scholarly journals Lithium-Rich Claystone in the McDermitt Caldera, Nevada, USA: Geologic, Mineralogical, and Geochemical Characteristics and Possible Origin

Minerals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 68 ◽  
Author(s):  
Stephen B. Castor ◽  
Christopher D. Henry
Keyword(s):  
Meteoric Water ◽  
Transitional Zone ◽  
Caldera Collapse ◽  
Additional Source ◽  
Residual Magma ◽  
High K ◽  
Hydrologic System ◽  
Volatile Phase ◽  
Diagenetic Fluids ◽  
Diagenetic Fluid

Lithium deposits in tuffaceous sediments of the McDermitt caldera constitute possibly the world’s largest Li clay resource, yet their characteristics and origin are not established. The 40 × 25 km McDermitt caldera collapsed during the eruption of ~1000 km3 of a 16.4 Ma, zoned peralkaline to metaluminous tuff; minor caldera magmatism ceased by 16.1 Ma. About 200 m of sediments mostly composed of glass from regional pyroclastic eruptions accumulated in the caldera until about 15.7 Ma. Closed hydrologic system diagenesis (CHSD) altered the tuffaceous sediments to a consistent vertical mineral zonation of clay, analcime, K-feldspar, and albite. Entire sedimentary sections in the southern and western parts of the caldera basin have ≥1500 ppm Li. Lithium-rich intervals are dominantly claystone. The most thoroughly studied deposit is a laterally continuous, ~3000 ppm Li zone in the lower sedimentary section that also has high K, Rb, Mo, As, and Sb (and partly Mg and F). Lithium occurs as an illitic clay (tainiolite?). The overlying, upper sedimentary section averages <2000 ppm Li which resides in smectite (hectorite). A transitional zone has variably mixed smectite–illite clay and averages ~2000 ppm Li. An 40Ar/39Ar age of ~14.9 Ma on authigenic K-feldspar in the illite zone is ~1.2 Ma younger than the 16.1 Ma end of magmatism in the caldera, which mitigates against a simple hydrothermal origin. Closed hydrologic system diagenesis was essential to Li mineralization, but Li budget calculations suggest a source of Li in addition to the tuffaceous sediments is required. This additional source could be Li originally in highly enriched magma that entered the diagenetic system through either (1) Li in magma exsolved into a hydrous volatile phase during eruption. The Li-rich volatile phase coated glass shards or was trapped in pumice and was quickly leached by surface or groundwater upon deposition in the caldera. (2) Residual magma immediately following ash-flow eruption and caldera collapse generated Li-rich hydrothermal fluids that mixed with meteoric water in the closed caldera basin, generating a hybrid diagenetic fluid. The hydrothermal fluid and hybrid diagenetic fluids would have existed only during initial basin sedimentation between about 16.4 and 16.1 Ma.

Generation of high-pH groundwaters and H2 gas by groundwater–kimberlite interaction, northeastern Ontario, Canada

2021 ◽  
Vol 59 (5) ◽  
pp. 1261-1276
Author(s):  
Jamil A. Sader ◽  
Anna L. Harrison ◽  
M. Beth McClenaghan ◽  
Stewart M. Hamilton ◽  
Ian D. Clark ◽  
...  
Keyword(s):  
Inorganic Carbon ◽  
Meteoric Water ◽  
Dissolved Inorganic Carbon ◽  
Carbon Sink ◽  
H2 Production ◽  
Hydrogen Gas ◽  
Isotopic Data ◽  
Northern Ontario ◽  
Ch4 Production ◽  
High K

ABSTRACT We report new isotopic data for H2 and CH4 gases and Sr for groundwater collected from Jurassic Kirkland Lake kimberlites in northern Ontario, Canada. Groundwaters interacting with kimberlites have elevated pH (up to 12.4), are reducing (Eh as low as the H2-H2O couple), are dominated by OH− alkalinity, and have non-radiogenic (mantle) 87Sr/86Sr values (∼0.706–0.707). Most significantly, the highest pH groundwaters have low Mg, high K/Mg, and are associated with abundant reduced gases (H2 ± CH4). Open system conditions favor higher dissolved inorganic carbon and CH4 production, whereas under closed system conditions low DIC, elevated OH− alkalinity, and H2 production are enhanced. Hydrogen gas is isotopically depleted (δ2HH2 = −771 to −801‰), which, combined with δ2HH2O, yields geothermometry temperatures of serpentinization of 5–25 °C. Deviation of H2-rich groundwaters (by up to 10‰) from the meteoric water line is consistent with Rayleigh fractionation during reduction of water to H2. Methane is characterized by δ13CCH4 = −35.8 to −68‰ and δ2HCH4 = −434‰. The origin of CH4 is inconclusive and there is evidence to support both biogenic and abiogenic origins. The modeled groundwater–kimberlite reactions and production of elevated concentrations of H2 gas suggest uses for diamond-production tailings, as a source of H2 for fuel cells and as a carbon sink.

