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The Cretaceous Abukuma metamorphic terrane consists of the oceanic Gosaisyo Series overthrust onto the terrigenous Takanuki Series. Although the dominant mineralogy defines one of the classic areas of andalusite-sillimanite type progressive metamorphism, there are several lines of evidence suggesting an earlier higher-pressure (up to c. 12 kbar) history of the Takanuki Series and the nearby Gosaisyo Series. These are: (1) the occurrence of rare although widespread relic kyanite in sillimanite+K-feldspar zonegrade pelitic rocks; (2) the high grossular content of garnet interiors (up to c. 30 mol %) overgrown by Ca-poor rims (c. 2 mol % grossular) in pelitic rocks containing Al 2SiO 5 minerals (sillimanite±relic kyanite±retrograde andalusite), plagioclase and quartz; (3) the occurrence of rutile as inclusions in garnet in pelitic rocks; and (4) the occurrence of relic corundum+almandine association in silica-poor and Al-Fe-rich rocks. Garnet in the Takanuki Series pelitic rocks commonly shows textural sector zoning and preserves growth zoning despite the high metamorphic grade, suggesting rapid changes in P-T conditions and a relatively short duration of high-temperature conditions. Combined with radiometric dating, these observations suggest that the Abukuma sillimanite+K-feldspar zone-grade rocks underwent a clockwise P-T path with very fast (>4 mm y−1) average burial and exhumation rates.

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