Hydrothermal Sphalerites from Ore Deposits of Baia Mare Area

Sphalerite is an abundant mineral in the hydrothermal deposits from the Baia Mare and Oaș areas (northwestern Romania). Sphalerite samples were analyzed with an electron probe microanalyzer and Raman spectroscopy. The obtained results indicated different amounts of Fe in the various deposits from the Baia Mare and Oaș areas. The sphalerites from Baia Sprie, Cavnic, Iba, Turț Penigher, and Breiner have a low Fe wt.% content. High Fe wt.% contents are at Herja and partly at Ghezuri and Nistru (copper stage) where sphalerite is associated with pyrrhotite. The correlation between iron and zinc from sphalerites is strongly negative. The negative correlation shows that iron is the main element that replaces zinc in the sphalerite structure. The manganese content of sphalerites in the Baia Mare and Oaș area is up to 0.84 wt.%. The cadmium content is quite uniform in the Baia Mare and Oaș area with contents ranging from 0.01 to 0.72 wt.%. The Fe content of sphalerites is an important indicator of the physico-chemical conditions of deposit formation because it is a function of temperature, pressure, and sulfur fugacity.

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Distribution of Metal Pollution in Groundwater Determined from Sump Sludges in Wells

Water Science & Technology ◽

10.2166/wst.1985.0086 ◽

1985 ◽

Vol 17 (9) ◽

pp. 115-132 ◽

Cited By ~ 8

Author(s):

Eduard Hoehn ◽

Hans R. von Gunten

Keyword(s):

Ground Water ◽

Near Field ◽

Manganese Content ◽

Dissolved Metals ◽

Physico Chemical ◽

Metal Trace Elements ◽

Chemical Conditions ◽

Different Grain Size ◽

A Site ◽

Interstitial Waters

Sludge material from the bottom of ground water sampling wells was investigated at a site near an infiltrating river in order to obtain information about the areal distribution and the partitioning of metals between sediments and interstitial waters. The concentrations of the dissolved metals in the interstitial water fluctuated more from well to well than the metal concentrations in the sludge sediments. The concentrations of most of the investigated heavy metal trace elements decreased with increasing grain sizes indicating their sorption from solution. A correlation was found between the concentration pattern at different grain size fractions and the organic carbon and the manganese content of the sediments. Some of the metals exhibited higher concentrations in the near field of the river than in the far field. This points to the river as a source for these metals. The physico-chemical conditions in the sludges are different from those in the aquifer with its flowing ground water.

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Origin and Evolution of the W mineralization in the Intrusion-related Hydrothermal Deposits of the Cerro Áspero Mining District, Sierras Pampeanas, Argentina

Anuário do Instituto de Geociências - UFRJ ◽

10.11137/1982-3908_2021_44_35969 ◽

2021 ◽

Vol 44 ◽

Author(s):

Sebastián González Chiozza

Keyword(s):

Stable Isotope ◽

Fluid Inclusion ◽

Ore Deposits ◽

Mining District ◽

Sierras Pampeanas ◽

Origin And Evolution ◽

Cooling Period ◽

Physico Chemical ◽

Chemical Conditions ◽

Two Stages

The Cerro Áspero Mining District (CAMD) is located at the Sierras Pampeanas of central Argentina and hosts significant intrusion-related wolframite mineralization. The ore deposits are associated to hydrothermal quartz veins and breccias, hosted by granitoids and metamorphic rocks at the northern contact zone of the Devonian post-orogenic Cerro Áspero Batholith (CAB). The physico-chemical conditions of the different mineralization styles are yet not totally understood, and aiming to deliver a metallogenetic model, the petrography and composition of the main ore and gangue minerals were investigated, and fluid inclusion and stable isotope studies were performed in quartz, muscovite, wolframite, apatite, pyrite, molybdenite, chalcopyrite, and galena. The integrated results revealed that the CAMD ore deposits were generated within the cooling period of the Cerro Áspero Batholith, throughout three late to post-magmatic hydrothermal mineralizing stages. Based on fluid inclusion studies and stable isotope processed data, it was found that the fluids of the first two stages were probably derived from a magmatic source, whereas the third stage solutions would have been originated from meteoric waters. The temperature of the system at the beginning of the hydrothermal phase, was estimated at 384°C; thereafter, the calculated values suggest a decreasing thermal path. Chemical analyses of wolframite showed that the CAMD ore deposit’s evolution was signed by initial formation of ferberite, and subsequently evolved with an increasing H/F ratio that conduced to hübnerite precipitation in the final stage.

