Self-activated, Nanostructured Composite for Improved CaL-CLC technology

The development of bifunctional CaO/CuO matrix composites with both high and stable reactivity is a research priority and key for the development of calcium looping integrated with chemical looping combustion (CaL-CLC), a new CO2 capture technology that eliminates the requirement for pure O2 for the regeneration of CaO-based sorbents. In this work, a simple but effective approach was first used, i.e., solution combustion synthesis (SCS), to produce various nanostructured CaO/CuO matrix composites with homogenous elemental distributions. All CaO/CuO matrix composites possessed increased CO2 uptake in the form of self-activation and excellent cyclically stable O2 carrying capacity over as many as 40 reaction cycles. For instance, the final carbonation conversion of CaO-CuO-1-800-30 was 51.3%, approximately 52.7% higher than that of the original material (33.6%). Here, the self-activation phenomenon have been observed for the first time in contrast to the rapid decay in CO2 uptake capacity previously reported, due mainly to the increase of both specific surface area and pore volume. In-situ X-ray diffraction (in-situ XRD) analysis revealed that no side reactions occurred between CaO/CaCO3 and CuO/Cu during the overall process. All of these results make CaO/CuO matrix composites an attractive candidate for CaL-CLC

Aridity-driven shift in biodiversity–soil multifunctionality relationships

From Springer Nature via Jisc Publications RouterHistory: received 2021-01-07, accepted 2021-08-12, registration 2021-08-25, pub-electronic 2021-09-09, online 2021-09-09, collection 2021-12Publication status: PublishedFunder: National Natural Science Foundation of China (National Science Foundation of China); doi: https://doi.org/10.13039/501100001809; Grant(s): 31770430Abstract: Relationships between biodiversity and multiple ecosystem functions (that is, ecosystem multifunctionality) are context-dependent. Both plant and soil microbial diversity have been reported to regulate ecosystem multifunctionality, but how their relative importance varies along environmental gradients remains poorly understood. Here, we relate plant and microbial diversity to soil multifunctionality across 130 dryland sites along a 4,000 km aridity gradient in northern China. Our results show a strong positive association between plant species richness and soil multifunctionality in less arid regions, whereas microbial diversity, in particular of fungi, is positively associated with multifunctionality in more arid regions. This shift in the relationships between plant or microbial diversity and soil multifunctionality occur at an aridity level of ∼0.8, the boundary between semiarid and arid climates, which is predicted to advance geographically ∼28% by the end of the current century. Our study highlights that biodiversity loss of plants and soil microorganisms may have especially strong consequences under low and high aridity conditions, respectively, which calls for climate-specific biodiversity conservation strategies to mitigate the effects of aridification

Major types and time–space distribution of Mesozoic ore deposits in South China and their geodynamic settings

The ore deposits of the Mesozoic age in South China can be divided into three groups, each with different metal associations and spatial distributions and each related to major magmatic events. The first event occurred in the Late Triassic (230–210 Ma), the second in the Mid–Late Jurassic (170–150 Ma), and the third in the Early–Mid Cretaceous (120–80 Ma). The Late Triassic magmatic event and associated mineralization is characterized by peraluminous granite-related W–Sn–Nb–Ta mineral deposits. The Triassic ore deposits are considerably disturbed or overprinted by the later Jurassic and Cretaceous tectono-thermal episodes. The Mid–Late Jurassic magmatic and mineralization events consist of 170–160 Ma porphyry–skarn Cu and Pb–Zn–Ag vein deposits associated with I-type granites and 160–150 Ma metaluminous granite-related polymetallic W–Sn deposits. The Late Jurassic metaluminous granite-related W–Sn deposits occur in a NE-trending cluster in the interior of South China, such as in the Nanling area. In the Early–Mid Cretaceous, from about 120 to 80 Ma, but peaking at 100–90 Ma, subvolcanic-related Fe deposits developed and I-type calc-alkaline granitic intrusions formed porphyry Cu–Mo and porphyry-epithermal Cu–Au–Ag mineral systems, whereas S-type peraluminous and/or metaluminous granitic intrusions formed polymetallic Sn deposits. These Cretaceous mineral deposits cluster in distinct areas and are controlled by pull-apart basins along the South China continental margin. Based on mineral assemblage, age, and space–time distribution of these mineral systems, integrated with regional geological data and field observations, we suggest that the three magmatic–mineralization episodes are the result of distinct geodynamic regimes. The Triassic peraluminous granites and associated W–Sn–Nb–Ta mineralization formed during post-collisional processes involving the South China Block, the North China Craton, and the Indo-China Block, mostly along the Dabie-Sulu and Songma sutures. Jurassic events were initially related to the shallow oblique subduction of the Izanagi plate beneath the Eurasian continent at about 175 Ma, but I-type granitoids with porphyry Cu and vein-type Pb–Zn–Ag deposits only began to form as a result of the breakup of the subducted plate at 170–160 Ma, along the NNE-trending Qinzhou-Hangzhou belt (also referred to as Qin-Hang or Shi-Hang belt), which is the Neoproterozoic suture that amalgamates the Yangtze Craton and Cathaysia Block. A large subduction slab window is assumed to have formed in the Nanling and adjacent areas in the interior of South China, triggering the uprise of asthenospheric mantle into the upper crust and leading to the emplacement of metaluminous granitic magma and associated polymetallic W–Sn mineralization. A relatively tectonically quiet period followed between 150 and 135 Ma in South China. From 135 Ma onward, the angle of convergence of the Izanagi plate changed from oblique to parallel to the coastline, resulting in continental extensional tectonics and reactivation of regional-scale NE-trending faults, such as the Tan-Lu fault. This widespread extension also promoted the development of NE-trending pull-apart basins and metamorphic core complexes, accompanied by volcanism and the formation of epithermal Cu–Au deposits, granite-related polymetallic Sn–(W) deposits and hydrothermal U deposits between 120 and 80 Ma (with a peak activity at 100–90 Ma)

