The Disuga Cu deposit,located in the eastern porphyry belt of the Zhongdian arc,southwest China,provides a window into magmatic-hydrothermal processes controlling porphyry Cu mineralization.Based on zircon U-Pb geochr...The Disuga Cu deposit,located in the eastern porphyry belt of the Zhongdian arc,southwest China,provides a window into magmatic-hydrothermal processes controlling porphyry Cu mineralization.Based on zircon U-Pb geochronology,hydrothermal mineral chemistry,short-wave infrared spectroscopy,and mass balance modeling,this study investigated the alteration zonation and element mobility in the Disuga Cu deposit.Zircon U-Pb ages of the ore-hosting quartz dioritic porphyries(222.4±3.1 and 219.3±2.4 Ma)are similar to those of Late Triassic subduction-related magmatism.High zircon-crystallization temperatures(727±26℃)and elevated oxygen fugacity(ΔFMQ+2.0)confirm these porphyries were favorable for mineralization.Hydrothermal sericite(Si=6.49 atoms per formula unit[apfu];Al^(Ⅵ)=3.39 apfu)and chlorite(Fe/(Fe+Mg)=0.59-0.63)compositions indicate an acidic reduced fluid.Three distinct hydrothermal stages were identified:(1)phyllic alteration(370℃);(2)propylitic alteration(315℃);and(3)low-temperature hydrothermal alteration(242℃).Mass balance calculations show that the Cu migration rate(155.6%/114.4%)in the propylitic/phyllic alteration zones was higher than that of Mo(14.3%;limited to the propylitic alteration zone).The alteration mineralization assemblages indicate the occurrence of deep potassic alteration zones and porphyry Cu-(Mo)mineralization in the Disuga area.展开更多
1.Objective.The Yidun arc within the Tethys-Himalaya metallogenic belt formed during the westward subduction of the Ganzi-Litang Ocean(237-206 Ma)during the Indosinian period,and then underwent the evolution stages of...1.Objective.The Yidun arc within the Tethys-Himalaya metallogenic belt formed during the westward subduction of the Ganzi-Litang Ocean(237-206 Ma)during the Indosinian period,and then underwent the evolution stages of the collisional orogeny(206-138 Ma)and the post-collisional orogeny(135-75 Ma).In recent years,a series of large and medium-sized Late Yanshanian intracontinental porphyry-skarn Mo-Cu-W deposits have been discovered in the southern part of the Yidun arc,including Xiuwacu,Relin,Hongshan,Tongchanggou,and Donglufang(Fig.1a).展开更多
Dabie-type porphyry Mo deposits were proposed as a new type of porphyry Mo deposits,and had unique geological characteristics.It is still poorly understood about the magmatic processes that led to the Dabie-type Mo mi...Dabie-type porphyry Mo deposits were proposed as a new type of porphyry Mo deposits,and had unique geological characteristics.It is still poorly understood about the magmatic processes that led to the Dabie-type Mo mineralization.Here,we present zircon U-Pb and Lu-Hf isotopic,whole-rock and biotite elemental,and whole-rock Sr-Nd isotopic analyses on the Lingshan granitic batholith in the Dabie Orogen.It consists of three units(ⅠtoⅢ)that were emplaced before,genetically accompanied with,and after the Mo mineralization.LA-ICP-MS zircon U-Pb dating yielded crystallization ages of 128.2±1.0 Ma(MSWD=1.14)for UnitⅠand ages of 127.8±1.2 Ma(MSWD=0.28)and 126.6±1.8 Ma(MSWD=1.6)for UnitⅡ,indicating that they were emplaced during 130 to 125 Ma.The granites have high SiO_(2)contents(75.84 wt.%to 78.94 wt.%)and low MgO contents(0.07 wt.%to 0.10 wt.%),and are classified as fractionatedⅠ-type granite.UnitsⅠandⅡhave similar Sr-Nd isotopic ratios(ε_(Nd)(t)=-16.2 to-17.2,(^(87)Sr/^(86)Sr)_(i)=0.70540 to 0.70692)and zirconε_(Hf)(t)values(-17.4 to-20.4),indicating they were derived from partial melting of the ancient Yangtze lower crust.Mo mineralized granite from UnitⅡis characterized by the lower oxygen fugacity,fluorine enrichment and high fractionation.Magmas of unitsⅠandⅡhave experienced fractional crystallization,with the assimilation of supracrustal materials that account for the increased TiO_(2),F and Mo contents,and the decreased fO_(2).We proposed that the assimilation in upper-crustal magmatic processes plays key factors for magmatic systems that led to the Dabie-type porphyry Mo deposits.展开更多
The Early Paleozoic porphyry-epithermal Au system of the Songshunangou District sits in the central segment of the North Qilian orogenic belt(NQOB).The porphyry Au mineralization is centered on the quartz diorite porp...The Early Paleozoic porphyry-epithermal Au system of the Songshunangou District sits in the central segment of the North Qilian orogenic belt(NQOB).The porphyry Au mineralization is centered on the quartz diorite porphyry(QDP),which is constrained to the Late Ordovician period.However,the geochemical signatures,the origin,and the tectonic setting of the QDP are not yet known and understood and are thus in the focus here.The QDP is a high-K calc-alkaline metaluminous rocks(K_(2)O+Na_(2)O:6.90-8.13;Al_(2)O_(3)/(CaO+Na_(2)O+K_(2)O):0.69-0.90)characterized by high(^(87)Sr/^(86)Sr)_(t)values(0.7093-0.7101)and lowε_(Nd)(t)values(-2.9 to-2.7)with corresponding T_(DM2)(Nd)ages of 1408 to 1430 Ma.Zirconε_(Hf)(t)values are low(-1.51 to+2.76)with corresponding T_(DM2)(Hf)ages of 1262 to 1533 Ma.The lead isotope values are 17.695-18.476 for(^(206)Pb/^(204)Pb)_(t),15.585-15.629 for(^(207)Pb/^(204)Pb)_(t),and 37.214-37.948 for(^(208)Pb/^(204)Pb)_(t).These data indicate that the QDP formed by the mixing of mantle-derived magmas(50%-70%)with lower crustal melts.The QDP is enriched in LREEs and LILE(Rb,Th,K)and is depleted in HFSE(Nb,Ta,Ti),expressing a clear volcanic arc affinity.High La and Th contents,and Zr/Y and Hf/Yb values suggest that the QDP formed in an Andean-type continental margin arc setting related to the northward subduction of the North Qilian oceanic slab.The Early Paleozoic subduction-related intermediate-acidic intrusions in NQOB have arc magma affinity,indicating that these rocks bear a great potential to discover further fertile porphyry deposits.展开更多
The Bainiuchang Ag-polymetallic ore deposit,located in southeastern Yunnan,China,is one of the region's largest deposits.However,the hyp abyssal granite porphyry within this mining area has yet to be comprehensive...The Bainiuchang Ag-polymetallic ore deposit,located in southeastern Yunnan,China,is one of the region's largest deposits.However,the hyp abyssal granite porphyry within this mining area has yet to be comprehensively investigated.In this study,we conducted geochemical,geochronological,whole-rock Sr-Nd isotope,and zircon Hf isotope analyses on granite porphyry samples collected from the Bainiuchang deposit.The results indicate that the granite porphyry formed between 87.5 and 87.4 Ma in the Late Yanshanian period.Geochemically,the granite is strongly peraluminous,with high silica and alkali contents consistent with S-type granite characteristics.The granite porphyry is enriched in large-ion lithophile elements(Rb,Th,U,and K)and is relatively depleted in Ba and Sr.The initial ^(87)Sr/^(86)Sr ratios are high(0.71392-0.71585),accompanied by low ε_(Nd)(t)values(-8.9 to-8.2).The zircons exhibited similarly low ε_(Hf)(t)values(-9.31 to-3.6).These data suggest that the porphyry-forming magma originated from a continental crustal source.The two-stage Hf and Nd model ages are estimated at 1534-1216 Ma and 1615-1561 Ma,respectively.Thus,the granite porphyry likely formed under a strike-slip extensional setting in the Late Yanshanian period and resulted from the re-melting of Proterozoic basement metagreywackes.This porphyry shares a similar magmatic origin with concealed granite bodies within the deposit and is associated with structural reactivation during the Yanshanian.The findings of this study provide valuable insights into the tectonomagmatic mineralization processes in the B ainiuchang area.展开更多
The Yangchuling porphyry W-Mo deposit(YPWD),located in the Jiangnan porphyryskarn tungsten ore belt,is one of the most important and large-scale porphyry W-Mo deposits in South China.While previous zircon U-Pb and mol...The Yangchuling porphyry W-Mo deposit(YPWD),located in the Jiangnan porphyryskarn tungsten ore belt,is one of the most important and large-scale porphyry W-Mo deposits in South China.While previous zircon U-Pb and molybdenite Re-Os data suggest that Yangchuling WMo ore bodies formed almost simultaneously with granodiorite and monzogranitic porphyry at~150–144 Ma,their post emplacement history remains poorly understood,making their preservation status at depth uncertain.In this paper,new zircon and apatite(U-Th)/He and apatite fission track(ZHe,AHe and AFT,respectively)data of one hornfels and five intrusive rocks from a 1000-meter borehole are presented.These,together with new inverse thermal history models and previous geochronological data,help elucidate the post-diagenetic exhumation history and preservation status of the Yangchuling porphyry W-Mo deposit.In general,ZHe and AHe ages decrease gradually from the near surface downwards and have relatively little intra-sample variation,ranging from 133 to 73Ma and 67 to 25 Ma,respectively.All four granodiorites yield similar AFT ages that range from 63 to 55 Ma with mean track lengths varying from 12.2±0.7 to 12.6±0.5μm.Thermal history modelling indicates that the Yangchuling ore district experienced slow,monotonic cooling since the Cretaceous.Age-depth relationships are interpreted as recording~3.7±0.8 km of Cretaceous-recent exhumation in response to regional extension throughout South China thought to have been driven by subduction retreat of the Paleo-Pacific Plate.Comparison of estimated net exhumation and previous metallogenic depth of~4–5 km suggests that W-Mo ore bodies could still exist at depths of up to~1.3±0.8 km relative to Earth surface in the YPWD region.Preservation of the YPWD is attributed to the limited amount of regional denudation during the Late Cretaceous and Cenozoic.展开更多