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Tourmaline Composition of the Kışladağ Porphyry Au Deposit, Western Turkey: Implication of Epithermal Overprint

Minerals ◽

10.3390/min10090789 ◽

2020 ◽

Vol 10 (9) ◽

pp. 789

Author(s):

Ömer Bozkaya ◽

Ivan A. Baksheev ◽

Nurullah Hanilçi ◽

Gülcan Bozkaya ◽

Vsevolod Y. Prokofiev ◽

...

Keyword(s):

Hydrothermal Process ◽

Western Turkey ◽

Magmatic Complex ◽

Fine Aggregates ◽

Physico Chemical ◽

Fe Content ◽

Argillic Alteration ◽

Intrusive Rocks ◽

Chemical Conditions ◽

Site Vacancy

The Kışladağ porphyry Au deposit occurs in a middle Miocene magmatic complex comprising three different intrusions and magmatic-hydrothermal brecciation related to the multiphase effects of the different intrusions. Tourmaline occurrences are common throughout the deposit, mostly as an outer alteration rim around the veins with lesser amounts disseminated in the intrusions, and are associated with every phase of mineralization. Tourmaline mineralization has developed as a tourmaline-rich matrix in brecciated zones and tourmaline-quartz and/or tourmaline-sulfide veinlets within the different intrusive rocks. Tourmaline was identified in the tourmaline-bearing breccia zone (TBZ) and intrusive rocks that had undergone potassic, phyllic, and advanced argillic alteration. The tourmaline is present as two morphological varieties, aggregates of fine crystals (rosettes, fan-shaped) and larger isolated crystals and their aggregates. Four tourmaline generations (tourmaline I to IV) have different compositions and substitutions. Tourmaline I in TBZ and INT#1 is distinguished by the highest Fetot and enriched in Fe3+. Tourmalines II and III occur as fine aggregates, accompanied by the formation of isolated crystals and are characterized by lower Fetot and Fe3+. Tourmaline IV is characterized by the lowest Fetot, enriched in Cl, and has the highest proportion of X-site vacancy among all the tourmalines. Tourmaline I may be attributed to the potassic stage in INT#1 and early tourmaline in TBZ. Tourmalines II and III from INT#1 and the TBZ could be referred to the phyllic stage. The low Fe content in tourmaline is caused by the simultaneous deposition of sulfide minerals. Tourmaline IV from the TBZ and tourmaline II from INT#3 are distinguished by the high X-site vacancy proportion up to the formation of X-site vacant species as well as enriched in Cl; they can be attributed to the argillic stage of the hydrothermal process. The textural and especially chemical data of the tourmaline from the Kışladağ Au deposit provide information on the physico-chemical conditions during the porphyry to epithermal transition and subsequent epithermal overprinting.

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Tourmalinisation in peraluminous granitic context : from experiment to thermodynamic modelling

10.5194/egusphere-egu21-11559 ◽

2021 ◽

Author(s):

Julien Fort ◽

Stanislas Sizaret ◽

Michel Pichavant ◽

Arnault Lassin ◽

Johann Tuduri ◽

...

Keyword(s):

