Epithermal deposits are important sources of nonferrous and precious metals as well as rare and critical metal resources such as indium. Due to their vectors toward deep porphyry mineralization, they have attracted the attentions of global geologists. The continental margin of Northeast China is one of the areas where epithermal ore deposits are widespread, characterized by epithermal Au and Ag-Pb-Zn-Cu polymetallic deposits being occur. According to the deposit geology, these epithermal-type deposits in Northeast China were divided into three types, low-sulfidation type (LS), intermediate-sulfidation type (IS) and high-sulfidation type (HS). The mineralization occurred in the Late Jurassic to Early Cretaceous volcanic basins and uplift areas spatially close to granite complex margins, comprising four separated mineralizationstages as a function of time, including (1) 151 to 141 Ma, (2) 140 to 131 Ma, (3) 123 to 120 Ma, and (4) 110 to 100 Ma. Stage 1 is restricted in the eastern portion of the Great Xing’an Range, characterized by regional epithermal HS copper polymetallic deposits. Stage 2 is developed in the western portion of the Great Xing’an Range, where large-scale epithermal LS-IS Ag-Pb-Zn mineralization. Stage 3 occurs in middle portion between the north of the Great Xing’an Range and the Lesser Xing’an Range and in Yanbian and western Liaoning, characterized by epithermal IS Cu and LS Te-Au mineralization. Stage 4 occurs in the Northern Great Xing’an Range-the Lesser Xing’an Range-Raohe-Dongning-Yanbian area. There is a younger mineralization time from the eastern portion of the Great Xing’an Range-the western portion of the Great Xing’an Range-the northern margin of the North China platform (Liaoxi+Yanbian)-the northern margin of the eastern portion of the Great Xing’an Range (Heihe) to the northern portion of the Great Xing’an Range-the Lesser Xing’an Range-Wanda Mountains-Taiping Mountains-Yanbian. There is a transition in mineralization type, from Cu polymetallic to Ag-Pb-Zn to Cu-Au + Te-Au to Au (± Sb) +large-scale Au and Cu. The tectonic environments for the various mineralization are related to the episodic subduction of ate Mesozoic Paleo-Pacific plate towards the eastern end of Eurasia, in which there is a transition from compressional to crustal extensional conditions. Except the mineralization in the Yanbian area occurring in the late stage of intermediate-basic volcanic eruption-hypabyssal emplacement, the remnant mineralization formed in the late stage of bimodal volcanic eruption-hypabyssal emplacement. Considering the genetic relation between epithermal metallic and porphyry Cu and Mo mineralization, the early-stage epithermal Ag-Pb-Zn-Cu mineralization and the coeval porphyry mineralization constitute the porphyry Mo-epithermal Ag-Pb-Zn system, whereas the epithermal LS Ag-IS Pb-Zn-HS Cu polymetallic and porphyry Cu-Mo mineralization constitute the porphyry Mo-Cu-epithermal Ag-Pb-Zn hydrothermal system. Similarly, the intermediate- and late-stage epithermal Au mineralization and Au-rich porphyry Cu mineralization constitute the Au-rich porphyry Cu-epithermal IS Cu-Au hydrothermalsystem and the Au-rich porphyry Cu-epithermal IS Cu-Au-epithermal HS Au (Cu) hydrothermal system. Nevertheless, more evidence is needed to clarify whether the epithermal LS Te-Au, Sb-Au, and Au deposits are individual ore system or not. Late Mesozoic epithermal ore systems are the results  the underplating of mantle-sourced basaltic magmas and their interactions with lower-crustal magmas during a roll-back of subducting slab and a thinning crust episode from Late Jurassic to Early Cretaceous.

 Due to its unique physical and chemical properties, cobalt is widely used in modern advanced technology fields, so some countries have listed it as an important strategic critical resource. There are few independent cobalt deposits, and co-associated deposits are the main cobalt deposits. China is a country with relatively poor cobalt resources, with external dependence exceeding 90.0%. Many large and medium cobalt deposits have been discovered and explored in northeast China, including Cu-associated deposits and Cu-Ni-Fe co-associated deposits. Therefore, it is necessary to further summarize its metallogenic geological characteristics, analyze its resource potential, and provide a reference for future exploration. In this paper, cobalt deposits are classified into four main types, i.e., sedimentary-metamorphic type, magmatic type, marine volcano-sedimentary-metamorphic type, and skarn type. The sedimentary-metamorphic type and magmatic type cobalt deposits are widely distributed, mainly in the Paleoproterozoic Liaoning-Jilin rift zone. Combined with the geological characteristics of typical deposits, regional geochemical and geophysical characteristics, 28 prospect areas were further delineated, including 4 prospect areas of class A, 8 prospect areas of class B, and 16 prospect areas of class C. Finally, four class A prospect areas are recommended as the priority areas to focus on in the deployment of prospecting and exploration in the future.