The Dabaoshan porphyry Cu deposit(420 kilotons(kt)of Cu@0.36%)is located in South China.The newly discovered Cu orebodies are hosted in the dacite porphyry adjacent to a granodiorite porphyry.The alteration and minera...The Dabaoshan porphyry Cu deposit(420 kilotons(kt)of Cu@0.36%)is located in South China.The newly discovered Cu orebodies are hosted in the dacite porphyry adjacent to a granodiorite porphyry.The alteration and mineralization timing and stages of the porphyry Cu deposit were not well-constrained.In this study,we combine field mapping,petrography,whole-rock geochemistry,hydrothermal rutile U-Pb dating and Cu isotopes to synthesize an ore model at Dabaoshan.In situ hydrothermal rutile U-Pb dating yields an age of 159±13 Ma,which brackets the timing of porphyry Cu mineralization.From top to bottom,the alteration zones in Dabaoshan are divided into quartz-sericite,biotite,chlorite-epidote,and chlorite-sericite subzones.Veins are classified into four stages(Stage 1 to 4)with Stage 4 quartz-sericite-chalcopyrite veins being the main Cu ore-bearing veins.The mineralized dacite porphyry has high SiO_(2),but low MgO,CaO,and Na_(2)O contents.The chalcopyrite hosted in veins exhibitsδ^(65)Cu=values ranging from−1.29‰to 0.51‰.Such copper isotope fractionation is attributed to vapor-brine phase separation,and mixing of fluids from different geochemical reservoirs.The timing of Cu mineralization and hydrothermal alteration support that the Jurassic granodiorite porphyry is an ore-forming intrusion at Dabaoshan.展开更多
0 INTRODUCTION The Haidewula uranium deposit is located in the Haidewula volcanic basin,which hosts a suite of basic,intermediate to felsic volcanic and subvolcanic rocks,including basalt,trachyte,trachyandesite.Previ...0 INTRODUCTION The Haidewula uranium deposit is located in the Haidewula volcanic basin,which hosts a suite of basic,intermediate to felsic volcanic and subvolcanic rocks,including basalt,trachyte,trachyandesite.Previous geochronological studies of the intrusions within this volcanic basin suggest that they primarily formed during the Silurian and Triassic periods(Dai et al.,2025;Sun et al.,2024;Wang et al.,2024;Zhu et al.,2022;Lei et al.,2021).展开更多
The key factor that controls the genesis of porphyry Cu deposits(PCDs)in collisional orogens remains a debated topic.This study employs whole-rock La/Yb proxies to quantitatively constrain the spatial and temporal var...The key factor that controls the genesis of porphyry Cu deposits(PCDs)in collisional orogens remains a debated topic.This study employs whole-rock La/Yb proxies to quantitatively constrain the spatial and temporal variations in crustal thickness of the South Armenian-Iranian magmatic belt(SAIMB)within the Zagros orogen(central Tethys region)since the Eocene.Our results show that rapid crustal thickening occurred first in the NW section of the SAIMB at~35 Ma,then propagated southeastward into the central and SE sections at~25 Ma and 20 Ma,respectively,indicating that the Arabia-Eurasia collision was diachronous.The formation of the large and giant collision-related PCDs in the SAIMB might have been controlled by the collision process because they developed first in the NW section of the SAIMB and subsequently propagated southeastward into the central and SE sections.More importantly,crustal thickness mapping shows that the PCDs are preferentially developed in the thickened crust areas(>50 km).Our findings propose that thickened crust is critical for the formation of the PCDs in collisional orogens by promoting Fe^(2+)-rich minerals as a fractionating phase,driving magmatic auto-oxidation and releasing Cu into the magmas.The Cu is then partitioned into magmatic fluids,sustaining the porphyry systems.Furthermore,our research highlights that the thickened crust hosting PCDs was characterized by a previously thinner crust(<40 km),where magmas had low oxygen fugacity due to the absence of the auto-oxidation process.Consequently,chalcophile elements(e.g.,Cu)efficiently separated from the melt through sulfide segregation,forming large Cu-bearing lower-crustal cumulates.These cumulates can be mobilized with an increase in oxygen fugacity,incorporating into subsequent porphyry mineralization.We thus propose that the crustal thickness evolution over time controls the formation of the PCDs in collisional orogens.There are two essential stages in the collision-related PCDs formation:the first is high-flux magmatism in the thin crustal setting(<40 km),leading to metal-fertilized lower crust through sulfide segregation,and the second is the intracrustal auto-oxidation during crustal thickening(>50 km)which facilitates pre-enriched sulfides in the lower crust to re-dissolve,releasing Cu into the magmas.展开更多
Numerous intermediate to felsic igneous rocks are present in both subduction and collisional orogens.However,porphyry copper deposits(PCDs)are comparatively rare.The underlying factors that differentiate fertile magma...Numerous intermediate to felsic igneous rocks are present in both subduction and collisional orogens.However,porphyry copper deposits(PCDs)are comparatively rare.The underlying factors that differentiate fertile magmas,which give rise to PCDs,from barren magmas in a specific geological setting are not well understood.In this study,three supervised machine learning algorithms:random forest(RF),logistic regression(LR)and support vector machine(SVM)were employed to classify metallogenic fertility in southeastern Tibet,Sanjiang orogenic belt,based on whole-rock trace element and Sr-Nd isotopic ratios.The performance of the RF model is better than LR and SVM models.Feature importance analysis of the models reveals that the concentration of Y,Eu,and Th,along with Sr-Nd isotope compositions are crucial variables in distinguishing fertile and barren samples.However,when the optimized models were applied to predict the datasets of Miocene Gangdese porphyry copper belt and Jurassic Gangdese arc representing collision and subduction settings respectively,a marked decline in metrics occurred in all three models,particularly on the subduction dataset.This substantial decrease indicates the compositional characteristics of intrusions across different tectonic settings could be diverse in a multidimensional space,highlighting the complex interplay of geological factors influencing PCD’s formation.展开更多
The porphyry copper belt in the Geza island arc in southwestern China is the only Indosinian porphyry copper metallogenic belt that has been discovered and evaluated so far.The Pulang porphyry copper deposit(also refe...The porphyry copper belt in the Geza island arc in southwestern China is the only Indosinian porphyry copper metallogenic belt that has been discovered and evaluated so far.The Pulang porphyry copper deposit(also referred to as the Pulang deposit)in this area has proven copper reserves of 5.11×106 t.This deposit has been exploited on a large scale using advanced mining methods,exhibiting substantial economic benefit.Based on many research results of previous researchers and the authors’team,this study proposed the following key insights.(1)The Geza island arc was once regarded as an immature island arc with only andesites and quartz diorite porphyrites occurring.This understanding was overturned in this study.Acidic endmember components such as quartz monzonite porphyries and quartz monzonite porphyries have been identified in the Geza island arc,and the mineralization is mainly related to the magmatism of quartz monzonite porphyries.(2)Complete porphyry orebodies and large vein orebodies have developed in the Pulang deposit.Main orebody KT1 occurs in the transition area between the potassium silicate alteration zone of quartz monzonite porphyries and the sericite-quartz alteration zone.Most of them have developed in the potassium silicate alteration zone.The main orebody occurs as large lenses at the top of the hanging wall of rock bodies,with an engineering-controlled length of 1920 m and thickness of 32.5‒630.29 m(average:187.07 m).It has a copper grade of 0.21%-1.56%(average:0.42%)and proven copper resources of 5.11×10^(6) t,which are associated with 113 t of gold,1459 t of silver,and 170×10^(3) t of molybdenum.(3)Many studies on diagenetic and metallogenic chronology,isotopes,and fluid inclusions have been carried out for the Pulang deposit,including K-Ar/Ar-Ar dating of monominerals(e.g.,potassium feldspars,biotites,and amphiboles),zircon U-Pb dating,and molybdenite Re-Os dating.The results show that the porphyries in the Pulang deposit are composite plutons and can be classified into pre-mineralization quartz diorite porphyrites,quartz monzonite porphyries formed during the mineralization,and post-mineralization granite porphyries,which were formed at 223±3.7 Ma,218±4 Ma,and 207±3.9 Ma,respectively.The metallogenic age of the Pulang deposit is 213‒216 Ma.(4)The petrogeochemical characteristics show that the Pulang deposit has the characteristics of volcanic arc granites.The calculation results of trace element contents in zircons show that quartz monzonite porphyries and granite porphyries have higher oxygen fugacity.The isotopic tracing results show that the diagenetic and metallogenic materials were derived from mixed crust-and mantle-derived magmas.展开更多
