Tetrad Effect Research Articles

Cannabinoid tetrad effects of oral Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) in male and female rats: sex, dose-effects and time course evaluations.

The legalization of medicinal use of Cannabis sativa in most US states and the removal of hemp from the Drug Enforcement Agency (DEA) controlled substances act has resulted in a proliferation of products containing Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) for oral consumption (e.g., edibles, oils, and tinctures) that are being used for recreational and medicinal purposes. This study examined the effects of cannabinoids THC and CBD when administered orally on measures of pain sensitivity, body temperature, locomotor activity, and catalepsy (i.e., cannabinoid tetrad) in male and female Sprague Dawley rats. Rats (N = 24, 6 per sex/drug group) were administered THC (1-20mg/kg), CBD (3-30mg/kg), or sesame oil via oral gavage. Thermal and mechanical pain sensitivity (tail flick assay, von Frey test), rectal measurements for body temperature, locomotor activity, and the bar-test of catalepsy were completed. A separate group of rats (N = 8/4 per sex) was administered morphine (5-20mg/kg; intraperitoneal, IP) and evaluated for pain sensitivity as a positive control. We observed classic tetrad effects of antinociception, hypothermia, hyper- and hypolocomotion, and catalepsy after oral administration of THC that were long lasting (> 7h). CBD modestly increased mechanical pain sensitivity and produced sex-dependent effects on body temperature and locomotor activity. Oral THC and CBD produced long lasting effects that differed in magnitude and time course when compared with other routes of administration. Examination of cannabinoid effects administered via different routes of administration, species, and in both males and females is critical to enhance translation.

Geochronological framework and ore genesis of the Tiantangshan Rb-Sn-W deposit, northeastern Guangdong, south China: Constraints from cassiterite and monazite U-Pb dating

The newly discovered Tiantangshan Rb-Sn-W deposit in the northeastern Guangdong is one of the largest Rb deposit in China. The deposit is hosted by volcanic rocks and characterized by hydrothermal mineralization of Rb and Sn-W, with minor Rb mineralization of granitic K-feldspar alteration. In this study, we conducted LA-ICP-MS U-Pb dating of cassiterite and monazite to constrain the ore-forming ages of Sn and Rb. Two stages of cassiterite (Cst) are developed in the wolframite-cassiterite quartz vein, and the Cst I and Cst II yielded weighted mean 206Pb/238U ages of 133.9 ± 2.0 Ma and 133.2 ± 1.6 Ma, respectively. Monazites from biotite quartz vein yielded weighted mean 206Pb/238U ages of 134.2 ± 1.8 Ma and 132.7 ± 1.1 Ma. Combined with previous studies, a geochronological framework of volcanic eruptions (ca. 137 Ma), alkali feldspar granite (ca. 136 Ma) and Rb-Sn mineralization (134 to 133 Ma) for the deposit was established. Thus, the Rb-Sn-W mineralization is genetically related to the alkali feldspar granite and a volcanic-intrusive connection. Most Rb resources of the deposit are hosted by hydrothermal biotite in biotite quartz vein and related biotite alteration of volcanic wall rocks. Meanwhile, the K-feldspar alteration of the alkali feldspar granite displays higher Rb contents (1992–2092 ppm), stronger REE tetrad effect and lower Zr/Hf, Nb/Ta and Y/Ho ratios than the unaltered granite, indicating important involvement of hydrothermal fluids in this type of Rb enrichment. In combination with recent age data, the Tiantangshan deposit, with Yanbei and Taoxihu in the southeastern Jiangxi, are related to the numerous Sn deposits in southeastern Guangdong, which together form an early Cretaceous Sn metallogenic belt in South China. The early Cretaceous Sn belt was formed under an extensional environment likely due to the roll back of the subducted paleo-Pacific plate. The Tiantangshan deposit is indicative of Sn and related rare-metal exploration potential in the early Cretaceous volcanic basins in adjacent areas.

Formation of the Jinchangyu Au deposit, eastern Heibei Province, China: Melts and fluids derived from a highly fractionated magma