Geology and age of the Morrison porphyry Cu–Au–Mo deposit, Babine Lake area, British Columbia

2016 ◽  
Vol 53 (9) ◽  
pp. 950-978 ◽  
Author(s):  
Lijuan Liu ◽  
Jeremy P. Richards ◽  
Robert A. Creaser ◽  
S. Andrew DuFrane ◽  
Karlis Muehlenbachs ◽  
...  
Keyword(s):  
Meteoric Water ◽  
Gold Mineralization ◽  
Lake Area ◽  
Calc Alkaline ◽  
Porphyry Cu ◽  
High K ◽  
Vein Type ◽  
Intrusive Suite ◽  
Stage 1 ◽  
Porphyry Intrusion

The Morrison porphyry Cu–Au–Mo deposit is genetically and spatially related to Eocene plagioclase–hornblende–biotite porphyry intrusions. One porphyry intrusion yielded a U–Pb age of 52.54 ± 1.05 Ma. Mineralization occurs in three stages: (1) vein-type and disseminated chalcopyrite and minor bornite (associated with potassic alteration and gold mineralization); (2) vein-type molybdenite (associated with weak phyllic alteration); and (3) polymetallic sulfide–carbonate veins (dolomite ± quartz–sphalerite–galena–arsenopyrite–chalcopyrite, associated with weak sericite–carbonate alteration). Re–Os dating of molybdenite yielded ages of 52.54 ± 0.22 and 53.06 ± 0.22 Ma, similar to the age of the host porphyry intrusion. Stage 1 vein fluids were predominantly of magmatic origin: Th = 400–526 °C; salinity = 39.8–47.8 wt.% NaCl equiv.; δ18Ofluid = 3.7‰–6.3‰; disseminated chalcopyrite–pyrite δ34SCDT = 0.2‰ and −0.8‰ (CDT, Canyon Diablo Troilite). Stage 2 fluids were a mixture of magmatic and meteoric water: Th = 320–421 °C; salinity = 37.0–43.1 wt.% NaCl equiv.; δ18Ofluid values range from 0.3‰ to 3.4‰; molybdenite and pyrite δ34SCDT = −2.1‰ and −1.2‰. Stage 3 fluids were predominantly of meteoric water origin: Th = 163–218 °C; salinity = 3.1–3.9 wt.% NaCl equiv.; δ18Ofluid = −2.3‰ to 3.9‰ for early vein quartz, and 1.1‰ to 6.1‰ for late vein dolomite; sphalerite and pyrite δ34SCDT = −7.1‰ to −5.6‰. Morrison is interpreted to be a typical porphyry Cu–Au–Mo deposit related to a calc-alkaline to a high-K calc-alkaline diorite to granodiorite intrusive suite, generated in a continental arc in response to early Eocene subduction of the Kula–Farallon plate beneath North America.

scholarly journals ALTERACE DETRITICKÉHO TITANITU V KULMU DRAHANSKÉ VRCHOVINY

2016 ◽  
Vol 22 (1-2) ◽  
Author(s):  
Aleš Novotný ◽  
Renata Čopjaková
Keyword(s):  
Sedimentary Rocks ◽  
Accessory Mineral ◽  
Authigenic Minerals ◽  
Magmatic Rocks ◽  
Deep Burial ◽  
Clastic Sediments ◽  
Diagenetic Fluids ◽  
Maximum Temperatures ◽  
Diagenetic Fluid ◽  
Detrital Mineral