 Lengshuigou Cu-Mo-Au deposit is located in the Shanyang-Zhashui ore concentration area, and is one of the representative deposits of the Late Mesozoic porphyry-skarn Cu(Mo) deposits in the South Qinling orogenic belt. In addition to the porphyry-skarn Cu-Mo mineralization, structural-altered rock-type Au mineralization in the Lengshuigou deposit is also developed, but there are always doubts about whether there is a genetic connection between Cu-Mo mineralization and Au mineralization. Therefore, Re-Os dating of molybdenite from the porphyry-skarn Cu-Mo mineralization and 40Ar-39Ar dating of altered potassium feldspar and sericite from structural-altered rock-type Au mineralization were carried out, respectively, in order to be able to pass mineralization ages to determine their genetic relationship between the two mineralization types. The results show that the Re-Os isochron age of molybdenite is (147.4±8.4) Ma, the 40Ar-39Ar ages of the altered potassium feldspar and sericite are 144 Ma, and these ages are consistent within the error range. It indicates that the porphyry-skarn Cu-Mo mineralization and structural-altered rock-type Au mineralization were formed in the Late Jurassic-Early Cretaceous, and they are the products of the same mineralization and magmatic events in the South Qinling orogenic belt. Combined with the regional tectonic evolution, the results show that the Lengshuigou Cu-Mo-Au deposit was formed in the background of the tectonic regime transition of the Qinling orogenic belt during the Late Mesozoic. In addition, the metallogenic epoch of Lengshuigou Au mineralization also shows that the Late Jurassic-Early Cretaceous Au mineralization existed in the South Qinling orogenic belt, which has important indicative significance for regional gold exploration.

 The Jiapigou mining district (JMD) is famous in the world for its numerous quartz vein- and altered rock-type gold deposits. The gold deposits in the JMD belong to mesothermal gold deposits and are characterized by fluids with moderate temperature and low salinity, Middle Jurassic mineralization, and genesis related to synchronic magmatism. In order to depict the process of synchronic magmatism-hydrothermalism, and tace the process of Au mineralization in this region, we present the deposit geology, petrology, and mineralogy, geochronology, and geochemistry of zircon from the Binghugou gold deposit in the JMD. The results show that: 1) Gold mainly occurs in cements of the shattered breccia; 2) Based on the morphology, internal structure, trace element composition, and U-Pb age, the zircons in the cements of the hydrothermal breccia and breccia-type ore can be divided into the captured (Group Ⅰ: 195-185 Ma), inherited (Group Ⅱ: 175-172 Ma) and hydrothermal zircons (Group Ⅲ: 176-173 Ma), and the U-Pb age of the hydrothermal zircons (Group Ⅲ) at 176-173 Ma indicating that Au mineralization occurred in the Middle Jurassic; 3) The zircons in the Groups Ⅱ-Ⅲ have low w(Y) values and high Y/Ho ratios, indicating that the late stage granitic melts coexist with the P- and Ti-rich hydrothermal fluids, and have systematic trends between w(Hf)-Th/U and w(Hf)-Yb/Gd, indicating that magma experienced gradual cooling and differentiation, and finally formed hydrothermal fluid; 4) The Ce/Ce* and Eu/Eu* ratios of the Group Ⅱ zircons are obviously higher than those of the Group Ⅲ zircons, indicating that the magma has high oxygen fugacity, and the hydrothermal fluid has low oxygen fugacity, while the values of the incompatible elements (P, Y, LREE, Nb, Th, and Pb*) gradual increase with the increase of the values of w(Hf) of the zircons (from the Group Ⅱ to Ⅲ), indicated that incompatible elements gradually entered the hydrothermal fluid phase and enriched during magmatic differentiation and magmatic-hydrothermal transition. Combined the geological observations, the magma is characterized by high temperature, high oxygen fugacity and volatile-rich components, which hindered the crystallization of sulfides in the early stage of its evolution, and promoted the enrichment of Au, S, Fe and incompatible elements in the late stage of its evolution/ hydrothermal fluid, resulting in the formation of the initial ore-bearing fluids. In the process of upward migration, abundant gold and sulfides precipitated from the ore-bearing fluids due to its unstable state caused by the intense fluid-rock interaction and decrease of pressure, temperature and oxygen fugacity, resulting in the formation of gold deposit. Combined with the regional metallogenic setting, ore geology, element geochemistry, ore-bearing fluid, and chronology of magmatism and mineralization, the above geological process is likely to have resulted in the giant gold mineralization observed in the JMD.