The Jinchangyu deposit is the largest Au lode deposit in eastern Hebei Province of China and is located along the northern margin of the North China Craton. It was previously thought that this deposit was a greenstone belt-type as the orebodies are controlled by ductile shear structures in amphibolite units of the Archean Zunhua Group. However, new geological and petrographic observations presented here show that the mineralization was actually controlled by the brittle schistosity in the amphibolite and the ore-bearing quartz–albite veins are actually albite-rich granite porphyry dikes that coexist with graphic pegmatite dikes. Based on geological and geochemical features, we propose that the Jinchangyu Au deposit is actually a magmatic–hydrothermal type formed by melt–fluid derived from a highly fractionated magma. The ore-bearing albite-rich granite porphyry and pegmatite dikes are metaluminous to weakly peraluminous, and belong to the low-K tholeiitic to shoshonitic and subalkaline series. All the samples have high SiO2, K2O + Na2O contents and differentiation index values, low CaO, MgO, P2O5, and TiO2 contents, are enriched in Th, U, Ta, Nb, Sr, Zr, and Hf, depleted in Ba, K, P, Ti, and δEu, and exhibit the tetrad rare earth element effect. The mineralogy and geochemistry indicate the dikes are highly fractionated I-type granites, and that the Jinchangyu Au deposit was generated during magmatic differentiation. δ34S values of pyrite vary from –6.3‰ to 4.2‰, and H–O isotopic compositions of quartz from quartz–pyrite veins indicate the mineralizing fluid had a predominantly magmatic source. Lead isotope ratios (206Pb/204Pb = 15.65–16.18, 207Pb/204Pb = 15.16–15.29) of pyrite in the quartz–pyrite veins indicate the ore-forming materials were derived from a mixed source containing mantle and crustal materials. Geochemical features indicate that the dikes formed in a post-collsional extensional tectonic setting during the Late Triassic, after closure of the Paleo-Asian Ocean. Combined with data from previous studies, we propose that the parental magma and ore-forming materials of the Jinchangyu Au deposit were derived from a mixed source containing mantle and crustal material, underwent extensive differentiation, and then sequentially formed the ore-bearing albite-rich granite porphyry dike dikes, graphic pegmatite dikes, and quartz–albite, quartz–pyrite, and quartz–carbonate veins.

Mineralogy of columbite-group minerals from the rare-element pegmatite dykes in the East-Qinling orogen, central China: Implications for formation times and ore genesis

The East-Qinling pegmatite district located in the North Qinling terrane is the largest one in the Qinling orogen, Central China. It is famous for its rare-element (REL) reserves, but its genesis is unraveled. We present in-situ major- and trace-element chemistry and U-Pb dating analysis of columbite-group minerals (CGM) and wodginite from representative Li-, Be-mineralized and barren pegmatite dykes. The mineralogical researches reveal that Li-mineralized pegmatite formed from a highly-evolved fluxes-rich magma, experiencing a magmatic stage at undercooling condition and a post-magmatic stage involving disturbance by alkali liquid or hydrothermal fluid. The lithium mineralization is accomplished by fractional crystallization after emplacement, alkali-fluid replacement or overprint of two Li-rich magmas. CGM Fe-Mn fractionation and REE distribution patterns with tetrad effect are considered as indicators to identify generations of CGM and trace the evolution of pegmatite formation. The CGM and zircon U-Pb ages suggest that the REL pegmatites formed in 422–410 Ma (Period I) and 399–384 Ma (Period II) and an early pegmatite magma activity occurred in 447–443 Ma. The late Ordovician-early Silurian and Period II pegmatite magmas stem from partial melting of North Qinling unit in collision and post-orogenic extensional settings, respectively, whereas Period I pegmatites formed in a weakening convergence setting by anatexis of fertile metasedimentary rocks or extremely fractional crystallization of granitic magma. The early-Paleozoic evolution of the North Qinling terrane contributes to the formation of large-scale East-Qinling REL pegmatites on the aspects of magma production and subsequent emplacement by crustal thickening, crustal reworking and dynamic extension during crust uplift.

Magmatic and hydrothermal evolution of highly-fractionated rare-metal granites at Gabal Nuweibi, Eastern Desert, Egypt

The Nuweibi intrusion was emplaced during the final tectono-magmatic stage of Arabian-Nubian Shield development (ANS). Two cogenetic phases of intrusion can be recognized in the field: the early phase is represented by porphyritic albite granite and the final phase by non-porphyritic albite granite. Mineralogically, both phases are essentially composed of albite, quartz, and K-feldspars with subordinate muscovite. Accessory minerals include fluorite, zircon, NbTa oxides, cassiterite, beryl, topaz, and garnet. Geochemically, the Nuweibi intrusion consists of extensively fractionated rare-metal granite with low contents of TiO2, FeOt, CaO, MgO, P2O5, Sr, and Ba in contrast to elevated concentrations of alkalis, Rb, Nb, Ta, and Hf. Their peraluminous (molar Al2O3/[CaO + Na2O + K2O] = 1.06–1.15) and low-P (P2O5 < 0.008 wt%) character identify them as highly fractionated I-type granites. The primary magma of the Nuweibi intrusion was most likely generated by partial melting of the juvenile crust of the ANS. We document numerous lines of evidence that the Nuweibi albite granite was formed by extensive fractional crystallization followed by interaction with magmatically-derived, F-rich hydrothermal solutions. The REE patterns of the Nuweibi albite granite show marked negative Eu anomalies (Eu/Eu⁎ = 0.01–0.15) as well as prominent M-type tetrad effects (TE1,3 = 1.332–3.536), typically seen in highly differentiated granites and attributed to exchange with hydrothermal fluid. Anomalous ratios of isovalent “twin” elements such as Nb/Ta, Zr/Hf, and Y/Ho likewise indicate exchange with hydrothermal fluid. The primary rare-metal accessory minerals are restricted to the Mn-rich part of the columbite-tantalite series; this manganoan trend is characteristic of highly fractionated granites. Likewise, the presence of wodginite, a Sn-bearing mineral, is a unique fingerprint of highly evolved rare-metal granites. Late-stage hydrothermal overprint of the primary rare-metal mineralization is preserved by rims of fluorcalciomicrolite partly replacing columbite-(Mn) and tantalite-(Mn). Accumulation of residual volatile-rich melt and exsolved fluids in the upper part of the magma chamber produced stockscheider pegmatite, greisen, and quartz veins that cut the peripheries of the Nuweibi intrusion and the surrounding country rocks.