Located in Lu-Zong ore concentration area, middle-lower Yangtze metallogenic belt, ShaXi porphyry copper deposit is a typical hydrothermal deposit. To investigate the distribution of deep ore bodies and spatial charac...Located in Lu-Zong ore concentration area, middle-lower Yangtze metallogenic belt, ShaXi porphyry copper deposit is a typical hydrothermal deposit. To investigate the distribution of deep ore bodies and spatial characteristics of host structures, an AMT survey was conducted in mining area. Eighteen pseudo-2D resistivity sections were constructed through careful processing and inversion. These sections clearly show resistivity difference between the Silurian sandstones formation and quartz diorite porphyry and this porphyry copper formation was controlled by the highly resistive anticlines. Using 3D block Kxiging interpolation method and 3D visualization techniques, we constructed a detailed 3D resistivity model of quartz diorite porphyry which shows the shape and spatial distribution of deep ore bodies. This case study can serve as a good example for future ore prospecting in and around this mining area.展开更多
The Naruo porphyry copper-gold deposit （hereinafter referred to as the Naruo deposit） in Tibet is a potentially ultra-large, typical gold-rich porphyry copper deposit, which was recently discovered in the Bangongco-...The Naruo porphyry copper-gold deposit （hereinafter referred to as the Naruo deposit） in Tibet is a potentially ultra-large, typical gold-rich porphyry copper deposit, which was recently discovered in the Bangongco-Nujiang metallogenic belt. This study analyzed U-Ph chronology and Hf isotopes of the ore-bearing granodiorite porphyry in the Naruo deposit using the LA-ICPMS dating technique. The results show that the weighted average age is 124.03±0.94Ma （MSWD=1.7, n=20）, and 2±6pb/23SU isocbron age is 126.2±2.7 Ma （MSWD=1.02, n=20）, both of which are within the error. The weighted average age represents the crystallization age of the granodiorite porphyry, which indicates that the ore-bearing porphyry in the Naruo deposit area was formed in the Early Cretaceous and further implies that the Neo-tethys Ocean had not been closed before 124 Ma under a typical island-arc subduction environment. The εGr（t） of zircons from the granodiorite porphyry varies from 2.14 to 9.07, with an average of 5.18, and all zircons have εRf（t） values greater than 0; 176Hf/177Hf ratio is relatively high （0.282725-0.282986）. Combined with the zircon age--Hf isotope correlation diagram, the aforementioned data indicate that the source reservoir might be a region that is mixed with depleted mantle and ancient crust, which possibly contains more materials sourced from depleted mantle. Rock-forming ages and ore-forming ages of the Duolong ore concentrate area are 120-124 Ma and 118-119 Ma, respectively, which indicate 124-118 Ma represents the main rockforming and ore-forming stage within the area. The Naruo deposit is located in the north of the Bangongco-Nujiang suture, and it yielded a zircon LA-ICPMS age of 124.03 Ma. This indicates the Bangongco-Nujiang oceanic basin subducted towards the north at about 124 Ma, and the Neo-tethys Ocean had not been closed before the middle Early Cretaceous. It is possible that the crust-mantle mixing formed the series of large and giant porphyry copper-gold deposits in the Bangongco.展开更多
The newly discovered Zhunuo porphyry Cu-Mo-Au deposit is located in the western part of the Gangdese porphyry copper belt in southern Tibet,SW China.The granitoid plutons in the Zhunuo region are composed of quartz di...The newly discovered Zhunuo porphyry Cu-Mo-Au deposit is located in the western part of the Gangdese porphyry copper belt in southern Tibet,SW China.The granitoid plutons in the Zhunuo region are composed of quartz diorite porphyry,diorite porphyry,granodiorite porphyry,biotite monzogranite and quartz porphyry.The quartz diorite porphyry yielded zircon U-Pb ages of 51.9±0.7 Ma(Eocene)using LA-ICP-MS,whereas the diorite porphyry,granodiorite porphyry,biotite monzogranite and quartz porphyry yielded ages ranging from 16.2±0.2 to 14.0±0.2 Ma(Miocene).CuMo-Au mineralization is mainly hosted in the Miocene granodiorite porphyry.Samples from all granitoid plutons have geochemical compositions consistent with high-K calc-alkaline series magmatism.The samples display highly fractionated light rare-earth element(REE)distributions and heavy REE distributions with weakly negative Eu anomalies on chondrite-normalized REE patterns.The trace element distributions exhibit positive anomalies for large-ion lithophile elements(Rb,K,U,Th and Pb)and negative anomalies for high-field-strength elements(Nb and Ti)relative to primitive mantlenormalized values.The Eocene quartz diorite porphyry yieldedεNd(t)values ranging from-3.6 to-5.2,(-(87)Sr/-(86)Sr)i values in the range 0.7046–0.7063 and initial radiogenic Pb isotopic compositions with ranges of 18.599–18.657-(206)Pb/-(204)Pb,15.642–15.673-(207)Pb/-(204)Pb and 38.956–39.199-(208)Pb/-(204)Pb.In contrast,the Miocene granitoid plutons yieldedε(Nd)(t)values ranging from-6.1 to-7.3 and(87Sr/86Sr)i values in the range 0.7071–0.7078 with similar Pb isotopic compositions to the Eocene quart diorite.The Sr-Nd-Pb isotopic compositions of the rocks are consistent with formation from magma containing a component of remelted ancient crust.Zircon grains from the Eocene quartz diorite haveε(Hf)(t)values ranging from-5.2 to+0.9 and two-stage Hf model ages ranging from 1.07 to 1.46 Ga,while zircon grains from the Miocene granitoid plutons haveε(Hf)(t)values from-9.9 to+4.2 and two-stage Hf model ages ranging from 1.05–1.73 Ga,indicating that the ancient crustal component likely derives from Paleo-to Mesoproterozoic basement.This source is distinct from that of most porphyry Cu-Mo-Au deposits in the eastern part of the Gangdese porphyry copper belt,which likely originated from juvenile crust.We therefore consider melting of ancient crustal basement to have contributed significantly to the formation Miocene porphyry Cu-Mo-Au deposits in the western part of the Gangdese porphyry copper belt.展开更多
: Zinccopperite (tentatively named) is a rare native alloy mineral discovered in quartz monzonite—porphyry in the Xifanping area, Yanyuan County, Sichuan Province. It is a new variety of zinc—copper alloy mineral fo...: Zinccopperite (tentatively named) is a rare native alloy mineral discovered in quartz monzonite—porphyry in the Xifanping area, Yanyuan County, Sichuan Province. It is a new variety of zinc—copper alloy mineral found for the first time in the porphyry-copper deposit in China. Its intergrown minerals are K—feldspar (mainly perthite), albite—oligoclase, quartz and biotite; and the associated minerals include pyrite and chalcopyrite. It is characterized by a golden reflection colour, being isotropic (isometric), with the grain size ranging from 10 to 50 μm, microhardness VHN10 = 190 kg/mm2, and reflectance RVM = 67.97%. Electron microprobe (Model JXA—733) analysis shows Cu = 59.15%–62.55% and Zn = 36.32%–39.85%. The crystallochemical formula is Cu6.27-7.0Zn4.0, simplified as Cu7Zn4.展开更多
