image/svg+xml
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al
k3a
1882–85
1919
1918–191892–941888–89
19211954195919688/719/717/749/829/7412/74197519794/82183218771790t1790f1974k4ypk4ykm4yk4olk4okk4oak4onm4om1om2m0m1ym3k2wk3kk3dk3nk3hk3ak4opk4yhk4yuk4oykpa1973197219711969khu
kulkpu
W4998960±60WW308400±50W4337620±70AA10602400±70WW302650±60W5785600±100WW370460±60WW301970±60
uncertain age
550±110 (1)627±34 (5)971±26 (6)509±41 (3) 571±42 (6)?
MAUNA LOA VOLCANOKAÿÜ BASALTSURFICIAL DEPOSITS
578±57 (2)375±20 (11)310±70 (1)265±42 (2)577±28 (5)8,645±71 (2)2,265±49 (2)760±70 (1)2,770±150 (1)1,50075010,0003,000400200+0??
AGEyears BP
HISTORIC UNITS (A.D.1790 and younger)PREHISTORICUNITS
CORRELATION OF MAP UNITS
[Immediately subjacent map units are shown in actual stratigraphic sequence.Not all known stratigraphic relationships can be shown]
KÏLAUEA VOLCANOPUNA BASALT
PleistoceneHolocene
Quaternary
CONTOUR INTERVAL 20 METERS
NATIONAL GEODETIC VERTICAL DATUM OF 1929
U.S. DEPARTMENT OF THE INTERIOR
U.S. GEOLOGICAL SURVEY
GEOLOGIC INVESTIGATIONS SERIES I–2759
Pamphlet accompanies map
SCALE 1:24 000
1/2
101 MILE1 KILOMETER1.50
INTERIOR—GEOLOGICAL SURVEY, RESTON, VA—2003
DESCRIPTION OF MAP UNITS
SURFICIAL DEPOSITSAlluvium (Holocene)
—Chiefly sand redistributed by running water; mixed with aeolian sand. Derived principally from the Keanakäkoÿi Ash Member of the Puna Basalt (
1790t
)
Talus (Holocene)
—Angular blocks of basalt forming steep rubble aprons along the base and lower walls of Kïlauea caldera, much of which formed during the surface wave magnitude (M
S
) 6.6 Kaÿöiki earthquake of November 16, 1983 (Buchanan-Banks, 1987)
KÏLAUEA VOLCANO
PUNA BASALT
Puna Basalt (Holocene)
—All units on this map derived from Kïlauea Volcano are part of the Puna Basalt, which includes all historic and prehistoric lava flows and tephras that overlie the main Pähala Ash. The base of the Puna Basalt is not precisely defined and may be as old as 39 ka (Beeson and others, 1996). Lavas and tephras of the Puna Basalt within this map area are tholeiitic in composition.Historic Units
Lava flows and spatter deposits of August 14, 1971
—Black, glassy, pähoehoe erupted from fissures on the caldera floor southeast of Halemaÿumaÿu and from fis-sure vents on the southeast caldera rim north of Keanakäkoÿi Crater. Lava flooded the eastern part of the caldera floor. Contain olivine phenocrysts (1 to 3 percent, 1 to 4 mm) in a dark-gray to black groundmass (Duffield and others, 1982)
Lava flows of August 22, 1968
—Black, glassy pähoehoe pad less than 1 m thick and covering about 5,000 m
2
erupted from fissure vent 1 km east-northeast of Pauahi Crater; additional spatter emitted from a second fissure 0.5 km northeast of Pauahi Crater is not shown owing to limited extent (these are vents 3 and 2, respectively, of Jackson and others, 1975). A third fissure vent just north of Pauahi Crater emitted only hot gasses. Contain scattered olivine phenocrysts (trace to 1 percent)
Lava flows, spatter deposits, and reticulite of November 14 to December 20, 1959
Lava flows of 1832
—Thin layer of tan-gray, vesicular, pähoehoe on Byron Ledge, now heavily masked by vegetation. Contain clear, glassy olivine phenocrysts (2 to 3 percent, 1 to 5 mm). Formerly exposed on the southwest wall of Kïlauea Iki. Loca-tion of buried fissure vent approximated from sketches in Brigham (1909, p. 46–47; see also Hitchcock, 1909, p. 182–185; Macdonald and Eaton, 1957, plate 1)
Keanakäkoÿi Ash Member, tephra and lava flow
—Complex assemblage of gray, bedded, primary and reworked phreatomagmatic and phreatic surge and fallout deposits (
1790t
