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Numerous small octahedra of a black, brittle, magnetic mineral were found in calciphyre and brucite marble, occurring in the northern part of the exocontact zone of the Kondyor ultramafic-alkalic massif (south-eastern part of the Aldan Shield, 250 km north west of sea port Ayan). Their composition corresponds to the group from titanium magnesioferrite (11.53% TiO2) to titanium-rich magnesian spinel (27.34% TiO2), similar to spinellide found in Greenland (Gittins et al., 1982) and in Iraq (Al-Hermezi, 1985) and approved by the Commission on New Minerals as a new mineral named qandilite. Hardness, specific gravity, and reflectance of Kondyor qandilite are similar to those of the Iraq mineral. Peaks of IR-absorption spectra are equal to 580-590 cm−1 (v2) and 431-438 cm−1 (v2). There is a positive correlation between lattice parameters and the amount of Mg2TiO4: from 8.368 Å at 26.6% to 8.429 Å at 60.4%. Kondyor qandilite crystallized together with geikielite, oxidized alumina spinel (8.55% Fe2O3, ftotal : 16.5%), periclase, and forsterite.

During Leg 61 of the Deep Sea Drilling Project the deepest (1068.5 m) hole was drilled in the Nauru Basin. It penetrated rocks of two magmatic cycles. The first ranged from Pleistocene to Oligocene and is represented by thin ash layers, composed of fragments of fresh scoriaceous alkalic and tholeiitic basalts, and crystal fragments of olivine, chrome-diopside, spinel, and feldspars. Specific features of the rocks are high calcium content (up to 14 wt.% CaO) and titanium content (up to 4 wt. % TiO 2), accompanied by high alkalinity. Rare varieties of titanium-rich (up to 30 wt.% TiO 2) magnetite and Fe-Ca-anorthoclase are present among the fragments. According to the rock and mineral assemblage, the fragments from the ash layers may be considered to be derivatives of a subaerial, Hawaii-type volcano. In the interval from Cenomanian to Hauterivian, a tholeiite sill complex was formed, the upper part of which (562-728 m) is represented by essentially holocrystalline dolerites alternating with the hyaloclastites, whereas in the lower part (728-1068 m), thin-layered, pillow-like basalt sills are dominant. Rocks of the upper part are characterized by high iron and titanium contents, and show considerable fractionation (differentiated tholeiites) as compared with the homogeneous, low-titanium and magnesia-rich basalts of the lower part (primitive tholeiites). Consolidation of dolerites was culminated by the formation of quartz-potassium feldspar granophyric aggregates. According to the compositions of liquidus spinel and olivine, crystallization of the magma began at T ~ 1210 to 1240°C and/ θ2) 10~8 to 1O~8• 5 atm. Within the low-temperature veins in dolerites, silica-bearing magnetite (up to 3.5% SiO 2) was discovered. On the basis of mineralogical-geochemical features, the Nauru sill complex is classified as an oceanic trap formation.

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