We have determined the ages of the ore-bearing Tinggong porphyries and the Eocene granites using the LA-ICPMS zircon U-Pb method.Zircons from one adamellite porphyry and two diorite porphyries yield ages of 15.54±...We have determined the ages of the ore-bearing Tinggong porphyries and the Eocene granites using the LA-ICPMS zircon U-Pb method.Zircons from one adamellite porphyry and two diorite porphyries yield ages of 15.54±0.28 Ma,15.02±0.25 Ma and 14.74±0.22 Ma,respectively.The ages of two granites are 50.48±0.71 Ma and 50.16±0.48 Ma.Light Rare Earth Elements （LREE） are enriched in the ore-bearing adamellite porphyries,which are high-K caic-alkaline and metaluminous,while Heavy Rare Earth Elements （HREE） and Y are strongly depleted,indicating an adakitic affinity.The Large Ion Lithophile Elements （LILE） of the adamellite porphyries are highly enriched,whereas some High Field Strength Elements （HFSE） are depleted.The diorite porphyry in this study is chemically similar to the adamellite porphyries,except that the Mg# of the diorite porphyry is a little higher,demonstrating more mantle contamination.Four samples from different rocks are selected for in situ zircon Hf isotopic analyses.The samples show positive εHf（t） values and young Hf model ages,indicating their derivation from juvenile crust.However,the adamellite porphyry and diorite porphyry formed in the Miocene exhibit more heterogeneous Hf isotopic ratios,with lower （Σ）Hf （t） values than the granites formed in the Eocene,suggesting the involvement of old Indian continent crust in their petrogenesis.The geochronology and geochemistry of the adamellite porphyries and the diorite porphyries indicate that they formed from the same source region in a post-collisional environment,but contaminated by crust and mantle materials in different ratios.The metallic minerals formed mainly during the older adamellite porphyry stage,but they were recycled and reactivated by the diorite porphyry intrusion.展开更多
The Habo deposit is a typical porphyry Cu-Mo deposit in the Ailaoshan–Red River metallogenic belt.Ore minerals in the Habo deposit typically occur as veins in the monzonite porphyry.Zircon U-Pb dating suggests that t...The Habo deposit is a typical porphyry Cu-Mo deposit in the Ailaoshan–Red River metallogenic belt.Ore minerals in the Habo deposit typically occur as veins in the monzonite porphyry.Zircon U-Pb dating suggests that the monzonite porphyry formed at 35.07±0.38 Ma.The monzonite porphyry is characterized by high SiO_(2),Al_(2)O_(3),K_(2)O and Na_(2)O contents,with A/CNK ratios ranging from 0.97 to 1.02.All samples exhibit fractionated REE patterns,characterized by high(La/Yb)N ratios(9.4–13.6,average of 11.2).They show adakite-like geochemical features,high Sr concentrations(627–751 ppm,average of 700 ppm),low Y concentrations(15.13–16.86 ppm,average of 15.81 ppm)and high Sr/Y values(39.5–47.4,average of 44.3).These samples have high initial^(87)Sr/^(86)Sr ratios(0.7074–0.7076)and negativeεNd(t)values(-5.1 to-3.7),whereas the zirconεHf(t)values range from-2.2 to+0.4,suggesting that the monzonite porphyry was derived from the partial melting of a thickened juvenile lower crust.The oxygen fugacity,calculated on the basis of the chemical composition of the amphiboles,shows?NNO values ranging from+1.65 to+2.16(average of 1.94)and lg(fO_(2))ranging from-12.72 to-11.99(average of-12.25),indicating that the monzonite porphyry has high oxygen fugacity.Zircons have high Ce^(4+)/Ce^(3+)ratios(29.29–164.24,average of 84.92),with high?FMQ values ranging from+0.50 to+1.51(average of 0.87)and high lg(fO_(2))values ranging from-14.72 to-12.85(average of-14.07),which also indicates that the oxygen fugacity of the magma was high.The dissolved water content of the Habo monzonite porphyry is 9.5–11.5 wt%,according to the geochemical characteristics,zircon-saturation thermometry(692–794°C)and the mineral phases(amphibole,no plagioclase)in the deep magma chamber.Combined with previous studies,we propose that the high oxygen fugacity and high water content of magma played key roles in controlling the formation of the Habo and other Cu-Mo-Au deposits in the Ailaoshan–Red River metallogenic belt.展开更多
The Daheishan supergiant porphyry molybdenum deposit(also referred to as the Daheishan deposit)is the second largest molybdenum deposit in Asia and ranks fifth among the top seven molybdenum deposits globally with tot...The Daheishan supergiant porphyry molybdenum deposit(also referred to as the Daheishan deposit)is the second largest molybdenum deposit in Asia and ranks fifth among the top seven molybdenum deposits globally with total molybdenum reserves of 1.65 billion tons,an average molybdenum ore grade of 0.081%,and molybdenum resources of 1.09 million tons.The main ore body is housed in the granodiorite porphyry plutons and their surrounding inequigranular granodiorite plutons,with high-grade ores largely located in the ore-bearing granodiorite porphyries in the middle-upper part of the porphyry plutons.Specifically,it appears as an ore pipe with a large upper part and a small lower part,measuring about 1700 m in length and width,extending for about 500 m vertically,and covering an area of 2.3 km^(2).Mineralogically,the main ore body consists of molybdenite,chalcopyrite,and sphalerite horizontally from its center outward and exhibits molybdenite,azurite,and pyrite vertically from top to bottom.The primary ore minerals include pyrite and molybdenite,and the secondary ore minerals include sphalerite,chalcopyrite,tetrahedrite,and scheelite,with average grades of molybdenum,copper,sulfur,gallium,and rhenium being 0.081%,0.033%,1.67%,0.001%,and 0.0012%,respectively.The ore-forming fluids of the Daheishan deposit originated as the CO_(2)-H_(2)O-NaCl multiphase magmatic fluid system,rich in CO_(2)and bearing minor amounts of CH4,N2,and H2S,and later mixed with meteoric precipitation.In various mineralization stages,the ore-forming fluids had homogenization temperatures of>420℃‒400℃,360℃‒350℃,340℃‒230℃,220℃‒210℃,and 180℃‒160℃and salinities of>41.05%‒9.8%NaCleqv,38.16%‒4.48%NaCleqv,35.78%‒4.49%NaCleqv,7.43%NaCleqv,and 7.8%‒9.5%NaCleqv,respectively.The mineralization of the Daheishan deposit occurred at 186‒167 Ma.The granites closely related to the mineralization include granodiorites(granodiorite porphyries)and monzogranites(monzogranite porphyries),which were mineralized after magmatic evolution(189‒167 Ma).Moreover,these mineralization-related granites exhibit low initial strontium content and high initial neodymium content,indicating that these granites underwent crust-mantle mixing.The Daheishan deposit formed during the Early-Middle Jurassic,during which basaltic magma underplating induced the lower-crust melting,leading to the formation of magma chambers.After the fractional crystallization of magmas,ore-bearing fluids formed.As the temperature and pressure decreased,the ore-bearing fluids boiled drops while ascending,leading to massive unloading of metal elements.Consequently,brecciated and veinlet-disseminated ore bodies formed.展开更多
The Dexing porphyry deposit is the largest porphyry Cu–Mo–Au deposit in South China.Biotite composition can record the physicochemical conditions and evolution history of magmatic-hydrothermal system.Biotite from th...The Dexing porphyry deposit is the largest porphyry Cu–Mo–Au deposit in South China.Biotite composition can record the physicochemical conditions and evolution history of magmatic-hydrothermal system.Biotite from the Dexing porphyry deposit could be divided to three types:primary magmatic biotite(Bi-M),hydrothermal altered magmatic biotite(Bi-A)and hydrothermal biotite(Bi-H).The temperature of Bi-M and Bi-H range from 719 to 767℃ and 690 to 727℃,respectively.Both magmatic and hydrothermal biotite have high Fe^(3+)/Fe^(2+)ratios(from 0.18 to 0.24)and XMgvalues(from 0.57 to 0.66),indicating a high oxygen fugacity.BiM has F lower than Bi-A and Bi-H(up to 0.26 wt%),but has Cl(Cl=0.18–0.30 wt%)similar to Bi-A and Bi-H(Cl=0.21–0.35 wt%),suggesting that high Cl/F ratios of early hydrothermal fluid may result from the exsolution from high Cl magma.From potassic alteration zone to phyllic and propylitic alteration zones,Cl decreases with increasing Cu,whereas F increases roughly.Therefore,Cl mostly originate from magma,but enrichment of F possibly results from reaction of fluids and Neoproterozoic strata.Negative correlation between Cl and Cu indicates that Cl might act as an important catalyst during Cu mineralization process.Biotite from Dexing has similar halogen compositions to other porphyry Cu-/Mo deposits in the world.Chlorine contents of hydrothermal fluid may be critical for Cu transportation and enrichment,while consumption of Cl would promote Cu deposition.展开更多
The term“porphyry”has a specific geological meaning but has been used freely by sculptors and art historians to name many types of stone that are not,geologically,porphyries.“Porphyries”have been associated with n...The term“porphyry”has a specific geological meaning but has been used freely by sculptors and art historians to name many types of stone that are not,geologically,porphyries.“Porphyries”have been associated with nobility and Imperial Monuments since Roman times.This paper discusses some examples from Karelia in Russia and from Sweden used in St Petersberg and the use of Russian Shoksha“porphyry”in Paris,France.It highlights several types of stone that have been referred to as porphyries but are not.The Shoksha stone has been of architectural and artistic importance both nationally and internationally for some 300 years.This might qualify it as a candidate for Global Heritage Stone Resource status.展开更多
基金granted by the Deep Earth Probe and Mineral Resource Exploration-National Science and Technology Major Project(Grant No.2024ZD1001602)a Second Tibetan Plateau Scientific Expedition and Research project(Grant No.2021QZKK0301)+1 种基金the National Natural Science Foundation of China(Grant No.42022021)the Jiangxi Provincial Youth Fund(Grant No.20224BAB213051).
