Metallogenic Epoch and Tectonic Setting of Saima Niobium Deposit in Fengcheng, Liaoning Province, NE China

The mineralization within the North China Craton (NCC) is intricately linked to Mesozoic large-scale extension in eastern China and is a consequence of a unified geodynamic tectonic background. Despite previous attempts to elucidate the relationship between large-scale mineralization and magmatic activity in the NCC, a lack of systematic research has hindered the identification of connections among deposits with inconsistent metallogenic ages. This study focuses on the coal measures of the Huanghebei Coalfield (HHBC) in western Shandong, presenting a regional magmatic–hydrothermal metallogenic system with a genetic connection. It delves into the intricate interplay between the multi-mineral enrichment mechanism, metallogenic regularity, and the NCC’s destruction. The findings reveal that: (1) Various stages of magmatic intrusion during the Yanshanian period significantly influenced the Late Paleozoic coal measures in the HHBC. The coal measures exhibit distinct ranks, ranging from medium-rank bituminous C to A and high-rank anthracite C, resulting in noticeable differences in gas generation among different coal ranks. The shale between the coal seams C5 and C7 emerges as excellent with a good hydrocarbon-generating capacity during the middle-maturity stage. (2) The “Intrusion along the rock layer type” proves most conducive to shale gas enrichment, while the “laccolith type” is more favorable for shale gas enrichment compared to “dike type” intrusions, which have a limited impact on shale gas enrichment. (3) The mineralization process of CBM, shale gas, and iron ore is influenced by Yanshanian-period magma. The enrichment degree of CBM and shale gas exhibits an inverse correlation with the distance from the magmatic intrusion. Iron deposits demonstrate a close association with the magmatic intrusion, with enhanced enrichment along the rock layer. The results indicate that the destruction of the NCC triggered intense metasomatism in the deep cratonic fluids, serving as the primary driving mechanism for large-scale mineralization during the Yanshanian period. Magmatic intrusions bring hydrothermal fluids conducive to mineralization, and the heat release from these intrusions promotes thermal evolution, hydrocarbon generation, and the enrichment of organic-rich strata.

Section: The Relationship Between Ncc Destruction and The Mineralizat...mentioning

confidence: 99%

Magmatic Intrusion during the Yanshanian Period and Multi-Mineral Enrichment Mechanisms in the Eastern Margin of the North China Craton

Yin,

Wang,

Wang

et al. 2024

“…The migration and concentration of ore-forming elements were facilitated by these faults (Figure 1). [7]).…”

Section: Geological Settingmentioning

confidence: 99%

“…The intrusive rocks in the Chang'anbu Mo deposit are early Yanshanian quartz diorites, diorites-granodiorites, adamellites-syenogranites, and alkali feldspar granites-alkali granites [7]. These are calc-alkaline rocks with mixed crust and mantle sources.…”

Section: Chang'anbu Mo Depositmentioning

confidence: 99%

See 1 more Smart Citation

Source and Tectonic Setting of Porphyry Mo Deposits in Shulan, Jilin Province, China

