The volcanic strata mainly consist of basalt, trachybasalt
, andesite, and basaltic andesite that are intruded by monzonite, monzodiorite, granodiorite, and syenite.
In tephrite and trachybasalt
the phenocryst of plagioclase, augite, olivine, pargasite and phlogopite are embedded in the groundmass of plagioclase, Ti-augite, pargasite, phlogopite, apatite, opaque minerals (ilmenite) and devitrified glass (Sawada et al.
The ultramafic unit is intruded by thin (a few meters to less than 2 cm wide) trachybasalts
and surrounded and overlain by massive basalts, trachybasalts
and basaltic trachy-andesite flows and breccias.
Basaltoid rocks are represented here by predominant tephrites and basanites, rare foidites, and singular basalts and trachybasalts
(Bolewski and Parachoniak, 1982; Kozlowska-Koch, 1987; Wierzcholowski, 1993; Lorenc et al.