GEOLOGY AND GROUND-WATER RESOURCES OF THE ISLAND OF KAUAI, HAWAII G. A. MACDONALD D. A. DAVIS AND D. C. COX BULLETIN 13 HAWAll DIVISION OF HYDROGRAPHY STATE OF HAVVAII WILLIAM F. QUINN, Governor Frank W. Hustace, Commissioner of Public Lands DIVISION OF HYDROGRAPHY HOWARD S. LEAK, Chief Hydrographer BULLETIN 13 GEOLOGY AND GROUND-WATER RESOURCES OF THE ISLAND OF KAUAI, HAWAII BY GORDON A. MACDONALD Former District Geologist, U.S. Geological Survey DAN A. DAVIS District Geologist, U.S. Geological Survey AND DOAK C. COX Geologist, Ha=aiian Sugar Planters' Association Prepared in cooperation with the Geological Survey, United States Department of the Interior Printed in tho State of Ilawaii, United Stalt;,,; vf America, 1960 CONTENTS PAGE Abstract ......................................................................................................................... 1 Introduction ........................... ... ............ ... ... ... .............. ......................... 4 Scope oi investigation and report.. ........................................................................ 4 Location and area..................................................................................................... 4 History ......................................................................................................................... 5 .Population ............. ..... .... ... ... ......... ... .... ......................................................... 9 Previous studies ........... ............ .......... .................. .. ................................................. 9 History of the investigation ........................................................................... 12 The geologic map............................................................................. 13 Acknowledgments .................................................................................................. 13 Geomorphology ........................................................................................................ 15 Features associated with calderas............................................................... 15 Features caused by faulting and collapse............. ........ ................ 15 Features caused by late volcanic activity........ .................... 16 Streams and valleys............................................................................................... 16 Sea cliffs ................................................................................... 19 LJeposi tional features ............................................................................................ 19 The rocks and their water-hearing properties.. ....................................................... 19 General statement ...................................................................................... 19 \Vaimea Canyon volcanic series ............................................................................. 21 General character and age of the rocks .................................................... 21 "'.\apali formation ............ .. ...................... .......................... 23 Definition .................. .... ... ...... .. ................................ 23 Distribution and attitude........ ...................... ....................................... 24 Lava Ho,vs ............................. ........................................................ 26 .Ash beds ........................... ...... .................................. 29 1 \ ents ................................................... ......................................... 30 \Vater-bearing properties ............... 31 ()lokele formation .............................................................................................. 32 Definition ......................... ........ ................................................................ 32 Distribution ............ ........... .. .................. ............................. .. ................ 33 The caldera boundary............ ..... ... ... .............................................. 33 Lava flows ................................................................................................ 38 Ash and soil beds .................................................................................... 38 Vents .......................................................................................................... 39 \\Tater-bearing prupertie;, ......................................................................... 39 Haupu ~0~~1ation .................................................................................. , ...... 40 Defnuhon ..................................................................................................... 40 Distribution ................................. ... ... .. ............................................... 40 Character of the rocks................................................................................ 41 \\Tater-bearing properties ..... ........................................................... 42 Makaweli formation .. ...... .......... ............................................ 42 Definition ............ ... ............. .................. ............................................ 42 Distribution and attitude............................................................................. 43 The grabeu boundary ................................................................................. 44 Lava flows ................................................................................................. 46 Pyrocl;i sti,· rnc-k.;; ......................................................................... 46 Mokuone member ............... 47 \\Tater-bearing propertie~ ................ ····--············· .......................... 48 Intrusive rocks ............................... ....................................................... 49 E:oloa volcanic series..................... ...................... .. ............ 52 Definition ................................................................................................... 52 General character and age of the rocb............................................ 52 Distribution ................................................................................................ 53 Relation to older rocks ............................................................................... 55 Unconformities within the Koloa vokanic series........................... 56 Volcanic rocks ................................................................................... 59 Lava Aows ........................................................................................... 59 A. sh and cinder beds.... .. ............. 65 iii CONTENTS PAGE Vents ...................................................................................................... 68 Intrusive rocks ...................................................................................... 74 \Yater-bearing properties .. ................................................................ 75 Palikea formation ........................................................................................ 75 Definition ................................................................................................ 75 Distribution 76 :Nature of the rocks...................................... ............................. ......... 76 Origin of the Palikea formatio11-....................................................... 81 W ater-be::i ring llroperties ... ...... ............................................... 84 Sedimentary deposits .......................................................................................... 84 Older alluvium .............................................................................................. 84 Lithified dune sands...................................................................................... 85 Lagoon deposits of the Mana plain....... ... ......... 86 Younger alluviun1 ........................................................................................ 86 Beach deposits ..................................................................... ... ...... ................ 86 Unconsolidated dune sand............................................................................ 87 Geologic structure ............................... B7 General features ..................... ......... ................... ... ...... ... ............. ......................... .... ..... 87 Caldera boundary faults.............................................................................................. 87 Kalalau fault .................................................................................................................. 88 Wainiha fault ................................................................................................................ 88 Napali fault ....................................................... ......................... .................................. 89 Minor faults ...................................................................... ............................................ 89 The Makaweli depression............................................................................................ 90 The Lihue 94 Geologic history ............................................................... ................... ............................... ... 95 Petrography, by G. A. Macdonald.................................................................................... 98 Introduction