Volcanogenic Deposits Research Articles

Provenance of Volcanogenic Deposits from the Shanxi Formation of the Daniudi Gas Field, Ordos Basin, and Its Tectonic Implications

Through detailed drill-core description, petrography, cathodoluminescence imaging, and geochemistry analysis, sedimentary deposits with a high content of volcanogenic components (27.6%) were discovered in the Shanxi Formation of the Daniudi Gas Field, Ordos Basin. The volcanogenic components include volcanogenic quartz, lava fragments (dominated by rhyolite fragments), tuff fragments, and tuffaceous matrix. In addition, at least two volcanic ash layers were discovered. Although the metamorphic rocks of the Precambrian succession in the ancient land of Yin Mountain are usually considered the primary source of the Shanxi formation, it is most likely that the volcanogenic components were derived from intermediate-acid volcanic materials that accumulated in the Daqingshan area during the Late Carboniferous to Early Permian. Those volcanogenic components are mainly transported by flowing water rather than by air from origin to basin. In addition, the accumulation of volcanic materials in the Daqingshan area was controlled by volcanic eruptions occurring solely in this area, rather than by the Inner Mongolia Orogenic Belt. Those volcanic eruptions were related to the southward subduction of the Paleo-Asian Ocean Plate beneath the northern margin of the North China Plate in the Late Carboniferous to Early Permian. The active continental margin related to the subduction of the Paleo-Asian Ocean Plate lasted at least until the Early Permian, and the closure of the Paleo-Asian Ocean must have occurred later than the Early Permian.

Moss as an indicator of rare earth elements across the area of the volcanogenic deposit in the Allchar Locality, North Macedonia

Moss as an indicator of rare earth elements across the area of the volcanogenic deposit in the Allchar Locality, North Macedonia

Genetic Peculiarities, Gold-Containing Volcanogenic Deposits of the Non-Ferrous Metals of the Paleoisland-Arc Structures of the Lesser Caucasus and East Pontides according to Gas-Fluid Inclusions Data and Isotopic Investigations

The geological settings of deposits exploration in Turkey, Azerbaijan, Armenia and Georgia have been determined in the article. Most of them can be related to the Kuroko type and they are differed by ore accumulation nature

Disentangling factors controlling earthquake-triggered soft-sediment deformation in lakes

In-situ soft sediment deformation structures (SSDS) are commonly used as paleoseismic indicators in marine and lacustrine sedimentary records. Earthquake-related shear can deform sediment in the shallow subsurface through Kelvin-Helmholtz instability. The SSDS related to Kelvin-Helmholtz instability have been used to quantify shaking strength of past earthquakes. However, the relative importance of i) lithology and physical properties, ii) potential basal shear surfaces (e.g. clastic deposits), iii) slope angle, and iv) seismic shaking strength (e.g. peak ground acceleration) for deformation related to Kelvin-Helmholtz instability remains poorly studied. Lake Riñihue (south-central Chile) is chosen as a natural laboratory for disentangling the effect of the aforementioned factors because i) the sediment composition of background sediment varies downcore and ii) volcanogenic clastic deposits are abundant within the sedimentary sequence. A previous study at lake Riñihue identified 25 SSDS intervals induced by historical earthquakes of varying rupture extent in 17 sediment cores taken at slope angles ranging from ~0.2° to ~4.9° (i.e. 16 slope sites and 1 basin site). Our study shows that deformation mostly occurs directly above volcanogenic deposits (i.e. 72 % of SSDS intervals), suggesting that volcanogenic deposits promote earthquake-induced deformation by strain softening, liquefaction or water film formation. Deformation thickness of SSDS increases with higher slope angles (i.e. strong positive correlation). Additionally, deformation thickness commonly corresponds to the stratigraphic depth of the youngest preceding volcanogenic deposit, but for steeper slope angles stratigraphically older volcanogenic deposits can function as basal shear surface. Therefore, we suggest that deformation thickness is primarily regulated by gravitational stress (i.e. slope angle) and secondarily by the stratigraphic depth of volcanogenic deposits. The earthquakes related to strongest shaking caused almost exclusively SSDS with highest deformation degrees (i.e. folds and intraclast breccia) as well as largest spatial extent of SSDS, resulting in highest numbers of related SSDS in the investigated cores. Thinner SSDS have higher deformation degrees at a given shaking strength, as seismically-induced shear energy acts more effectively on thinner deforming sequences. Therefore, we suggest that deformation degree is primarily controlled by shaking strength and secondarily modulated by the thickness of the deforming sequences. We infer that deformation thickness is not a reliable indicator of paleoseismic shaking strength as this relies on many preconditioning factors independent of shaking strength. On the other hand, deformation degree can be a good proxy for shaking strength also in settings with varying lithotypes and intercalated clastic event deposits, provided multiple cores are studied to avoid under- or overestimation of paleoseismic shaking strength.