A model involving amphibolite lower crust melting and subsequent melt extraction for leucogranite generation

Abstract In the southern Tibetan Plateau, leucogranites are dominantly distributed in the Himalayan orogenic belt with minor occurrences in the southern Lhasa subterrane. In this paper, we report the first Miocene Anglonggangri leucogranites in the northern Lhasa subterrane. This finding provides important constraints on both leucogranite petrogenesis and the tectono-magmatic evolution of the Lhasa terrane. The Anglonggangri leucogranites include biotite-muscovite granite and slightly younger garnet-muscovite granite and pegmatite. Zircon U-Pb and muscovite 40Ar-39Ar dating of these leucogranites yields Miocene ages of 11.1–10.2 Ma. The biotite-muscovite and garnet-muscovite granites are characterized by high SiO2 (72.3–74.4 wt.%) and Al2O3 contents (14.4–15.4 wt.%) and are peraluminous. The biotite-muscovite granite displays geochemical signatures with high Sr/Y (29.2–81.0) and (La/Yb)N (37.5–98.9) ratios, low Y (4.30–7.22 ppm) and Yb contents (0.26–0.47 ppm), low to moderate initial (87Sr/86Sr)i ratios (0.7085–0.7192), and moderate εNd(t) values (−10.17 to −6.94). Furthermore, they also exhibit radiogenic Pb isotope and variable zircon εHf(t) values (−9.6 to +4.4) with Proterozoic Nd (1.1–1.4 Ga) and Hf model ages (0.8–1.7 Ga). By comparison, the garnet-muscovite granite has lower CaO, MgO, TiO2, and total FeO contents and is enriched in Rb (380–466 ppm) and depleted in Sr (24.1–38.5 ppm) and Ba (30.7–58.6 ppm) and further characterized by a significant rare earth element (REE) tetrad effect and non-charge and radius-controlled (CHARAC) trace element behaviors. The garnet-muscovite granite shows a negative Eu anomaly and positive correlations among Sr and Eu, Sr and Ba, and Th and light rare earth elements (LREEs). Pegmatite comprising Nb-Ta oxides and cassiterite occurs in the garnet-muscovite granite. Geochronological and geochemical characteristics of the Anglonggangri leucogranites indicate that the magma of the biotite-muscovite granite was derived from partial melting of amphibolite lower crust contaminated with Proterozoic-Archean upper crustal materials. The garnet-muscovite granite was generated through melt extraction from the biotite-muscovite granite crystal mush. These results confirm that partial melting of the amphibolite lower crust not only occurred in the southern and central Lhasa subterranes but also in the northern Lhasa subterrane.

REE Tetrad Effect and Sr-Nd Isotope Systematics of A-Type Pirrit Hills Granite from West Antarctica

The Pirrit Hills are located in the Ellsworth–Whitmore Mountains of West Antarctica. The Pirrit Hills granite exhibits significant negative Eu anomalies (Eu/Eu* = 0.01~0.25) and a REE tetrad effect indicating intensive magmatic differentiation. Whole-rock Rb-Sr and Sm-Nd geochronologic analysis of the Pirrit Hills granite gave respective ages of 172.8 ± 2.4 Ma with initial 87Sr/86Sr = 0.7065 ± 0.0087 Ma and 169 ± 12 Ma with initial 144Nd/143Nd = 0.512207 ± 0.000017. The isotopic ratio data indicate that the Pirrit Hills granite formed by the remelting of Mesoproterozoic mantle-derived crustal materials. Both chondrite-normalized REE patterns and Sr-Nd isotopic data indicate that the Pirrit Hills granite has geochemical features of chondrite-normalized REE patterns indicating that REE tetrad effects and negative Eu anomalies in the highly fractionated granites were produced from magmatic differentiation under the magmatic-hydrothermal transition system.

Quantifying the Tetrad Effect, Shape Components, and Ce\u2013Eu\u2013Gd Anomalies in Rare Earth Element Patterns

Plots of chondrite-normalised rare earth element (REE) patterns often appear as smooth curves. These curves can be decomposed into orthogonal polynomial functions (shape components), each of which captures a feature of the total pattern. The coefficients of these components (known as the lambda coefficients—lambda ) can be derived using least-squares fitting, allowing quantitative description of REE patterns and dimension reduction of parameters required for this. The tetrad effect is similarly quantified using least-squares fitting of shape components to data, resulting in the tetrad coefficients (tau ). Our method allows fitting of all four tetrad coefficients together with tetrad-independent lambda curvature. We describe the mathematical derivation of the method and two tools to apply the method: the online interactive application BLambdaR, and the Python package pyrolite. We show several case studies that explore aspects of the method, its treatment of redox-anomalous REE, and possible pitfalls and considerations in its use.