Titanite is a common accessory mineral of magmatic rocks, low- and medium-grade metamorphic rocks and it occurs as a detrital mineral in clastic sediments. Our paper deals with titanite alterations as a result of interaction of diagenetic fluids with detrital titanite during deep burial of sedimentary rocks of Drahany Upland, Protivanov Formation. Detrital titanites and their alteration products were examined by electron microprobe. Titanite dissolution was observed from the rim and along the cracks, accompanied by the formation of an authigenic calcite, TiO2 phase, synchysite-(Ce), and rarely chlorite. With an increasing degree of alteration, detrital titanite occurs as small irregular relics inside a mixture of authigenic minerals. Based on the composition of authigenic minerals, we can suppose diagenetic fluid rich in CO2, F and Ca responsible for alteration of detrital titanite. The maximum temperatures in this area during deep burial of sedimentary rocks reached 250–300 °C, corresponding to the conditions of very low-grademetamorphism. Contents of REE (0.67–3.55 wt. % REE2O3) in detrital titanite are rather high and vary significantly. Authigenic synchysite-(Ce) compared with detrital titanite strongly prefers LREE over HREE, indicating that LREE released during dissolution of detrital titanite were preferentially incorporated into the structure of synchysite-(Ce), whereas HREE were mobilized and removed away by diagenetic fluids.

scholarly journals Lithological control on fracture cementation in the Keuper Marl (Triassic), north Somerset, UK

2017 ◽  
Vol 155 (8) ◽  
pp. 1761-1775 ◽  
Author(s):  
QINGFENG MENG ◽  
JOHN HOOKER ◽  
JOE CARTWRIGHT
Keyword(s):  
Host Rock ◽  
Meteoric Water ◽  
Spatial Arrangement ◽  
Hydraulic Fractures ◽  
Low Permeability ◽  
Connate Water ◽  
Discrete Fracture ◽  
Through Diffusion ◽  
Diagenetic Fluids ◽  
Host Rocks

AbstractThe spatial arrangement of gypsum veins as preserved natural hydraulic fractures have been characterized in the Triassic Keuper Marl Formation (UK), a caprock for hydrocarbon reservoirs and CO2 sequestration. The marls cropping out are subdivided into five discrete fracture units based on the presence and abundance of gypsum veins. The nodular gypsum in evaporite horizons provides excess gypsum for nodule-rooted horizontal gypsum veins. Our petrographic observations demonstrate that the development of gypsum veins in beds lacking macroscopic evaporites is closely associated with disseminated gypsum cement in the marls. We interpret that the gypsum veins in marl are sourced from disseminated gypsum cements in the host rocks, based on stratigraphic correlations, and much lower Sr concentrations than gypsum nodules. Gypsum was transported to adjacent veins mainly through diffusion in the low-permeability marls. The localization of gypsum veins and varied Sr concentrations of veins and nodules indicate that the diagenetic fluids are a mix of connate water with meteoric water rather than brines transported from evaporite beds along faults to non-evaporite beds. This results in the absence of gypsum fillings in fractures in rocks without primary gypsum cements. The study implies that the cementation of natural fractures in low-permeability rocks can highly depend on the presence of cement minerals in the host rock.

scholarly journals Coupling Relationship between Multistage Fluid Activity and Reservoir Abnormally High-Porosity Zones in the Songtao–Baodao Region, Qiongdongnan Basin

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Xu Chen ◽  
Yao Wang ◽  
Ao Su
Keyword(s):  
Pore Space ◽  
Qiongdongnan Basin ◽  
Petroleum Exploration ◽  
High Porosity ◽  
Fluid Type ◽  
Positive Effects ◽  
Thermal Fluids ◽  
Diagenetic Minerals ◽  
Diagenetic Fluids ◽  
Diagenetic Fluid

An abnormally high-porosity zone (AHPZ) is beneficial for petroleum exploration, especially for the deep tight reservoirs in a petroliferous basin. Because of lacking effective research methods, it is hard to analyze the formation process of AHPZs in different geological periods. From the perspective of the diagenetic fluid type and activity history, geochemical characteristics and fluid inclusions of diagenetic minerals were utilized to reconstruct the diagenetic fluid type and dynamic evolution. The ultimate goal is to study the genetic process of AHPZs in the Songtao–Baodao region of the Qiongdongnan basin, South China Sea. It was found that there are three sections of AHPZs at different burial depths, which are generally favorable for high-quality reservoirs. Moreover, it can be concluded that the AHPZs are closely related to multiple actions of various diagenetic fluids. The meteoric waters, organic acid, and thermal fluids facilitated the enlargement of porosity by dissolving minerals to form secondary pore spaces. The hydrocarbon fluids have positive effects on the preservation of pores by preventing cement from filling the pore space.

