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

Minerals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 789
Author(s):  
Ömer Bozkaya ◽  
Ivan A. Baksheev ◽  
Nurullah Hanilçi ◽  
Gülcan Bozkaya ◽  
Vsevolod Y. Prokofiev ◽  
...  

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.

Minerals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1323
Author(s):  
Gheorghe Damian ◽  
Andrei Buzatu ◽  
Andrei Ionuţ Apopei ◽  
Floarea Damian ◽  
Andreea Elena Maftei

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.


2021 ◽  
Author(s):  
Julien Fort ◽  
Stanislas Sizaret ◽  
Michel Pichavant ◽  
Arnault Lassin ◽  
Johann Tuduri ◽  
...  

<p>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.  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-<sup>IV</sup>B and valence state, make the approach of solid solution properties complex (Hughes et al., 2001; Henry et al., 2011; Bačík, 2015; Morgan, 2016). Thus, thermodynamic properties are most often estimated  (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).</p><p>This study aims to investigate experimentally the stability field of schorl (Na-Fe) – dravite (Na-Mg) solid solution at 2 kbar total pressure between 400° and 600°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.</p>


2000 ◽  
Vol 42 (10-11) ◽  
pp. 371-374 ◽  
Author(s):  
S. Araki ◽  
J. M. González ◽  
E. de Luis ◽  
E. Bécares

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.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Matteo Callegari ◽  
Elena Crotti ◽  
Marco Fusi ◽  
Ramona Marasco ◽  
Elena Gonella ◽  
...  

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.


2021 ◽  
Author(s):  
Patricia M. Glibert ◽  
Cynthia A. Heil ◽  
Christopher J. Madden ◽  
Stephen P. Kelly

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.


1896 ◽  
Vol 59 (353-358) ◽  
pp. 308-312

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.


Author(s):  
M.A. Tugarova

The article considers the secondary transformations of carbonate rocks of oil and gas complexes, which are of fundamental importance in the formation of reservoir properties. For the first time, a schematic diagram, illustrating the regularities of secondary processes in carbonate reservoirs and their relationship with the physico-chemical conditions of the stratosphere is proposed.


2015 ◽  
Vol 11 (A29B) ◽  
pp. 416-419 ◽  
Author(s):  
Emmanuel Dartois ◽  
Ivan Alata ◽  
Cécile Engrand ◽  
Rosario Brunetto ◽  
Jean Duprat ◽  
...  

AbstractThe composition of interstellar matter is driven by environmental parameters and results from extreme interstellar medium physico-chemical conditions. Astrochemists must rely on remote observations to monitor and analyze the interstellar solids composition. They bring additional information from the study of analogues produced in the laboratory, placed in simulated space environments. Planetologists and cosmochemists access and spectroscopically examine collected extraterrestrial material in the laboratory. Diffuse interstellar medium and molecular clouds observations set constraints on the composition of organic solids that can then be compared with collected extraterrestrial materials analyses, to shed light on their possible links.


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