The Jiapigou gold ore concentration area, located in the collage section between the northeastern margin of the North China craton and the Xing’an-Mongolian orogenic belt, is one of the most important gold-producing areas in China. However, the origin of the ore-forming fluids and genetic types of the gold deposits in the Jiapigou gold ore concentration area  are still widely disputed. Moreover, there is still a chronic lack of systematic research on evolution of the ore-forming fluids and ore-forming mechanism. To address the problems above, this paper selects the most representative Sandaocha gold deposit in the Jiapigou gold ore concentration area  as an example to carry out a detailed analysis of fluid inclusions, laser Raman spectroscopy and H-O isotopes. Four stages of mineralization have been identified in the Sandaocha gold  deposit: (Ⅰ) milky quartz, (Ⅱ) quartz-pyrite, (Ⅲ) quartz-polymetallic sulfide, and (Ⅳ) quartz-carbonate. The stages Ⅱ and Ⅲ represent the main gold mineralization. Three types of primary fluid inclusions (FIs) are identified in quartz formed at different stages: NaCl-H2O-CO2 (C-type), NaCl-H2O (W-type) and pure CO2 (PC-type). The early-stage quartz contains C- and W-type FIs, which have homogenization temperatures of 283-411 ℃ and salinities of 4.26%-17.48% NaCl equiv. The main-stage quartz contains all three types of FIs, with homogenization temperatures of 210-288 ℃ and salinities of 2.07%-15.76% NaCl equiv. The late-stage quartz contains only W-type FIs with homogenization temperatures of 131-210 ℃ and salinities of 2.57%-14.04% NaCl equiv. The H-O isotope results indicate that the initial ore-forming fluid is the mixture of magmatic water and a small amount of meteoric water, and the meteoric water was continuously added to the ore-forming fluids during mineralization. The ore-forming fluid system evolved from a moderate-temperature and moderate- to low-salinity NaCl-H2O-CO2 system in the early stage to a NaCl-H2O system with a low temperature and salinity in the late stage. Water-rock interactions generally occurred between ore-forming fluids and metamorphic wall-rocks during fluids migration. The sudden decompression and the addition of meteoric water led to fluid immiscibility and the exsolution of CO2, H2S, and other volatiles. This process destroyed the stability of Au-S complexes and facilitated the precipitation of gold and other ore-forming elements. Comprehensive studies of geology, fluid inclusions and H-O isotopes confirm that the Sandaocha gold deposit is a mesothermal hydrothermal vein gold deposit.

 Duhuangling gold deposit is one of the high-sulphidation epithermal gold deposits in  Yanji area, northeast China, where a large number of Early Cretaceous igneous rocks are developed. In order to understand the magmatism, magma sources and ore-forming condition of  Duhuangling gold deposit, integrated with the results of previous research, we conducted trace element analyses of zircons from the ore-bearing quartz diorite, granodiorite and granodiorite porphyry in ore district. The majority of zircons possess high Th/U values (>0.1), and their chondrite-normalized REE patterns of all zircons are characterized by HREE enrichment relative to LREE and MREE with distinctive positive Ce and negative Eu anomalies, which are typical of magmatic zircons. All the zircons yield different Ti-in-zircon temperatures, with most zircon crystals between 700 to 900 ℃. Zircon trace elements provide that the ore-bearing rocks were derived from the partial melting of the lower crustal materials and formed in the arc environment related to the plate subduction. In addition, the zircon grains have higher Ce4+/Ce3+ values and lower temperature in the melt of ore-forming granodiorite porphyry than pre-ore rocks, indicating that granodiorite porphyry has high oxygen fugacity, water contents and ore-forming potential. Therefore, the difference in magmatic oxygen fugacity and water contents may be the reasons why the quartz diorite and granodiorite are not mineralized

