The natural high-pressure phase of cubic CdSe in impact glass from Zhamanshin crater

A CdSe high-pressure polymorph of the NaCl structural type of a₀ = 0.549 nm and Fm–3m space group was discovered in nature for the first time. Its composition is within range of CdSe–CdSe_1–х where x = 0.2 apfu. The phase was discovered as abundant nanosize inclusions in irgizite-type condensate glass separated from the sample of impact rock of the Zhamanshin crater (Central Kazakhstan). The treated mineral was presumably formed within a gas–plasma cloud at the moment of impact.     

Cosmogenic Substances in the Zhamanshin Crater

Using high-resolution analytical electron microscopy, heterogeneous fragments of cosmogenic substances, such as nickelphosphide Ni₃P and the unnamed intermetallide ZnAl₂, are detected for the first time for a large meteorite crater, the Zhamanshin circular structure. Due to the impossibility of simultaneous finding these phases in the same meteorite, an assumption is made on the cometary nature of the impactor of the Zhamanshin crater.     

Ziminaite,Fe3+VO4, a new howardevansite-group mineral from the Bezymyannyi volcano,Kamchatka, Russia

Mineralogy and Petrology - The new mineral ziminaite, ideally Fe3+VO4, was found in fumarole sublimates at the Bezymyannyi volcano, Kamchatka, Russia. Ziminaite occurs as lamellar, tabular or...     

Native ytterbium of regolith AS Luna-24

Native ytterbium first identified in a single brownish orange glass fragment collected from the deepest part (184–189 cm) of the bore core delivered from the Mare Crisium of the Moon to the Earth by the Luna-24 Automatic Station is described. As follows from X-ray elemental maps, the ytterbium grain is metallic. Possible mechanisms of its formation and reasons for its elevated corrosion stability are discussed.     

Mineral phases on the fracture of a glass particle and in the fines of a Luna 24 regolith sample

This paper reports new findings of native molybdenum and iron from Mare Crisium. Native tin, copper, and nickel were detected for the first time in this area of the lunar surface. Native tantalum and indium, intermetallic compound Ta₂Mo, and barium titanate Ba₂TiO₄ were found for the first time on the Moon. The latter two phases were observed for the first time in nature. It was shown that the investigated mineral phases correspond to different genetic groups (preimpact, impact, and postimpact mineral assemblages), which is in general typical of lunar regolith. Based on the morphological features of the identified mineral phases, the history of the formation of impact glass particles was reconstructed in part. They were probably affected by at least three impact events. It was concluded that the peculiar molybdenum geochemical anomaly observed in a group of orange impact glass fragments was not related to the impactor material but rather to the intrinsic enrichment in molybdenum of lunar rocks (target) in the area of the impact events. It was supposed that this enrichment could be of exhalative (fumarole) nature.     

The behavior of seasonal variations in induced seismicity in the Koyna–Warna region,western India

Based on the earthquake catalog data for the Koyna–Warna region of induced seismicity in western India, the seasonal variations in seismic activity associated with annual fluctuations in the reservoir water level are analyzed over the time span of the entire history of seismological observations in this region. The regularities in the time changes in the structure of seasonal variations are revealed. The seasonal seismic activity is minimal in May–June when the reservoir level is lowest. During the remaining part of the year, the activity has three peaks: the fall peak in September, winter peak in November–December, and spring peak in February–March. The first mentioned peak, which falls in the phase of the water level reaching its maximal seasonal value is considered as the immediate response of the fluid saturated medium to the additional loading under the weight of reservoir water. The two subsequent maxima concur with the decline phase in the reservoir level and are interpreted as the delayed response associated with the changes in the properties of the medium due to water diffusion. It is shown that the intensities of the immediate and delayed responses to the seasonal water level variations both vary with time as does their ratio. The probable factors affecting the variations in the intensity of the seasonal components of the reservoir-induced seismicity are discussed.