文摘The Disuga Cu deposit,located in the eastern porphyry belt of the Zhongdian arc,southwest China,provides a window into magmatic-hydrothermal processes controlling porphyry Cu mineralization.Based on zircon U-Pb geochronology,hydrothermal mineral chemistry,short-wave infrared spectroscopy,and mass balance modeling,this study investigated the alteration zonation and element mobility in the Disuga Cu deposit.Zircon U-Pb ages of the ore-hosting quartz dioritic porphyries(222.4±3.1 and 219.3±2.4 Ma)are similar to those of Late Triassic subduction-related magmatism.High zircon-crystallization temperatures(727±26℃)and elevated oxygen fugacity(ΔFMQ+2.0)confirm these porphyries were favorable for mineralization.Hydrothermal sericite(Si=6.49 atoms per formula unit[apfu];Al^(Ⅵ)=3.39 apfu)and chlorite(Fe/(Fe+Mg)=0.59-0.63)compositions indicate an acidic reduced fluid.Three distinct hydrothermal stages were identified:(1)phyllic alteration(370℃);(2)propylitic alteration(315℃);and(3)low-temperature hydrothermal alteration(242℃).Mass balance calculations show that the Cu migration rate(155.6%/114.4%)in the propylitic/phyllic alteration zones was higher than that of Mo(14.3%;limited to the propylitic alteration zone).The alteration mineralization assemblages indicate the occurrence of deep potassic alteration zones and porphyry Cu-(Mo)mineralization in the Disuga area.
基金jointly supported by the Selection Project of High-level Scientific and Technological Talents and Innovative Teams Project in Yunnan Province(202305AT350004-4)the National Natural Science Foundation of China(42362010 and 42464005)+3 种基金the Field Scientific Observation and Research Station of Mountain Agroecosystem in the Lower Reaches of Nujiang River,Yunnan Province(202305AM340031)the Yunnan Provincial Department of Education Science Research Fund Project(2025J0983)the Wen Bang-chun Academician Workstation in Yunnan Province(202205AF150032)the Undergraduate Innovative Training Program(2310603235).
文摘1.Objective.The Yidun arc within the Tethys-Himalaya metallogenic belt formed during the westward subduction of the Ganzi-Litang Ocean(237-206 Ma)during the Indosinian period,and then underwent the evolution stages of the collisional orogeny(206-138 Ma)and the post-collisional orogeny(135-75 Ma).In recent years,a series of large and medium-sized Late Yanshanian intracontinental porphyry-skarn Mo-Cu-W deposits have been discovered in the southern part of the Yidun arc,including Xiuwacu,Relin,Hongshan,Tongchanggou,and Donglufang(Fig.1a).
基金supported by the National Science and Technology Major Project(No.2024ZD1001005)the National Natural Science Foundation of China(No.42172103)+2 种基金the Natural Science Foundation of Hubei Province(Nos.2023AFD206,2024AFD401,2025AFD439,2025AFD452)the Research Fund Program of Hubei Key Laboratory of Resources and Eco-Environment Geology(Nos.HBREGKFJJ-202302,HBREGKFJJ-202402)the State Key Laboratory of Geological Processes and Mineral Resources(No.GPMR202424)。
文摘Dabie-type porphyry Mo deposits were proposed as a new type of porphyry Mo deposits,and had unique geological characteristics.It is still poorly understood about the magmatic processes that led to the Dabie-type Mo mineralization.Here,we present zircon U-Pb and Lu-Hf isotopic,whole-rock and biotite elemental,and whole-rock Sr-Nd isotopic analyses on the Lingshan granitic batholith in the Dabie Orogen.It consists of three units(ⅠtoⅢ)that were emplaced before,genetically accompanied with,and after the Mo mineralization.LA-ICP-MS zircon U-Pb dating yielded crystallization ages of 128.2±1.0 Ma(MSWD=1.14)for UnitⅠand ages of 127.8±1.2 Ma(MSWD=0.28)and 126.6±1.8 Ma(MSWD=1.6)for UnitⅡ,indicating that they were emplaced during 130 to 125 Ma.The granites have high SiO_(2)contents(75.84 wt.%to 78.94 wt.%)and low MgO contents(0.07 wt.%to 0.10 wt.%),and are classified as fractionatedⅠ-type granite.UnitsⅠandⅡhave similar Sr-Nd isotopic ratios(ε_(Nd)(t)=-16.2 to-17.2,(^(87)Sr/^(86)Sr)_(i)=0.70540 to 0.70692)and zirconε_(Hf)(t)values(-17.4 to-20.4),indicating they were derived from partial melting of the ancient Yangtze lower crust.Mo mineralized granite from UnitⅡis characterized by the lower oxygen fugacity,fluorine enrichment and high fractionation.Magmas of unitsⅠandⅡhave experienced fractional crystallization,with the assimilation of supracrustal materials that account for the increased TiO_(2),F and Mo contents,and the decreased fO_(2).We proposed that the assimilation in upper-crustal magmatic processes plays key factors for magmatic systems that led to the Dabie-type porphyry Mo deposits.
基金jointly funded by the National Natural Science Foundation of China(Nos.42230813,41972084)the National Key R&D Program of China(No.2022YFC2905000)the Everest Scientific Research Program of the Chengdu University of Technology(No.2020ZF11407)。
文摘The Early Paleozoic porphyry-epithermal Au system of the Songshunangou District sits in the central segment of the North Qilian orogenic belt(NQOB).The porphyry Au mineralization is centered on the quartz diorite porphyry(QDP),which is constrained to the Late Ordovician period.However,the geochemical signatures,the origin,and the tectonic setting of the QDP are not yet known and understood and are thus in the focus here.The QDP is a high-K calc-alkaline metaluminous rocks(K_(2)O+Na_(2)O:6.90-8.13;Al_(2)O_(3)/(CaO+Na_(2)O+K_(2)O):0.69-0.90)characterized by high(^(87)Sr/^(86)Sr)_(t)values(0.7093-0.7101)and lowε_(Nd)(t)values(-2.9 to-2.7)with corresponding T_(DM2)(Nd)ages of 1408 to 1430 Ma.Zirconε_(Hf)(t)values are low(-1.51 to+2.76)with corresponding T_(DM2)(Hf)ages of 1262 to 1533 Ma.The lead isotope values are 17.695-18.476 for(^(206)Pb/^(204)Pb)_(t),15.585-15.629 for(^(207)Pb/^(204)Pb)_(t),and 37.214-37.948 for(^(208)Pb/^(204)Pb)_(t).These data indicate that the QDP formed by the mixing of mantle-derived magmas(50%-70%)with lower crustal melts.The QDP is enriched in LREEs and LILE(Rb,Th,K)and is depleted in HFSE(Nb,Ta,Ti),expressing a clear volcanic arc affinity.High La and Th contents,and Zr/Y and Hf/Yb values suggest that the QDP formed in an Andean-type continental margin arc setting related to the northward subduction of the North Qilian oceanic slab.The Early Paleozoic subduction-related intermediate-acidic intrusions in NQOB have arc magma affinity,indicating that these rocks bear a great potential to discover further fertile porphyry deposits.
基金supported by Yunnan Major Scientific and Technological Project(202202AG050006)National Natural Science Foundation of China(42362010)The Open Fund of Key Laboratory of Sanjiang Metallogeny and Resources Exploration and Utilization,Ministry of Nature Resources(ZRZYBSJSYS2022002)。
文摘The Bainiuchang Ag-polymetallic ore deposit,located in southeastern Yunnan,China,is one of the region's largest deposits.However,the hyp abyssal granite porphyry within this mining area has yet to be comprehensively investigated.In this study,we conducted geochemical,geochronological,whole-rock Sr-Nd isotope,and zircon Hf isotope analyses on granite porphyry samples collected from the Bainiuchang deposit.The results indicate that the granite porphyry formed between 87.5 and 87.4 Ma in the Late Yanshanian period.Geochemically,the granite is strongly peraluminous,with high silica and alkali contents consistent with S-type granite characteristics.The granite porphyry is enriched in large-ion lithophile elements(Rb,Th,U,and K)and is relatively depleted in Ba and Sr.The initial ^(87)Sr/^(86)Sr ratios are high(0.71392-0.71585),accompanied by low ε_(Nd)(t)values(-8.9 to-8.2).The zircons exhibited similarly low ε_(Hf)(t)values(-9.31 to-3.6).These data suggest that the porphyry-forming magma originated from a continental crustal source.The two-stage Hf and Nd model ages are estimated at 1534-1216 Ma and 1615-1561 Ma,respectively.Thus,the granite porphyry likely formed under a strike-slip extensional setting in the Late Yanshanian period and resulted from the re-melting of Proterozoic basement metagreywackes.This porphyry shares a similar magmatic origin with concealed granite bodies within the deposit and is associated with structural reactivation during the Yanshanian.The findings of this study provide valuable insights into the tectonomagmatic mineralization processes in the B ainiuchang area.