Major, Trace, and Rare-Earth Element Geochemistry of Nb-V Rich Andradite-Schorlomite-Morimotoite Garnet from Ambadungar-Saidivasan Alkaline Carbonatite Complex, India: Implication for the Role of Hydrothermal Fluid-Induced Metasomatism

In situ major, trace and rare-earth element composition of Ti-rich garnets from Ambadungar-Saidivasan alkaline carbonatite complex (ASACC) are presented to constrain its likely genesis. The garnets are characterized by high andradite (42.7–57.3), schorolomite (22.0–31.0), and morimotoite (15.6–26.5) end members. No distinct chemical zonation is noticed except for minor variations in Ti content. The garnets are enriched in LREE (average 731 ppm) and relatively depleted in HREE (average 186 ppm) and show an M-type first tetrad that leads to a convex upward pattern between Ce and Gd. Mildly positive to no Eu anomalies are observed (Eu/Eu* = 1.06–1.17). The REE patterns (LaN/YbN = 1.11–2.11) are similar to those of garnets from skarn deposits. The presence of tetrad effect in the LREE pattern suggests an active role of metasomatic processes involving hydrothermal fluids during the growth of the garnets. These garnets also contain high Nb (282–2283 ppm) and V (1083–2155 ppm) concentrations, which stand out against the composition of the host rock. Therefore, late-stage metasomatic reactions of earlier formed minerals with hydrothermal fluid enriched in Fe, Si, LREE, Nb, V, and Ti led to the formation of garnet. The primary source for these elements could be magnetite, ilmenite, and pyrochlore present in different varieties of carbonatites in the ASACC, with the required elements being released during their interaction with the hydrothermal fluid. The hydrothermal fluid was likely to be moderately acidic, and having fluoride and sulfate as the primary ligands.

Mineralogy and Geochemistry of Uraniferous Sandstones in Fault Zone, Wadi El Sahu Area, Southwestern Sinai, Egypt: Implications for Provenance, Weathering and Tectonic Setting

AbstractPaleozoic rocks in the Wadi El Sahu area are affected by many major faults in different directions. A reverse fault trending NE‐SW is exposed for about 300 m of its length as it cuts through the Abu Hamata and Adedia formations on the south side of Wadi El Sahu. A secondary ascending hydrothermal solution carrying heavy metals and radioactive minerals passed through the fault plain and the surrounding fractures, forming mineralized and radioactive zone. The mineralized zone thickness ranges from 60 cm to 200 cm along the fault plain. These rocks were analyzed radiometrically using a portable gamma‐ray spectrometer, chemically by employing ICP‐ES and ICP‐MS, as well as mineralogically by both binocular and Environmental Scanning Electron microscope. Gold content was also determined by fire assay. REE and U contents reached up to 2682 and 1216 ppm, respectively. Mineralogical investigations indicated the presence of uraninite, torbernite, autunite, sklodowskite, kasolite as uranium minerals, thorite as a thorium mineral, monazite, allanite and xenotime as REE‐bearing minerals, zircon and columbite as accessory minerals, gold and nickel as precious and base metals, in addition to cassiterite, chalcopyrite, chalcocite and chrysocolla. High REE and U contents are attributed to the circulation of epigenetic U and REE‐bearing hydrothermal solutions along the fault plain and its surrounding fractures. Hydrothermal alteration processes could then be confirmed by the presence of the M‐type tetrad effect in the REE‐patterns of the ferruginous sandstone. The non‐chondritic ratio of Nb/Ta, Zr/Hf and Y/Ho in the studied sandstone may be attributed to the tetrad effect. The Ce and Eu anomaly with unusual REE‐patterns was represented by the presence of conjugated M‐W tetrad effects, indicating either the dual effect of hydrothermal solutions or groundwater with seawater. The results clarify that the tetrad‐effects could be used as evidence for the environment of deposition and as an indication for gold mineralization.

Petrogenesis and tectonic significance of the middle Neoproterozoic highly fractionated A-type granite in the South Qinling block

AbstractThe South Qinling block, a segment of the Yangtze craton involved in the Qinling–Dabie orogen, is critical for understanding the tectonic evolution of eastern China. However, the tectonic setting of the South Qinling block and the northern margin of the Yangtze block during middle Neoproterozoic time has long been the subject of debate, with two distinctly different models (continental rift or volcanic arc) proposed. Here, a comprehensive study of zircon U–Pb geochronology and geochemistry has been carried out on the Chengwan granitic pluton from the Suizao terrane in the South Qinling block. The granites are monzogranite and syenogranite in lithology, and are mainly composed of potash feldspar, quartz, plagioclase and biotite. This suite has long been regarded as a Palaeozoic magmatic pluton, but zircon U–Pb ages of 809 ± 9 Ma and 816 ± 4 Ma are obtained in this study. The granites are metaluminous to strongly peraluminous with high alkali contents, and exhibit highly fractionated features, including high SiO2, low Zr/Hf ratios, rare earth element tetrad effects and enrichment of K and Rb. They show Hf–Nd isotopic decoupling, which may be genetically related to their petrogenetic process. Based on the geochemical features and the positive εHf(t) values of the zircons, it is indicated that the granites may have been derived from partial melting of juvenile tonalitic rocks by biotite breakdown under fluid-absent conditions. The Chengwan granite geochemically belongs to the A2-subtype granites, suggesting that it might have formed in a post-orogenic tectonic setting. The highly fractionated A-type granite in this study may represent extensional collapse shortly after the collisional events in the South Qinling block, and thus indicate a tectonic regime switch, from compression to extension, as early as middle Neoproterozoic time. Integrating our new data with documented magmatic, metamorphic and sedimentary events during middle Neoproterozoic time in the region may support a continental rift model, and argues against arc models.

