Periodico di Mineralogia

Fires in natural systems and their impact on the environment in Albania

Sherif Lushaj — 2024-01-12

In recent years, globally, there has been an increase in the number of fires and the destruction of nature with environmental, social, and economic impacts. Even in Albania, fires are intense and widespread, threatening residential areas, life safety, property, natural and environmental ecosystems, etc. Fires endanger natural resources, forests, pastures, and agricultural lands, destruction of nature, biodiversity, landscape, flora, and fauna, and worsen the physical, chemical, and biological qualities of the soil and air due to the discharge of carbon and harmful chemicals formed during burning, intensification of erosion, etc. However, public awareness remains at a low level and fires are a repeated phenomenon. Therefore, the objective of this paper is to evaluate the environmental impacts caused by fires, the dimensions of the spread, the consequences, the prevention measures, and the necessary legal, administrative, and technical improvements. The frequency of fires in recent years has been developing at a high rate. In 2021, 329 fires were recorded, burning a total of 31,275 ha of land, in addition to other affected areas. Studies show that about 84% of fire events in Albanian forests in 2021 were caused by anthropogenic factors. Extinguishing the fires was difficult due to the mountainous terrain on ¾ of the surface, the type of vegetation, high slope, high temperature, and low rainfall during the summer, as well as the lack of tools. In the general area of the territory of 2,874,800 ha, natural systems (forests and pastures) and agricultural systems, which are endangered by fires, occupy about 80% of the surface. Exactly, for these reasons, the main alternative in the country remains the planning and implementation of fire prevention measures. The impact of climate change on weather conditions, towards repeated heat and droughts, contributes to favoring the spread of massive fires.

Evaluation of some granitic rocks of the Algerian coast as a source of feldspar raw material

Hassni Belaidi — 2024-02-27

Feldspar, a mineral group found in the Earth’s crust, is crucial for the glass and ceramics industries. Traditionally extracted from pegmatites, it is now increasingly extracted from various deposits, predominantly alkaline and high calc-alkaline granitic rocks. Despite the significant global demand for feldspar and Algeria’s rich reserves and diversity of feldspar-bearing rocks, the country has yet to fully exploit these resources. Among the magmatic formations of Algeria, there are numerous high calc-alkaline granitic rocks. Petrographic studies have classified these rocks into granite, microgranite, and pegmatite, each consisting predominantly of potassium feldspar (orthoclase and microcline), plagioclase feldspar (albite and andesine), quartz and micas (biotite and muscovite), with hematite as a minor component. Secondary minerals such as sericite, calcite, and chlorite were identified, and X-ray diffraction studies also revealed the presence of additional secondary minerals, namely smectite and kaolinite. Geochemical analysis indicated sodium oxide (Na₂O) content ranged from 2.61 to 4.91 wt%, averaging 3.45 wt%, potassium oxide (K₂O) from 3.40 to 5.11 wt%, averaging 4.45 wt%, iron (III) oxide (Fe₂O₃) from 0.34 to 3.08 wt%, averaging 1.68 wt%, and titanium dioxide (TiO₂) from 0.02 to 0.37 wt%, averaging 0.17 wt%. These chemical profiles highlight the high calc-alkaline nature of the rock bodies with a low magnetic phase content and position these Massifs as promising feldspar reserves.

Reliability of the Planned Consumer Quality of Ores Based on the Estimated Accuracy of Their Average Grade

Azimhan Kurmankozhaev — 2024-04-22

The relevance of the study stems primarily from the fact that it is the first time that the reliability of the planned quality of ores has been established by creating a methodological and applied framework for the prospective development of the presented method. The purpose of the study is to provide a validated guideline approach and applied mechanism for eliminating errors made when estimating the planned quality of ore products. The methods used include the analytical, functional, statistical, and other approaches. The method is based on the concept of qualimetrically averaged aggregate and frequency averaged grade totals, zonally based on distribution and homogeneity, using the qualimetric geoindicator property of modal ore quality characterisation. The study highlights the features of the method and analyses the errors that occur in its applications, considering the impact on the prospective use of the method. Based on the results of grade averaging, qualimetric maps are compiled showing the geological zones of high-grade, good-grade, average, and contour ores, stabilised at the level of natural minimum limits. The minimum limits for the deviation of the initial mining contents entering the processing plant from the planned contents have been experimentally proven to be feasible. The practical value consists of the application of the revealed results, solutions to errors in method development, reliability of this approach, which would help create geological and geometrical bases for the modernisation of processes of exploration, evaluation, preparation of reserves, reducing expenses for technical homogenisation, eliminating metal losses in mining wastes and tailings.

Rare earth element (REE) partitioning in amphibole-bearing medium grade metamorphic rocks from the Alvand Complex (Sanandaj-Sirjan Zone, NW Iran)

Mirmohammad Miri — 2024-02-19

In this work we explore the distribution of rare earth elements (REE) in hornblende-bearing metamorphic rocks from the Jurassic Alvand plutonic complex (Sanandaj-Sirjan Zone, NW Iran) focusing on the understanding the effect of rock-forming silicates in controlling compositional variations during metamorphism. The studied rocks contain two distinct amphibole-dominated paragenesis: a first one including hornblende + epidote + plagioclase (“amphibolite”) and a second on made up of hornblende + garnet + epidote + plagioclase (“garnet amphibolite”). The bulk high Al2O3 (average 17.7 wt%), CaO (average 11.9 wt%) and low Fe2O3* (average 5.9 wt%), MgO (average 2.3 wt%), and TiO2 (average 0.8 wt%) contents together with the Zr/Ti (average 280), Na2O/ Al2O3 (average 0.05) and Na2O+K2O (average 1.7 wt%) values indicate these rocks are para-amphibolite formed by metamorphism of a marl (calcareous shale) protolith. With respect to the rock-forming phases, the epidotes have the highest ΣREE contents (ΣREE=86-210 ppm). The garnets (ΣREE=27-87 ppm) and hornblendes (ΣREE=10-22 ppm) have moderate values, whereas the plagioclase shows the lowest REE (2-4.7 ppm) amounts. Inverse and forward modelling thermobarometry was applied to unravel the pressure-temperature history of the studied samples and therefore to reveal the impact of each phase on the REE partitioning during the recorded metamorphic evolution, considering that REE are mostly immobile during crust processes and therefore their bulk budget is that of the protolith.