 Yidong Linchang gold polymetallic deposit is a recently discovered gold deposit in Lesser Xing’an range. The volcanic-subvolcanic rocks are widely distributed in the mining area, among which the diorite porphyrite and dacite are closely related to the mineralization. In this contribution, we reported petrogeochemistry，zircon U-Pb ages and Sr, Nd and Hf isotope compositions of the diorite porphyrite and dacite at Yidong Linchang gold polymetallic deposit. Geochemical studies show that the volcanic-subvolcanic rocks closely related to mineralization are peraluminous calc-alkaline volcanic rocks. All these rocks have arc magma characteristics related to subduction and are enriched in LREEs and weak negative Eu anomaly, enriched in large-ion lithophile elements (Rb, Ba) and incompatible elements (Th, U), and relatively depleted of high field-strength elements (Nb, P and Ti). Zircon U-Pb ages of diorite porphyrite and dacite are (99.60±0.62) Ma and (98.50±0.50) Ma, respectively, both formed in the Early Cretaceous. Sr-Nd-Hf isotope analysis showed that the samples have high (87Sr/86Sr)i ratios (0.707 20-0.707 70), low εNd(t) values (-3.47--2.42) and εHf(t) values (-2.22-4.11), revealing that the source area is mainly mantle with the strong contamination of crustal materials. Research results reveal that the diorite porphyrite and dacite in Yidong Linchang gold polymetallic deposit were formed in the continental arc environment of the active continental margin. The magmas were likely derived from deep-formed magmas by the partial melting of the overlying mantle wedge by the fluids released by the dehydration of the subducting Pacific Oceanic plate, and are strongly contaminated by the crust during the evolution process. On the basis of the above research and combined with the regional geological background, it is inferred that the volcanic-subvolcanic rocks of the Early Cretaceous were formed in the tectonic background of lithospheric extension as a consequence of the rollback of the subducted Paleo-Pacific Oceanic plate.

Laozuoshan gold deposit in Heilongjiang Province is a large-scale gold deposit located in the north-central part of Jiamusi block, Xing-Meng orogenic belt. The ore bodies are closely related to skarn, and hosted in the contacting belt between granodiorite and calcium marble and gneiss schist of Mashan Group, as well as in the ore-controlling structures such as the NW and NWW-trending extensional fractures. The studies of deposit geology, petrography, zircon U-Pb isotope chronology and geochemical characteristics reveal that Laozuoshan gold deposit develops two superimposed mineralization stages, including the skarn-type mineralization in late Middle Permian of Variscan and the hydrothermal mineralization in Yanshan Peried. The skarn-type mineralization during the main metallogenic period is closely related to the granodiorite, and its diagenetic age is (262.6±3.9) Ma. The Variscan granodiorite in this deposit is a kind of weak peraluminous and high potassium calc-alkaline rock series, characterized by high w(SiO2), low Mg# value and MgO, with features of enrichment of large ion lithophile elements and light rare earth elements, while depletion of high field strength elements and heavy rare earth elements, showing the characteristics of I-type granite, and the magma source originates from partial melting of crustal materials. The comprehensive studies show that the Variscan skarn-type mineralization and magmatism occurred during the transition period of the tectonic regime from ocean-continent subduction to continental collision, and the granodiorite is the product of partial melting of crustal materials.

Baituyingzi molybdenum deposit is located in the south of the Xilamulun molybdenum metallogenic belt, which is a new exploration discovered medium porphyry type molybdenum deposit in recent years. This paper reports the geological characteristics, Re-Os age of molybdenite, fluid inclusions and H-O-S-Pb isotope data of  Baituyingzi molybdenum deposit to determine its metallogenic age and fluid characteristics. Molybdenum mineralization mainly exists in veinlet-disseminated, breccia-type and vein-type forms in Indosinian granite porphyry. The Re-Os isochron age of (245.4 ± 4.1) Ma for the molybdenite indicates that molybdenum mineralization occurred in the Middle Triassic. Four types of inclusions were identified: gas-liquid two-phase inclusions (W), CO2-bearing three-phase inclusions (C),  daughter crystals-bearing three-phase inclusions (S) and pure gas-phase inclusions. The Ore-forming fluid in the early stage of mineralization belongs to the CO2-H2O-NaCl system with medium-high temperature and medium-low salinity, while the main mineralization stage is characterized by medium temperature, high-salt and low-salinity coeval, and the gas-phase composition is gradually transformed into H2O-based. The fluid undergoes immiscibility during the ore-forming process, accompanied by the separation and precipitation of a large number of metal minerals. With the continuous reduction of temperature and pressure, and the addition of atmospheric water, the fluid evolved into H2O-NaCl system with medium-low temperature and low salinity and low CO2 in the late stage of mineralization. Combined with the H-O-S-Pb isotopic data, it is believed that the ore-forming materials are mainly derived from the mantle, the crust-derived materials are added in the late stage of mineralization, and the source of the crust-mantle mixture as a whole. The ore-forming fluid is derived from magmatic hydrothermal solution in the early stage, atmospheric water is added in the late stage. Therefore, we suggest that  Baituyingzi porphyry-type molybdenum deposit was formed in the post-orogenic extension environment in the Early-Middle Triassic. The source of the ore-forming materials in porphyry molybdenum deposits is mainly crust-mantle mixed or crust, while the source of ore-forming materials of copper is mantle. The oxygen fugacity and pH value of the fluid are two of the main factors for the precipitation of molybdenite.

