Springer Science and Business Media LLC

Textural and compositional zoning within plagioclase phenocrysts records the magma chamber processes, such as magma differentiation, magma recharge and mixing, and crustal contamination. The plagioclase phenocrysts in the Daqiao and Qiaojia plagioclase-phyric basalts from the Emeishan Large Igneous Province (LIP) show complex textural and compositional zoning patterns, e.g., normal, reverse, oscillatory, and patchy zoning patterns. Most plagioclase phenocrysts exhibit a core–rim normal zoning pattern (Pl-A) with euhedral high-An cores (An = 76–78%, in mole fraction) and low-An rims (An = 68–72%), indicative of the crystal regrowth processes caused by recharge of relatively evolved magmas after the formation of high-An cores. Some phenocrysts have a core–rim reverse zoning pattern (Pl-B) with irregular ovaloid cores, characterized by extremely low An (60–61 mol%) and Ba (84–88 ppm) contents and extremely high 87Sr/86Sr ratios (0.7120–0.7130). The rims of the Pl-B have relatively high An (69–72 %), Ba (~160 ppm) contents, and low 87Sr/86Sri (~0.7056). These Pl-B plagioclase phenocrysts preserve the information about the interaction between the crustal xenocrysts and the transporting magmas. Some plagioclase phenocrysts show a core–mantle–rim oscillatory zoning pattern (Pl-C) with multiple oscillations of An (70–80 %), Ba (88–147ppm) from core to rim, revealing replenishment and mixing of multiple batches of basaltic melts with diverse compositions. 87Sr/86Sr ratios of the Pl-C do not vary significantly (0.7050–0.7054). A small portion of phenocrysts has patchy patterns in the cores (Pl-D), where the low-An patches (72–75 %) in form of elliptical or irregular elongated shapes were enclosed by the high-An domains (80–87 %). These features can be attributed to crystal dissolution and regrowth processes during the reaction between early-formed low-Cumulates and recharged hot primitive melts. The cores, mantles, and rims of different types of plagioclase phenocrysts (except the core of Pl-B) commonly display nearly constant Sr isotopic compositions, implying insignificant wall-rock assimilation at shallow-level magma reservoir(s) during the growth of these plagioclase phenocrysts. In conclusion, the massive crystallization of plagioclase in the late stage was an important controlling factor for the formation of iron-rich basalts in the Emeishan LIP.

The lunar ferroan anorthosites, formed by plagioclase flotation from the crystallization of the lunar magma ocean, have an age span of over ~ 200 Ma. However, previous thermal models predicted a much shorter time range. We propose that a much smaller thermal conductivity of anorthositic crust due to its high porosity may have delayed the solidification of the lunar magma ocean. Our thermal simulation results, using the thermal conductivity of porous lunar crust, show that crystallization of a 1000 km deep magma ocean could be prolonged to tens of millions of years, and up to 180 Ma under some extreme conditions. The porous crust alone can’t explain the large crustal age span, however. Other circumstances must be taken into consideration, such as a thick lunar soil.

In the present study, the Lower-Middle Pliocene Cheleken Formation in the south of Ghaemshahr city was studied to determine the provenance of the comprising sediments, paleoclimatic conditions, and tectonic setting of the rocks. Petrographic and geochemical analyses of major and minor elements of the samples were used for this purpose. This Formation is composed of three major facies including conglomerate, fine sandstone, and mudstone. The source formations which were recognized to be supplying sediments to the Cheleken Formation depositional basin include Lalun, Ziarat, Tizkuh, Dalichai, and Cretaceous formations. According to the discrimination diagrams and other ratios for minor elements of the studied samples, a complex of felsic to intermediate igneous rocks in the source region was deciphered. The depositional environment of the rocks experienced humid and semi-arid climatic conditions during deposition. According to the CIW index, the samples underwent a high level of weathering (97%) in the source area or during transportation. From a tectonic point of view, the Cheleken Formation was deposited in an Active Continental Margin setting.

The fault-controlled Nibao Carlin-type gold deposit, together with the strata-bound Shuiyindong deposit, comprise a significant amount of the disseminated gold deposits in southwestern Guizhou Province, China. Five main types and two sub-types of pyrite at the Nibao deposit (Py1a/Py1b, Py2, Py3, Py4, Py5) were distinguished based on detailed mineralogical work. Py1, Py2 and Py3 are Au-poor, whereas Py4 and Py5 are Au-rich, corresponding to a sedimentary and hydrothermal origin, respectively. Through systematic in situ analyses of NanoSIMS sulfur isotopes, the framboid pyrite Py1a with negative δ34S values (− 53.3 to − 14.9‰) from the Nibao deposit were found to originate from bacterial sulfate reduction (BSR) processes in an open and sulfate-sufficient condition while the superheavy pyrite Py1b (73.7–114.8‰) is probably due to the potential influence of closed-system Rayleigh fractionation or the lack of preservation of deep-sea sediments. Data of Py2 and Py3 plot within the area of S isotope compositions from biogenic and abiogenic sulfate reduction. In view of few coeval magmatic rocks in the mining district, the near zero δ34S values of the Au-rich pyrites (Py4 and Py5) may discount the potential involvement of magmatic but metamorphic or sedimentary origin. LA-ICP-MS and TEM work show that Au in ore-related pyrite is present as both nanoparticles and structurally bound. LA-ICP-MS analyses show that the Au-rich pyrite also contains higher As, Cu, Sb, Tl and S than other types of pyrite, which inferred a distal manifestation of deep hydrothermal mineralization systems.