) up to 12 m thick where exposed in the south caldera rim. Within the caldera, the deposit is overlain by coarse, blocky debris from the 1924 eruption at Halemaÿumaÿu. Most of the Keanakäkoÿi Ash Member erupted over weeks or months from a source near Halemaÿumaÿu Crater (Powers, 1948; Decker and Chris-tiansen, 1984; McPhie and others, 1990). Approximate 1-m isopach (R.L. Christian-sen, unpublished data) illustrates the general distribution of the original deposit, now heavily reworked and unevenly redistributed throughout the Kaÿü Desert. Thin, vesicular, gray-black pähoehoe flow (
1790f
), 1.7 km long, is interbedded with tephra of the Keanakäkoÿi Ash Member south of the caldera. It erupted from an arc-uate fissure marked by spatter and 3-m-high spatter cones, all obscured by the upper parts of the Keanakäkoÿi Ash Member. Flow contains olivine phenocrysts (1 to 3 percent, 1 to 5 mm) in an aphanitic, medium-gray groundmassPrehistoric Units
Units 200 to 400 years old
Lava flows and spatter deposits of young southwest rift zone vents
—Thin, highly localized, gray-brown, aphyric, vesicular pähoehoe erupted from two, small fissure vents in the upper southwest rift zone. Grouped on the basis of appearance; these flows probably represent separate eruptions. Mantled by the Keanakäkoÿi Ash Member (
1790t
and
1790f
). Overlies
k4oy
Lava flow and spatter deposits of outlet vent
—Gray-brown ÿaÿä and slabby pähoe-hoe 1 to 2 m thick erupted from 1- to 3-m-high spatter rampart 2.7 km south of Halemaÿumaÿu Crater. Heavily mantled by the Keanakäkoÿi Ash Member (
1790t
). Contain phenocrysts of olivine (1 to 3 percent) and plagioclase (2 to 4 percent) in a medium- to dark-gray matrix. Overlie
k4oy
and
k4oa
Lava flows and spatter deposits of Kïlauea Military Camp
—Dark-gray to purple, vesicular pähoehoe erupted from 250-m-long, 2- to 4-m-high spatter rampart that crosses the eastern access road to the Kïlauea Military Camp. Contain scattered oli-vine phenocrysts (trace to 1 percent, generally less than 1 mm). Heavily mantled by the Keanakäkoÿi Ash Member (
1790t
). Overlie
k4oy
exposed in outer caldera fault scarp just west of Volcano Golf Course access road
Lava flows and spatter deposits of Hiÿiaka Crater
—Brownish-gray shelly pähoe-hoe erupted from fissure vent on the north rim of Hiÿiaka Crater. Contain scattered olivine phenocrysts (trace to 1 percent). In places, fluid pähoehoe from this eruption poured into cracks circumferential to Hiÿiaka Crater; due to subsequent calving of the crater walls, this pähoehoe is now exposed as surface-fed dikes
Basalt of Uwëkahuna laccolith
—Dense intrusion, lenticular in shape. Fine-grained, displays strong vertical zonation in olivine phenocryst abundance. Exposed in cal-dera wall beneath Uwëkahuna Bluff (Murata and Richter, 1961; Casadevall and Dzurisin, 1987a). Intrudes prehistoric lavas that overlie the Uwëkahuna Ash Mem-ber but predates modern caldera collapse. Possibly originated by lateral intrusion from a pre-caldera lava lake 0.5 to 2.0 ka
Prehistoric lava flows and tephra deposits, undivided
—Prehistoric lava flows and tephra deposits exposed in the caldera walls and walls of upper east rift zone pit cra-ters. Age control is poor except for Uwëkahuna Bluff section studied with paleo-magnetic techniques by Doell and Cox (1965), Holcomb and others (1986), and Holcomb (1987). Casadevall and Dzurisin (1987a) conclude that lava flows in the Uwëkahuna Bluff section range in age from approximately 2.8 ka near the base to as young as 0.2 ka at the top, based on available paleomagnetic data and radiocar-bon dating of possibly correlative lava flows. Hagstrum and Champion (1995) pre-fer an age of about 3.0 ka for the base of the Uwëkahuna Bluff