Jinya gold deposit is one of the typical Carlin-type gold deposits in the “Golden Triangle” area of Yunnan, Guizhou and Guangxi provinces. The ore bodies are obviously controlled by fault structures and are mainly layered, pod-shaped, and lenticular in argillaceous siltstone and silty mudstone of the Middle Triassic Baifeng Formation. In order to explore the metallogenic fluid properties and mineralization mechanism, the petrographic study, micro temperature measurement and Laser Raman spectroscopy analysis on the fluid inclusions in the study area were carried out. The metallogenic hydrothermal process of this deposit can be divided into three metallogenic stages: Quartz-pyrite stage (Ⅰ), pyrite-arsenopyrite stage (Ⅱ) and quartz-carbonate stage (Ⅲ), and stage Ⅱ is the main metallogenic stage. The petrographic study of fluid inclusions shows that the fluid inclusions in the metallogenic period are mainly two-phase vapor inclusions, and the liquid phase is mainly water; The gas composition is mainly CO2, N2, SO2 and CH4, and the average homogenization temperature from Ⅰ stage to Ⅲ stage is 189, 157, and 137 ℃, respectively; The average w(NaCleq) is 6.01%, 4.18%, and 2.01% in sequence. The initial ore-forming fluid is characterized by H2O-NaCl system fluid with medium-low temperature, low salinity, low density and contains volatile components such as CO2, N2 and SO2. In the early stage of mineralization, the hot brine in the basin with medium-high temperature and reducibility had a strong water-rock reaction with the surrounding strata, activating and migrating Au and S; In the main metallogenic period, the ore-forming fluid continuously flows upward driven by abnormally high pressure and faulting activities, and reacts with Fe and other elements in dolomite to form pyrite and arsenopyrite. At the same time, it mixes with atmospheric precipitation, the temperature and salinity drop rapidly, and Au and other ore-forming elements are unloaded in large quantities. In the late stage of mineralization, the ore-forming elements in the fluid were consumed, the atmospheric precipitation continued to mix in, the temperature and salinity dropped significantly, and the mineralization ended. The mineralization mechanism is fluid mixing and water-rock reaction.

 Tuolahaihe graphite deposit is the first super-large scale crystalline graphite deposit discovered in Qinghai Province, which is located in the southern margin of Qaidam basin and the middle part of East Kunlun. The ore bodies appear in bedded and near bedded within gneiss, calcareous gneiss, quartz schist and marble of the Lower Proterozoic Jinshuikou Group, which belong to a typical gneiss graphite deposit. In order to discuss ore genesis, detailed petrography, whole-rock geochemistry and isotope geochemistry studies have been carried out on the ore-bearing strata. The results show that ΣREE in graphite gneiss and graphite quartz schist containing graphite is 82.95×10-6-154.86×10-6,enriched in light rare earth elements, with obvious Eu negative anomaly and weak Ce negative anomaly, showing the protoliths formed in anoxic depositional environment of the shallow sea at the continental margin. The protoliths of ore-hosting metamorphic rocks are organic-rich sandy rocks, greywacke and calcium silicate rocks, and the material sources are mainly terrigenous debris and a small amount of them are shallow marine carbonate rocks. The δ13C isotopic composition of graphite gneiss and marble indicating that   the carbon in graphite comes from bioorganic carbon, while and carbon of marble is inorganic carbon. Tuolahaihe graphite deposit is a regional metamorphic graphite deposit that formed in Paleoproterozoic.