Zhang

Kou

et al. 2019

Self Cite

The Shulan area in Jilin Province is a part of the Lesser Xing’an–Zhangguangcai Range polymetallic ore belt, which is an important Cu–Mo ore region of northeast China. The discovery of three large Mo ore deposits (Fu’anbu, Chang’anbu, and Jidetun) highlights its potential for porphyry Mo ore deposits. Here we investigated the tectonic setting and mineralization of Mo ore deposits in the Shulan area, based on comparative study of the Fu’anbu, Chang’anbu, and Jidetun deposits. The ore-controlling structures are NE–SW- and NW–SE-trending faults. The main ore mineral in all three deposits is molybdenite. The ore bodies are all hosted in granites, have a stratiform or lenticular shape, and have strongly altered wall rocks. These observations indicate the Mo deposits in the Shulan area are typical porphyry Mo deposits. All were formed during the early Yanshanian (199.6–133.9 Ma). Biotite adamellites from the Chang’anbu deposit yield a U–Pb age of 182.10 ± 1.20 Ma. Molybdenites from the Fu’anbu and Jidetun deposits have Re–Os isochron ages of 166.9 ± 6.7 and 169.1 ± 1.8 Ma, respectively. Quartz and ore minerals were analysed for H–O and S–Pb isotopes, respectively. The results suggest the ore-forming materials were predominantly of upper-mantle origin, with secondary contributions from the lower crust. The ore-hosting granites have high concentrations of SiO2 (66.67–75.43 wt.%) and Al2O3 (12.91–16.44 wt.%), low concentrations of MgO (0.09–1.54 wt.%), and Ritman index (σ = K2O + Na2O)2/(SiO2 − 43)) ratios of 2.09–2.57. The granites are enriched in large-ion lithophile elements and depleted in high-field-strength elements, and have negative Eu anomalies. The ore-hosting rocks are geochemically similar to granites in northeastern China that were generated in a collisional orogeny. We conclude that early Yanshanian (199.6–133.9 Ma) mantle–crust-derived magmatism caused by the subduction of the Palaeo-Pacific Plate was the main source of Mo deposits in the Shulan area.

“…In addition, garnet Sm-Nd dating is conducted on the Hongshan skarn deposits to further constrain the timing of skarn formation in Zu et al [27]. The emplacement ages and geochemical and isotopic signatures of ore-related intrusions are also proved to be genetically linked with the formation of mineral deposits [28][29][30][31][32][33][34].…”

mentioning

confidence: 99%

Editorial for Special Issue “Polymetallic Metallogenic System”

Yang

2019

In the last century, following the development of Earth System Science, the metallogenic system has become an important topic in the study of mineral deposits. The term "metallogenic system" firstly presented in 1970s, connotes a natural system with ore-forming functions [1]. The metallogenic system includes geological factors controlling ore-formation and preservation, and ore-forming processes and their products-ore deposit series and anomaly series [1]. It emphasizes the integration of tectonic settings, controlling factors, metallogenic mechanisms, and conditions and mechanisms of post-mineralization transformation and preservation (i.e., the source, transport, trap, transformation, and preservation). On the basis of the theory of the metallogenic system, Deng et al. [2][3][4] defined the composite metallogenic system and summarized the distribution and characteristics of composite metallogenic systems in China.While economic geology typically focuses on the differences between individual deposits, the metallogenic system looks for broad similarities in each system [5]. The metallogenic system model allows for multiple mineralization styles to be identified within a single system [5]. For example, a porphyry copper system may develop associated high and low sulfidation epithermal gold mineralization, and skarn-type or hydrothermal vein-type Cu-Pb-Zn-Ag mineralization [6][7][8]. By integrating all geological ingredients and processes that are necessary for the formation of mineral deposits, the investigation of the metallogenic system is more useful for revealing the geodynamic evolution of a region, and more effective for regional prospecting exploration [9][10][11] From the perspective of regional metallogeny, the study by Niu et al. [12] relates deep dynamic processes in the Earth to gold deposits at the crustal surface (core → mantle → crust) in Jiaodong Province. Zircon Hf and whole-rock Nd isotopic mapping presented in Zhang et al. [13] precisely illustrate the controls of lithospheric architecture on the distribution of regional polymetallic mineralization. Liu et al. [14] and Wei et al. [15] propose the main gold deposition mechanisms by studying the fluid inclusions and corresponding H-O-S isotopic compositions of different ore-forming stages in the Sanshandao and Sizhuang gold deposits, respectively. Zhao et al. [16] classifies the Koka gold deposit in NE Africa as an orogenic gold deposit based on the similar features of geology and ore-forming fluids.The study by Chen et al. [17] describes the occurrence of texturally heterogeneous gold-hosting quartz types and variations in trace element geochemistry, offering a more multi-generational perspective on precipitation mechanisms that fluid inclusion studies may not be able to offer. Guo et al. [18] investigates the rare earth element geochemistry and C-O isotope characteristics of hydrothermal calcites to provide new insights into the fluid-rock interactions and ore-forming processes. Li N. et al. [19] present a textural and trace-element analysi...