
S. M. F. Sheppard
Keyword(s):  
Hot Spring ◽  
Isotope Analysis ◽  
Volcanic Rocks ◽  
Geothermal Activity ◽  
Spring System ◽  
Spring Type ◽  
Hydrothermal Environment ◽  
Hydrogen And Oxygen Isotope ◽  
Acid Volcanics ◽  
Host Rocks

AbstractAlunite-kaolinite deposits occur in argillized zones in acid volcanic rocks at Tolfa. Over seventy samples were examined by one or more of the following methods: thin section, DTA, X-ray, IR, TG, SEM, chemical, and hydrogen and oxygen isotope analysis. Kaolinite and dickite, of high structural order, are the dominant clays with micamontmorillonite and halloysite subordinate. In many samples kaolinite and dickite coexist; their relative amounts are variable but the dickite content tends to increase with depth. SEM studies show that dickite crystals—up to 30 µm—are bigger than kaolinite.The D/H and 18O/16O ratios of six clays, a whole rock, two biotites from fresh host rock, two chalcedony veins and three local meteoric waters indicate that the clays formed in a meteoric-hydrothermal environment of acid hot spring type at about 80°C. The fresh volcanic host rocks are strongly enriched in 18O relative to ‘normal’ igneous rocks due to derivation from or exchange with 18O-rich sedimentary rocks at depth prior to hydrothermal and solfataric activity. In the absence of present-day geothermal activity the life of this hot spring system was less than 4 m.y.

scholarly journals Low-temperature hydrothermal synthesis of hierarchical flower-like CuB2O4 superstructures

2020 ◽  
Vol 14 (2) ◽  
pp. 113-118
Author(s):  
Daniel Ursu ◽  
Anamaria Dabici ◽  
Marinela Miclau ◽  
Nicolae Miclau
Keyword(s):  
Thermal Stability ◽  
Low Temperature ◽  
Self Assembly ◽  
Hydrothermal Solution ◽  
Optical Measurements ◽  
Oriented Attachment ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
One Step

We report for the first time the fabrication of hierarchical ordered superstructure CuB2O4 with flower-like morphology via a one-step, low temperature hydrothermal method. The tetragonal structure of CuB2O4 was determined by X-ray diffraction and high-resolution transmission electron microscopy. Optical measurements attested of the quality of the fabricated CuB2O4 and high temperature X-ray diffraction confirmed its thermal stability up to 600 ?C. The oriented attachment growth and the hierarchical self-assembly of micrometer-sized platelets producing hierarchical superstructures with flower-like morphology are designed by pH of the hydrothermal solution. The excellent band gap, high thermal stability and hierarchical structure of the CuB2O4 are promising for the photovoltaic and photocatalytic applications.

Interaction of submarine volcanic and high-temperature hydrothermal activity proposed for the formation of the Agrokipia, volcanic massive sulfide deposits of Cyprus

1992 ◽  
Vol 29 (9) ◽  
pp. 1928-1936 ◽  
Author(s):  
James M. Hall
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Hydrothermal Vents ◽  
Massive Sulfide ◽  
Hydrothermal Activity ◽  
Hydrothermal Fluids ◽  
Spreading Ridge ◽  
Sulfide Deposits ◽  
Original Surface ◽  
Massive Sulfide Deposits

The results of drilling near the spreading-ridge-type, volcanic-hosted, massive sulfide deposits of Agrokipia, Cyprus, are described. Mineralization and associated argillic hydrothermal alteration occur over intervals of 5–130 m and at depths of 80–230 m beneath the original surface of the oceanic crust. Mineralization occurs in massive flows that probably represent a locally ponded sequence up to 300 m thick. Abundant glass–aphanitic basalt transitions are present from about 100 m below the surface of the ponded sequence, with glass abundances locally reaching 60% of the section. A novel hypothesis, involving the presence of active, high-temperature hydrothermal vents beneath the cooling ponded sequence, with the passage of hydrothermal fluids through the still molten lava, is proposed to account for the observations. While this hypothesis is reasonable, the inferred processes have not, as yet, been demonstrated under either laboratory or field conditions. The seafloor expression of this system was probably one of widely distributed, low-temperature, fluid emission over the surface of a lava pond in the axial graben of a spreading ridge.