 The Middle Jurassic acidic volcanic-subvolcanic rocks are widely distributed in  Derbur area of the northern part of the western slope of the Great Xing’an Range. The rock assemblages are mainly composed of rhyolite, rhyolitic lithic tuff and quartz porphyry, and no systematic chronological and geochemical studies have been carried out on their diagenetic age, petrogenesis and diagenetic dynamic mechanism. In this paper, petrography, LA-ICP-MS zircon U-Pb dating, geochemistry and zircon Hf isotope studies were carried out on the rhyolites in  Biliya leal-zine polymetallic mining area. LA-ICP-MS single grain zircon U-Pb concordance age is (164.2±1.6) Ma (MSWD=7.7, n=14), belongs to Middle Jurassic. They have relatively high contents of major elements Si, K and Al, and belong to high-K, calc-alkaline and peraluminous rock series. Trace elements show that they are enriched in large ion lithophile elements, weakly enriched in high field strength elements, and obviously depleted in Ba, Sr, Ti and other elements.The ratios of Nb/Ta, Zr/Hf and Th/U are 13.05-22.36, 39.57-43.57 and 3.37-3.51, respectively. There are negative Eu anomalies in REE (the values of  δEu are 0.69-0.76), the ratios of LaN/YbN, La/Ce and La/Yb are  9.95-10.12, 0.48-0.50 and 14.13-15.05, respectively. In addition, they also have low 10 000Ga/Al (2.33-2.34) and (K2O+Na2O)/Cao (9.54-9.96) ratios. According to the calculation of Ti element in zircon, the saturation temperatures of zircon are between 683 and 756 ℃. These characteristics indicate that the Middle Jurassic rhyolite has the property of I-type rhyolite, and the diagenetic magma has the characteristics of volcanic arc or active continental margin magma. The 176Hf/177Hf ratios in zircons are 0.282 853-0.282 990, the corresponding εHf(t) values range from 6.22 to 10.83, and the two-stage Hf model ages range from 734.2 to 474.0 Ma, which are similar to the one-stage Hf model ages (592.6-410.1 Ma), indicating that their diagenetic magma is mainly derived from the partial melting of the juvenile lower crust. The magma was contaminated by crustal materials during the process of emplacement or diagenesis, and constituted the characteristics of “bimodal volcanic rocks” with the contemporaneous intermediate-basic volcanic rocks in this area. Combined with the temporal and spatial distribution of regional magmatic rocks and the evidence of geophysical data, it is further believed that the diagenetic geodynamic background of the Middle Jurassic acid lavas (rhyolite, rhyolitic lithic tuff and quartz porphyry) in this area is closely related to the passive continental margin which influenced by the subduction of the paleo-Pacific plate into Eurasia.

 Longgang volcanic area is located in Huinan and Jingyu County, Eastern Jilin Province, and is an important part of the Quaternary continental volcanic rock area on the continental margin of Northeast China. In order to further explore the genesis and tectonic significance of basaltic lava in the study area, based on field geological investigation, Rb-Sr isotopic dating, element geochemistry and whole rock Pb isotopic analysis were carried out. The experimental results show that: 1) The Rb-Sr isochron age of whole rocks, plagioclase and amphibole from seven trachybasalt lava samples is (1.81 ± 0.34) Ma (MSWD=0.17, n=7). 2) The values of Na2O + K2O in trachybasaltic lavas range from 6.44% to 6.65%, with high A/CNK (1.24-1.27) and Mg# (39.09-39.81) values. Compared with the primitive mantle, the trachybasaltic lavas significantly enriched in Rb, Ba, Sr and other large ion lithophile elements (LILE), enriched in light rare earth elements (LREE), weakly enriched high field strength elements (HFSE) such as Nb, Ta, Zr, Hf, U and Th, depleted heavy rare earth elements (HREE), with weak Eu anomalies (δEu=0.95-1.07) and weakly enriched in Pb. 3) The (87Sr/86Sr) i values in the studied rocks range from 0.705 074 to 0.705 206, and the ratios of 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb in the whole rocks are 17.984-18.329, 15.490-15.523 and 38.315-38.400, respectively. Combined with the recent research results and the existing understanding of regional tectonic evolution, it shows that the diagenetic age of basaltic lava is the Calabrian stage of the Early Pleistocene. The diagenetic magma is mainly formed by mantle-derived magma, with a small amount of young lower crust components added, showing the attributes of oceanic island basalts (OIB) or intraplate metasomatic basalt. In addition, the formation of trachybasaltic lava and its associated volcanic activity occurred in an extensional tectonic environment at about 1.81 Ma, which may be related to the roll-back after the subduction of the Pacific plate under the northeastern Eurasia continent.