Typification of volcanogenic deposits of the Carboniferous complex of the Mindyak graben-syncline of the Voznesensko-Prisakmarskaya structural-formational zone of the Southern Urals

The results of the studies show that the volcanogenic deposits of the Carboniferous complex of the Mindyak graben-syncline in the Southern Urals were formed as a result of successively manifested synsedimentary volcanism: early moderately alkaline basaltoid fissure type and subsequent moderately alkaline basalt-basalt-andesite-dacitic type, more extensive in the area. 
 According to the conditions of localization, composition and petrochemical characteristics, the considered volcanic rocks are comparable with typical for the Ural-Tien Shan region volcanogenic deposits of the Varissky rift structures of deep fault zones (Magnitogorsk-Bogdanovskaya in the Southern Urals and Boztau-Kokpatasskaya in the Southwestern Tien Shan). Together they can serve as indicators for the riftogenic settings of the Late Paleozoic early orogenic (early collisional) tectonic-magmatic activation of this region. 
 The obtained data can be used to refine the geological structure and metallogeny of the Southern Urals.

Using the approach of step-by-step lithological dissection of the section of volcanogenic sedimentary deposits

The article implements an approach of step-by-step lithological dissection of the section of volcanogenic sedimentary rocks of the Sredne-Nazymskoye field using comparisons of methods of geophysical surveys of rocks at the qualitative and quantitative level.The predominantly acidic composition of the rocks determines the use of unified petrophysical algorithms for the section of the Pre-Jurassic complex with additional division into enlarged groups of lithotypes: lavobreccia, tuffs and unchanged effusions. An important factor influencing the interpretation of geophysical surveys is the presence of rock fracturing in the Pre-Jurassic complex interval.The assessment of the possibility of lithological dissection of the section, taking into account the additional division of rocks into collector-non-collector, which allows us to identify promising zones of development of pore and fractured reservoirs.We propose an approach of step-by-step lithological dissection of the section, including qualitative and quantitative criteria, which ensures the improvement of existing technologies.

Volcanogenic Deposits of Non-ferrous Metals in the Lesser Caucasus and Eastern Pontides

The paper presents brief characteristics of geological environments of ore deposit occurrences in Turkey, Georgia and Armenia. They can be attributed to Kuroko-type deposits, being distinguished by the character of ore accumulation. To the west, in Turkey, there are epigenetic and hydrothermal-sedimentary copper-zinc deposits that were formed in deep restricted basinal settings. An example of the latter is the Chayeli deposit.To the east, in the Caucasus, we have predominantly only epigenetic deposits. Besides, in the Bolnisi mining district (Georgia) there is the Madneuli deposit which represents an example of polyformational deposit. Here, within the restricted territory, have been concentrated:barite, barite-polymetallic, gold-bearing secondary quartzite, large-scale stockworks of copper ores. Judged by the 87Sr/86Sr ratios, some volcanites which are spatially associated with ores, might have been products of the “differentiation” of undepleted mantle, or other magmas that were generated in the lower part of the earth crust.In the Alaverdi ore district in Armenia, there are Jurassic volcanodepressions that host copper, copper-zinc and barite-sulfide ores. All the deposits of the Alaverdi district, porphyry copper including, contain economic reserves of ores.On the basis of available literature material and our own data, there has been created a mental-logical geological-genetic model of volcanogenic deposits.

Upper Mesozoic stratigraphy of Sikhote-Alin (Russian Far East) and northeastern China: Non-marine and marine correlations. Part 1: Upper Jurassic–Hauterivian