The Yao’an Pb–Ag deposit, located in the Chuxiong Basin, western Yangtze Block, is an important component of the Jinshajiang–Ailaoshan alkaline porphyry–related polymetallic intrusive belt. This complex suite of rock bodies includes a vein of pseudoleucite porphyry within deposits of syenite porphyry and trachyte. The pseudoleucite is characterized by a variable greyish, greyish-white, and greyish-green porphyritic texture. Phenocrysts are mainly pseudoleucite with small amounts of alkali feldspar and biotite. In an intense event, leucite phenocrysts altered to orthoclase, kaolinite, and quartz. Both the pseudoleucite porphyry and the syenite porphyry samples were typical alkali-rich, K-rich, al-rich rocks with high LaN/YbN ratios; enriched in light rare earth elements and large-ion lithophile elements, and depleted in high field strength elements; and with strongly negative Ta, Nb, and Ti (TNT) anomalies and slightly negative Eu anomalies—all characteristics of subduction-zone mantle-derived rock. We obtained a LA-ICP-MS zircon U–Pb age of 34.1 ± 0.3 Ma (MSWD = 2.4), which is younger than the established age of the Indian and Eurasian Plate collision. The magma derived from a Type-II enriched mantle formed in a post-collisional plate tectonic setting. The geochemical characteristics of the Yao’an pseudoleucite porphyry are powerful evidence that the porphyry’s development was closely linked to the Jinshajiang–Ailaoshan fault and to the Indian-Eurasian collision.

The Jilin H5 chondrite, the largest known stony meteorite in the world, with its No.1 fragment weighing 1770 kg. It contains submillimeter- to centimeter-sized FeNi metal particles/nodules. Our optical microscopic and electron microprobe analyses revealed that the formation of metal nodules in this meteorite is a complex and long-term process, The early stage is the thermal diffusion-caused migration and concentration of dispersed metallic material along fractures to form root-hair shaped metal grains during thermal metamorphism of this meteorite. The later two collision events experienced by this meteorite led to the further migration and aggregation of metallic material into the shock-produced cracks and openings to form larger-sized metal grains. The shock-produced shear movement and frictional heating occurred in this meteorite greatly enhanced the migration and aggregation of metallic material to form the large-sized nodules. It was revealed that the metal nodule formation process in the Jilin H5 chondrite might perform in the solid or subsolidus state, and neither melting of chondritic metal grains nor shock-induced vaporization of bulk chondrite material are related with this process.

A bidirectional labeling method was established to distinguish the proportions of HCO3− and CO2 utilization pathways of microalgae in Lake Hongfeng. The method was based on microalgae cultured in a medium by adding equal concentrations of NaH13CO3 with different δ13C values simultaneously. The inorganic carbon sources were quantified according to the stable carbon isotope composition in the treated microalgae. The effects of extracellular carbonic anhydrase (CAex) on the HCO3− and CO2 utilization pathways were distinguished using acetazolamide, a potent membrane-impermeable carbonic anhydrase inhibitor. The results show utilization of the added HCO3− was only 8% of the total carbon sources in karst lake. The proportion of the HCO3− utilization pathway was 52% of total inorganic carbon assimilation. Therefore, in the natural water of the karst area, the microalgae used less bicarbonate that preexisted in the aqueous medium than CO2 derived from the atmosphere. CAex increased the utilization of inorganic carbon from the atmosphere. The microalgae with CAex had greater carbon sequestration capacity in this karst area.

Heavy use of chemical fertilizer causes increasing soil and environmental crisis, and the use of organic fertilizer increases obvious in recent years. In this study, mineral organic fertilizer (MOF) and compound fertilizer (CF) were applied in amaranth culture to explore the effects of these two kinds of fertilizers on soil quality and the potential function for CO2 fixation. Some soil parameters were tested, e.g. pH value, organic carbon content, microbial biomass, urease activity, and available potassium content. In addition, some parameters of soil infiltration water were also determined, such as pH and HCO3 − concentration. Experimental results showed that MOF improved soil quality and amaranth biomass and increased possible soil carbon sink. On the contrary, the utilization of CF worsened soil quality and made the soil acidize. These results suggested that MOF can partially replace CF to improve plant growth, soil quality and possible CO2 sink.