Returned samples indicate volcanism on the Moon 120 million years ago.

There is extensive geologic evidence of ancient volcanic activity on the Moon, but it is unclear how long that volcanism persisted. Magma fountains produce volcanic glasses, which have previously been found in samples of the Moon's surface. We investigated ~3000 glass beads in lunar soil samples collected by the Chang'e-5 mission and identified three as having a volcanic origin on the basis of their textures, chemical compositions, and sulfur isotopes.

Latitude-dependent oxygen fugacity in arc magmas.

The redox state of arc mantle has been considered to be more oxidized and diverse than that of the mid-ocean ridge, but the cause of the variation is debated. We examine the redox state of the Cenozoic global arc mantle by compiling measured/calculated fO of olivine-hosted melt inclusions from arc magma and modeled fO based on V/Sc and Cu/Zr ratios of arc basaltic rocks. The results indicate that the redox state of Cenozoic arc mantle is latitude dependent, with less oxidized arc mantle in the low latitudes, contrasting with a near constant across-latitude trend in the mid-ocean ridges.

Low Ni and Co olivine in Chang'E-5 basalts reveals the origin of the young volcanism on the Moon.

Mare basalts returned by the Chang'E-5 (CE5) mission extend the duration of lunar volcanism almost one billion years longer than previously dated. Recent studies demonstrated that the young volcanism was related neither to radiogenic heating nor to hydrous melting. These findings beg the question of how the young lunar volcanism happened.

Extensive crystal fractionation of high-silica magmas revealed by K isotopes.

Fractional crystallization plays a critical role in generating the differentiated continental crust on Earth. However, whether efficient crystal-melt separation can occur in viscous felsic magmas remains a long-standing debate because of the difficulty in discriminating between differentiated melts and complementary cumulates. Here, we found large (~1 per mil) potassium isotopic variation in 54 strongly peraluminous high-silica (silicon dioxide >70 weight %) leucogranites from the Himalayan orogen, with potassium isotopes correlated with trace elemental proxies (e.

Fusible mantle cumulates trigger young mare volcanism on the cooling Moon.

The Chang'E-5 (CE5) mission has demonstrated that lunar volcanism was still active until two billion years ago, much younger than the previous isotopically dated lunar basalts. How the small Moon retained enough heat to drive such late volcanism is unknown, particularly as the CE5 mantle source was anhydrous and depleted in heat-producing elements. We conduct fractional crystallization and mantle melting simulations that show that mantle melting point depression by the presence of fusible, easily melted components could trigger young volcanism.

Does Large-Scale Crustal Flow Shape the Eastern Margin of the Tibetan Plateau? Insights From Episodic Magmatism of Gongga-Zheduo Granitic Massif.

The mechanisms driving crustal deformation and uplift of orogenic plateaus are fundamental to continental tectonics. Large-scale crustal flow has been hypothesized to occur in eastern Tibet, but it remains controversial due to a lack of geologic evidence. Geochemical and isotopic data from Cenozoic igneous rocks in the eastern Tibet-Gongga-Zheduo intrusive massif, provide a way to test this model.

Felsic volcanism as a factor driving the end-Permian mass extinction.

The Siberian Traps large igneous province (STLIP) is commonly invoked as the primary driver of global environmental changes that triggered the end-Permian mass extinction (EPME). Here, we explore the contributions of coeval felsic volcanism to end-Permian environmental changes. We report evidence of extreme Cu enrichment in the EPME interval in South China.

Non-KREEP origin for Chang'e-5 basalts in the Procellarum KREEP Terrane.

Mare volcanics on the Moon are the key record of thermo-chemical evolution throughout most of lunar history. Young mare basalts-mainly distributed in a region rich in potassium, rare-earth elements and phosphorus (KREEP) in Oceanus Procellarum, called the Procellarum KREEP Terrane (PKT)-were thought to be formed from KREEP-rich sources at depth. However, this hypothesis has not been tested with young basalts from the PKT.

Two-billion-year-old volcanism on the Moon from Chang'e-5 basalts.

The Moon has a magmatic and thermal history that is distinct from that of the terrestrial planets. Radioisotope dating of lunar samples suggests that most lunar basaltic magmatism ceased by around 2.9-2.

An origin of ultraslow spreading ridges for the Yarlung-Tsangpo ophiolites.

As relics of ancient ocean lithosphere, ophiolites are the most important petrological evidence for marking the sutures and also play a key role in reconstructing plate configuration. They also provide valuable windows for studying crustal accretion and mantle processes occurring at modern ocean ridges. Abundant ophiolites are distributed along the Yarlung-Tsangpo suture and represent the relics of ocean lithosphere of the Neo-Tethys.

Natural Clinopyroxene Reference Materials for Sr Isotopic Analysis via LA-MC-ICP-MS.

Clinopyroxene is a major host mineral for lithophile elements in the mantle lithosphere, and therefore, its origin is vital for constraints on mantle evolution and melt generation. Sr isotopic measurement of clinopyroxene has been available since the recent development of laser ablation multicollector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS) in the 2000s. Therefore, there is an increasing demand for natural clinopyroxene reference materials for Sr isotope microanalysis.

GZ7 and GZ8 - Two Zircon Reference Materials for SIMS U-Pb Geochronology.

Here, we document a detailed characterisation of two zircon gemstones, GZ7 and GZ8. Both stones had the same mass at 19.2 carats (3.

Pliocene-Quaternary crustal melting in central and northern Tibet and insights into crustal flow.

There is considerable controversy over the nature of geophysically recognized low-velocity-high-conductivity zones (LV-HCZs) within the Tibetan crust, and their role in models for the development of the Tibetan Plateau. Here we report petrological and geochemical data on magmas erupted 4.7-0.

Magmatic record of India-Asia collision.

New geochronological and geochemical data on magmatic activity from the India-Asia collision zone enables recognition of a distinct magmatic flare-up event that we ascribe to slab breakoff. This tie-point in the collisional record can be used to back-date to the time of initial impingement of the Indian continent with the Asian margin. Continental arc magmatism in southern Tibet during 80-40 Ma migrated from south to north and then back to south with significant mantle input at 70-43 Ma.

A 'hidden' 18O-enriched reservoir in the sub-arc mantle.

Plate subduction continuously transports crustal materials with high-δ(18)O values down to the mantle wedge, where mantle peridotites are expected to achieve the high-δ(18)O features. Elevated δ(18)O values relative to the upper mantle value have been reported for magmas from some subduction zones. However, peridotites with δ(18)O values significantly higher than the well-defined upper mantle values have never been observed from modern subduction zones.