Upper Mesozoic (Upper Jurassic and Cretaceous) rocks are widely distributed in Sikhote-Alin (Russian Far East) and northeastern China. In Sikhote-Alin, the Upper Jurassic and Lower Cretaceous rocks are represented mainly by marine deposits, whereas the Upper Cretaceous rocks are mainly volcanic and non-marine sedimentary-volcanic. In northeastern China, the upper Mesozoic rocks are, on the contrary, mainly non-marine. Fully marine Upper Jurassic–Valanginian deposits are restricted to the northeastern Heilongjiang Province near the border with Russia. Barremian–Albian non-marine deposits alternating with marine ones also occur in this region. They contain marine and non-marine fauna and, therefore, represent an important object for non-marine and marine correlation. On the rest of the territory of northeastern China, upper Mesozoic rocks are represented by non-marine sedimentary and volcanogenic deposits. The complex geological structure of the region as well as different types of sedimentary basins cause difficulties in correlation between the upper Mesozoic rocks of Sikhote-Alin and northeastern China. Despite the long history of investigations, their correlation schemes are still rare. Creation of a correlation scheme between Sikhote-Alin and northeastern China should be based on revision of published stratigraphic data on both regions. This article is the first in a series of articles devoted to the upper Mesozoic stratigraphy of Sikhote-Alin and northeastern China. In the present article the Upper Jurassic–Hauterivian stratigraphy of Sikhote-Alin and northeastern China is reviewed. The Upper Jurassic–Hauterivian deposits of Sikhote-Alin and northeastern China contain abundant Buchia and rarer ammonites. Based on stratigraphic distribution of buchiid assemblages, the correlation scheme for Kimmeridgian–Valanginian (possibly lowermost Hauterivian) strata of northeastern China and Sikhote-Alin is proposed. The succession of Jurassic–Cretaceous buchiid assemblages of Sikhote-Alin and northeastern China is similar to those of the other regions, e.g., Northern Siberia (Arctic Realm) and California (North Pacific Realm).

Exploration of Rhenium Volcanogenic Deposit and Technology of Its Development

Rhenium is widely used in manufacturing industry and metallurgy. Today the consumption of rhenium is high, but there are very few deposits in the world where it is mined. Thus, the aim of the study is to identify areas of distribution of rhenium on Kudryavy volcano, located on the islands of the Kuril ridge (Russia). In this connection, during the field period, we took samples of a volcanic massif weighing 70 kg, and also studied the geothermal fields with a pyrometer. Laboratory research included the study of composition of samples by the method of inductively coupled plasma mass spectrometry and spectrometric analysis. The article defines the zones of distribution of rhenium mineralization, presents the results of measurements of the temperature of geothermal fields and the elemental composition of technological samples. The geology, development technology is described, the analysis of the destruction of rocks, determined by the acoustic method, the specific resistance of breakdown during electrothermal loosening is given. The parameters of the tubular shovel conveyor at which the productivity of 88 m3/h is achieved. The results obtained will make it possible to identify promising geothermal fields, determine the development technology, and contribute to the study of volcanic deposits.

Volcanic rocks in Lower Jurassic marine carbonate successions in the southeastern Iberian Range (Spain): biochronostratigraphic dating

The Ligurian Tethys began to open in a roughly NE–SW direction in Pliensbachian times. West of the Ligurian oceanic crust, a carbonate-platform system constituted the eastern Iberian paleomargin. Lower and Middle Jurassic marine sediments deposited in these shallow platforms are well exposed today in the southeastern Iberian Range and host multiple volcanogenic deposits, mainly volcaniclastic in nature. Regional mapping reveals that volcanic outcrops show NW and NE (or NNE) oriented lineaments following tracks of cortical weakness. Volcanic ages were estimated by using biochronostratigraphic methods and sequence-stratigraphic correlations. As a result, ten Lower Jurassic volcanic episodes have been identified. The chronostratigraphic positions of the volcanic deposits span from the early Pliensbachian (Jamesoni Zone or later) to the late Toarcian (Thouarsense Zone). The extension-dominated regime of the eastern Iberian paleomargin also affected the southern Iberian paleomargin (Betic Cordillera) as a result of the eastward prolongation of the central Pangea fragmentation. The break-up of wide platforms and the first volcanic emissions seem to be roughly coeval in the Betic and Iberian domains and synchronous with the onset of rifting and spreading events of the Ligurian Tethys Ocean.

Fungal transformation of selenium and tellurium located in a volcanogenic sulfide deposit.