scholarly journals Tracking the Origin and Evolution of Diagenetic Fluids of Upper Jurassic Carbonate Rocks in the Zagros Thrust Fold Belt, NE-Iraq

Water ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3284
Author(s):  
Namam Salih ◽  
Alain Préat ◽  
Axel Gerdes ◽  
Kurt Konhauser ◽  
Jean-Noël Proust
Keyword(s):  
Carbonate Rocks ◽  
Meteoric Water ◽  
Upper Jurassic ◽  
Strontium Isotope ◽  
Fold Belt ◽  
Origin And Evolution ◽  
Lack Of Information ◽  
Initial Stage ◽  
Diagenetic Fluids ◽  
Late Diagenesis

Utilizing sophisticated tools in carbonate rocks is crucial to interpretating the origin and evolution of diagenetic fluids from the Upper Jurassic carbonate rocks along the Zagros thrust-fold Belt. The origin and evolution of the paleofluids utilizing in-situ strontium isotope ratios by high resolution laser ablation ICP-MS, integrated with stable isotopes, petrography and fieldwork are constrained. Due to the lack of information on the origin of the chemistry of the fluids, the cements that filled the Jurassic carbonate rocks were analysed from the fractures and pores. This allowed us to trace the origin of fluids along a diagenetic sequence, which is defined at the beginning from the sediment deposition (pristine facies). Based on petrography and geochemistry (oxygen-, carbon- and strontium-isotope compositions) two major diagenetic stages involving the fluids were identified. The initial stage, characterized by negative δ13CVPDB values (reaching −10.67‰), involved evaporated seawater deposited with the sediments, mixed with the input of freshwater. The second stage involved a mixture of meteoric water and hot fluids that precipitated as late diagenetic cements. The late diagenetic cements have higher depleted O–C isotope compositions compared to seawater. The diagenetic cements display a positive covariance and were associated with extra- δ13CVPDB and δ18OVPDB values (−12.87‰ to −0.82‰ for δ18OVPDB and −11.66‰ to −1.40‰ for δ13CVPDB respectively). The distinction between seawater and the secondary fluids is also evident in the 87Sr/86Sr of the host limestone versus cements. The limestones have 87Sr/86Sr up to 0.72859, indicative of riverine input, while the cements have 87Sr/86Sr of (0.70772), indicative of hot fluid circulation interacting with meteoric water during late diagenesis.

scholarly journals Chromite Paleoplacer in the Permian Sediments at the East Edge of the East European Platform: Composition and Potential Sources

Minerals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 691
Author(s):  
Ildar R. Rakhimov ◽  
Evgenii V. Pushkarev ◽  
Irina A. Gottman
Keyword(s):  
East European Platform ◽  
Melt Inclusions ◽  
Volcanic Rocks ◽  
Compositional Analysis ◽  
Transitional Zone ◽  
Ural Region ◽  
Additional Source ◽  
East European ◽  
Chromite Ore ◽  
Mantle Peridotites

A chromite occurrence called the Sabantuy paleoplacer was discovered in the Southern Pre-Ural region, at the east edge of the East-European Platform in the transitional zone to the Ural Foredeep. A ca. 1 m-thick chromite-bearing horizon is traced at a depth of 0.7–1.5 m from the earth’s surface for the area of ca. 15,000 m2. The chromspinel content in sandstones reaches 30–35%, maximum values of Cr2O3 are 16–17 wt.%. The grain size of detrital chromspinel ranges from 0.15 to 0.25 mm. Subangular octahedral crystals dominate; rounded grains and debris are rare. The composition of detrital chromspinel varies widely and is constrained by the substitution of Al3+ and Cr3+, Fe2+ and Mg2+ cations. Chemically, low-Al (Al2O3 = 12 wt.%) and high-Cr (Cr2O3 = 52–56 wt.%) chromspinel prevail. The compositional analysis using discrimination diagrams showed that most chromites correspond to mantle peridotites of subduction settings. Volcanic rocks could be an additional source for detrital chromites. It is confirmed by compositions of monomineralic, polymineralic and melt inclusions in chromspinels. The presented data indicates that ophiolite peridotites and related chromite ore associated with oceanic and island-arc volcanic rocks, widespread in the Ural orogen, could be the main sources of the detrital chromspinel of the Sabantuy paleoplacer.