Multistage magmatism recorded in a single gneiss dome: Insights from the Lhagoi Kangri leucogranites, Himalayan orogen

Determining the geochronological framework and geochemical nature of magmatism associated with orogenic processes is crucial to decipher the evolution of orogenic belts. The Himalayan orogen has recorded considerable information regarding deformation, metamorphism, and magmatism related to orogenic processes. Here, we identify four stages of granitic magmatism on the basis of monazite U–Th–Pb dating of rocks from the Lhagoi Kangri dome, north Himalayan antiform, southern Tibet: middle Eocene (42–40 Ma), late Eocene (ca. 36 Ma), Oligocene (ca. 26 Ma), and Miocene (16–13 Ma). The middle Eocene tourmaline-bearing leucogranite is characterized by (1) relatively high SiO2 (78.7 wt%), Al2O3 (12.6 wt%), and Na2O (6.3 wt%) contents; (2) enrichment in light rare earth elements (LREEs), depletion in heavy REEs, high abundances of REEs, and pronounced negative Eu anomalies; and (3) relatively low values of whole-rock SrNd isotope compositions (87Sr/86Sr(t) = 0.72101 and εNd(t) = −9.8). And the coeval garnet–bearing two–mica granite has a pronounced negative Eu anomaly (Eu/Eu* = 0.07) and a significate lanthanide tetrad effect (TE1,3 = 1.46). These geochemical data suggest that these leucogranites underwent fractional crystallization. They provide a robust evidence for that anatexis of the lower crust of Indian plate began at 42–40 Ma in the central Himalayan orogen. The Oligocene and Miocene two–mica granites share broadly similar geochemical characteristics, such as moderate REE contents and weak negative Eu anomalies, and are distinct from the garnet-bearing muscovite leucogranite. Whole-rock SrNd isotope compositions of the Oligocene and Miocene leucogranites differ from those of the middle Eocene leucogranites, with higher 87Sr/86Sr(t) ratios (0.73524–0.74188) and lower εNd(t) values (−14.7 to −13.7). These geochemical data indicate that the Oligocene and Miocene leucogranites are products of muscovite-dehydration melting of metasedimentary rocks. The garnet-bearing muscovite leucogranite shows the REE tetrad effect, which suggests that it is more evolved than the coeval two–mica granite. We therefore infer that the variations in age and isotopic characteristics of the studied leucogranites were caused by a change in melt source resulting from the compression–extension evolution of the Himalayan collisional orogenic system.

Major Metabolites of the Synthetic Cannabinoid 5F‐ADB Retain High Affinity and Full Efficacy at CB1 Receptors; Potential Mechanism Contributing to Enhanced Toxicity?

Synthetic cannabinoids (SCs) are a large group of abused psychoactive compounds that elicit numerous toxic effects not observed with marijuana, including death. SCs are abused worldwide and metabolites of these drugs are often detected as a means of drug identification. SC metabolites resulting from Phase I metabolism have been shown to retain affinity and activity at cannabinoid receptors. However, whether these active compounds contribute to toxicity of SCs is unknown. 5-Fluoro-ADB (5F-ADB), also known as 5-Fluoro-MDMB-PINACA, is a commonly abused third-generation synthetic cannabinoid agonist based on an indazole-structure. Significantly, over 40 recent fatalities have been attributed to 5F-ADB overdose. A potential mechanism underlying 5F-ADB-induced mortality is drug-related dysrhythmia resulting in sudden death. Analysis of postmortem central and peripheral blood samples have revealed abnormally high concentrations of an ester-hydrolysis Phase I metabolite of 5F-ADB, identified as metabolite 7 (5F-ADB-M7). We propose that high concentrations of potent and efficacious active metabolites, such as 5F-ADB-M7 and others, accumulate with the parent drug 5F-ADB and produce additive and/or synergistic effects that possibly contribute to fatal intoxication following overdose. As a first step to test this hypothesis, in vitro studies were conducted to compare the affinity and activity of tetrahydrocannabinol (THC; the primary psychoactive component in marijuana), 5F-ADB, 5F-ADB-M7 and a second major metabolite, 5F-ADB-M2 at cannabinoid type-1 (CB1) receptors. Competition receptor binding studies, using mouse brain membranes, showed that all four cannabinoids bound with high affinity to CB1 receptors with a rank order of affinity (Ki values) of 5F-ADB > 5F-ADB-M2 > THC > 5F-ADB-M7. Furthermore, functional experiments examining modulation of G-protein activity demonstrated that 5F-ADB and both Phase I metabolites acted as full agonists at CB1 receptors, relative to partial agonist effects produced by THC. Subsequently, in vivo studies were conducted utilizing the cannabinoid tetrad in mice to compare the effects of THC with those of 5F-ADB-M2. Both 5F-ADB-M2 and THC produced CB1-mediated dose-dependent hypothermia, analgesia, and locomotor suppression, within 30 minutes of injection; however, catalepsy was not elicited by the metabolite. Consistent with higher CB1 affinity determined from in vitro studies, 5F-ADB-M2 produced tetrad effects with higher potency compared to THC. Future studies are planned to examine in vivo effects of 5F-ADB-M7 compared to THC. If 5F-ADB metabolites exhibit in vivo activity similar to that predicted from the in vitro studies presented here, this suggests that the enhanced, often fatal, effects of 5F-ADB may be due to an accumulation of the parent and active, high affinity metabolites acting at CB1 receptors.

