GEOLEX

Summary of Citation: Hamakua

Publication:
Macdonald, G.A., 1945, Ring structures at Mauna Kea, Hawaii:
   American Journal of Science, v. 243, no. 4, pt. 1, p.
   210-217

Usage in Publication:
Hamakua volcanic series*

Modifications:	Geologic Province:	Dominant Lithology:
Named	Hawaii	Basalt

Summary:
Named for exposures along Hamakua coast, NW of Hilo, Island of Hawaii which is designated as type locality. Consists largely of olivine basalts with few thin intercalated ash beds. Greatest exposed thickness is 650 ft at Maula Gulch. Base is not exposed. In some places erosional unconformity separates unit from overlying Laupahoehoe volcanic series (new). In other places there is no sharp separation. Much of surface of unit is buried beneath cover of ash which is correlative in age with Pahala Ash on Mauna Loa.

Summary of Citation: Hamakua

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

Usage in Publication:
Hamakua volcanic series*

Modifications:	Geologic Province:	Dominant Lithology:
Age modified	Hawaii

Summary:
Forms the major part of mountain [Mauna Kea, Island of Hawaii]. Usually carries blanket of tan colored vitric Pahala Ash 4 to 15 ft thick which separates it from overlying Laupahoehoe volcanic series. Stratigraphic chart assigns Pliocene and early and middle Pleistocene age.

Summary of Citation: Hamakua

Publication:
Stearns, H.T. and Macdonald, G.A., 1946, Geology and ground-water
   resources of the Island of Hawaii: Hawaii Division of
   Hydrography Bulletin, no. 9, 363 p., (incl. geologic map,
   scale 1:125,000)

Usage in Publication:
Hamakua volcanic series*

Modifications:	Geologic Province:	Dominant Lithology:
Overview	Hawaii

Summary:
Type section is S wall of Laupahuehue Gulch [19 deg 59' 49" N, 155 deg 14' 39"W, Papaalua 7.5' quad, Mauna Kea Volcano, Island of Hawaii, HI]. Measured section is divided into upper member (consisting of olivine basalt, picrite-basalt of ankaramite type, and andesine andesite) and lower member (consisting largely of olivine basalt with minor amounts of picrite-basalt of oceanite type). Map shows lava flows capped by Pahala ash and cinder and spatter cone at source of flows. Stratigraphic section assigns Pleistocene age.

Summary of Citation: Hamakua

Publication:
Macdonald, G.A., 1949, Petrography of the Island of Hawaii, IN
   Shorter contributions to general geology, 1947-1949: U.S.
   Geological Survey Professional Paper, 214-D, p. D51-D96

Usage in Publication:
Hamakua volcanic series*

Modifications:	Geologic Province:	Dominant Lithology:
Overview	Hawaii

Summary:
Measured section along road up S wall of Laupahoehoe Gulch [near Laupahoehoe on Hamakua coast of Island of Hawaii] is divided into upper and lower members.

Summary of Citation: Hamakua

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:
Hamakua volcanic series*

Modifications:	Geologic Province:	Dominant Lithology:
Age modified	Hawaii

Summary:
In part later than, and probably in part coeval with Pololu volcanic series. No fossils. Older than Pahala ash. Probably correlative with Kahuku and Hilina volcanic series. Assigned Quaternary and late Tertiary(?) age.

Summary of Citation: Hamakua

Publication:
Doell, R.R. and Cox, Allan, 1965, Paleomagnetism of Hawaiian
   lava flows: Journal of Geophysical Research, B, Solid Earth
   and Planets, v. 70, no. 14, p. 3377-3405, Also, 1961, Nature,
   v. 192, no. 4803, p. 645-646.

Usage in Publication:
Hamakua volcanic series*

Modifications:	Geologic Province:	Dominant Lithology:
Paleomagnetics	Hawaii

Summary:
"All lavas now exposed on the island [of Hawaii] are less than 1 m.y. old (Pleistocene)." 26 flows of Hamakua volcanic series were sampled along S side of Laupahoehoe Gulch (essentially the lower member because the upper was too weathered).