Comparative Study of Gacun and Youre Silver-Lead-Zinc-Copper Deposits in Sichuan, SW China, and their Mineralization Significance

The large Gacun silver-lead-zinc-copper deposit in Sichuan Province is one of the largest volcanogenic massive sulfide (VMS) deposits in China. The deposit consists of western and central ore bodies, which form a vein-stockwork mineralization system corresponding to hydrothermal channels, and eastern ore bodies, which form an exhalative chemical sedimentary system derived from a brine pool in a submarine basin. The Youre lead-zinc deposit, which is currently under exploration and lies adjacent to the southern part of the Gacun deposit, is characterized by intense silicification and vein-stockwork structures and consists of massive silicified rhyolitic volcanics, banded rhyolitic tuff, and phyllitic sericite tuff. From a comparison of their ore-bearing horizons, the Gacun and Youre deposits have a continuous and stable hanging wall (calcareous slate and overlying andesite) and foot wall (rhyolite-dacite breccia and agglomerate), and the lithologic sequence includes lower intermediate to felsic rocks and upper felsic rocks. Thus, the Youre deposit, which comprises relatively thinly layered low-grade ore, is regarded as forming a southward extension of the Gacun deposit. A further comparison of the structures of the ore-bearing belts between the two deposits suggests that the Youre ore bodies are similar to the western ore bodies of the Gacun deposit. Moreover, the characteristics of fluid inclusions and stable isotopes in the Youre deposit are also similar to those of the western ore bodies of the Gacun deposit. Genetic models of the deposits are proposed for the Gacun-Youre ore district, and massive concealed ore bodies may occcur in the Youre deposit at depths that are similar to those of the eastern ore bodies of the Gacun deposit.This study was financially supported by the National Basic Research Program of China (Grant No.2014CB440902) and the National Natural Science Foundation of China (Grant No. 41572072)

Mineralisation associated with the fractionated Cretaceous Baoshan Monzogranite: Tectonic implications for South China

Jurassic and Late Cretaceous granites are spatially and temporally associated with mineralisation in the Paleozoic Dayaoshan Terrane in South China (also known as South China Block). The porphyritic Baoshan Monzogranite of Late Cretaceous is an example that is petrographically studied in this contribution. Sensitive High-Resolution Ion-Microprobe (SHRIMP) zircon U-Pb ages, in-situ zircon O-Hf isotopic analyses, and whole-rock geochemistry are here used to better constrain the genesis of the monzogranite, which is porphyritic, and located in the Baoshan Cu mining area. SHRIMP zircon dating yields a weighted mean 206Pb/238U age of 89 ± 1 Ma, interpreted to be the crystallisation age of the porphyritic monzogranite. Its geochemical data indicates it is derived from partial melting of the lower to crust, followed by fractionation, and emplacement in secondary faults related to the major Bobai-Cenxi Fault. The monzogranite has a Paleo- to Mesoproterozoic source in the crust, which was metasomatised during Neoproterozoic subduction. The rotation of Izanagi Plate’s subduction from NW to NE resulted into the reactivation of NW and NE-trending thrust faults as transpressional or extensional ones. It was during this period that Late Cretaceous intrusions such as the Baoshan porphyritic monzogranite were emplaced in the terrane near the NW-trending faults and other intrusions at the edges of basins such as Yangchun, Luoding and Bobai basins near NE-trending faults.This research was financially supported by the National Natural Science Foundation of China (Projects 41572072) and the National Key Basic Research Program of China (Project 2014CB440902)