Evidence for extreme Sm[sbnd]Nd fractionation during chemical weathering

During subaerial chemical weathering, submarine weathering and other intracrustal processes, SmNd chemical fractionation remains uncertain, while a little is known about the conditions, scale and magnitude, specific processes and actual mechanism for possible SmNd fractionation. Here, an in situ terra rossa weathering profile developed on dolostone is chosen for the study. Based on sequential extraction experiments and measurements of the mineral and geochemical compositions including SrNd isotopic compositions, we suggest that subaerial chemical weathering not only leads to considerable SmNd mobilization, redistribution and secondary enrichment, but also gives rise to extreme SmNd fractionation, apparent 143Nd isotope homogenization, nearly complete resetting of the 147Sm143Nd isotope system, anomalous initial 143Nd/144Nd ratios, and meaningless 143Nd model age (TDM) for weathering products. We found that the lanthanide tetrad effect, rather than mineralogical control, is responsible for the observed substantial SmNd fractionation and for the other rare earth element fractionation. Under domination of the lanthanide tetrad effect, the mobility of Sm is preferential to that of Nd during their migration in the form of dissolved organic complexes. Our results also illustrate that resetting of the 147Sm143Nd isotope system in weathering products is controlled by the combined effect of the extraneous dissolved SmNd input and additional SmNd fractionation. Finally, we argue that similar scenarios may occur in submarine weathering, diagenesis and other geological processes.

Regularities of the property changes in the compounds EuLnCuS3 (Ln = La-Lu)

This work contains the results of complex experimental research of the compounds EuLnCuS3 (Ln = La-Lu) enhanced by the DFT calculations. It is aimed at the data replenishment with particular attention to the revelation of regularities in the property changes, in order to extend the potential applicability of the materials of the selected chemical class. The ab initio calculations of the fundamental vibrational modes of the crystal structures were in good agreement with experimental results. The wavenumbers and types of the modes were determined, and the degree of the ion participation in the modes was also estimated. The elastic properties of the compounds were calculated. The compounds were found out to be IR-transparent in the range of 4000–400 cm–1. The estimated microhardness of the compounds is in the range of 2.68–3.60 GPa. According to the DSC data, the reversible polymorphous transitions were manifested in the compounds EuLnCuS3 (Ln = Sm, Gd-Lu): for EuSmCuS3 Tα↔β = 1437 K, ΔНα↔β = 7.0 kJ·mol-1, Tβ↔γ = 1453 K, ΔНβ↔γ = 2.6 kJ·mol-1; for EuTbCuS3 Tα↔β = 1478 K, ΔНα↔β = 1.6 kJ·mol-1, Tβ↔γ = 1516 K, ΔНβ↔γ = 0.9 kJ·mol-1, Tγ↔δ = 1548 K, ΔНγ↔δ = 1.6 kJ·mol-1; for EuTmCuS3 Tα↔β = 1543 K, Tβ↔γ = 1593 K, Tγ↔δ = 1620 K; for EuYbCuS3 Tα↔β = 1513 K, Tβ↔γ = 1564 K, Tγ↔δ = 1594 K; for EuLuCuS3 Tα↔β = 1549 K, Tβ↔γ = 1601 K, Tγ↔δ = 1628 K. In the EuLnCuS3 series, the transition into either ferro- or ferrimagnetic states occurred in the narrow temperature range from 2 to 5 K. The tetrad effect in the changes of incongruent melting temperature and microhardness conditioned on rLn3+ as well as influencing of phenomenon of crystallochemical contraction were observed. For delimiting between space groups Cmcm and Pnma in the compounds ALnCuS3, the use of the tolerance factor t’ = IR(A)·IR(C) + a×IR(B)2 was verified.