In order to further understand the origin and tectonic setting of basaltic dyke related to Middle and Late Pleistocene volcanic activities in the Heishigou area of Tianchi volcano, based on remote sensing interpretation and field geological investigation, the  geochemistry, whole rock Sr-Nd isotope and geochronology analysis of the basaltic dykes were carried out. The results show that: 1) The major elements of the dykes have relatively high MgO, CaO, K2O and relatively low Na2O, belonging to the series of potassium, metaaluminous and subalkaline basalts. They are enriched in LILEs, such as Li, Cs, Be, Rb, Ba and Sr, and weakly enriched in HFSEs, such as Nb, Ta, Zr, Hf, U and Th, and the corresponding ratios of Zr/Hf, Nb/Ta and Th/U are 40.92-45.10, 15.77-16.34 and 3.49-3.76, respectively. 2) The values of (87Sr/86Sr)i and (143Nd/144Nd)i in the whole rocks range from 0.704 570 to 0.704 690 and 0.512 552 to 0.512 571, respectively, the εNd (t) values range from 0.87 to 1.45. The K-Ar isotopic ages of (0.35-0.34 Ma) obtained by previous research in dykes and tectonic-magmatic evolution together suggest that the basaltic magmatism occurred in the Chibanian stage of Late Pleistocene, and the diagenetic parent magma has the characteristics of enriched Ⅰ-type mantle source, with a small amount of lower crust components were added during the ascent of the magma, showing the characteristic of ocean island basalt (OIB). The formation of the basalt dykes and the contemporaneous volcanic activities occurred in a compressional tectonic environment at 0.35-0.34 Ma, which may be related to the rollback or subsidence of the Pacific plate after it was subducted into the northeastern Eurasia continent.

 Hydrothermal copper mineralization in the Dashihu-Dataizi area of Ji’an area, southern Jilin Province is closely related to the intermediate-acid complexes such as monzonite diorite, diorite porphyrite, monzonite porphyry and syenite granite. In order to determine the lower limit of metallogenic ages and geodynamic background, the lithography, zircon U-Pb isotopic geochronology, geochemistry and zircon Lu-Hf isotope of the medium-acid complex have been studied on the basis of field investigation. The results reveal that monzonite diorite, diorite porphyrite, monzonite porphyry and syenite granite are all products of the Early Cretaceous magmatism, and the zircon U-Pb crystallization ages are (122.7±1.8)(122.0±1.9)(120.1±1.5) and (121.4±1.9) Ma, respectively. The magma emplacement of the mineralized system occurred in the Early Cretaceous (122.7-120.1 Ma), indicating that the mineralization age of the Dashihu-Dataizi copper mineralization area was later than or approximately equal to 120.1 Ma. The geochemical data reveal that they are all enriched in light rare earth elements (LREEs) and large ion lithophile elements (LILEs), relatively depleted in high field strength elements (HFSEs) such as Nb, Ta and Ti, and the Eu anomaly is not obvious. All of them present high potassium calc-alkaline quasi-aluminous rocks, which are the products of different evolutionary sequences of homologous magmas. The results of zircon Lu-Hf isotope analysis shows that εHf(t) values of monzonite diorite range from -7.5 to -5.2 and TDM2 range from 1 647 to 1 500 Ma, and εHf(t) values of syenite granite range from -13.1 to -4.2 and TDM2 range from 2 004 to 1 445 Ma， fLu/Hf ranges from -0.99 to -0.95, indicating that the magma originated from the partial melting of ancient crustal materials in the Mesoproterozoic, during which there was the addition of mantle end-member materials, and the ancient materials were mixed during the ascent and emplacement of the syenogranite magma. Combined with relevant research results, it is concluded that the Early Cretaceous granitic magmatism in the study area was formed in the extensional environment formed by the subduction and roll-back of the Paleo-Pacific plate to Eurasia.

 The southern part of Jilin is located in the eastern section of the northern margin of the North China craton, which has experienced a long geological evolution in the Archean, Proterozoic, Paleozoic, Mesozoic and Cenozoic. The alkali-feldspar granite enriched in rare earth elements in the Late Mesozoic is widely developed in this area. In this paper, the Dachuan granite enriched in rare earth elements was selected to carry out petrography, zircon U-Pb dating and Hf isotope, petrogeochemistry analysis. The results show that the granite is mainly composed of fine-grained, medium-grained and coarse-grained biotite alkali-feldspar granite, followed by granite-pegmatite. The main elements have the characteristics of high silicon (w (SiO2) =72.56%-84.09%), low aluminum (w (Al2O3) =8.15%-14.76%), quasi aluminum-strong peraluminum (A/CNK= 0.98-1.60), belonging to the high potassium calc-alkaline series. The samples have a high rare earth mass fraction (w (ΣREE) =88.53×10-6-839.95×10-6), (La/Yb)N=2.30-41.24, enriched in light rare earth elements, depleted in heavy rare earth elements. The partition pattern of rare earth elements is right-leaning type, with obvious negative Eu anomaly and δEu value ranging from 0.05 to 0.60. The differentiation index (ID=86.72-97.69) is high, and the consolidation index (IS=0.16-1.13) is low, indicating that the magma evolution has experienced different degrees of separation and crystallization of plagioclase, biotite, apatite and other minerals. Combined with the petrographic characteristics, the Dachchuan alkali-feldspar granite is preliminarily considered as highly differentiated granite. The single zircon U-Pb isotopic age of coarse-grained biotite alkali feldspar granite is (120.8±1.6) Ma. The εHf(t) values of zircons are all negative (-10.7--5.2), and the corresponding Hf isotope second-order model ages of the zircons are 2 587-2 090 Ma. Based on isotope and petrogeochemical data, the initial magma originated from partial melting of the Neoarchean and Paleoproterozoic continental crust, and the rock mass was the product of magma emplacement after magma crystallization differentiation in the homologous magma chamber. Mineral identification and whole rock trace elements show that with the evolution of magma, the quartz content gradually increased, the biotite content gradually decreased, and the total rare earth contents also gradually decreased. The rare earth elements are mainly enriched in coarse-grained biotite alkali feldspar granite phase.

