C—9.

Sess. 11.—1897. NEW ZEALAND.

REPORT ON THE GEOLOGY OF THE CAPE COLVILLE PENINSULA, AUCKLAND. BY ALEXANDER McKAY, F.G.S., HON. M., N.Z. INST., GOVERNMENT GEOLOGIST.

Presented to both Houses of the General Assembly by Command of Hts Excellency.

OCOSTTEiTTS.

Page. Upper Miocene Formation— continued. Page. Introduction .. .. .. .. .. 1 Beeson's Island Group— continued. Physical Geography .. .. .. .. 1 In the Waiwawa and Kauaeranga Valleys ~ 62 Previous Geological Explorations .. .. .. 6 In the Puriri, Omaha, and Hikutaia Valleys .. 63 By Yon Hochstetter .. .. .. .. 6 Near Mackaytown, and thence to Te Aroha .. 63 By Sir James Hector, 1864-70 .. .. ..8 Relations of the Beeson's Island Group.. 63-64 By Captain Hutton .. .. .. .. 12 Older Pliocene .. .. .. .. .. 64 By Sir James Hector, 1870 .. .. .. 17 Acidic Group .. .. .. .. .. 64 By S. H. Cox, 1880-82 .. .. .. .. 19 At Mercury Bay .. .. .. .. 64 By A. McKay, 1883 .. .. .. ..26 On East Side of Cook Bay .. .. ..65 By James Park, 1893 .. .. .. 26 Round Sources of Purangi Creek, thence to Stony By Professor Hutton, 1887 .. .. ..28 Creek .. .. ; .. ..65 By James Park, 1890 .. .. .. 34 Stony Creek to Lower Tairua River .. 65 Description of the Different Formations present .. 40 i Bull's Run to Upper Kauaeranga .. .. 65 Table of Formations .. .. .. .. 40 West of Table Mountain .. .. .. 66 Maitai Series .. .. .. .. 41 In Fourth Branch, Tairua Valley .. .. 66 Slate in the Northern Part of Peninsula .. 41-42 On Marsh's Farm, Upper Landing, Tairua River 66 Slate at Cabbage Bay .. .. .. 42 On the Main Divide south of Puriri Stream .. 66 Slate at Kennedy Bay .. .. .. ..43 In the Middle Tairua and Wharekawa Valleys .. 67 Slate in the Tokatea Ranges .. .. 43 Round Sources of Tairua and Hikutaia Rivers .. 67 Slate in the Success Ranges .. .. ..44 In Upper Ohinemuri Valley .. .. ..67 Slate at. the Tiki .. .. .. .. 44 Between Waitekauri and Owharoa .. .. 67 Slate in the Manaia Valley .. .. ..44 Near Mackaytown .. .. .. ..68 Slate, Kirita Bay to Tapu Creek .. ..45 Forming Hikurangi Mountain .. ..68 Slate in Kuaotunu Peninsula .. .. ..45 Age and Relation of Acidic Group .. ..68 Metalliferous Deposits of the Slate Formation .. 46 Where Gold-bearing, yielding Opals, &c. .. 69 Remarks on the Relations of the Older Rocks of Cape Its Building-stones, Spherulite, Perlite, Ac. .. 69 Colville Peninsula .. .. .. ..47 Newer Pliocene or Pleistocene .. .. ..70 Cretaceo-tertiary or Goal-bearing Formation .. 47 Kauaeranga Beds .. .. .. ..70 Description of the Bods at Cabbage Bay .. .. 48 Recent .. .. .. .. .. 70 Their Relation to the Volcanic Series .. ..49 Dyke-intrusions.. .. .. .. ..70 Volcanic Formations .. .. .. .. 49 Thermal Springs, Sinter Deposits .. .. .. 71 Thames-Tokatea Group .. .. .. ..49 Faults .. .. .. .. .. ..73 Thames-Coromandel Area .. .. .. 50 Gold .. .. .. .. .. 73 Puriri Area .. .. .. .. 54 Concluding Remarks .. .. .. 75 Karangabake Area .. .. .. ..54 Silver-bearing Lodes, Great Barrier Island .. .. 75 Te Aroha Area .. .. .. 55 General Geological Sketch of Great Barrier Island .. 75 Kapanga Group .. .. .. .. ..55 Extract from Professor Huttou's Report.. .. 75 Coromandel Area .. .. .. ..56 Rocks compared with those of Cape Colville PeninNeavesville Area. .. .. .. 58 sula .. .. .. .. 76 Southern Area .. .. .. .. £9 Area specially examined .. * .. ..76 The Kapanga Group compared with the Thames- The Reefs .. .. .. .. 78 Tokatea Group .. .. .. 59 Proprietary and Premier Claims .. 78 Upper Miocene Formation .. .. .. 60 Aotea No. 2 .. .. .. .. .. 78 Beeson's Island Group .. .. .. 60 lona Claim .. .. .. .. 78 Beeson's Island to Kirita Bay.. .. ..60 Kaitokai Claim .. .. .. ..79 At Cabbage Bay .. .. .. 60 Great Barrier Claim .. .. .. 79 Stony Bay to Port Charles .. .. .. 61 Ryan's Freehold .. .. .. .. 79 Kennedy Bay to Whangapoua .. 62 Egerton's Claim .. .. .. 80 Whangapoua to Kuaotunu .. .. 62 Mount Argentine, &c. .. .. .. 80 In the Mahakirau Valley .. .. .. 62 Great Barrier Excelsior and Other Claims .. 80

ERRATA.—Page 37, fourth paragraph, third-last line, for " scalanohendrons," read " scalenhedrons." Page 41, third paragraph from bottom, first line, for "Thames, Port Charles," read "Thames for Port Charles."