Magmatic Evolution of Garnet-Bearing Highly Fractionated Granitic Rocks from Macao, Southeast China: Implications for Granite-Related Mineralization Processes

The widespread W-(Mo)-Sn-Nb-Ta polymetallic mineralization in Southeast (SE) China is genetically associated with Mesozoic highly fractionated granitic rocks. Such rocks have enigmatic mineralogical and geochemical features, making its petrogenesis an intensely debated topic. To better understand the underlying magma evolution processes, petrography, garnet chemistry and whole-rock major and trace element data are reported for Jurassic highly fractionated granitic rocks and associated microgranite and aplitepegmatite dikes from Macao and compared with coeval similar granitic rocks from nearby areas in SE China. Despite the fact that the most evolved rocks in Macao are garnet-bearing aplite-pegmatite dikes, the existence of coeval two-mica and garnet-bearing biotite and muscovite granites displaying more evolved compositions (e.g, lower Zr/Hf ratios) indicates that the differentiation sequence reached higher degrees of fractionation at a regional scale. Although crystal fractionation played an important role, late-stage fluid/melt interactions, involving F-rich fluids, imparted specific geochemical characteristics to Macao and SE China highly fractionated granitic rocks such as the non-CHARAC (CHArge-and-RAdius-Controlled) behavior of trace elements, leading, for example, to non-chondritic Zr/Hf ratios, Rare Earth Elements (REE) tetrad effects and Nb-Ta enrichment and fractionation. Such process contributed to the late-stage crystallization of accessory phases only found in these highly evolved facies. Among the latter, two populations of garnet were identified in MGI (Macao Group I) highly fractionated granitic rocks: small grossular-poor euhedral grains and large grossular-rich skeletal garnet grains with quartz inclusions. The first group was mainly formed through precipitation from highly evolved Mn-rich slightly peraluminous melts under low-pressure and relatively low temperature (∼700 °C) conditions. Assimilation of upper crust metasedimentary materials may have contributed as a source of Mn and Al to the formation of garnet. The second group has a metasomatic origin related to the interaction of magmatic fluids with previously crystallized mineral phases and, possibly, with assimilated metasedimentary enclaves or surrounding metasedimentary strata. The highly fractionated granitic rocks in Macao represent the first stage in the development of granite-related W-(Mo)-Sn-Nb-Ta mineralization associated with coeval more evolved lithotypes in SE China.

Origin of highly fractionated peraluminous granites in South China: Implications for crustal anatexis and evolution

Voluminous Mesozoic intra-continental granitic rocks occur in South China, which provide insights into the processes and associated P-T conditions of crustal anatexis and evolution in an intra-continental setting. Most granitic plutons contain multiple phase intrusions, commonly with an early-stage main-phase granite and a late-stage minor-phase highly fractionated granite, and the latter is generally thought to result from extreme differentiation of the main-phase granite. We challenge this model based on our case study on the Tianmenshan composite pluton that is composed of an early-stage biotite granite and a late-stage two-mica granite. Zircon U-Pb dating yields similar emplacement ages of 157.3 ± 3.1 Ma for the biotite granite and 158.5 ± 3.4 Ma for the two-mica granite. The two rock types are peraluminous with A/CNK = 1.07 to 1.17 and show comparable Nd isotopic compositions, with εNd(t) = −9.4 to −11.5 for the biotite granite and −10 to −11.2 for the two-mica granite. The two-mica granite is characterized by high silica (SiO2 = 75.2–77.5%), low abundances of Sr (2.3–42 ppm) and Ba (10–114 ppm), large negative Eu anomalies in the chondrite-normalized REE patterns and typical REE tetrad effect, which, along with its high Ga/Al ratios, Fe-index and F contents, suggesting its affinity to highly fractionated granite. Nevertheless, the petrographic observations, zircon REE concentrations and biotite compositions consistently demonstrate that the late-stage two-mica granite formed under more water-deficient and reduced conditions than the early-stage biotite granite. This, along with a modeling study of trace elements (Rb, Sr, Ba,Y and Nb) and the lack of continuum in terms of whole-rock chemistry and biotite compositions between the two rock units, suggests that the two-mica granite cannot be formed through differentiation of the main-phase biotite granite. We suggest that the parental magma to the late-stage two-mica granite could have been derived from partial melting of a granulitic residue after extraction of granitic melts to form the biotite granite from the Neoproterozoic metavolcano-sedimentary rocks, followed by a significant feldspar-dominated fractionation during magma ascent. This model may apply to most other composite granite plutons in South China, and is of significance to better understand the process of crustal anatexis and evolution in an intra-continental setting.

The Genesis of the Askartor Be-Mo Deposit in the North Xinjiang, Northwest China: Evidence From Geology, Geochemistry, U-Pb, and Re-Os Geochronology

The Askartor Be-Mo deposit is located in the southeastern area of the Chinese Altay orogenic belt in Xinjiang, NW China. Zircon U-Pb data show that there are two periods of magmatic activities in the Askartor Be-Mo ore district, namely, the Devonian granodiorite (386.8 ± 2.6 Ma) and biotite granite (385.4 ± 4.4 Ma), and the Triassic two-mica granite (247.5 ± 2.2 Ma) and muscovite granite (231.4 ± 2.0 Ma). The zircon U-Pb age of pegmatoid orebody is 220.6 ± 1.6 Ma which coincides with the molybdenite Re-Os isochron age of 228.7 ± 7.1 Ma. The two-mica and muscovite granites belong to the high-K Calc-alkaline series with peraluminous features, and are characterized by high SiO2 (71.92–75.41 wt%), and Al2O3 (13.43–15.98 wt%), and low TiO2 (0.01–0.25 wt%), Fe2O3 (0.11–1.14 wt%) and CaO (0.07–0.76 wt%). The highly fractionated element ratios of Y/Ho, Zr/Hf and Nb/Ta, and the rare earth element tetrad effect occur in the muscovite granite, indicating the fluid exsolution occurs at the late stage of magma evolution, and the muscovite granite experienced the strong self-metasomatism. Rayleigh fractional calculations show that the Askartor Be-Mo deposit is the product of multistage fractional crystallization of initial Be-enriched magma.