section based on new paleomagnetic interpretations. We infer a 0.5 ka age for the top of the section based on additional radiocarbon dating. No flows of Mauna Loa origin are known in the Uwëkahuna Bluff section (Casadevall and Dzurisin, 1987b), but Rhodes and others (1989) found flows that have chemistry similar to Mauna Loa lavas in the walls of Kïlauea Iki and Pauahi Craters and suggested that they represent Mauna Loa magma processed through the Kïlauea plumbing system. At Pauahi Crater along the upper east rift zone and at Pit Craters in the Kaÿü Desert, a portion of the lower crater walls predate the Uwëkahuna Ash Member (Dzurisin and others, 1995)
Lava flows and spatter deposits of the Upper East Rift Zone
—Composite unit rep-resenting multiple eruptions. Undivided due to uncertain internal contact relations in heavily vegetated terrain of the upper east rift zone. Include gray to black, dense pähoehoe and brownish-gray shelly pähoehoe erupted from poorly exposed fissure vents north and east of Hiÿiaka Crater. Contain scattered olivine phenocrysts (trace to 1 percent)
Spatter deposits and lava flows of Cone Crater
—Spatter cone atop a small lava shield composed of thin, short, shelly pähoehoe flows and minor ÿaÿä about 7 km southwest of Halemaÿumaÿu Crater. Additional small spatter vents 650 m and 2 km northeast of Cone Crater erupted small fluid pähoehoe flows and two thin ÿaÿä lobes; these are similar in appearance and chemical composition and are grouped with Cone Crater flows. Contain scattered olivine phenocrysts (trace to 1 percent, 1 to 3 mm). Flow field from main vent is cut by two collapse pits, the Pit Craters. The walls of these craters are mantled in places by red, oxidized drainback. Cone Crater flow overlies pähoehoe flow of
k4yk
Lava flows and spatter deposits of Koÿokoÿolau Crater
—Gray-brown to black, thin, vesicular, glassy pähoehoe erupted from spatter cone cut by Koÿokoÿolau Cra-ter in the upper east rift zone. Typically contains 7 to 10 percent glassy olivine phe-nocrysts. Unit is heavily vegetated and contacts are difficult to trace. Age and mapped extent differs from that in Holcomb (1987) and Wolfe and Morris (1996) based on new field data. Overlie
k4ol
and
k4ya
; overlain by dense pähoehoe of
k4yu
. Additional outcrops southeast of its mapped extent have probably gone unrecog-nized due to poor exposure
Lava flows and spatter deposits of Puÿukoaÿe
—Gray to black, pähoehoe and ÿaÿä erupted from Puÿukoaÿe, a 35-m-tall spatter cone and two, partially buried spatter cones about 7 km southwest of Halemaÿumaÿu Crater. Pähoehoe (mapped as sepa-rate unit by Walker, 1969) erupted first followed by ÿaÿä. Main ÿaÿä flow traveled nearly 9 km south. Lavas are chiefly aphyric. Small fissure vents and vesicular pähoehoe flows 1.8 km northeast of Puÿukoaÿe (Walker, 1969), mostly buried by 1974 lavas, are grouped with Puÿukoaÿe lavas. Overlie ÿaÿä flow of
k4yp
just west of Puÿukoaÿe
Younger lava flows of ÿAilaÿäu
—Black, glassy, vesicular surface-fed pähoehoe and dense, tube-fed pähoehoe erupted from vent(s) near the east margin of Kïlauea Iki Crater. Lava flows in the map area include the youngest flows from the ÿAilaÿäu vent (fig. 3), the source of voluminous lava flows containing large lava tubes extending to the east coast of Kïlauea (Holcomb, 1981; 1987). The youngest ÿAila-ÿäu flows are well exposed along Crater Rim Drive near Thurston Lava Tube (Kea-nakakina). Typically contain semi-equant and acicular olivine phenocrysts (5 to 15 percent). Age estimated on the basis of superposition and multiple radiocarbon dates from beneath surface flows correlated with the ÿAilaÿäu shield northeast of map area.
