GEOLEX

Summary of Citation: Koolau

Publication:
Wentworth, C.K., 1926, Pyroclastic geology of Oahu: Bernice P.
   Bishop Museum Bulletin, no. 30, 121 p.

Usage in Publication:
Koolau Basalt

Modifications:	Geologic Province:	Dominant Lithology:
First used	Oahu

Summary:
Koolau Basalt is oldest formation on Oahu making up main mass of NE Oahu. Next youngest is complex calcareous reef formation.

Summary of Citation: Koolau

Publication:
Stearns, H.T. and Vaksvik, K.N., 1935, Geology and ground-water
   resources of the Island of Oahu, Hawaii: Hawaii Division of
   Hydrography Bulletin, no. 1, 479 p.

Usage in Publication:
Koolau volcanic series*

Modifications:	Geologic Province:	Dominant Lithology:
Named	Oahu	Basalt Tuff Breccia

Summary:
Named for Koolau Range, Island of Oahu. [Formerly Koolau basalt of Wentworth, 1926]. Consists of basalt, beds of vitric and lithic tuff, dike complex, breccia, and intercalated soils making up Koolau Range. Basalt exceeds 3100 ft in thickness. Conformably overlies Kailua volcanic series. Unconformably overlaps Waianae volcanic series in Schofield Plateau area. Underlies with erosional unconformity Honolulu volcanic series.

Summary of Citation: Koolau

Publication:
Stearns, H.T., 1939, Geologic map and guide of the Island of
   Oahu, Hawaii: Hawaii Division of Hydrography Bulletin, no.
   2, 75 p., (incl. geologic map, scale 1:62,500)

Usage in Publication:
Koolau volcanic series*

Modifications:	Geologic Province:	Dominant Lithology:
Mapped	Oahu

Summary:
Basalt flows, tuff beds, dikes, and breccia members mapped separately. Unconformably underlies Pleistocene consolidated sediments and Recent unconsolidated sediments in valleys and along beaches. Map shows Tertiary and early Pleistocene(?) age.

Summary of Citation: Koolau

Publication:
Stearns, H.T., 1940, Supplement to the geology and ground-water
   resources of the Island of Oahu, Hawaii: Hawaii Division of
   Hydrography Bulletin, no. 5, 164 p.

Usage in Publication:
Koolau volcanic series*

Modifications:	Geologic Province:	Dominant Lithology:
Areal limits	Oahu

Summary:
Present interpretation is that Kailua lavas accumulated as flows in caldera of Koolau volcano. Now proposed to group these rocks with Koolau throat breccia and call them all caldera complex.

Summary of Citation: Koolau

Publication:
Stearns, H.T., 1946, Geology of the Hawaiian Islands: Hawaii
   Division of Hydrography Bulletin, no. 8, 106 p.

Usage in Publication:
Koolau volcanic series*

Modifications:	Geologic Province:	Dominant Lithology:
Age modified	Oahu

Summary:
Stratigraphic chart gives Pliocene age but correlation chart (p.23) gives Pliocene and older age.

Summary of Citation: Koolau

Publication:
Macdonald, G.A., 1949, Hawaiian petrographic province: Geological
   Society of America Bulletin, v. 60, no. 10, p. 1541-1596

Usage in Publication:
Koolau volcanic series*

Modifications:	Geologic Province:	Dominant Lithology:
Age modified	Oahu

Summary:
Figure map shows age to be Pliocene(?).

Summary of Citation: Koolau

Publication:
Macdonald, G.A. and Davis, D.A., 1956, Zone des Hawaii, Chapter
   2, IN Avias, Jacques, and others, Oceanie proprement dite;
   Fasc. 2 of V. 6, Oceanie: Lexique Stratigraphique International,
   p. 70-143, Prepared by Centre National de la Recherche
   Scientifique (Paris), International Geological Congress,
   Commission on Stratigraphy.

Usage in Publication:
Koolau volcanic series*

Modifications:	Geologic Province:	Dominant Lithology:
Revised	Oahu

Summary:
Includes [improperly, since series cannot be part of series], Kailua volcanic series. Rocks of Koolau volcanic series, known variously as Koolau basalt [Wentworth, 1926], Koolau series [Wentworth and Winchell, 1947], and Koolau formation [Wentworth and Winchell, 1947]. Well exposed in Nuuanu Pali, great cliff on NE side of Koolau Range. Age assignment of Pliocene(?) based on degree of weathering and unconformable relationships to later Pleistocene rocks and shorelines.