Analysis and lattice imaging of a transitional event on garnets

1978 ◽  
Vol 36 (1) ◽  
pp. 270-271
Author(s):  
J.Y. Laval
Keyword(s):  
Yttrium Iron Garnet ◽  
Reciprocal Lattice ◽  
Transitional Zone ◽  
Lattice Imaging ◽  
Yttrium Iron ◽  
X Ray ◽  
Ionic Process ◽  
The Matrix ◽  
High Resolution Technique ◽  
Iron Garnet

The exsolution of magnetite from a substituted Yttrium Iron Garnet, containing an iron excess may lead to a transitional event. This event is characterized hy the formation of a transitional zone at the center of which the magnetite nucleates (Fig.1). Since there is a contrast between the matrix and these zones and since selected area diffraction does not show any difference between those zones and the matrix in the reciprocal lattice, it is of interest to analyze the structure of the transitional zones.By using simultaneously different techniques in electron microscopy, (oscillating crystal method microdiffraction and X-ray microanalysis)one may resolve the ionic process corresponding to the transitional event and image this event subsequently by high resolution technique.

Electron Probe Analysis of Vertebrate Smooth Muscle: Distribution of Ca and Ci

1976 ◽  
Vol 34 ◽  
pp. 334-335 ◽  
Author(s):  
Avril V. Somlyo ◽  
H. Shuman ◽  
A.P. Somlyo
Keyword(s):  
Smooth Muscle ◽  
Electron Probe ◽  
Preliminary Report ◽  
Cell Damage ◽  
Electron Probe Analysis ◽  
Perinuclear Space ◽  
Probe Analysis ◽  
High K ◽  
Low K ◽  
Initial Results

This is a preliminary report of electron probe analysis of rabbit portal-anterior mesenteric vein (PAMV) smooth muscle cryosectioned without fixation or cryoprotection. The instrumentation and method of electron probe quantitation used (1) and our initial results with cardiac (2) and skeletal (3) muscle have been presented elsewhere.In preparations depolarized with high K (K2SO4) solution, significant calcium peaks were detected over the sarcoplasmic reticulum (Fig 1 and 2) and the continuous perinuclear space. In some of the fibers there were also significant (up to 200 mM/kg dry wt) calcium peaks over the mitochondria. However, in smooth muscle that was not depolarized, high mitochondrial Ca was found in fibers that also contained elevated Na and low K (Fig 3). Therefore, the possibility that these Ca-loaded mitochondria are indicative of cell damage remains to be ruled out.

Hair cell changes after cationic stimulation of corti's organ

1989 ◽  
Vol 47 ◽  
pp. 798-799
Author(s):  
Cesar D. Fermin ◽  
Hans-Peter Zenner
Keyword(s):  
Organ Of Corti ◽  
Cross Sectional ◽  
Surface Areas ◽  
High K ◽  
Anatomical Arrangement ◽  
Cell Cytosol ◽  
High Concentrations ◽  
K Concentration ◽  
Cell Changes

Contraction of outer and inner hair cells (OHC&IHC) in the Organ of Corti (OC) of the inner ear is necessary for sound transduction. Getting at HC in vivo preparations is difficult. Thus, isolated HCs have been used to study OHC properties. Even though viability has been shown in isolated (iOHC) preparations by good responses to current and cationic stimulation, the contribution of adjoining cells can not be explained with iOHC preparations. This study was undertaken to examine changes in the OHC after expossure of the OHC to high concentrations of potassium (K) and sodium (Na), by carefully immersing the OC in either artifical endolymph or perilymph. After K and Na exposure, OCs were fixed with 3% glutaraldehyde, post-fixed in osmium, separated into base, middle and apex and embedded in Araldite™. One μm thick sections were prepared for analysis with the light and E.M. Cross sectional areas were measured with Bioquant™ software.Potassium and sodium both cause isolated guinea pig OHC to contract. In vivo high K concentration may cause uncontrolled and sustained contractions that could contribute to Meniere's disease. The behavior of OHC in the vivo setting might be very different from that of iOHC. We show here changes of the cell cytosol and cisterns caused by K and Na to OHC in situs. The table below shows results from cross sectional area measurements of OHC from OC that were exposed to either K or Na. As one would expect, from the anatomical arrangement of the OC, OHC#l that are supported by rigid tissue would probably be displaced (move) less than those OHC located away from the pillar. Surprisingly, cells in the middle turn of the cochlea changed their surface areas more than those at either end of the cochlea. Moreover, changes in surface area do not seem to differ between K and Na treated OCs.

Sign in / Sign up

Export Citation Format

Share Document