Determination of the Thermophysical Characteristics of the Lunar Soil Using Solar Heat

Solar System Research - The possibility of determining the thermophysical characteristics of the lunar soil by a penetrating probe when using solar heat as a heater is considered. The effectiveness...     

Hydrothermal activity on the CV parent body: New perspectives from the giant Transantarctic Mountains minimeteorite TAM5.29

TAM5.29 is an extraterrestrial dust grain, collected on the Transantarctic Mountains (TAM). Its mineralogy is dominated by an Fe‐rich matrix composed of platy fayalitic olivines and clasts of andradite surrounded by diopside‐jarosite mantles; chondrules are absent. TAM5.29 records a complex geological history with evidence of extensive thermal metamorphism in the presence of fluids at T < 300 °C. Alteration was terminated by an impact, resulting in shock melt veins and compaction‐orientated foliation of olivine. A second episode of alteration at lower temperatures (<100 °C) occurred postimpact and is either parent body or terrestrial in origin and resulted in the formation of iddingsite. The lack of chondrules is explained by random subsampling of the parent body, with TAM5.29 representing a matrix‐only fragment. On the basis of bulk chemical composition, mineralogy, and geological history TAM5.29 demonstrates affinities to the CV_ox group with a mineralogical assemblage in between the Allende‐like and Bali‐like subgroups (CV_oxA and TAM5.29 are rich in andradite, magnetite, and FeNiS, but CV_oxA lacks hydrated minerals, common in TAM5.29; conversely, CV_oxB are rich in hydrated phyllosilicates but contain almost pure fayalite, not found in TAM5.29). In addition, TAM5.29 has a slightly different metasomatic history, in between the oxidized and reduced CV metamorphic grades while also recording higher oxidizing conditions as compared to the known CV chondrites. This study represents the third CV‐like cosmic dust particle, containing a unique composition, mineralogy, and fabric, demonstrating variation in the thermal metamorphic history of the CV parent body(‐ies).     

Geophysical signature of the Tunnunik impact structure,Northwest Territories,Canada

In 2011, the discovery of shatter cones confirmed the 28 km diameter Tunnunik complex impact structure, Northwest Territories, Canada. This study presents the first results of ground‐based electromagnetic, gravimetric, and magnetic surveys over this impact structure. Its central area is characterized by a ~10 km wide negative gravity anomaly of about 3 mGal amplitude, roughly corresponding to the area of shatter cones, and associated with a positive magnetic field anomaly of ~120 nT amplitude and 3 km wavelength. The latter correlates well with the location of the deepest uplifted strata, an impact‐tilted Proterozoic dolomite layer of the Shaler Supergroup exposed near the center of the structure and intruded by dolerite dykes. Locally, electromagnetic field data unveil a conductive superficial formation which corresponds to an 80–100 m thick sand layer covering the impact structure. Based on the measurements of magnetic properties of rock samples, we model the source of the magnetic anomaly as the magnetic sediments of the Shaler Supergroup combined with a core of uplifted crystalline basement with enhanced magnetization. More classically, the low gravity signature is attributed to a reduction in density measured on the brecciated target rocks and to the isolated sand formations. However, the present‐day fractured zone does not extend deeper than ~1 km in our model, indicating a possible 1.5 km of erosion since the time of impact, about 430 Ma ago.     

The Meteoritical Bulletin,No. 107

Meteoritical Bulletin 107 contains 2714 meteorites including 16 falls (Aba Panu, Ablaketka, Andila, Gueltat Zemmour, Hamburg, Karimati, Mahbas Arraid, Mangui, Mazichuan, Mukundpura, Ozerki, Parauapebas, Renchen, San Pedro de Urabá, Sokoto, Tintigny), with 2226 ordinary chondrites, 168 HED achondrites, 132 carbonaceous chondrites (including 41 CM, 34 CV, 26 CO, 21 CK, 4 CR, 5 ungrouped), 43 ureilites, 30 iron meteorites (including 2 ungrouped), 29 lunar meteorites, 22 Martian meteorites, 16 primitive achondrites (including 3 brachinites), 12 Rumuruti chondrites, 9 enstatite chondrites, 7 ungrouped achondrites, 6 pallasites, 5 mesosiderites, 3 enstatite achondrites, 3 ungrouped chondrites, and 2 angrites. 1569 meteorites are from Antarctica, 835 from Africa, 206 from South America, 62 from Asia, 21 from North America, 11 from unknown locations, 8 from Europe (including one from Russia), and 1 from Oceania.     

Redshift Measurements for Galaxies in Clusters by Multislit Spectroscopy at the 1.5-m Telescope RTT150

Astronomy Letters - An example of simultaneous spectroscopic redshift measurements for a large number of galaxies in a cluster by multiobject spectroscopy with the medium- and low-resolution TFOSC...     

3D Static Modeling and Petrographic Aspects of the Albian/Cenomanian Reservoir,Komombo Basin,Upper Egypt

Natural Resources Research - The Albian/Cenomanian reservoir is one of the two main reservoirs composing the petroleum system in the Komombo Basin. However, these reservoirs have not previously...     

Effects of Artefacts on Natural Gradient Single-Borehole Tracer Dilution Tests

Natural Resources Research - Single-borehole tracer dilution tests are used to estimate the Darcy velocity (vd) which is important for investigating contaminant transport and distribution within...     

Co-simulated Size Number: An Elegant Novel Algorithm for Identification of Multivariate Geochemical Anomalies

Natural Resources Research - Identification of geochemical anomalies is of particular importance for tracing the footprints of anomalies. This can be implemented by advanced techniques of...     

Mini-inflation prior to the cosmic confinement transition?

The onset of the confinement transition in the early universe is studied within the Friedmann model. Exploiting a bag model equation of state for the deconfined matter, which is generalized to include also metastable states, the possibility of a mini-inflationary epoch is demonstrated. A criterion of metastability is derived to estimate parameters of this mini-inflation.