基金supported by the National Natural Science Foundation of China(Nos.42162013,42002095)the Foundation of State Key Laboratory of Nuclear Resources and Environment(Nos.2022NRE34,NRE2021-01)+1 种基金Jiangxi Provincial Natural Science Foundation(Nos.20242BAB26048,20242BAB25178)Fund of National Key Laboratory of Science and Technology on Remote Sensing Information and imagery Analysis,Beijing Research Institute of Uranium Geology(No.6142A01210405)。
文摘The Yangchuling porphyry W-Mo deposit(YPWD),located in the Jiangnan porphyryskarn tungsten ore belt,is one of the most important and large-scale porphyry W-Mo deposits in South China.While previous zircon U-Pb and molybdenite Re-Os data suggest that Yangchuling WMo ore bodies formed almost simultaneously with granodiorite and monzogranitic porphyry at~150–144 Ma,their post emplacement history remains poorly understood,making their preservation status at depth uncertain.In this paper,new zircon and apatite(U-Th)/He and apatite fission track(ZHe,AHe and AFT,respectively)data of one hornfels and five intrusive rocks from a 1000-meter borehole are presented.These,together with new inverse thermal history models and previous geochronological data,help elucidate the post-diagenetic exhumation history and preservation status of the Yangchuling porphyry W-Mo deposit.In general,ZHe and AHe ages decrease gradually from the near surface downwards and have relatively little intra-sample variation,ranging from 133 to 73Ma and 67 to 25 Ma,respectively.All four granodiorites yield similar AFT ages that range from 63 to 55 Ma with mean track lengths varying from 12.2±0.7 to 12.6±0.5μm.Thermal history modelling indicates that the Yangchuling ore district experienced slow,monotonic cooling since the Cretaceous.Age-depth relationships are interpreted as recording~3.7±0.8 km of Cretaceous-recent exhumation in response to regional extension throughout South China thought to have been driven by subduction retreat of the Paleo-Pacific Plate.Comparison of estimated net exhumation and previous metallogenic depth of~4–5 km suggests that W-Mo ore bodies could still exist at depths of up to~1.3±0.8 km relative to Earth surface in the YPWD region.Preservation of the YPWD is attributed to the limited amount of regional denudation during the Late Cretaceous and Cenozoic.
基金funded by the China Geological Survey(Grant Nos.DD20190379,DD20221695 and DD20221684)a collaboration program(2019-2024)between the Institute of Mineral Resources(Chinese Academy of Geological Sciences)and the Guangdong Dabaoshan Mining Co.,Ltd.
文摘The Dabaoshan porphyry Cu deposit(420 kilotons(kt)of Cu@0.36%)is located in South China.The newly discovered Cu orebodies are hosted in the dacite porphyry adjacent to a granodiorite porphyry.The alteration and mineralization timing and stages of the porphyry Cu deposit were not well-constrained.In this study,we combine field mapping,petrography,whole-rock geochemistry,hydrothermal rutile U-Pb dating and Cu isotopes to synthesize an ore model at Dabaoshan.In situ hydrothermal rutile U-Pb dating yields an age of 159±13 Ma,which brackets the timing of porphyry Cu mineralization.From top to bottom,the alteration zones in Dabaoshan are divided into quartz-sericite,biotite,chlorite-epidote,and chlorite-sericite subzones.Veins are classified into four stages(Stage 1 to 4)with Stage 4 quartz-sericite-chalcopyrite veins being the main Cu ore-bearing veins.The mineralized dacite porphyry has high SiO_(2),but low MgO,CaO,and Na_(2)O contents.The chalcopyrite hosted in veins exhibitsδ^(65)Cu=values ranging from−1.29‰to 0.51‰.Such copper isotope fractionation is attributed to vapor-brine phase separation,and mixing of fluids from different geochemical reservoirs.The timing of Cu mineralization and hydrothermal alteration support that the Jurassic granodiorite porphyry is an ore-forming intrusion at Dabaoshan.
基金financially supported by projects from the National Natural Science Foundation of China(No.42321001)the Qinghai Provincial Department of Science and Technology Key R&D Project(No.2025-SF-141)+1 种基金the Qinghai“Kunlun Talent”Program(Qing RC Talent Zi(2024)No.1)the Academician Zhao Pengda Innovation Center in Qinghai Geological Bureau of Nuclear Industry。
文摘0 INTRODUCTION The Haidewula uranium deposit is located in the Haidewula volcanic basin,which hosts a suite of basic,intermediate to felsic volcanic and subvolcanic rocks,including basalt,trachyte,trachyandesite.Previous geochronological studies of the intrusions within this volcanic basin suggest that they primarily formed during the Silurian and Triassic periods(Dai et al.,2025;Sun et al.,2024;Wang et al.,2024;Zhu et al.,2022;Lei et al.,2021).
基金funded by the National Key R&D Program of China(Grant No.2022YFC2905000)the NSFC(Grant No.42230813)+4 种基金the Opening Foundation of State Key Laboratory of Continental Dynamics,Northwest University(Grant No.23LCD12)the Opening Foundation of the Key Laboratory of Continental Dynamics of Ministry of Natural Resources(Grant No.J2408)the Sichuan Province Natural Science Foundation(Grant Nos.2024NSFSC1954,2025ZNSFSC1196)the Open Research Fund Program of Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring(Central South University),Ministry of Education(11300-502401003)the Everest Scientific Research Program of Chengdu University of Technology(Grant No.2024ZF11407).
文摘The key factor that controls the genesis of porphyry Cu deposits(PCDs)in collisional orogens remains a debated topic.This study employs whole-rock La/Yb proxies to quantitatively constrain the spatial and temporal variations in crustal thickness of the South Armenian-Iranian magmatic belt(SAIMB)within the Zagros orogen(central Tethys region)since the Eocene.Our results show that rapid crustal thickening occurred first in the NW section of the SAIMB at~35 Ma,then propagated southeastward into the central and SE sections at~25 Ma and 20 Ma,respectively,indicating that the Arabia-Eurasia collision was diachronous.The formation of the large and giant collision-related PCDs in the SAIMB might have been controlled by the collision process because they developed first in the NW section of the SAIMB and subsequently propagated southeastward into the central and SE sections.More importantly,crustal thickness mapping shows that the PCDs are preferentially developed in the thickened crust areas(>50 km).Our findings propose that thickened crust is critical for the formation of the PCDs in collisional orogens by promoting Fe^(2+)-rich minerals as a fractionating phase,driving magmatic auto-oxidation and releasing Cu into the magmas.The Cu is then partitioned into magmatic fluids,sustaining the porphyry systems.Furthermore,our research highlights that the thickened crust hosting PCDs was characterized by a previously thinner crust(<40 km),where magmas had low oxygen fugacity due to the absence of the auto-oxidation process.Consequently,chalcophile elements(e.g.,Cu)efficiently separated from the melt through sulfide segregation,forming large Cu-bearing lower-crustal cumulates.These cumulates can be mobilized with an increase in oxygen fugacity,incorporating into subsequent porphyry mineralization.We thus propose that the crustal thickness evolution over time controls the formation of the PCDs in collisional orogens.There are two essential stages in the collision-related PCDs formation:the first is high-flux magmatism in the thin crustal setting(<40 km),leading to metal-fertilized lower crust through sulfide segregation,and the second is the intracrustal auto-oxidation during crustal thickening(>50 km)which facilitates pre-enriched sulfides in the lower crust to re-dissolve,releasing Cu into the magmas.
基金financially supported by the National Key Research and Development Program of China(2019YFA0708602,2022YFF0800903)National Natural Science Foundation of China(42472112,U2244217,41973045)+1 种基金Basic Science and Technology Research Fundings of the Institute of Geology,CAGS(JKYZD202312)Geological Survey Projects of the China Geological Survey(DD20242878,DD20243512).
文摘Numerous intermediate to felsic igneous rocks are present in both subduction and collisional orogens.However,porphyry copper deposits(PCDs)are comparatively rare.The underlying factors that differentiate fertile magmas,which give rise to PCDs,from barren magmas in a specific geological setting are not well understood.In this study,three supervised machine learning algorithms:random forest(RF),logistic regression(LR)and support vector machine(SVM)were employed to classify metallogenic fertility in southeastern Tibet,Sanjiang orogenic belt,based on whole-rock trace element and Sr-Nd isotopic ratios.The performance of the RF model is better than LR and SVM models.Feature importance analysis of the models reveals that the concentration of Y,Eu,and Th,along with Sr-Nd isotope compositions are crucial variables in distinguishing fertile and barren samples.However,when the optimized models were applied to predict the datasets of Miocene Gangdese porphyry copper belt and Jurassic Gangdese arc representing collision and subduction settings respectively,a marked decline in metrics occurred in all three models,particularly on the subduction dataset.This substantial decrease indicates the compositional characteristics of intrusions across different tectonic settings could be diverse in a multidimensional space,highlighting the complex interplay of geological factors influencing PCD’s formation.
基金jointly funded by the national key research and development program project“Strategic Mineral Information and Metallogenic Regularity of the Tethyan Metallogenic Domain”(2021YFC2901803)a project of the National Natural Science Foundation of China entitled“Geological Structure Mapping and Regional Comparative Study of the Tethyan Tectonic Domain”(92055314),International Geoscience Programme(IGCP-741)a project initiated by the China Geological Survey(DD20221910).