Summary of Citation: Koolau

Publication:
McDougall, Ian, 1964, Potassium-argon ages from lavas of the
   Hawaiian Islands: Geological Society of America Bulletin, v.
   75, no. 2, p. 107-128

Usage in Publication:
Koolau volcanic series*

Modifications:	Geologic Province:	Dominant Lithology:
Isotopic dating	Oahu

Summary:
K-Ar ages on samples of tholeiitic basalt of Koolau volcanic series (collected from roadcuts at Waimea Bay, adjacent to University of Hawaii and Kamehameha Hwy) indicate range of 2.56 to 2.14 Ma.

Summary of Citation: Koolau

Publication:
O'Neil, J.R., Hedge, C.E. and Jackson, E.D., 1970, Isotopic
   investigations of xenoliths and host basalts from the Honolulu
   Volcanic Series: Earth and Planetary Science Letters Journal,
   v. 8, no. 3, p. 253-257

Usage in Publication:
Koolau Volcanic Series*

Modifications:	Geologic Province:	Dominant Lithology:
Isotopic dating	Oahu

Summary:
Koolau Volcanic Series form 2.3 Ma tholeiitic shield in SE part of Oahu. Shield, cut by vents of Honolulu Volcanic Series of late Pleistocene and Holocene age.

Summary of Citation: Koolau

Publication:
Doell, R.R. and Dalrymple, G.B., 1973, Potassium-argon ages and
   paleomagnetism of the Waianae and Koolau volcanic series,
   Oahu, Hawaii: Geological Society of America Bulletin, v. 84,
   no. 4, p. 1217-1242

Usage in Publication:
Koolau Volcanic Series*

Modifications:	Geologic Province:	Dominant Lithology:
Isotopic dating Paleomagnetics	Oahu

Summary:
Subaerial Koolau Volcano formed entirely during early half of Matuyama Reversed Polarity Epoch. K-Ar ages ranged from 2.6 to 1.8 Ma.

Summary of Citation: Koolau

Publication:
Lanphere, M.A. and Dalrymple, G.B., 1979, Age and strontium
   isotopic composition of the Honolulu Volcanics: U.S. Geological
   Survey Professional Paper, 1150, p. 180

Usage in Publication:
Koolau Volcanics*

Modifications:	Geologic Province:	Dominant Lithology:
Revised	Oahu

Summary:
Koolau Volcanic Series (Stearns and Vaksvik, 1935) reduced in rank and renamed Koolau Volcanics.

Summary of Citation: Koolau

Publication:
Easton, R.M. and Easton, E.G., 1983, Geology of the Hawaiian
   Islands; Hawaii, Maui and Oahu; Trip 16, IN Preto, Vic,
   chairperson, Joint annual meeting of Geological Association
   of Canada, Mineralogical Association of  Canada, and Canadian
   Geophysical Union; Volume 2, Trips 9 to 16: Geological
   Association of Canada, Victoria Section, Field Trip Guidebook,
   91 p.

Usage in Publication:
Koolau Formation

Modifications:	Geologic Province:	Dominant Lithology:
Revised	Oahu

Summary:
Koolau Volcanic Series (Stearns and Vaksvik, 1935) reduced in rank and renamed Koolau Formation. "most volcanic series have been renamed formation" p.2

Summary of Citation: Koolau

Publication:
Langenheim, V.A.M. and Clague, D.A., 1987, Stratigraphic framework
   of volcanic rocks of the Hawaiian Islands; Part II of The
   Hawaiian-Emperor volcanic chain, Chapter 1, IN Decker, R.W.,
   Wright, T.L., and Stauffer, P.H., eds., Volcanism in Hawaii:
   U.S. Geological Survey Professional Paper, v. 1, 1350, p.
   55-84

Usage in Publication:
Koolau Basalt*

Modifications:	Geologic Province:	Dominant Lithology:
Redescribed Age modified	Oahu

Summary:
Koolau Volcanics of Lanphere and Dalrymple (1979) is here renamed Koolau Basalt to reflect its lithology of shield-stage tholeiitic basalt. Kailua Volcanic Series is here reduced in rank and renamed Kailua Member of Koolau Basalt. Principal reference locality of Koolau Basalt is Nuuanu Pali [21 deg 22' 13"N, 157 deg 47' 49"W, Honolulu 7.5' quad, Island of Oahu, HI] Assigned Pliocene age based on K-Ar ages ranging from 2.7 to 1.8 Ma (Doell and Dalrymple, 1973) However Pleistocene(?) age cannot be ruled out for youngest flows.