14
C ages range from <200 to 620±70 (table 1). Some or all of these dated flows may actually be older than
k4ya
Lava flows and spatter deposits of Cone Peak
—Gray-brown vesicular pähoehoe, slabby pähoehoe, and ÿaÿä erupted from Cone Peak, a 900-m-long spatter rampart 2 km southwest of Halemaÿumaÿu Crater. Unit includes thin, vesicular pähoehoe flows from fissure vents extending as much as 5 km downrift. Initial fissure may have extended uprift to the southwest margin of the caldera. Pähoehoe is denser in exposures on caldera side of Cone Peak vent. Contain scattered olivine phenocrysts (trace to 1 percent; generally less than 1 mm) in a dark-gray matrix. Overlies
k4oy
and underlies
k4yk
Older lava flows of ÿAilaÿäu
—Black, glassy, dense tube-fed pähoehoe erupted from unknown vent(s) in the Kïlauea summit area. Contain scattered olivine phenocrysts (trace to 1 percent, generally less than 1 mm). Poorly exposed in heavily vegetated terrain. Underlie olivine-rich flows of
k4ya
.
14
C age 310±70 (table 1)
Units 400 to 750 years old
Younger lava flows of the Observatory vent
—Tan-gray, chiefly dense, tube-fed pähoehoe and five prominent ÿaÿä lobes erupted from unknown vent(s) near Uwëka-huna Bluff (Observatory vent of Holcomb, 1987). Flows extend southwest from the summit caldera and typically contain phenocrysts of olivine and intergrown clino-pyroxene (3 to 10 percent) and conspicuous plagioclase (1 to 5 percent). Large tree molds are preserved in this flow 1 km west of the Kïlauea Military Camp. In the upper southwest rift zone and southwest caldera wall, the uppermost flow (or flows) of this unit is a vesicular to dense picritic pähoehoe (indicated by small
v
pattern), in places only a few cm thick, that contains olivine phenocrysts up to 7 mm across. This flow is characterized in places by strong vertical zonation in olivine abundance (scattered outcrops indicated by asterisk) and is correlative with the patches of pic-ritic basalt mapped by Walker (1969) and the regional prehistoric pähoehoe picrite complex of Wright (1971). It may represent a late, olivine-rich phase from the Observatory vent (fig. 3) or a separate eruption possibly fed by a dike exposed in the southwest caldera wall (dike 5S; see fig. 14.1 in Casadevall and Dzurisin, 1987a). Contacts between the picrite and earlier, less olivine-rich flows of
k4oy
are obscured by the Keanakäkoÿi Ash Member (
1790t
). In a caldera-wall exposure just east of BM 3724 in unit
k4yp
, the picrite is overlain by olivine-rich scoria, ash, and reticulite of unknown origin.
