The Masjed Daghi mineralization is located 30 km southeast of Jolfa city at the bank of Araxes River, northwest Iran. This area is situated in the AlborzAzarbaijan structural zone of Iran. The most widespread rocks in the mineralization area are andesite and trachyandesite, while there are rock units of latite tuff, andesitic agglomerate, and hornblende porphyry basalt in eastern hills and Eocene flysch in the southern part of the area. Several intrusive bodies are present in the study area, from which the dominant intrusive rock hosting the mineralization is diorite porphyry.

About the Special Issue Editor
Preface to ”Experimental and Thermodynamical Modeling of Ore-Forming Processes in Magmatic and Hydrothermal Systems”
Galina Palyanova Editorial for the Special Issue: Experimental and Thermodynamic Modeling of Ore-Forming Processes in Magmatic and Hydrothermal Systems Reprinted from
Alexander V. Zotov, Nikolai N. Kuzmin, Vladimir L. Reukov and Boris R. Tagirov Stability of AuCl2 − from 25 to 1000 ◦C at Pressures to 5000 bar and Consequences for Hydrothermal Gold Mobilization
Vladimir L. Tauson, Sergey V. Lipko, Nikolay V. Smagunov and Raisa G. Kravtsova Trace Element Partitioning Dualism under Mineral–Fluid Interaction: Origin and Geochemical Significance

The gold deposit at La Josefina, in the Deseado Massif of Argentina, is a low-sulfidation epithermal deposit with some features of the intermediate sulfidation style; the Au occurs in quartz veins and hydrothermal breccias hosted by acid pyroclastic rocks produced by Jurassic bimodal volcanism. Exploration for this deposit type uses geochemical data for vectoring to mineralized rocks. Although a general suite of elements with anomalous concentrations around low-sulfidation deposits is known, that suite varies amongst individual deposits, which should be studied individually.

The El Dorado Au-Cu deposit is located in an extensive intra-caldera zone of hydrothermal alteration affecting Upper Cretaceous andesites of the Los Elquinos Formation at La Serena (
29470 S Lat., 70430 W Long., Chile). Quartz-sulfide veins of economic potential are hosted by N25W and N20E fault structures associated with quartz-illite alteration (þsupergene kaolinite).

The Sari Gunay epithermal gold deposit is located within a mildly alkaline latitic to trachytic volcanic complex in central-northwest Iran. Intrusive and volcanic rocks that host the deposit have been dated at between 11.7 and 11.0 Ma (with one younger sample at 8.0 Ma; 40Ar/39Ar dating of igneous biotite and hornblende), whereas sericitic alteration associated with an early stage of hydrothermal activity occurred between ~10.8 and ~10.3 Ma (the best age estimate is 10.7 Ma obtained by 40Ar/39Ar dating of sericite).

Epithermal gold (± Cu & Ag) deposits form at shallower crustal levels than porphyry Cu-Au systems, and are primarily distinguished as low and high sulphidation using criteria of varying gangue and ore mineralogy, deposited by the interaction of different ore fluids with host rocks and groundwaters. Low sulphidation deposits are in turn further divided according to mineralogy related to the depth and environment of formation, while high sulphidation systems vary with depth and permeability control, and are distinguished from several styles of barren acid alteration.

1. Тенденции ГРР за рубежом в 2020-21 гг.
2. Геохимическая дисперсия первичных ореолов рудных месторождений (Австралия)
3. Геохимические методы поисков скрытых рудных месторождений
4. Изучение минералого-геохимических индикаторов эпитермального  оруденения (кратон Голера, Южная Австралия
5. Минералого-геохимические и изотопные характеристики W-Sn месторождения Такатори (Япония)
6. Анализ микроэлементов в шеелите м-ние W Инцзуйхуншань (Северный Китай)

Since the freeing of the market price of gold in 1971. exploration for epithermal gold deposits in the southwest Pacific region has been intense, and has been encouraged by some major successes. Sufficient discoveries have been made to summarise what has been found to date, and to assess what implications may be drawn for future exploration. Data are tabulated for 137 epithermal precious metal deposits and prospects in Australia (30), Fiji (2). Indonesia (43 ). New Zealand (22), Palau and Yap (2), Papua New Guinea (18), the Philippines (19), and Solomon Islands (1).

Comparison of the character of epithermal deposits in the southwest Pacific with those in other regions (e.g., the northeastern Pacific margin) suggests that they are in most respects similar with, however, three differences: (i) through much of the region (especially the Philippines and Indonesia) low-sulfidation style deposits commonly show characteristics suggestive of formation at deeper levels than is typical elsewhere; (ii) high-sulfidation deposits appear to be more common than along the northeast Pacific margin; (iii) many of the largest deposits show atypical features, particularly those suggestive of a transition to porphyry or mesothermal conditions, or indicating overprinting of an epithermal system on a porphyry environment. These differences can be partly understood in terms of the tectonic setting and evolution of the volcanic arcs of the southwest Pacific, and the consequent hydrological conditions that existed during mineralization.

The results of exploration in the southwest Pacific indicate that, while the principles of formation of epithermal deposits still apply, deposit models developed in other tectonic/volcanic settings should not be rigidly applied. Gold explorers should first consider the character of the geologic environment at the time of mineralization to try to predict the hydrological conditions during mineralization. Once the likely volcanic environment and paleorelief have been established, then the types, distribution, and zoning of hydrothermal alteration, coupled with observations of deposit form, vein textures and mineralogy, will allow a judgement to be made on the level of system that is now exposed, and on the probable controls that localized mineralization.

The very dynamic character of the tectonic and volcanic setting throughout much of the southwest Pacific has resulted in deposits that reflect changes in the environment of the deposit, in some cases even while deposition was occurring. This has produced some deposits with unusual characteristics which could not have been predicted before exploration.

Постаккреционная металлогения Восточной Якутии характеризуется доминирующим развитием эпитермальной Au-Hg минерализации (Суплецов, 2001).  Конформные металлогенические зоны золотоносного Hg оруденения, контролируемые продольными разломами, расположены в структурах Колымо-Омолонского микроконтинента и Верхоянского складчатого пояса. Данные разломы, как правило, трассируются свитами кайнотипных даек щелочных базальтоидов. Металлогенические построения позволили выделить две генетически близкие группы Au-Hg месторождений, локализованные в карбонатных и терригенных комплексах пород, отличающихся морфоструктурой, гидротермальными изменениями и масштабами оруденения. Ртути и сурьме в данных месторождениях, скорее всего, принадлежит второстепенное значение, и они выступают в качестве бипродукта.