Geology, geochemistry and genesis of Kafang copper deposit in Gejiu, Yunnan Province

Gejiu is the largest polymetallic tin ore-field over the world. Kafang copper deposit is a main copper provider in Gejiu. There are two kinds of ore-body in Kafang copper deposit. One is stratiform-like ore-body, and the other is contact ore-body. The main wall-rock alterations comprise skarnization, actinolitization and phlogopitization. The analytical results of electron microprobe show that the clinopyroxene is diopside-andradite series. The end member of garnet is dominated by andradite and grossular, with minor spessartine and almandine. Fluid inclusion analysis indicate that the temperature of ore-forming fluid decreased significantly (260-360°C to 160 - 280°C) and the salinity of ore-forming fluid keeps constant basically ( 1.74% - 12.51% to 1.74% -11.93% ) from main mineralization stage to post mineralization stage. Hydrogen isotope analysis and oxygen isotope analysis show that the ore-forming fluid is dominated by magmatic water in the early stage, but in late stage, it could be mixed with magmatic and meteoric water. The compositions of sulfur isotope show that sulfur of stratiform-like ore-body was derived from Triassic basalt, yet both of Triassic basalt and Yanshanian granite provide sulfur for contact ore-body. The compositions of lead isotope show that the source of ore-forming material of stratiform-like ore-body is Triassic basalt, yet the source of lead of contact ore-body is Yanshanian granite

Geology, geochemistry and genesis of Kafang copper deposit in Gejiu, Yunnan Province

Gejiu is the largest polymetallic tin ore-field over the world. Kafang copper deposit is a main copper provider in Gejiu. There are two kinds of ore-body in Kafang copper deposit. One is stratiform-like ore-body, and the other is contact ore-body. The main wall-rock alterations comprise skarnization, actinolitization and phlogopitization. The analytical results of electron microprobe show that the clinopyroxene is diopside-andradite series. The end member of garnet is dominated by andradite and grossular, with minor spessartine and almandine. Fluid inclusion analysis indicate that the temperature of ore-forming fluid decreased significantly (260-360°C to 160 - 280°C) and the salinity of ore-forming fluid keeps constant basically ( 1.74% - 12.51% to 1.74% -11.93% ) from main mineralization stage to post mineralization stage. Hydrogen isotope analysis and oxygen isotope analysis show that the ore-forming fluid is dominated by magmatic water in the early stage, but in late stage, it could be mixed with magmatic and meteoric water. The compositions of sulfur isotope show that sulfur of stratiform-like ore-body was derived from Triassic basalt, yet both of Triassic basalt and Yanshanian granite provide sulfur for contact ore-body. The compositions of lead isotope show that the source of ore-forming material of stratiform-like ore-body is Triassic basalt, yet the source of lead of contact ore-body is Yanshanian granite

Petrogenesis of the Yupo W-bearing and Dali Mo-bearing granitoids in the Dayaoshan area, South China: Constraints of geochronology and geochemistry

The geological significance of Early Paleozoic (Caledonian) magmatism and associated mineralization in South China is, as yet, poorly understood compared to the well-documented Mid-Late Mesozoic (Yanshanian) magmatism and associated mineralization. The Early Paleozoic granitoids were previously thought to be rarely mineralized. Both Caledonian granitoids and Yanshanian granitoids occur in the Dayaoshan area from the Qin–Hang metallogenic belt, South China. Zircon U–Pb ages of granodiorite at the Yupo skarn W deposit and the monzonite and granodiorite at the Dali porphyry Mo deposit, all I-type granites, analyzed by Sensitive High Resolution Ion Micro-Probe (SHRIMP) and/or laser ablation inductively coupled mass spectrometry (LA–ICP–MS) are 441.9 ± 1.9 Ma (2σ), 104.6 ± 1.6 Ma (2σ) and 105.3 ± 1.4 Ma (2σ), respectively. Both elevated zircon δ18OV-SMOW values (5.8–7.7‰) and negative εHf(t) values (−3.2 to −0.2) indicate that these plutons formed via partial melting of a Mesoproterozoic continental crust with minor mantle materials. The Caledonian W-bearing Yupo granodiorite is relatively reduced (FMQ−0.57), whereas the Yanshanian Mo-bearing granodiorite at Dali (FMQ+1.11) is more oxidized than the associated ore-barren monzonite (FMQ+0.52). Thus, it is likely that the contrasting mineralization between the two plutons was controlled by redox states of granitic magmas.This study was financially supported by the Guangxi Bureau of Geology & Mineral Prospecting & Exploitation (Grant No. [2014]17), National Basic Research Program of China (973 Program: 2012CB416704) and the China Scholarship Council Fund (No. 201506400020