Microbial reduction of soluble selenium (Se) or tellurium (Te) species results in immobilization as elemental forms and this process has been employed in soil bioremediation. However, little is known of direct and indirect fungal interactions with Se-/Te-bearing ores. In this research, the ability of Phoma glomerata to effect transformation of selenite and tellurite was investigated including interaction with Se and Te present in sulfide ores from the Kisgruva Proterozoic volcanogenic deposit. Phoma glomerata could precipitate elemental Se and Te as nanoparticles, intracellularly and extracellularly, when grown with selenite or tellurite. The nanoparticles possessed various surface capping molecules, with formation being influenced by extracellular polymeric substances. The presence of sulfide ore also affected the production of exopolysaccharide and protein. Although differences were undetectable in gross Se and Te ore levels before and after fungal interaction using X-ray fluorescence, laser ablation inductively coupled plasma mass spectrometry of polished flat ore surfaces revealed that P. glomerata could effect changes in Se/Te distribution and concentration indicating Se/Te enrichment in the biomass. These findings provide further understanding of fungal roles in metalloid transformations and are relevant to the geomicrobiology of environmental metalloid cycling as well as informing applied approaches for Se and Te immobilization, biorecovery or bioremediation.

Geochemical Characteristics of Volcanogenic Deposits and Exhalation Mineralization in the Crater Part of the Active Kudryavy Volcano (Iturup Island of the Kuril Arc)

Geochemical Characteristics of Volcanogenic Deposits and Exhalation Mineralization in the Crater Part of the Active Kudryavy Volcano (Iturup Island of the Kuril Arc)

On the Stratigraphic Position of the Grebenka Plant-Bearing Cretaceous Deposits, Northeast Russia

The late Albian–early Turonian Grebenka flora is one of the most representative mid-Cretaceous floras of Northeast Russia. However, the stratigraphic position of the Grebenka beds relative to plant-bearing deposits of similar age is still debatable. It is shown that the Salamikha volcanogenic sequence, bearing the Buor-Kemyuss plant fragments, is the most probable stratigraphic analog of the Krivorechenskaya terrigenous formation. The deposits bearing the Grebenka flora lie stratigraphically below volcanogenic deposits including the Chaun flora.

The Kyzyl–Tashtyg Ore Deposit of Eastern Tuva—A Standard for the Ancient Volcanogenic Formation of Pyrite-Polymetallic Ores

Abstract —The Kyzyl–Tashtyg deposit and the ore field of the same name are included in the Kyzyl–Tashtyg ore cluster, which is located in the southeastern part of the Ulugoi structural-metallogenic zone. The geological section of the ore field consists of lower Cambrian terrigenous and volcanogenic deposits of the Tumat-Taiga and Tapsa Formations that include a homodromous sequence of early andesite-basalts transitioning to acid dacite-rhyolite rocks with widespread subvolcanic intrusions. The pyrite-polymetallic mineralization of the ore field associates spatially with a central-type volcanic structure and is localized within the “motley” unit, consisting of three lithological-stratigraphic horizons. The Kyzyl–Tashtyg pyrite-polymetallic deposit is the main ore occurrence of the ore field, which contains the main reserves of pyrite-polymetallic ores. The mineralization outcrops on the surface are 650 m in length and 60–65 m wide. Reserves of commercial ore are 12,920 mln tons with average concentrations: Pb—2.8%, Zn—10.3%, Cu—0.65%, Au—1.03 ppm, Ag—48.71 ppm. The ores have typically simple mineral compositions consisting of pyrite, chalcopyrite, sphalerite, galena and barite. Secondary minerals include enargite, hessite, sylvanite, proustsite, and native silver. Ores are classified based on the dominant mineral or groups of minerals into sulfur-pyrite (pyrite), copper-zinc (pyrite-chalcopyrite-sphalerite), polymetallic (sphalerite-galena), and barite-polymetallic (barite-sphalerite-galena) varieties. The main commercial type is represented by the copper-zinc mineralization. The widest range of impurity elements and their highest concentrations have been identified in copper-zinc and polymetallic ores, where the main mineral is sphalerite—the carrier of the largest amount of impurity elements. In these ores, commercial concentrations of gold and silver have been detected: Au—0.8; 2.3 ppm, and Ag—26; 78 ppm correspondingly. Formation temperatures of different types of ores of the deposit range from 400–305 °C to 270–150 °C. There is a pattern of decreasing formation temperatures from the sulfur-pyrite to the copper-zinc and to the barite-polymetallic ores. This pattern forms a vertical mineralization zoning from the bottom to the top of the deposit. The formation of the deposit was related to early Cambrian volcanism and included different mechanisms of ore deposition. The hill-like shape of the main ore lode with intense hydrothermal alteration of rocks in its base indicates a mineralization zone with veinlet-disseminated and massive ore structures, which indicates a hydrothermal-metasomatic origin.