Temperatures of Neoproterozoic Regional Carbonate Alteration in the Eastern Desert of Egypt

2020 ◽  
Author(s):  
Arman Boskabadi ◽  
Tobias Kluge ◽  
Iain Pitcairn ◽  
Rabea Ali ◽  
Mokhles Azer ◽  
...  
Keyword(s):  
Low Temperature ◽  
Homogenization Temperature ◽  
Eastern Desert ◽  
Ultramafic Rocks ◽  
Wide Range ◽  
Two Samples ◽  
Ophiolitic Rocks ◽  
Clumped Isotope ◽  
Host Rocks ◽  
Different Sources

<p>Neoproterozoic ophiolites in the Eastern Desert (ED) of Egypt are pervasively carbonated and listvenitized. Two types of carbonation are recognized: 1) intergrown magnesite (and to lesser extent dolomite) with serpentine and talc that in cases form pure carbonate veins, and 2) cryptocrystalline magnesite veins filling the fractures crosscutting other ophiolitic host rocks. Few studies address the conditions of carbonate alteration of ultramafic rocks, especially the temperature of altering fluids. We employ clumped isotope thermometry on natural dolomite and magnesite from 17 variably carbonated ophiolitic rocks and veins in the ED. Five samples of antigorite-bearing serpentinite, talc-carbonate, and associated carbonate veins yield wide range temperatures of magnesite and dolomite between 213 to 426°C (285±73°C). These temperatures are comparable with previous fluid inclusion thermometry carried out on some of the vein samples (homogenization temperature between 225 to 383°C; Boskabadi et al. 2017). Ten samples of fully quartz-carbonate altered peridotites (i.e. listvenites) record even a wider range of clumped isotope carbonation temperatures between 90 and 452°C (227±112°C). In contrast, two samples of late-stage veins of cryptocrystalline magnesite record lower temperatures of 19 and 28°C. While the constraints on the pressure of carbonation are lacking, the wide range of temperatures for the carbonates in antigorite-bearing serpentinite, talc-carbonate, and listvenite lithologies suggest that carbonation probably occurred at variable depths, whereas the low temperature of cryptocrystalline magnesite veins points to conditions nearer the surface most likely associated with post-obduction processes. Therefore, different sources of carbon and CO<sub>2</sub>-bearing fluids should have been responsible for the formation of high- and low-temperature carbonates in the region.</p><p> </p><p>  Boskabadi et al. 2017. International Geology Review 59, 391–419.</p>

Low-temperature thermochronology of fault zones

2020 ◽  
Author(s):  
Takahiro Tagami
Keyword(s):  
Low Temperature ◽  
Fault Zone ◽  
Fission Track ◽  
Thermal Sensitivity ◽  
Fault Zones ◽  
Fault System ◽  
Vein Formation ◽  
Fission Track Thermochronology ◽  
Mineral Vein ◽  
Host Rocks

<p>Thermal signatures as well as timing of fault motions can be constrained by thermochronological analyses of fault-zone rocks (e.g., Tagami, 2012, 2019).  Fault-zone materials suitable for such analyses are produced by tectocic and geochemical processes, such as (1) mechanical fragmentation of host rocks, grain-size reduction of fragments and recrystallization of grains to form mica and clay minerals, (2) secondary heating/melting of host rocks by frictional fault motions, and (3) mineral vein formation as a consequence of fluid advection associated with fault motions.  The geothermal structure of fault zones are primarily controlled by the following three factors: (a) regional geothermal structure around the fault zone that reflect background thermo-tectonic history of studied province, (b) frictional heating of wall rocks by fault motions and resultant heat transfer into surrounding rocks, and (c) thermal influences by hot fluid advection in and around the fault zone.  Geochronological/thermochronological methods widely applied in fault zones are K-Ar (<sup>40</sup>Ar/<sup>39</sup>Ar), fission-track (FT), and U-Th methods.  In addition, (U-Th)/He, OSL, TL and ESR methods are applied in some fault zones, in order to extract temporal information related to low temperature and/or recent fault activities.  Here I briefly review the thermal sensitivity of individual thermochronological systems, which basically controls the response of each method against faulting processes.  Then, the thermal sensitivity of FTs is highlighted, with a particular focus on the thermal processes characteristic to fault zones, i.e., flash and hydrothermal heating.  On these basis, representative examples as well as key issues, including sampling strategy, are presented to make thermochronological analysis of fault-zone materials, such as fault gouges, pseudotachylytes and mylonites, along with geological, geomorphological and seismological implications.  Finally, the thermochronological analyses of the Nojima fault are overviewed, as an example of multidisciplinary investigations of an active seismogenic fault system.</p><p> </p><p>References:</p><ol><li>Tagami, 2012. Thermochronological investigation of fault zones. Tectonophys., 538-540, 67-85, doi:10.1016/j.tecto.2012.01.032.</li> <li>Tagami, 2019. Application of fission track thermochronology to analyze fault zone activity. Eds. M. G. Malusa, P. G. Fitzgerald, Fission track thermochronology and its application to geology, 393pp, 221-233, doi: 10.1007/978-3-319-89421-8_12.</li> </ol>