14
C ages range from 410±100 to 960±60 (table 1)
Lava flows of Steaming Bluff
—Dense, tube-fed pähoehoe erupted from unknown vent(s) in the Kïlauea summit area. Flows extend north of the summit caldera and contain conspicuous plagioclase, olivine, and clinopyroxene phenocrysts in a crys-talline groundmass. Overlie
k4ov
in road cuts along Highway 11. Heavily mantled by the Keanakäkoÿi Ash Member (
1790t
; see isopach on map). May be correlative with
Lava flows of Kïpukanënë
—Gray to orange-tan, hummocky, dense, tube-fed pähoe-hoe and small patches of rubbly ÿaÿä erupted from unknown vent(s) in the Kïlauea summit area. Flows extend from the south edge of the map to the coast. Part of Kipuka Nene flows of Holcomb (1987). Weathered surface nearly white where devoid of glass. Surface glass is more intact in vegetated areas. Contain olivine phe-nocrysts (3 to 5 percent) in a feldspathic groundmass. Age estimated on the basis of weathering and paleomagnetic data. Unit overlain by
k3k
,
k4ok
,
k4ol
Lava flows of ÿÄinahou Ranch
—Dense, gray-brown, aphyric tube-fed pähoehoe erupted from unknown vent(s) in the Kïlauea summit areas. Located in southeast corner of map. In low-lying areas covered by prehistoric lithic ash of unknown ori-gin up to 35 cm thick. Part of Kipuka Nene flows of Holcomb (1987). Age esti-mated on the basis of weathering; overlain by
k4ol
and tube-fed pähoehoe of
k4yu
Lava flows of hornet kïpuka
—Light-gray pähoehoe that has a distinctive knobby surface; erupted from unknown vent(s) in the Kïlauea summit area. Flows exposed in two small kïpuka along Hilina Pali Road about 2.4 km southwest of the intersec-tion with Chain of Craters Road. Contain equant and lath-shaped olivine phenoc-rysts (5 to 7 percent) and scattered, finely fractured, tabular olivine as much as 1 cm across in a feldspathic groundmass. Surface glass contains visible olivine phenoc-rysts that display a yellowish alteration. Age estimated on the basis of outcrop weathering and paleomagnetic data; overlain by
k4ol
Units 1,500 to 3,000 years old
Lava flows of Wright Road
—Dense, tube-fed pähoehoe erupted from unknown vent(s) in Kïlauea summit area. Flows extend northeast of the summit caldera. Con-tain rounded olivine phenocrysts (3 to 4 percent). Outcrops are rare owing to exten-sive cover of the Uwëkahuna (30 to 50 cm thick) and Keanakäkoÿi (1 to 80 cm thick) Ash Members.
14
C age 2,770±150 (table 1)Pleistocene and Holocene
Pähala Ash
—The Pähala Ash is a general term that has been used for thick sequences of deeply weathered yellow, yellow-orange, and reddish ash over large parts of the Island of Hawai’i. Consists of lithic and vitric fallout and possibly surge deposits which are widely reworked by water and wind. The Pähala Ash is often divided into the Main Pähala Ash, which overlies lava flows and tephras of the Hilina Basalt (age greater than 39 ka; Beeson and others, 1996), and the Upper Pähala Ash, which is intercalated with lava flows of the Puna Basalt as young as 3 to 5 ka (Easton, 1987). Within the map area the Pähala Ash is exposed in kïpuka on the surface of Mauna Loa where it is as much as 4 m thick. It consists of multiple pyroclastic units from explosive eruptions from the late Pleistocene to middle or late Holocene. The source of the Pähala Ash is most likely Kïlauea Volcano (Easton, 1987; Beeson and others, 1996)
MAUNA LOA VOLCANOKaÿü Basalt (Holocene and Pleistocene)
—Within the map area, all lava flows derived from Mauna Loa Volcano are part of the Kaÿü Basalt, which includes all historic lava flows and tephras as well as prehistoric lava flows and tephras that overlie the main Pähala Ash. The base of the Kaÿü Basalt is at least 31 ka (Wolfe and Morris, 1996) and perhaps as old as 39 ka (Beeson and others, 1996). Lavas and tephras of the Kaÿü Basalt within this map area are tholeiitic in compositionPrehistoric Holocene Units
Units 200 to 400 years old
Younger Keamoku lava flows of Kïpukakï
—Dark brown to tan, dense, massive ÿaÿä flow enclosing Kïpukakï. Erupted from a fissure vent trending obliquely across Puÿukülua, 15 km northwest of the map area on Mauna Loa's northeast rift zone at 9,000' elevation. Contain trace amounts of clear olivine phenocrysts (less than 1 percent, as large as 4 mm) and anhedra of plagioclase (generally less than 1 mm). Overlain by discontinuous, thin, accretionary lapilli-rich beds of the Keanakäkoÿi Ash Member of the Puna Basalt (
1790t
). This is the youngest of several separate ÿaÿä flows labeled the Keamoku Flows on previous maps and was termed the lobe of Kipuka Kekake by Peterson (1967). The flow traveled southeast down Mauna Loa's flank until reaching the Kïlauea shield, where it was deflected westward along the Kïlauea-Mauna Loa boundary.