文摘The porphyry copper belt in the Geza island arc in southwestern China is the only Indosinian porphyry copper metallogenic belt that has been discovered and evaluated so far.The Pulang porphyry copper deposit(also referred to as the Pulang deposit)in this area has proven copper reserves of 5.11×106 t.This deposit has been exploited on a large scale using advanced mining methods,exhibiting substantial economic benefit.Based on many research results of previous researchers and the authors’team,this study proposed the following key insights.(1)The Geza island arc was once regarded as an immature island arc with only andesites and quartz diorite porphyrites occurring.This understanding was overturned in this study.Acidic endmember components such as quartz monzonite porphyries and quartz monzonite porphyries have been identified in the Geza island arc,and the mineralization is mainly related to the magmatism of quartz monzonite porphyries.(2)Complete porphyry orebodies and large vein orebodies have developed in the Pulang deposit.Main orebody KT1 occurs in the transition area between the potassium silicate alteration zone of quartz monzonite porphyries and the sericite-quartz alteration zone.Most of them have developed in the potassium silicate alteration zone.The main orebody occurs as large lenses at the top of the hanging wall of rock bodies,with an engineering-controlled length of 1920 m and thickness of 32.5‒630.29 m(average:187.07 m).It has a copper grade of 0.21%-1.56%(average:0.42%)and proven copper resources of 5.11×10^(6) t,which are associated with 113 t of gold,1459 t of silver,and 170×10^(3) t of molybdenum.(3)Many studies on diagenetic and metallogenic chronology,isotopes,and fluid inclusions have been carried out for the Pulang deposit,including K-Ar/Ar-Ar dating of monominerals(e.g.,potassium feldspars,biotites,and amphiboles),zircon U-Pb dating,and molybdenite Re-Os dating.The results show that the porphyries in the Pulang deposit are composite plutons and can be classified into pre-mineralization quartz diorite porphyrites,quartz monzonite porphyries formed during the mineralization,and post-mineralization granite porphyries,which were formed at 223±3.7 Ma,218±4 Ma,and 207±3.9 Ma,respectively.The metallogenic age of the Pulang deposit is 213‒216 Ma.(4)The petrogeochemical characteristics show that the Pulang deposit has the characteristics of volcanic arc granites.The calculation results of trace element contents in zircons show that quartz monzonite porphyries and granite porphyries have higher oxygen fugacity.The isotopic tracing results show that the diagenetic and metallogenic materials were derived from mixed crust-and mantle-derived magmas.
基金supported jointly by the National Natural Science Foundation Fund of China(Grant No.40930418)ChineseGovernment-funded Scientific Programmed of SinoProbe Deep Exploration in China(SinoProbe-03)the Basic Scientific Research-fund of Institute of Mineral Resources,Chinese Academy of Geological Sciences(Grant No.K1008)
文摘Located in Lu-Zong ore concentration area, middle-lower Yangtze metallogenic belt, ShaXi porphyry copper deposit is a typical hydrothermal deposit. To investigate the distribution of deep ore bodies and spatial characteristics of host structures, an AMT survey was conducted in mining area. Eighteen pseudo-2D resistivity sections were constructed through careful processing and inversion. These sections clearly show resistivity difference between the Silurian sandstones formation and quartz diorite porphyry and this porphyry copper formation was controlled by the highly resistive anticlines. Using 3D block Kxiging interpolation method and 3D visualization techniques, we constructed a detailed 3D resistivity model of quartz diorite porphyry which shows the shape and spatial distribution of deep ore bodies. This case study can serve as a good example for future ore prospecting in and around this mining area.
基金financially supported by the Study on mineralization background and conditions of copper-gold in the western part of Bangongco-Nujiang metallogenic belt of Ministry of land and resources of Public industry research and special projects(201011013)Opening Foundation of Key Laboratory of Tectonic Controls on Mineralization and Hydrocarbon Accumulation,Ministry of Land and Resources(gzck2013006)Tectonic metallogeny theory development and practice team fund of Sichuan Province(13TD0008)
文摘The Naruo porphyry copper-gold deposit （hereinafter referred to as the Naruo deposit） in Tibet is a potentially ultra-large, typical gold-rich porphyry copper deposit, which was recently discovered in the Bangongco-Nujiang metallogenic belt. This study analyzed U-Ph chronology and Hf isotopes of the ore-bearing granodiorite porphyry in the Naruo deposit using the LA-ICPMS dating technique. The results show that the weighted average age is 124.03±0.94Ma （MSWD=1.7, n=20）, and 2±6pb/23SU isocbron age is 126.2±2.7 Ma （MSWD=1.02, n=20）, both of which are within the error. The weighted average age represents the crystallization age of the granodiorite porphyry, which indicates that the ore-bearing porphyry in the Naruo deposit area was formed in the Early Cretaceous and further implies that the Neo-tethys Ocean had not been closed before 124 Ma under a typical island-arc subduction environment. The εGr（t） of zircons from the granodiorite porphyry varies from 2.14 to 9.07, with an average of 5.18, and all zircons have εRf（t） values greater than 0; 176Hf/177Hf ratio is relatively high （0.282725-0.282986）. Combined with the zircon age--Hf isotope correlation diagram, the aforementioned data indicate that the source reservoir might be a region that is mixed with depleted mantle and ancient crust, which possibly contains more materials sourced from depleted mantle. Rock-forming ages and ore-forming ages of the Duolong ore concentrate area are 120-124 Ma and 118-119 Ma, respectively, which indicate 124-118 Ma represents the main rockforming and ore-forming stage within the area. The Naruo deposit is located in the north of the Bangongco-Nujiang suture, and it yielded a zircon LA-ICPMS age of 124.03 Ma. This indicates the Bangongco-Nujiang oceanic basin subducted towards the north at about 124 Ma, and the Neo-tethys Ocean had not been closed before the middle Early Cretaceous. It is possible that the crust-mantle mixing formed the series of large and giant porphyry copper-gold deposits in the Bangongco.
基金financially supported by National key research and development program of China:2016YFC0600308Chinese Geological survey project No.121201010000150014,1212011221073,12120114050701
文摘The newly discovered Zhunuo porphyry Cu-Mo-Au deposit is located in the western part of the Gangdese porphyry copper belt in southern Tibet,SW China.The granitoid plutons in the Zhunuo region are composed of quartz diorite porphyry,diorite porphyry,granodiorite porphyry,biotite monzogranite and quartz porphyry.The quartz diorite porphyry yielded zircon U-Pb ages of 51.9±0.7 Ma(Eocene)using LA-ICP-MS,whereas the diorite porphyry,granodiorite porphyry,biotite monzogranite and quartz porphyry yielded ages ranging from 16.2±0.2 to 14.0±0.2 Ma(Miocene).CuMo-Au mineralization is mainly hosted in the Miocene granodiorite porphyry.Samples from all granitoid plutons have geochemical compositions consistent with high-K calc-alkaline series magmatism.The samples display highly fractionated light rare-earth element(REE)distributions and heavy REE distributions with weakly negative Eu anomalies on chondrite-normalized REE patterns.The trace element distributions exhibit positive anomalies for large-ion lithophile elements(Rb,K,U,Th and Pb)and negative anomalies for high-field-strength elements(Nb and Ti)relative to primitive mantlenormalized values.The Eocene quartz diorite porphyry yieldedεNd(t)values ranging from-3.6 to-5.2,(-(87)Sr/-(86)Sr)i values in the range 0.7046–0.7063 and initial radiogenic Pb isotopic compositions with ranges of 18.599–18.657-(206)Pb/-(204)Pb,15.642–15.673-(207)Pb/-(204)Pb and 38.956–39.199-(208)Pb/-(204)Pb.In contrast,the Miocene granitoid plutons yieldedε(Nd)(t)values ranging from-6.1 to-7.3 and(87Sr/86Sr)i values in the range 0.7071–0.7078 with similar Pb isotopic compositions to the Eocene quart diorite.The Sr-Nd-Pb isotopic compositions of the rocks are consistent with formation from magma containing a component of remelted ancient crust.Zircon grains from the Eocene quartz diorite haveε(Hf)(t)values ranging from-5.2 to+0.9 and two-stage Hf model ages ranging from 1.07 to 1.46 Ga,while zircon grains from the Miocene granitoid plutons haveε(Hf)(t)values from-9.9 to+4.2 and two-stage Hf model ages ranging from 1.05–1.73 Ga,indicating that the ancient crustal component likely derives from Paleo-to Mesoproterozoic basement.This source is distinct from that of most porphyry Cu-Mo-Au deposits in the eastern part of the Gangdese porphyry copper belt,which likely originated from juvenile crust.We therefore consider melting of ancient crustal basement to have contributed significantly to the formation Miocene porphyry Cu-Mo-Au deposits in the western part of the Gangdese porphyry copper belt.
文摘: Zinccopperite (tentatively named) is a rare native alloy mineral discovered in quartz monzonite—porphyry in the Xifanping area, Yanyuan County, Sichuan Province. It is a new variety of zinc—copper alloy mineral found for the first time in the porphyry-copper deposit in China. Its intergrown minerals are K—feldspar (mainly perthite), albite—oligoclase, quartz and biotite; and the associated minerals include pyrite and chalcopyrite. It is characterized by a golden reflection colour, being isotropic (isometric), with the grain size ranging from 10 to 50 μm, microhardness VHN10 = 190 kg/mm2, and reflectance RVM = 67.97%. Electron microprobe (Model JXA—733) analysis shows Cu = 59.15%–62.55% and Zn = 36.32%–39.85%. The crystallochemical formula is Cu6.27-7.0Zn4.0, simplified as Cu7Zn4.
