Mineral resources, particularly copper, are crucial for the sustained economic growth of developing countries like Kazakhstan. Over the past four decades, the diversity and importance of critical minerals for high technology and environmental applications have increased dramatically. Today, copper is a critical metal due to its importance in electrification. Porphyry deposits are important sources of copper and other critical metals. Conventional exploration methods for mapping alteration zones as indicators of high-potential zones in porphyry deposits are often associated with increased cost, time and environmental concerns. Remote sensing imagery is a cutting-edge technology for the exploration of minerals at low cost and in short timeframes and without environmental damage. Kazakhstan hosts several large porphyry copper deposits, such as Aktogay, Aidarly, Bozshakol and Koksai, and has great potential for the discovery of new resources. However, the potential of these porphyry deposits has not yet been fully discovered using remote sensing technology. In this study, a remote sensing-based mineral exploration approach was developed to delineate hydrothermal alteration zones associated with Aktogay porphyry copper mineralization in eastern Kazakhstan using Landsat-8 and ASTER satellite sensors. A comprehensive suite of image processing techniques was used to analyze the two remote sensing datasets, including specialized band ratios (BRs), principal component analysis (PCA) and the Crosta method. The remote sensing results were validated against field data, including the spatial distribution of geological lineaments and petrographic analysis of the collected rock samples of alteration zones and ore mineralization. The results show that the ASTER data, especially when analyzed with specialized BRs and the Crosta method, effectively identified the main hydrothermal alteration zones, including potassic, propylitic, argillic and iron oxide zones, as indicators of potential zones of ore mineralization. The spatial orientation of these alteration zones with high lineament density supports their association with underlying mineralized zones and the spatial location of high-potential zones. This study highlights the high applicability of the remote sensing-based mineral exploration approach compared to traditional techniques and provides a rapid, cost-effective tool for early-stage exploration of porphyry copper systems in Kazakhstan. The results provide a solid framework for future detailed geological, geochemical and geophysical studies aimed at resource development of the Aktogay porphyry copper mineralization in eastern Kazakhstan. The results of this study underpin the effectiveness of remote sensing data for mineral exploration in geologically complex regions where limited geological information is available and provide a scalable approach for other developing countries worldwide.

The study is devoted to the analysis of metasomatic zoning and features of mineralization of porphyry copper deposits of the North-Eastern Balkhash region, comparing them with other analogs around the world. Based on geological, mineralogical, and hydrothermal changes, the key characteristics of the Aktogay, Aidarly and Kyzylkiya fields were identified. Methods included rock and mineral analysis, geochemical studies, and comparative analysis with global deposits. The results showed the uniqueness of Kazakhstan deposits in terms of mineral composition and zoning structure. The conclusion emphasizes the importance of these deposits for understanding the formation of porphyry copper systems and the potential for further research in this direction. The copper ore deposit of North-Eastern Balkhash region is located 450 km northeast of Almaty, within the Balkhash-Ili suite of the Central Asian Orogenic Belt, an orogenic structure over 800 million years old. The porphyry formations are found within the Koldar plutonic massif, which dates from the Late Devonian to the Early Carboniferous period. Laccolith intrusions of diorite-granodiorites extend 17 km in an east-west direction here. The Koldar plutonic massif includes plates of volcanogenic sedimentary rocks consisting of Carboniferous andesites and dacite-rhyolites. The Aktogay deposit occupies the central plate, composed of volcanic rocks and bounded by magmatic formations. The stocks of porphyritic granodiorites that intrude into the volcanic layers date from the Middle Carboniferous period.

This paper analyzes the increasing global demand for mineral resources, particularly non-ferrous metals, and the growing challenge of finding new deposits as easily accessible ones are depleted. The study focuses on copper-porphyry deposits, which are crucial for meeting this demand. It highlights the importance of improving exploration methods and integrating various geological, geophysical, and geochemical techniques. The research emphasizes the unique metallogenic potential of Kazakhstan, specifically the Dzungar-Balkhash folded region, which hosts significant copper deposits like Kounrad, Bozshakol, Koksai, Aktogay, and Aidarly. The study uses the Koldar massif as a reference site to analyze the geological and mineralogical characteristics of these deposits. The methodology involved field studies, sample collection, and macro- and microscopic mineralogical analysis. A key finding of the study is the identification of widespread kalishpatization and argillitization zones within the Kyzylkiya deposit, which were confirmed through both spectral analysis and micromineralogical studies. The research also details the mineralogical and geochemical characteristics of different types of copper-porphyry ores, linking them to specific petrological features of the ore-bearing plutonism. The paper concludes by presenting prospect and prospecting signs for copper-porphyry deposits in various geological settings.

Анализ разломных зон, магматических комплексов и гидротермальных изменений позволил выявить структурно-геологические и минералогические закономерности размещения рудных тел в субдукционных обстановках. Сравнение порфировых систем Центрального Казахстана (позднепалеозойская субдукция) и северо-западных районов США (мезозойско-кайнозойская субдукция) показало сходные рудоконтролирующие факторы: активные разломы, калиевые изменения, кварц-серицитовые ассоциации. Отличия касаются интенсивности изменений, состава рудных минералов и масштаба магматизма. Полевые работы (2019, 2024) включали картирование и отбор образцов, лабораторные анализы охватывали минералогию, петрографию и геохимию. Интеграция данных позволила уточнить условия формирования порфировых систем и выделить признаки перспективных объектов в сходных геодинамических условиях. Результаты применимы для планирования поисков Жарылымдық зоналар, магмалық кешендер мен гидротермальдық өзгерістерді талдау субдукция жағдайларындағы кен денелерінің құрылымдықгеологиялық және минералогиялық заңдылықтарын анықтауға мүмкіндік берді. Қазақстанның орталығындағы (палеозой) және АҚШ-тың солтүстік-батысындағы (мезозой-кайнозой) порфирлік жүйелерді салыстыру ұқсас руданы бақылаушы факторларды көрсетті: белсенді жарылымдар, калийлі өзгеру аймақтары, кварц-серициттік ассоциациялар. Айырмашылықтар гидротермальдық өзгеру қарқындылығы мен кен минералдарының құрамында байқалады. 2019 және 2024 жылдардағы далалық жұмыстар құрылымдық карталау мен үлгілер жинауды қамтыды. Лабораториялық зерттеулер минералогияны, петрографияны және геохимияны талдауды қамтыды. Бұл деректер перспективалы аудандарды анықтауға және геологиялық барлау жұмыстарын жоспарлауға мүмкіндік береді Analysis of fault zones, magmatic complexes, and hydrothermal alterations revealed structural and mineralogical controls on ore body localization in subduction settings. A comparison between porphyry systems of Central Kazakhstan (Paleozoic subduction) and the northwestern USA (Mesozoic-Cenozoic subduction) shows common ore-controlling factors: active faults, potassic alteration zones, and quartz-sericite associations. Differences lie in the intensity of hydrothermal alteration, ore mineral composition, and the scale of magmatic events. Fieldwork in 2019 and 2024 included structural mapping and sampling, while laboratory studies covered mineralogical, petrographic, and geochemical analyses. The integrated data refined the formation conditions of porphyry systems and identified indicators of prospective areas in similar geodynamic settings. Results are applicable to future exploration planning