Mineralization of the Daolundaba Cu–Sn–W–Ag deposit in the southern Great Xing'an Range, China: Constraints from geochronology, geochemistry, and Hf isotope

Abstract The Daolundaba deposit, located in the southern Great Xing'an Range, is a medium-sized Cu–Sn–W–Ag deposit dominated by Cu. The intrusive rocks in the ore district mainly include the Early Permian Qianjinchang medium-grained biotite monzogranite and the Early Cretaceous Zhangjiayingzi fine-grained granite and porphyritic granite. Cassiterite U–Pb dating for two Cu–W–Sn ore samples yielded ages of 134.7 Ma and 136.8 Ma, respectively. Zircon U–Pb dating for fine-grained granite and porphyritic granite of the Zhangjiayingzi intrusion yielded ages of 134–136 Ma and 135 Ma, respectively. The Zhangjiayingzi intrusion is high-K calc-alkaline and featured by enrichment of Rb, Th, U, K, Nd, Zr, Hf, and Sm and steady depletion of Ba, Sr, P, Eu, and Ti, with extremely negative Eu anomalies and noticeable tetrad effect of rare earth elements, indicating the intrusion has a highly fractionated granite affinity. The Zhangjiayingzi intrusion has high zircon eHf(t) values (4.1–10.2) and relatively young zircon Hf two-stage model ages (541–929 Ma), suggesting that it dominated originated from the partial melting of a Neoproterozoic juvenile lower crust. The geochronology and geochemistry indicate that the mineralization of the Daolundaba deposit is closely related to Early Cretaceous highly fractionated granites. Fractional crystallization of granitic magmas is the important controlling factor for the formation of the Zhangjiayingzi highly fractionated granite and the Daolundaba Cu–W–Sn–Ag deposit.

Reworking of juvenile crust beneath the Bangong–Nujiang suture zone: Evidence from Late Cretaceous granite porphyries in Southern Qiangtang, Central Tibet

Crustal reworking in the collisional zones is commonly considered as an important process to result in continental crust differentiation and maturation. However, the reworking mechanism remains unclear. Here, a combined study of zircon SIMS U–Pb age, whole-rock major and trace element, Sr–Nd–Hf and zircon Hf–O isotopic geochemistry was carried out for the Duoma–Namuqie (DM–NMQ) granite porphyry intrusions, including DM, NMQ I, II and III intrusions, in southern Qiangtang, central Tibet. Zircon SIMS U–Pb dating yielded ages of 79–76 Ma, suggesting that they were formed in the later stage of Late Cretaceous. The DM granite porphyries are metaluminous to peraluminous with slightly low SiO2 (69.2–71.4 wt%) and high MgO (0.67–0.79 wt%) contents. They are depleted in high-field-strength elements (HFSEs) and enriched in light rare earth elements (LREEs), large ion lithophile elements (LILEs), and show weakly negative Eu anomalies. The NMQ III granite porphyries show similar elemental features to the DM granite porphyries, but have relatively high SiO2 (69.8–72.2 wt%) and low MgO (0.25–0.28 wt%) contents. Both of them belong to I-type granites. The NMQ I and II granite porphyries are relatively differentiated with high SiO2 (76.4–77.9 wt%), low MgO (0.11–0.16 wt%) contents, and significantly negative Eu anomalies. Extremely low LREE contents and notable REE tetrad effect can be observed in the NMQ II granite porphyries. The NMQ I and II intrusions are fractionated I-type granites. The whole-rock Sr–Nd–Hf and zircon Hf–O isotope data exhibit an enriched trend from the DM granite porphyries ((87Sr/86Sr)i = 0.7049–0.7050, εNd(t) = 1.2–1.6, εHf(t)whole-rock = 9.9–12.0, εHf(t)zircon = 7.4–11.5, δ18O = 6.2–7.1‰) to the NMQ III granite porphyry ((87Sr/86Sr)i = 0.7058–0.7067, εNd(t) = −0.9 to −1.1, εHf(t)whole-rock = 7.0–7.4, εHf(t)zircon = 2.7–9.5, δ18O = 7.2–7.6‰) to the NMQ I and II granite porphyries (εNd(t) = −3.0 to −4.3, εHf(t)whole-rock = 5.3–6.6, εHf(t)zircon = 1.5–7.4, δ18O = 6.6–9.2‰). We suggest that the DM–NMQ granite porphyries were mainly derived by partial melting of the juvenile mafic lower crust with variable volumes of ancient crustal components involved in their magma sources. The way in which these granite porphyries were formed provides evidence for the crustal differentiation and maturation in a post-collisional extensional setting triggered by the far-field rollback of the subducted Neo-Tethys oceanic slab