基金supported by the "Researches of tectonics, magmatism evolution, and metallogeny in the Gangdese belt, Tibet" Program of China Geological Survey (1212010818098)
文摘We have determined the ages of the ore-bearing Tinggong porphyries and the Eocene granites using the LA-ICPMS zircon U-Pb method.Zircons from one adamellite porphyry and two diorite porphyries yield ages of 15.54±0.28 Ma,15.02±0.25 Ma and 14.74±0.22 Ma,respectively.The ages of two granites are 50.48±0.71 Ma and 50.16±0.48 Ma.Light Rare Earth Elements （LREE） are enriched in the ore-bearing adamellite porphyries,which are high-K caic-alkaline and metaluminous,while Heavy Rare Earth Elements （HREE） and Y are strongly depleted,indicating an adakitic affinity.The Large Ion Lithophile Elements （LILE） of the adamellite porphyries are highly enriched,whereas some High Field Strength Elements （HFSE） are depleted.The diorite porphyry in this study is chemically similar to the adamellite porphyries,except that the Mg# of the diorite porphyry is a little higher,demonstrating more mantle contamination.Four samples from different rocks are selected for in situ zircon Hf isotopic analyses.The samples show positive εHf（t） values and young Hf model ages,indicating their derivation from juvenile crust.However,the adamellite porphyry and diorite porphyry formed in the Miocene exhibit more heterogeneous Hf isotopic ratios,with lower （Σ）Hf （t） values than the granites formed in the Eocene,suggesting the involvement of old Indian continent crust in their petrogenesis.The geochronology and geochemistry of the adamellite porphyries and the diorite porphyries indicate that they formed from the same source region in a post-collisional environment,but contaminated by crust and mantle materials in different ratios.The metallic minerals formed mainly during the older adamellite porphyry stage,but they were recycled and reactivated by the diorite porphyry intrusion.
基金supported by grants from the National Key Research and Development Program of China(Grant Nos.2016YFC0600310 and 2019YFA0708602)the National Natural Science Foundation of China(Grant Nos.41702091,41872083 and 42022014)+2 种基金the Yunnan Applied Basic Research Project(Grant No.202101AT070073)the China Fundamental Research Funds for the Central Universities(Grant No.2652018133)the Scientific Research Fund of the Yunnan Provincial Education Department(Grant No.2022Y016)。
文摘The Habo deposit is a typical porphyry Cu-Mo deposit in the Ailaoshan–Red River metallogenic belt.Ore minerals in the Habo deposit typically occur as veins in the monzonite porphyry.Zircon U-Pb dating suggests that the monzonite porphyry formed at 35.07±0.38 Ma.The monzonite porphyry is characterized by high SiO_(2),Al_(2)O_(3),K_(2)O and Na_(2)O contents,with A/CNK ratios ranging from 0.97 to 1.02.All samples exhibit fractionated REE patterns,characterized by high(La/Yb)N ratios(9.4–13.6,average of 11.2).They show adakite-like geochemical features,high Sr concentrations(627–751 ppm,average of 700 ppm),low Y concentrations(15.13–16.86 ppm,average of 15.81 ppm)and high Sr/Y values(39.5–47.4,average of 44.3).These samples have high initial^(87)Sr/^(86)Sr ratios(0.7074–0.7076)and negativeεNd(t)values(-5.1 to-3.7),whereas the zirconεHf(t)values range from-2.2 to+0.4,suggesting that the monzonite porphyry was derived from the partial melting of a thickened juvenile lower crust.The oxygen fugacity,calculated on the basis of the chemical composition of the amphiboles,shows?NNO values ranging from+1.65 to+2.16(average of 1.94)and lg(fO_(2))ranging from-12.72 to-11.99(average of-12.25),indicating that the monzonite porphyry has high oxygen fugacity.Zircons have high Ce^(4+)/Ce^(3+)ratios(29.29–164.24,average of 84.92),with high?FMQ values ranging from+0.50 to+1.51(average of 0.87)and high lg(fO_(2))values ranging from-14.72 to-12.85(average of-14.07),which also indicates that the oxygen fugacity of the magma was high.The dissolved water content of the Habo monzonite porphyry is 9.5–11.5 wt%,according to the geochemical characteristics,zircon-saturation thermometry(692–794°C)and the mineral phases(amphibole,no plagioclase)in the deep magma chamber.Combined with previous studies,we propose that the high oxygen fugacity and high water content of magma played key roles in controlling the formation of the Habo and other Cu-Mo-Au deposits in the Ailaoshan–Red River metallogenic belt.
基金This study was jointly funded by a project of the National Natural Science Foundation of China(42102087)a project of the China Postdoctoral Science Foundation(2022M712966)a key special project of the Ministry of Science and Technology of China(2021QZKK0304).
文摘The Daheishan supergiant porphyry molybdenum deposit(also referred to as the Daheishan deposit)is the second largest molybdenum deposit in Asia and ranks fifth among the top seven molybdenum deposits globally with total molybdenum reserves of 1.65 billion tons,an average molybdenum ore grade of 0.081%,and molybdenum resources of 1.09 million tons.The main ore body is housed in the granodiorite porphyry plutons and their surrounding inequigranular granodiorite plutons,with high-grade ores largely located in the ore-bearing granodiorite porphyries in the middle-upper part of the porphyry plutons.Specifically,it appears as an ore pipe with a large upper part and a small lower part,measuring about 1700 m in length and width,extending for about 500 m vertically,and covering an area of 2.3 km^(2).Mineralogically,the main ore body consists of molybdenite,chalcopyrite,and sphalerite horizontally from its center outward and exhibits molybdenite,azurite,and pyrite vertically from top to bottom.The primary ore minerals include pyrite and molybdenite,and the secondary ore minerals include sphalerite,chalcopyrite,tetrahedrite,and scheelite,with average grades of molybdenum,copper,sulfur,gallium,and rhenium being 0.081%,0.033%,1.67%,0.001%,and 0.0012%,respectively.The ore-forming fluids of the Daheishan deposit originated as the CO_(2)-H_(2)O-NaCl multiphase magmatic fluid system,rich in CO_(2)and bearing minor amounts of CH4,N2,and H2S,and later mixed with meteoric precipitation.In various mineralization stages,the ore-forming fluids had homogenization temperatures of>420℃‒400℃,360℃‒350℃,340℃‒230℃,220℃‒210℃,and 180℃‒160℃and salinities of>41.05%‒9.8%NaCleqv,38.16%‒4.48%NaCleqv,35.78%‒4.49%NaCleqv,7.43%NaCleqv,and 7.8%‒9.5%NaCleqv,respectively.The mineralization of the Daheishan deposit occurred at 186‒167 Ma.The granites closely related to the mineralization include granodiorites(granodiorite porphyries)and monzogranites(monzogranite porphyries),which were mineralized after magmatic evolution(189‒167 Ma).Moreover,these mineralization-related granites exhibit low initial strontium content and high initial neodymium content,indicating that these granites underwent crust-mantle mixing.The Daheishan deposit formed during the Early-Middle Jurassic,during which basaltic magma underplating induced the lower-crust melting,leading to the formation of magma chambers.After the fractional crystallization of magmas,ore-bearing fluids formed.As the temperature and pressure decreased,the ore-bearing fluids boiled drops while ascending,leading to massive unloading of metal elements.Consequently,brecciated and veinlet-disseminated ore bodies formed.
基金supported by the Chinese National Science Fund for Distinguished Young Scholars to Dr.Gao Jian-Feng(42025301).
文摘The Dexing porphyry deposit is the largest porphyry Cu–Mo–Au deposit in South China.Biotite composition can record the physicochemical conditions and evolution history of magmatic-hydrothermal system.Biotite from the Dexing porphyry deposit could be divided to three types:primary magmatic biotite(Bi-M),hydrothermal altered magmatic biotite(Bi-A)and hydrothermal biotite(Bi-H).The temperature of Bi-M and Bi-H range from 719 to 767℃ and 690 to 727℃,respectively.Both magmatic and hydrothermal biotite have high Fe^(3+)/Fe^(2+)ratios(from 0.18 to 0.24)and XMgvalues(from 0.57 to 0.66),indicating a high oxygen fugacity.BiM has F lower than Bi-A and Bi-H(up to 0.26 wt%),but has Cl(Cl=0.18–0.30 wt%)similar to Bi-A and Bi-H(Cl=0.21–0.35 wt%),suggesting that high Cl/F ratios of early hydrothermal fluid may result from the exsolution from high Cl magma.From potassic alteration zone to phyllic and propylitic alteration zones,Cl decreases with increasing Cu,whereas F increases roughly.Therefore,Cl mostly originate from magma,but enrichment of F possibly results from reaction of fluids and Neoproterozoic strata.Negative correlation between Cl and Cu indicates that Cl might act as an important catalyst during Cu mineralization process.Biotite from Dexing has similar halogen compositions to other porphyry Cu-/Mo deposits in the world.Chlorine contents of hydrothermal fluid may be critical for Cu transportation and enrichment,while consumption of Cl would promote Cu deposition.
文摘The term“porphyry”has a specific geological meaning but has been used freely by sculptors and art historians to name many types of stone that are not,geologically,porphyries.“Porphyries”have been associated with nobility and Imperial Monuments since Roman times.This paper discusses some examples from Karelia in Russia and from Sweden used in St Petersberg and the use of Russian Shoksha“porphyry”in Paris,France.It highlights several types of stone that have been referred to as porphyries but are not.The Shoksha stone has been of architectural and artistic importance both nationally and internationally for some 300 years.This might qualify it as a candidate for Global Heritage Stone Resource status.
