B. KOTO, ARCHiEAX FORMATION OF THE ABUKUMA PLATEAU, 293 



COTsTTEISrTS. 



I. — Introduction 



IL — The Abukuma Plateau 



III. — Arch^an geology 



iy._STRATIGRAPHICAL RELATIONS AND STRUCTURE— SECTIONS 



Y. — Petrography of the Laurentian rocks 



A. AmPHIBOLE-CtRANITES and BIOTITE-CtRANITE 



B. Structural varieties of granites ... 



a) A mphibole-granite 



b) Imperfectly scJtistose ampJiiboIe-grauife 



c) ScJiistose amphibole-granife 



d) Schistose epklote-granite 



e) Biofite-grcmite 



f) Caught-up granite 



VI. PfTROGRAPHY of the TaKANUKI SERIFS 



A. Gneiss-mica-schists 



Aa) Gneiss-mica-scliist 



A b) Two- mica- schist 



Ac) Gariiet-biotite-schist 



Ad) Horvbleude-biotite-schist 



B. Titanite-amphibole-schists 



Ba) Titanite-biotite-amphibolite 



Bb) Titanite-salite-amphiboJite 



Be) Titan ite-feldspar-aviphibolite 



Bd) Biotite-amphihoJe-gneiss 



Yir. — Petrography of the Gozaisho series 



A. Amphibolites of the Gozaisho road 



B. Mica-schists 



C. Garnet-chloritoid-quartz-schists 



D. Amphibole-picrites 



VIII. — Dyke-rocks 



A. Pegmatophyritic dykes 



B. Dykes of augite-dioritic lamprophyre 



C. Dykes of diorite-porphyrites 



IX. — Summary 



Fagb. 

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