About metallogeny of the pacific volcanic belts

The article discusses the actual aspects of the metallogeny of the Pacific volcanic belts (PVB), which are a complexes of volcanogenic-plutogenic formations associated with the development of the marginal lithosphere and has an expressive specificity of ore formation. It is shown that over time the notions of metallogenic homogeneity of PVB have received a new justification from the position of global plate tectonics. Metallogenic significance of Ag/Au relationships in ore deposits of the PVB is shown. The correlation between porphyry-epithermal and the VMS ore-forming systems, regenerated and rejuvenated epithermal deposits is discussed. Global metallogenic homogeneity of the Pacific ore belt suggests a wide development of analogues of American volcanogenic deposits in its Asian half, including in the North-East of Russia. The main part of the internal zone of the Okhotsko-Chukchi marginal volcanic belt the Udo-Murgal island-arc belt, as well as the Uyandino-Yasachensky and Oloysky volcanic belts, are similar in geological structure not only to the Japanese green tuffs province, but also to other Pacific volcanic zones of the island-arc type and, therefore, within their limits, there is a high probability of revealing the entire variety of deposits of the VMS ore-formation series.

Groundwater applications of towed TEM in diverse geology at farm scale

SummaryVehicle towed transient TEM systems have opened up possibilities of comprehensive mapping of groundwater resources at farm scale. At this scale airborne TEM usually has too much setup cost and conventional TEM conducted on foot is usually too laborious and rarely economically viable. Interpretation of data requires understanding of diverse geology, from alluvial geomorphology, volcanogenic deposition, weathering and erosion processes and the often complex combination of these. Further, impacts on the data by fences, buried cables and modelling imperfections must be separated from geological impact. Typically, it is the detail of the survey that renders it interpretable rather than system quality alone.

On the Metallogeny at the Pacific Volcanic Belts

This paper discusses currently interesting aspects of metallogeny at the Pacific volcanic belts (PVBs); these consist of complex volcanogenic–plutonic features related to the evolution of the marginal-sea lithosphere, which exhibits a remarkable mineralization peculiarity. We show that as time has passed, the ideas of a metallogenetic homogeneity of the PVBs received a new substantiation from the standpoint of plate tectonics. We show the metallogenetic value of the Ag/Au ratio in ore deposits at the PVBs. We consider the relationships between porphyritic epithermal and pyritaceous complex mineralizing systems, as well as regenerated and rejuvenated epithermal deposits. The global metallogenetic homogeneity of the Pacific ore belt suggests a wide occurrence of analogues of the American volcanogenic deposits in its Asian half, including the Russian Northeast. The bulk of the Okhotsk–Chukchi Volcanic Belt (OChVB), namely, the Uda–Murgali island arc belt, equally as the Uyandina–Yasachnaya and Oloi belts, are similar in geological structure not only to the Japanese green tuff province, but also to the other Pacific volcanic belts of the island arc type; hence, they are very likely to contain the entire diversity of deposits that belong to the complex pyritaceous ore–formation type.

Post-mining groundwater geochemistry evolution in on the Levikha sulfide deposits of the Middle Urals (Russia)

Mining of volcanogenic copper pyrite deposits of the Middle Urals leads to the rock disintegration, their grinding, increasing the interaction surface. Sulfide minerals are oxidized by interaction with oxygen-enriched meteoric water and secondary minerals are formed (crystallo-hydrates of sulphates, hydroxides). Here technogenic zone hypergene (sulfuric acid weathering crust) is being formed. Once the water pumping activities are finished, the piezometric level recovers its position decreasing the unsaturated zone created during the mining activity, this increases the water-rock ratio increasing the amount of suppliers of sulphates, iron, non-ferrous metals and other elements to groundwater. It defines a low rate of rehabilitation of mining areas after the completion of mining and cessation of dewatering. The regularities of acidic water formation after filling the depression cone are investigated on the abandoned copper mines of the Middle Urals (Russia). The longevity of formation of extremely acidic and polluted waters is determined by the degree of saturation of the supergene zone with secondary minerals and the intensity of water exchange. Seasonal decrease in the component’s concentrations t in the period of winter and summer low water was recorded. The unstable character of groundwater components changes with a half-life of more than 5 thousand days is established. The duration of rehabilitation and restoration of groundwater quality will be at least a hundred years.