 The Early Jurassic medium-grained syenogranite in Kaoshan area of central Jilin Province is exposed in the southern part of Zhangguangcai range, and emplaced in contact with the Middle Triassic granitoids and Devonian-Carboniferous intrusive rocks. Its main rock-forming minerals are composed of K-feldspar, quartz, plagioclase and biotite. In order to explore the diagenetic age, geochemical characteristics and geodynamic background of the granites in Kaoshan area, we carried out petrographic, chronological, geochemical and Hf isotope studies on the Early Jurassic non-orogenic A-type medium-grained syenogranite exposed in the study area. Zircon U-Pb geochronology and geochemical studies show that: The concordant age of the medium-grained syenogranite in the study area is (193.2±0.9) Ma, and the diagenetic time should be attributed to the Early Jurassic. It has a high SiO2 (75.49%-75.82%) and total alkali (8.28%-9.17%) mass fraction, together with high A/CNK (1.08-1.13), LREE (20.89×10-6-46.38×10-6) and FeO/MgO (3.29-5.83) values. It is also enriched in large ionic lithophile elements (LILE, such as Rb, K and Pb) and high-field strength elements (HFSE, such as Th, U, Hf, Nb and Zr). It has low MgO (0.06%-0.14%), TiO2 (0.05%-0.12%), P2O5 (0.02%-0.04%), Sr (24.20×10-6-62.59×10-6), HREE (5.14×10-6-11.80×10-6) mass fraction and medium δEu (0.41-0.56) value, which is similar to the lithogeochemical characteristics of non-orogenic A-type granite.  Hf isotopic analysis results of zircons show that the εHf (t) values range from 9.7 to 15.7, and the two-stage Hf-isotope model ages (TDM2) range from 612 to 225 Ma. Combined with the regional research data, we think the diagenetic parent magma of the medium-grained syenogranite in the Kaoshan area was probably derived from the juvenile lower crust in an extensional environment. The tectonic environment of asthenosphere mantle upwelling and back-arc extension caused by the subduction of the early paleo-Pacific plate, may be an important geodynamic factor for the Early Jurassic non-orogenic A-type granitic magmatism in the study area.

The monzogranite in the Jiazishan of Inner Mongolia is located in the middle part of the Daxing’anling Mountains. To determine its intrusive age and tectonic environment, the geochronology and petrogeochemistry of the monzogranite have been systematically studied. The results show that the zircon U-Pb age of the monzogranite is (302.9±1.2) Ma, which is the product of Late Carboniferous magmatism. The monzogranite is characterized by high silica (w (SiO2)=74.73%-76.60%), rich alkali (w (Na2O+K2O)=6.20%-7.03%) and high aluminum saturation index (A/CNK=1.43-1.58), belonging to the high-K calc-alkaline series. Rb, K, Th and U are enriched, while Ba, Sr, Ti, Nb and P are obviously V-shaped depleted. The REE pattern shows a right-leaning enrichment type of LREE, with negative Eu anomaly (δEu=0.46- 0.67). The high differentiation index (ID) (88.89-91.55) and low solidification index (IS) (1.68-4.78) indicate that the monzogranite has undergone the evolution of high differentiation and is a type highly differentiation I-type granite with a tendency to evolve to A-type granite. The 176Hf/177Hf value is 0.282 850-0.282 951, the εHf (t) value is 9.2-12.5, and the two-stage mode age (TDM2) is 910-603 Ma, suggesting that the monzogranite may be the product of partial melting of juvenile crust in Neoproterozoic. The monzogranite in the Jiazishan area of Inner Mongolia was formed in the post-orogenic stage, and its formation may be related to the transformation of the tectonic setting from extrusion to post-collisional extension after the closure of the Paleo-Asian Ocean.