Moon’s Crust Underwent Resurfacing after Forming from Magma Ocean

A research team took to the lab to recreate the magmatic melt that once formed the lunar surface and uncovered new insights on how the modern moonscape came to be. Their study found found that one of the great mysteries of the lunar body’s formation – how it could develop a crust composed largely of just one mineral – cannot be explained by the initial crust formation and must have been the result of some secondary event.

ZF 8 TX Powershift Transmission Successfully Deployed for the First Time in Eastern Europe for Oil and Gas Production

High-pressure pump system equipped with the ZF 8 TX used for the first time in gas fields in the Ukraine
In operation since January 2017, it has shown outstanding reliability under severe temperature fluctuations
Benefits include low-maintenance operation and simple, comfortable use
Shifting the ZF 8 TX allows control of pressure and rate to ramp up under any pressure and any speed

An integrated approach for extraction of lithology information using the SPOT 6 imagery in a heavily Quaternary-covered region—North Baoji District of China

We studied the applicability of SPOT (Systeme Probatoire d’Observation de la Terre) 6 satellite imagery for red sandstone interpretation in the heavily loess-covered northern Baoji District, China, which is always a crucial but challenging issue in remote sensing geological mapping. First, the non- or sparsely vegetated subareas were outlined in order to narrow the interpretation target area; second, band-math and the fractal “DN-N” (digital number-frequency) algorithm was conducted to extract the sandstone-associated anomalies; third, a series of spatial analysis, for example, overlaying and clumping, was employed for elimination of the false anomalies; finally, we took advantage of matched filtering to discern the non- (red) sandstone outcrops in local areas. Generally, the interpretation accuracy based on this novel technical proposal is acceptable—74% or slightly less (taking the geological sketch as reference criteria)—and can be well proven by field investigation. This study may have contributed a useful case study for remote-sensing lithological mapping in the Quaternary-covered areas.

Geochronology and geochemistry of the Late Jurassic bimodal volcanic rocks from Hailisen area, central-southern Great Xing’an Range, Northeast China

Zircon U–Pb dating and whole-rock geochemical analysis have been studied on the Late Jurassic volcanic rocks in the Hailisen area, Northeastern China, with the aim of constraining the tectonic evolution of the central-southern Great Xing’an Range during the Late Jurassic. The volcanic rocks mainly consist of andesite from the Tamulangou Formation, and rhyolite and minor dacite from the Manketouebo Formation. The results of inductively coupled plasma-mass spectrometry Zircon U–Pb dating for two andesites and one dacite indicate that they formed in the Late Jurassic (161–150 Ma). The mafic rocks are characteristic of low TiO2 (1.01–1.04 wt.%) and P2O5 (0.23–0.31 wt.%) contents, and high Al2O3 (17.19–20.18 wt.%) and CaO (6.69–7.45 wt.%) contents, and belong to the low-K tholeiitic series. These mafic rocks are also characterized by moderately enriched light rare earth element (LREE) patterns and high abundances of Th, U, Zr, and Hf but negative Nb, Ta, and Ti anomalies. The felsic rocks are enriched in alkalis, Th, U, and LREEs; depleted in Ba, Sr, Nb, Ta, and Ti; and exhibit moderately LREE-enriched patterns. These features indicate that the mafic volcanic rocks were likely formed by the partial melting of a lithospheric mantle that was metasomatized by subduction-derived components, but the felsic rocks could derived by partial melting of a crustal source. The Tamulangou and Manketouebo formations have compositions of typical bimodal volcanism, an extensional environment, similar to a post-orogenic setting, which might be related to the closure of Mongol–Okhotsk Ocean.

Early Paleozoic arc magmatism and metamorphism in the northern Qilian Block, western China: Petrological and geochronological constraints

The Datong–Menyuan Complex, located in the northern margin of the Qilian Block, is composed dominantly of high-grade metamorphic rocks covered by a Paleozoic–Mesozoic sedimentary sequence. In this study, we present petrographic observation, conventional thermobarometry and P–T pseudosection modelling, whole-rock major and trace geochemistry, zircons U–Pb dating and Hf isotopic data together, to reveal the relationship between the magmatism and metamorphism along the northern margin of the Qilian Block. The anticlockwise P–T paths of gneiss and amphibolites are obtained using the garnet isopleths thermobaromety combined with phase equilibria modelling. The P–T pseudosection also shows that the gneiss and amphibolite underwent similar retrograde metamorphism with slightly different peak metamorphic conditions at ~720 °C and ~6.4 kbar for the former and ~700 °C and ~7.1 kbar for the latter. This indicates the Datong–Menyuan Complex recorded an amphibolite–granulite-facies metamorphism. The zircon U–Pb analyses of 3 intrusive rocks including granitic dike, diorite, and granite are dated at ca. 499.8 ± 4.3, 495.9 ± 3.3, and 505.5 ± 3.2 Ma, and 3 representative metamorphic rocks underwent contemporaneous metamorphism at ca. 498.9 ± 4.1, 504.4 ± 3.9, and 499.3 ± 2.9 Ma. Zircon Hf isotopic analyses show that 505-Ma zircons from the granitoid have positive εHf(t) values ranging from +8.5 to +12.8, indicating a depleted mantle source. Based on the penecontemporaneous magmatic and metamorphic event, we suggest that the southward subduction of the north Qilian Ocean triggered the activity of mantle-derived magma and coeval metamorphic event. A subsequent compression is attributed to crustal thickening, indicating counter clockwise P–T paths. Combining these data with previous studies, it suggests paired metamorphic belts: the penecontemporaneous high-temperature metamorphic belt related to an arc along the northern Qilian Block and high-pressure/low-temperature metamorphic belt existed in the north Qilian suture.