Ezochiite, a newly-discovered platinum-group mineral in the thiospinel group having the ideal formula Cu⁺(Rh³⁺Pt⁴⁺)S₄, was discovered in samples from the Tomamae coast near Tomamae town, Hokkaido, Japan. Additional specimens were later found in the Shosanbetsu river, Ainusawa river and Obira coast, Hokkaido. Ezochiite crystallized in melt pockets trapped in isoferroplatinum grains, occurring in the form of anhedral grains less than 5 μm in length. Ezochiite is associated with sulfide minerals such as braggite, cooperite, torryweiserite and chalcopyrite. It is opaque and has a metallic luster with a bluish gray color in reflected light. The Mohs hardness of this mineral was estimated to be 5 by analogy with related thiospinel group minerals and a density of 6.66 g·cm^-3 was calculated from the empirical formula and powder X-ray diffraction data. The empirical formula, on the basis of 7 apfu was (Cu⁺_0.85Fe³⁺_0.15)_Σ1.00(Rh³⁺_1.09Pt⁴⁺_0.78Ir³⁺_0.08Pt²⁺_0.05)_Σ2.00S_4.00 for a specimen obtained from the Tomamae coast. The powder X-ray diffraction study indicated that the mineral exhibits the spinel structure, space group Fd3m, with lattice parameters a = 9.8559(14) Å and V = 957.4(4) ų (Z = 8). Evidence for a spinel structure was also provided by Raman spectra. Data from samples of ezochiite and cuprorhodsite from samples sourced in Hokkaido showed a compositional relationship based on coupled Fe³⁺_0.5Rh³⁺-Cu⁺_0.5Pt⁴⁺ substitution. Ezochiite is not rare. It is also found various other geological environments, including in ophiolites, Ural-Alaskan intrusions and mafic-ultramafic intrusions.

A WNW-ESE-trending mafic dyke intruding across major structures in high-grade metamorphic rocks was found at Niban Iwa (translated as “Number Two Rock”) in the Proterozoic Lützow-Holm Complex of East Antarctica. It is holocrystalline and aphyric, and comprises biotite, hornblende, plagioclase, orthoclase, quartz, apatite, and titanite. Chemically the dyke rock is alkali basalt with high K₂O/Na₂O and total Fe contents, and low Cr and Ni contents, indicating that it was formed by the differentiation of olivine from a primary alkali basaltic magma derived from the subcontinental mantle. The Rb-Sr mineral isochron age was obtained of 487 ± 15 Ma with Sr_IR = 0.70486 ± 0.00007. Considering that the metamorphic age of the gneisses at Niban Iwa was estimated to be 532 Ma, the dyke probably intruded after metamorphism as part of the post-orogenic igneous activity following the collision of East and West Gondwana.

The 2021 eruption of Fukutoku-Oka-no-Ba (FOB), which is a submarine volcano located at the southern end of the Izu-Ogasawara arc, produced a large number of pumice clasts that drifted to many places in the islands of Japan and eastern Asia. Amongst the typical gray pumice clasts, several peculiar clasts have been discovered, such as those with a black coloration and containing mafic enclaves. This study found a mostly bimineralic enclave consisting of plagioclase phenocrysts and an alkali feldspar matrix, with minor cristobalite, TiO₂ minerals (anatase and rutile), and Fe sulfide. The chemical composition of the plagioclase phenocrysts is similar to that reported from the FOB pumice, and the tie line of the alkali feldspar and plagioclase in a Ca-Na-K ternary diagram indicates that they originated from melt extracted from the crystal mush of the FOB magma reservoir. The cristobalite occurs in the voids in the matrix, in which surrounding alkali feldspar compositions changed gradually along the ternary feldspar solvus of ∼850 °C. The formation of a cristobalite-bearing bimineralic enclave can be explained by (1) the melt was extracted and accumulated at the shallow part of the magma reservoir, which crystallized as syenitic rocks; (2) subsequent degassing-related alteration within the volcanic conduit that caused plagioclase breakdown and cristobalite crystallization; and (3) entrainment of the syenitic rock fragment by the nanolite-bearing magma being erupted from the conduit.

The Southern Granulite Terrain of peninsular India consists of a wide range of metamorphic rocks with formation ages that span the late Archean Era to the Cambrian Period. It consists of numerous tectonic blocks dissected by deep crustal-scale shear zones. The Madurai Block is the largest crustal block, comprising Neoarchean to Ediacaran-Cambrian gneisses that include charnockite, hornblende-biotite gneiss, mafic granulite and metapelite, amongst other lesser rock types. This study focuses on the geochemistry of granulite-facies rocks from the western part of the Madurai Block, how these rocks correlate with similar types in other tectonic blocks of the Southern Granulite Terrain, and the implication of such correlations for East Gondwana tectonics. The geochemistry of the various granulite-facies rocks from the western Madurai Block reveals metaluminous to slightly peraluminous, calcic to alkalic, and ferroan to magnesian signatures. Geochemical tectonic discrimination diagrams indicate both A-type granitoid and Cordilleran affinities, consistent with petrogenesis in active continental margin and extensional tectonic settings, with chemical variation also generated through magmatic differentiation. Similar lithological, geochronological and geochemical features have been reported from granulites of the Antananarivo Block of Madagascar, based on which a correlation can be made with the western Madurai Block that predates Gondwana assembly.