14
C ages range from 230±60 to 300±60 (table 1)
Units 400 to 750 years old
Older Keamoku lava flows of Kïpukapuaulu
—Gray-brown to tan pähoehoe and ÿaÿä, this unit is the most widespread of the Keamoku flows. It directly underlies
m4y
and surrounds Kïpukapuaulu. Erupted from a fissure system that cuts Puÿuÿula-ÿula along the northeast rift zone about 13 km northwest of the map area. Contain conspicuous anhedral laths and aggregates of plagioclase (5 to 10 percent, laths generally less than 1 mm, aggregates as large as 2 mm across) and anhedral, sugary phenocrysts of olivine (2 to 6 percent, as much as 1.5 mm across). ÿAÿä of this unit was mapped as one of the lower lobes of the Keamoku lava flows by Peterson (1967). The bulk of the unit consists of pähoehoe emplaced as fast-moving, highly fluid lava after most of the ÿaÿä was emplaced. This pähoehoe ponded in the saddle between Mauna Loa and the Kïlauea shield and is characterized by pseudo-karst pits caused by lateral drainage and crustal subsidence. Large tree molds and casts occur in several places north of the map area.
14
C ages range from 330±60 to 830±60 (table 1)
Units 750 to 1,500 years old
Lava flows of Keauhou Ranch
—Dark gray, glassy (where undisturbed) tube-fed pähoehoe erupted from unknown, possibly-buried vents along the northeast rift zone. Unit is exposed in several grass-covered kïpuka along the north margin of the map area. Contain inconspicuous, sugary, anhedral olivine phenocrysts (4 to 10 per-cent, as much as 3 mm across) and subhedral plagioclase phenocrysts (2 to 8 per-cent, generally less than 1 mm). Surface outcrops are similar to those of the overlying pähoehoe of the Keamoku lava flow of Kïpukapuaulu, but they can be distinguished by more dense grass cover and also by a speckled surface caused by weathered olivine phenocrysts.
14
C age 760±70 (table 1)
Units 1,500 to 3,000 years old
ÿAÿä flows of eastern Kaÿöiki Pali
—Distinctive, dense, flinty ÿaÿä lobes that drape the Kaÿöiki faults at the north-central edge of the map area (fig. 1). Erupted from unknown, now-buried vents along the northeast rift zone. Contain conspicuous anhedral plagioclase phenocrysts (3 percent, as much as 0.5 mm across). Unit is mantled by thin, discontinuous deposits of the Keanakäkoÿi Ash Member (1790t) and the upper Uwëkahuna Ash Member of the Puna Basalt, which support dense grass. Typical exposures consist of isolated blocks of ÿaÿä projecting above grass-covered areas; well-exposed in a small quarry where the Puÿu ÿÖÿö Trail crosses the Kaÿöiki faults.