Kamphaugite-(Y) from La Cabrera massif, Spain: a low-temperature hydrothermal Y-REE carbonate

2006 ◽  
Vol 70 (4) ◽  
pp. 397-404 ◽  
Author(s):  
J. González del Tánago ◽  
A. La Iglesia ◽  
A. Delgado
Keyword(s):  
Low Temperature ◽  
Carbon Source ◽  
Alkali Feldspar ◽  
Hydrothermal Activity ◽  
Average Composition ◽  
Central System ◽  
Free Surfaces ◽  
Spanish Central System ◽  
Miarolitic Cavities ◽  
Very Low Temperature

AbstractKamphaugite-(Y) occurs as white to cream-coloured spherical to semi-spherical aggregates of radial crystals in the La Cabrera granitic pluton (Spanish Central System). It mainly occurs on the free surfaces of alkali feldspar, quartz, calcite, kainosite-(Y) and laumontite, and inside miarolitic cavities. La Cabrera kamphaugite-(Y) has an average composition of Ca0.94Y0.89REE0.21(CO3)2 [F0.05(OH)0.95]·1.19H2O. Negative δ13CV-PDB values (–14 to –15‰) indicate a meteoric carbon source. Textural relations between kamphaugite-(Y) and coexisting minerals, its relatively high δ18OV-SMOW values (+25 to +26‰), and the occurrence of laumontite inclusions in kamphaugite-(Y), point to a genesis at < 50°C during very low-temperature post-magmatic hydrothermal activity.

Manufacturing Technology of Space Optical Materials

2013 ◽  
Vol 785-786 ◽  
pp. 1018-1021
Author(s):  
Ya Chen
Keyword(s):  
Silicon Carbide ◽  
Low Temperature ◽  
Glass Ceramics ◽  
Performance Comparison ◽  
Manufacturing Technology ◽  
Surface Shape ◽  
Element Analysis ◽  
Shape Precision ◽  
Lightweight Structure ◽  
Materials Used

In this paper, the performance comparison between glass ceramics (Zerodur) and silicon carbide (SiC) which are two kinds of common materials used for space optical reflector is carried out, and several lightweight structure forms are analyzed. The oval plane reflector is applied in ultra-low temperature environment of space, take this kind of reflector as an example, its lightweight structure is optimized by CAD, then through finite element analysis, deformation of the planar lightweight mirror is 0.014λ (rms) in gravity condition, and deformation is 0.002λ (rms) in ultra-low temperature of-150 degrees environment. The actual lightweight processing is controled by the CNC system in a graphical way, and using chemical method to eliminate the stress and micro crack generated during processing, its final surface shape precision reaches 0.022λ (rms). Finally, this paper introduces the manufacture method of novel silicon carbide (SiC), and analyzes the current situation and development trends of the spatial lightweight reflector manufacturing technology.

scholarly journals Geochemistry, Paragenesis, and Wall-Rock Alteration of the Qatruyeh Iron Deposits, Southwest of Iran: Implications for a Hydrothermal-Metasomatic Genetic Model

2014 ◽  
Vol 2014 ◽  
pp. 1-25 ◽  
Author(s):  
Sina Asadi ◽  
Mohammad Ali Rajabzadeh
Keyword(s):  
Genetic Model ◽  
Wall Rock ◽  
Hydrothermal Activity ◽  
Low Grade ◽  
Wall Rock Alteration ◽  
Propylitic Alteration ◽  
Iron Deposits ◽  
Geochemical Analyses ◽  
Southwest Of Iran ◽  
Host Rocks

The Qatruyeh iron deposits, located on the eastern border of the NW-SE trending Sanandaj-Sirjan metamorphic zone, southwest of Iran, are hosted by a late Proterozoic to early Paleozoic sequence dominated by metamorphosed carbonate rocks. The magnetite ores occurred as layered to massive bodies, with lesser amounts of disseminated magnetite and hematite-bearing veins. Textural evidences, along with geochemical analyses of the high field strengths (HFSEs), large ion lithophiles (LILEs), and rare earth elements (REEs), indicate that the main mineralization stage occurred as low-grade layered magnetite ores due to high-temperature hydrothermal fluids accompanied by Na-Ca alteration. Most of the main ore-stage minerals precipitated from an aqueous-carbonic fluid (3.5–15 wt.% NaCl equiv.) at temperatures ranging between 300° and 410°C during fluid mixing process, CO2 effervescence, cooling, and increasing of pH. Low-temperature hydrothermal activity subsequently produced hematite ores associated with propylitic alteration. The metacarbonate host rocks are LILE-depleted and HFSE-enriched due to metasomatic alteration.

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