Solid Solution ◽

Thermodynamic Properties ◽

Stability Field ◽

Peraluminous Granite ◽

Physico Chemical ◽

Fe Content ◽

Chemical Conditions ◽

Using Data ◽

The Stability

Tourmaline records the physico chemical conditions during its cristallisation, as its primary chemical zonations are generally unbalanced, its occurrence as alteration product could be used to decipher the physicochemical properties of mineralizing fluids. However, the role of the tourmalinisation in hydrothermal processes remains little studied, if not poorly understood. &#160;The complexity of its thermodynamic properties is related to the presence of four cationic sites allowing the accommodation of a wide variety of elements (Henry and Dutrow, 2018). Moreover the phenomena of deprotonation, Si-IVB and valence state, make the approach of solid solution properties complex (Hughes et al., 2001; Henry et al., 2011; Ba&#269;&#237;k, 2015; Morgan, 2016). Thus, thermodynamic properties are most often estimated&#160; (Garofalo et al., 2000; Hinsberg and Schumacher, 2007) and only a few measurements could be carried out on a reduced number of near-endmembers crystals (Kuyunko et al., 1984; Ogorodova et al., 2012).This study aims to investigate experimentally the stability field of schorl (Na-Fe) &#8211; dravite (Na-Mg) solid solution at 2 kbar total pressure between 400&#176; and 600&#176;C as a function of the boron content of the fluid and fO2 condition, using an internally heated gas apparatus. Those metasomatic experiments have been conducted on a mixture of naturals crystals of cordierite + albite, representing a peraluminous granite composition in a Na-Mg-Fe-Al-Si-B-O-H system, characterized by a high-Mg, low-Fe content. These experiments were performed in order to simulate a classic aluminous host of these tourmaline alterations in granitic context. The results will be studied, in terms of stability of the tourmaline species, chemistry variation and texture. They will be compared with thermodynamic models build using data from the literature (Korges et al., 2018; Pan et al., 2019 among others) . Ultimately, the objective is to characterize in a P, T, W/R space, the chemical evolution of fluids, the alteration sequence of rocks and the variations in volumes related to the successive reactions.

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Sphalerite Composition in Low- and Intermediate-Sulfidation Epithermal Ore Bodies from the Roșia Montană Au-Ag Ore Deposit, Apuseni Mountains, Romania

Minerals ◽

10.3390/min11060634 ◽

2021 ◽

Vol 11 (6) ◽

pp. 634

Author(s):

Călin Gabriel Tămaș ◽

Mădălina Paula Andrii ◽

Réka Kovács ◽

Sergiu Drăgușanu ◽

Béatrice Cauuet

Keyword(s):

Manganese Content ◽

Ore Deposits ◽

Ore Deposit ◽

Apuseni Mountains ◽

Epithermal Deposits ◽

Epithermal Mineralization ◽

Ore Bodies ◽

Baia Mare ◽

Low Sulfidation ◽

Rosia Montana

We evaluated the significance of the iron and manganese content in sphalerite as a tool for distinguishing between low-sulfidation and intermediate-sulfidation epithermal deposits on the basis of new and previously published electron probe microanalyses data on the Roșia Montană epithermal ore deposit and available microchemical data from the Neogene epithermal ore deposits located in the Apuseni Mountains and Baia Mare region, Romania. Two compositional trends of the Fe vs. Mn content in sphalerite were delineated, a Fe-dominant and a Mn-dominant, which are poor in Mn and Fe, respectively. The overlapping compositional range of Fe and Mn in sphalerite in low-sulfidation and intermediate-sulfidation ores suggests that these microchemical parameters are not a reliable tool for distinguishing these epithermal mineralization styles.

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Viability of nematode eggs in high rate algal ponds: the effect of physico-chemical conditions

Water Science & Technology ◽

10.2166/wst.2000.0683 ◽

2000 ◽

Vol 42 (10-11) ◽

pp. 371-374 ◽

Cited By ~ 8

Author(s):

S. Araki ◽

J. M. González ◽

E. de Luis ◽

E. Bécares

Keyword(s):

Hydraulic Retention Time ◽

Pilot Scale ◽

High Rate ◽

Sterile Water ◽

Egg Viability ◽

High Rate Algal Ponds ◽

Helminth Eggs ◽

Physico Chemical ◽

Nematode Eggs ◽

Chemical Conditions

The viability of Parascaris equorum eggs was studied in two experimental pilot-scale high-rate algal ponds (HRAPs) working in parallel with 4 and 10 days hydraulic retention time respectively. Semi-permeable bags of cellulose (15000 daltons pore size) were used to study the effect of physico-chemical conditions on the survival of these helminth eggs. Three thousand eggs were used in each bag. Replicates of these bags were submerged for 4 and 10 days in the HRAPs and egg viability was compared with that in control bags submerged in sterile water. After 4 days exposure, 60% reduction in viability was achieved, reaching 90% after 10 days, much higher than the 16% and 25% found in the control bags for 4 and 10 days respectively. Ionic conditions of the HRAP may have been responsible for up to 50–60% of the egg mortality, suggesting that mortality due to the ionic environment could be more important than physical retention and other potential removal factors.