Summary of Citation: Hamakua

Publication:
Porter, S.C., 1973, Stratigraphy and chronology of late Quaternary
   tephra along the south rift zone of Mauna Kea Volcano, Hawaii:
   Geological Society of America Bulletin, v. 84, no. 6, p.
   1923-1940

Usage in Publication:
Hamakua Group

Modifications:	Geologic Province:	Dominant Lithology:
Revised	Hawaii

Summary:
"These major units, the Hamakua and Laupahoehoe Volcanic Series have been redefined in the present study as groups and further split into several formations and members (S.C. Porter, 1973, in prep)."

Summary of Citation: Hamakua

Publication:
Porter, S.C., 1974, Mauna Kea, IN Greeley, Ronald, ed., Guidebook
   to the Hawaiian planetary conference: National Aeronautics
   and Space Administration, Space Sciences Division, Ames
   Research Center, p. 239-246

Usage in Publication:
Hamakua Group

Modifications:	Geologic Province:	Dominant Lithology:
Revised	Hawaii

Summary:
Divided into Hopukani Formation (pre-Pohakuloa lava flows) (new) and Pohakuloa Formation. Hopukani Formation is characterized as volcanic unit. Pohakuloa Formation (which includes Pohakuloa drift) is characterized as glacial unit. Pohakuloa Formation is overlain by Liloe Formation of Laupahoehoe Group.

Summary of Citation: Hamakua

Publication:
Porter, S.C., 1979, Quaternary stratigraphy and chronology of
   Mauna Kea, Hawaii; a 380,000-yr record of mid-Pacific volcanism
   and ice-cap glaciation: Geological Society of America Bulletin,
   v. 90, no. 7, pts. 1-2, p. 609-611, 980-1093

Usage in Publication:
Hamakua Group

Modifications:	Geologic Province:	Dominant Lithology:
Areal limits Isotopic dating	Hawaii

Summary:
Includes lower member of Stearns and Macdonald (1946), Hopukani and Pohakuloa Formations. Hopukani Formation interfingers with Pohakuloa Formation. Carbon-14 and K/Ar methods estimate 382,100 +/-60,600 yr to approximately 278,500 +/-68,500 yr B.P. (the ages of the Pre-Kilohanan rocks and Kilohanan stage) for age of Hamakua Group.

Summary of Citation: Hamakua

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:
Hamakua Volcanics*

Modifications:	Geologic Province:	Dominant Lithology:
Revised	Hawaii

Summary:
Because the use of Hamakua as unit of group rank, Hamakua Volcanic Series (Stearns and Macdonald, 1946) and Hamakua Group (Porter, 1973), is not consistent with approach used for rest of volcanoes of HI, it is here reduced to formation rank and renamed Hamakua Volcanics. Subdivisions are reduced to member rank and renamed to reflect overall nature of their lithologies. Hamakua Volcanics is divided (ascending) into unnamed lower member, Hopukani Volcanic Member, and Pohakuloa Glacial Member.

Summary of Citation: Hamakua

Publication:
Wolfe, E.W., Wise, W.S. and Dalrymple, G.B., 1997, The geology
   and petrology of Mauna Kea Volcano, Hawaii; a study of
   postshield volcanism: U.S. Geological Survey Professional
   Paper, 1557, 129 p., (incl. geologic maps, scale 1:24,000
   and 1:100,000)

Usage in Publication:
Hamakua Volcanics*

Modifications:	Geologic Province:	Dominant Lithology:
Revised	Hawaii

Summary:
Unit stratigraphically extended to include overlying Waihu Glacial Member (formerly of Laupahoehoe Volcanics) and basaltic rocks of now-abandoned Waikahalulu Volcanic Member (of Laupahoehoe Volcanics). Includes two newly-named members: Hopukani Springs Volcanic Member and Liloe Spring Volcanic Member. Also still includes Pohakuloa Glacial Member. Age remains Pleistocene.