Delineation of a buried volcanic system in Kora prospect off New Zealand using artificial neural networks and its implications

The Kora volcano, a submarine Miocene andesitic stratovolcano, is documented to be buried below ~1700 m sedimentary strata in the northern Taranaki basin off New Zealand. The buried volcano and enclosing older sedimentary strata, structurally modulated the subsurface architecture leading to the formation of structural and stratigraphic traps for hydrocarbon reservoirs. The Kora field is known for accumulating sub-commercial hydrocarbon resources within the volcanogenic deposits. Here, we attempt to image such a complex geological system from 3D time-migrated seismic data using state-of-the-art artificial neural networks coupled with interpreter's acquaintances. For this, we have computed several attributes; optimally amalgamated these and trained over interpreter's intelligence. This has resulted into a single new attribute, defined as the intrusion cube (IC) meta-attribute, to produce the best possible image of the subsurface. The resultant IC meta-attribute has successfully brought out the extension and distribution of volcanic edifice within the buried volcanic system along with several structural elements such as the sill networks, dyke swarms, forced folds, drag folds, jacked up strata and pinch-outs (along flanks of the volcano) in the host sedimentary successions, which are very essential in understanding the petroleum system of the Kora field. This interpretational approach, based on a blended output of neural intelligence of artificial networks and interpreters' knowledge, can be suitably employed for imaging any complex volcanic system from 3D seismic data.

Genesis of ore‐bearing volcanic rocks in the Derbur lead–zinc mining area of the Erguna Massif, western slope of the Great Xing'an Range, NE China: Geochemistry, Sr–Nd–Pb isotopes, and zircon U–Pb geochronology

The Derbur lead–zinc deposit is located in the Derbugan metallogenic belt in the north‐western portion of the Mesozoic Hailaer‐Genhe volcanic basin in the northern Great Xing'an Range. This deposit occurs in the Middle Jurassic intermediate–mafic volcanic rocks of the Tamulangou Formation and is spatially and temporally associated with acidic pyroclastic rocks. The host rocks are bedded trachyandesite and rhyolitic lithic‐crystal tuffs, and basaltic‐andesitic aplite veins are associated with the ore body. Because the deposit is a hypabyssal low‐temperature hydrothermal Pb–Zn deposit associated with volcanism, to determine the precise petrogenesis of the volcanic rocks, this study analysed the zircon U–Pb ages of the trachyandesite and rhyolitic lithic‐crystal tuffs, the Sr–Nd–Pb isotopic geochemistry of the trachyandesite and basaltic‐andesitic aplite, and the whole‐rock geochemistry of all three rock types. The results showed that the trachyandesite and basaltic‐andesitic aplite belong to the shoshonitic series and have similar whole‐rock and isotopic geochemical characteristics, including enrichments in large‐ion lithophile elements and light rare earth elements and depletions in high‐field‐strength elements. They also have low initial 87Sr/86Sr values of 0.705007–0.705240 and εNd(t) values of +0.6 to +1.7, with model ages (TDM) of 699–883 Ma. The ratios of 206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb vary from 18.438 to 18.476, 15.570 to 15.577, and 38.254 to 38.320, respectively, with μ values of 9.40–9.41. In contrast, the rhyolitic lithic‐crystal tuffs are characterized by high SiO2 contents (73.44–79.48 wt.%); low Al2O3 (11.36–12.53 wt.%), TiO2 (0.14–0.18 wt.%), and K2O + Na2O (3.48–3.89 wt.%, Na2O ≤ K2O) contents; and low Mg# values (0.17–0.41), indicating that they belong to the calc–alkaline series. Additionally, they have relatively low REE contents and strong Sr depletions. LA‐ICP‐MS zircon U–Pb dating of the trachyandesite and rhyolitic lithic‐crystal tuffs indicates that their ages are 167.0 ± 2.0 Ma and 164.8 ± 1.6 Ma, respectively. We conclude that the trachyandesite and the basaltic‐andesitic aplite were derived from the partial melting of lower crustal material assimilated by a depleted lithospheric mantle that was subsequently metasomatized by subducted slab‐derived fluids. The rhyolitic lithic‐crystal tuffs likely originated from the partial melting of accreted lower crust. In summary, because the acidic volcanism was accompanied by increasingly felsic volcanism, bimodal volcanic rocks were produced. Among volcanogenic deposits, bimodal volcanic rocks are the most favourable ore‐hosting rocks, and ore‐forming materials were contributed by the magmatic system. These processes created conditions conducive to the formation of large‐scale Ag, Pb, and Zn mineralization in this area.