plasters are produced from a light refractory material, mainly mgo (m.p. 2800ºc), a binder, and a void forming substance for insulating purposes. different oxides from the slag penetrate into these voids and provide low melting-point phases suchasrhodonite (mnsio3) (1290ºc), tephorite (mn2sio4) (1345ºc), merwinite (ca3mgsi2o8) (1575ºc), monticellite (camgsio4) (1490ºc), and enstatite (mgsio3) (...

The nature of the planetary noble gas (PNG) carrier or Q-phase [1] in meteorites is still a subject of discussion. Failure to identify and isolate this carrier since the first successful concentration of it by a factor of ~200 in an Allende HF-HCl residue [1] and establishing it to be carbonaceous in nature [2], led eventually to the so-called “labyrinth” theory [3], according to which PNG init...

Introduction: In a companion abstract [1], we report evidence for tiny amounts of most likely primordial noble gases with solar-like elemental and isotopic composition admixed to Q-type primordial noble gases in an E chondrite. Here, we discuss possible implications of this finding for terrestrial planet formation. The genetic relation of the noble gases in planetary bodies to those in the Sun,...

Geophysical observations including surface heat flow data indicate the subducting slab becomes fully coupled to overlying mantle wedge at ?70–80 km depth. This maximum depth of decoupling (MDD) separates cool, stagnant forearc from warmer, convecting capable generating arc magmas. Thermodynamic calculations demonstrate that talc is stable in H2O-undersaturated parts where its stability controll...

Meteoritical Bulletin 109 contains the 2790 meteorites approved by Nomenclature Committee of Society in 2020. It includes 17 falls (Al Farciya, Auckland, Cavezzo, Flensburg, Gatuto, Kolang, Mahadeva, Matarka, Narashino, Novo Mesto, Oslo, Saint-Ouen-en-Champagne, Santa Filomena, Tarda, Tiros, Wad Lahteyba, Zhob), with 2336 ordinary chondrites, 131 carbonaceous chondrites (including 8 ungrouped o...