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Compartmentalization of bacterial and fungal microbiomes in the gut of adult honeybees

npj Biofilms and Microbiomes ◽

10.1038/s41522-021-00212-9 ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Matteo Callegari ◽

Elena Crotti ◽

Marco Fusi ◽

Ramona Marasco ◽

Elena Gonella ◽

...

Keyword(s):

Gut Microbiome ◽

Bacterial Phylotypes ◽

Specific Variable ◽

The Core ◽

Physico Chemical ◽

Metabolic Conditions ◽

Chemical Conditions ◽

And Behavior

AbstractThe core gut microbiome of adult honeybee comprises a set of recurring bacterial phylotypes, accompanied by lineage-specific, variable, and less abundant environmental bacterial phylotypes. Several mutual interactions and functional services to the host, including the support provided for growth, hormonal signaling, and behavior, are attributed to the core and lineage-specific taxa. By contrast, the diversity and distribution of the minor environmental phylotypes and fungal members in the gut remain overlooked. In the present study, we hypothesized that the microbial components of forager honeybees (i.e., core bacteria, minor environmental phylotypes, and fungal members) are compartmentalized along the gut portions. The diversity and distribution of such three microbial components were investigated in the context of the physico-chemical conditions of different gut compartments. We observed that changes in the distribution and abundance of microbial components in the gut are consistently compartment-specific for all the three microbial components, indicating that the ecological and physiological interactions among the host and microbiome vary with changing physico-chemical and metabolic conditions of the gut.

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Dissolved organic nutrients at the interface of fresh and marine waters: flow regime changes, biogeochemical cascades and picocyanobacterial blooms—the example of Florida Bay, USA

Biogeochemistry ◽

10.1007/s10533-021-00760-4 ◽

2021 ◽

Author(s):

Patricia M. Glibert ◽

Cynthia A. Heil ◽

Christopher J. Madden ◽

Stephen P. Kelly

Keyword(s):

Water Quality ◽

Anthropogenic Activities ◽

Florida Bay ◽

Climate Conditions ◽

Regime Changes ◽

Physico Chemical ◽

Organic Nutrients ◽

High Concentrations ◽

Chemical Conditions ◽

Favorable Conditions

AbstractThe availability of dissolved inorganic and organic nutrients and their transformations along the fresh to marine continuum are being modified by various natural and anthropogenic activities and climate-related changes. Subtropical central and eastern Florida Bay, located at the southern end of the Florida peninsula, is classically considered to have inorganic nutrient conditions that are in higher-than-Redfield ratio proportions, and high levels of organic and chemically-reduced forms of nitrogen. However, salinity, pH and nutrients, both organic and inorganic, change with changes in freshwater flows to the bay. Here, using a time series of water quality and physico-chemical conditions from 2009 to 2019, the impacts of distinct changes in managed flow, drought, El Niño-related increases in precipitation, and intensive storms and hurricanes are explored with respect to changes in water quality and resulting ecosystem effects, with a focus on understanding why picocyanobacterial blooms formed when they did. Drought produced hyper-salinity conditions that were associated with a seagrass die-off. Years later, increases in precipitation resulting from intensive storms and a hurricane were associated with high loads of organic nutrients, and declines in pH, likely due to high organic acid input and decaying organic matter, collectively leading to physiologically favorable conditions for growth of the picocyanobacterium, Synechococcus spp. These conditions, including very high concentrations of NH4+, were likely inhibiting for seagrass recovery and for growth of competing phytoplankton or their grazers. Given projected future climate conditions, and anticipated cycles of drought and intensive storms, the likelihood of future seagrass die-offs and picocyanobacterial blooms is high.

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Croonian lecture.—Observations on isolated nerve. Electrical changes a measure of physico-chemical change

Proceedings of the Royal Society of London ◽

10.1098/rspl.1895.0095 ◽

1896 ◽

Vol 59 (353-358) ◽

pp. 308-312

Keyword(s):

Chemical Change ◽

Physico Chemical ◽

Chemical Conditions

The present investigation arises from experiments undertaken to determine autographically the varying relations between the magnitude of electrical change and the magnitude of stimulation in nerve under various chemical conditions.

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