14
C ages range from 2,190±70 to 2,340±70 (table 1)
Units 3,000 to 10,000 years old
ÿAÿä flow west of Kïpukakï
—Distinctive ÿaÿä west of Kïpukakï. Erupted from unknown, now-buried vents along the northeast rift zone. Contains clear, euhedral olivine phenocrysts (6 to 8 percent, as much as 6 mm across) and subhedral plagio-clase phenocrysts (3 to 5 percent, generally less than 1 mm) in a dense, medium-gray matrix. The flow is as much as 9 m thick and forms bold, brush-covered out-crops above adjoining grass-covered older flows. Unit is mantled by discontinuous deposits of the Uwëkahuna Ash Member of the Puna Basalt, but overlies the Pähala Ash. Its age is estimated by outcrop weathering at 4,000 to 5,000 years
Lava flows of Puÿuÿulaÿula
—Deeply weathered pähoehoe along the northwest boun-dary of the map area. On the basis of chemical and paleomagnetic data, the likely source of this flow is Puÿuÿulaÿula, about 13 km northwest of the map area at 10,000’ elevation on the northeast rift zone. Typically aphyric but contains scattered, inconspicuous, anhedral, olivine phenocrysts (1 to 2 percent, generally 1 mm across). Unit is buried by as much as 2 m of the Uwëkahuna Ash Member of the Puna Basalt and upper units of the Pähala Ash in the map area, and it is exposed only in deep gullies, where it overlies thick older units of the Pähala Ash. The sizes of ash-free exposures have been exaggerated on the map. At higher elevations this flow has an orange-weathered surface.
14
C ages range from 8,550±100 to 8,740±100 (table 1)Pleistocene Unit
ÿAÿä flow northeast of Volcano Golf Course
—Distinctive, plagioclase-rich ÿaÿä at the north edge of the map. Erupted from unknown vents on the northeast rift zone. Generally covered by as much as 2.5 m of the Uwëkahuna Ash Member of the Puna Basalt and the upper part of the Pähala Ash. Where artificially exposed, the surface is deeply weathered to orange clay around ÿaÿä clasts and along fractures. Fresh rock contains subhedral plagioclase phenocrysts (15 to 18 percent, as much as 5 mm in length) and clear, euhedral olivine phenocrysts (5 to12 percent, as much as 8 mm across). Its age is unknown but almost certainly is pre-Holocene
ÿAÿä lava flowCinder or spatter conePicrite
—Picritic lava flow of unit
k4oy
. Scattered outcrops of picrite indicated by aster-isk ( ). Correlative with
llkp
of Walker (1969)
Uwëkahuna Ash
—Shown where greater than approximately 30 cm in thickness. Deposits are typically yellow-brown in contrast to the gray Keanakäkoÿi and yel-low-orange Pähala Ash
Pähala Ash
—Shown where greater than approximately 1.5 m in thickness
Dikes
—Located in walls of Kïlauea and Kïlauea Iki Craters. Bars represent approximate location and strike; solid circles denote variable or unknown orientation. Size exag-gerated for clarity. From Casadevall and Dzurisin (1987a)
Contact
—Dashed where approximately located; dotted where concealed; queried where inferred and highly uncertain. Internal contacts distinguish ÿaÿä or cinder or spatter cones of same map unit
APPROXIMATE MEANDECLINATION, 2002
Base from U.S. Geological Survey, Kilauea Crater, Volcano, Kau Desert, Makaopuhi Crater, 1981Universal Transverse Mercator projectionGeology mapped by C.A. Neal (1987–1989, 1997), J.P. Lockwood (1978–1993), and modified from Holcomb (1987)Digital cartography by P.E. Bruggman, D. Dutton, T.J. Felger, J.P. Lock-wood, Ellen Lougee, Sandy Margriter, and Patrick Showalter; cartogra-phy by D.A. Ryan; edited by J.L. ZiglerManuscript approved for publication December 10, 2001155 12'30"17'30"15'155° 20'19 20'
25'
19 20'22'30"
25'
22'30"
HAWAIIAN ISLANDS
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Kaoiki Fault Zone
ZONE
Kipuka Puaulu
HuluhuluPu'u
VOLCANOVILLAGE
Koa'e Fault System
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T
R
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MAGNETIC NORTH
TRUE NORTH
9
1
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19° 27'30"
155 12'30"17'30"15'155° 20'
19° 27'30"
MAP LOCATION
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09 / 198204 / 1982197512 / 197409 / 197407 / 197409 / 197108 / 197119591954192119191918-191892-941888-891882-85187718321790f1790tkhu (âge indéterminé)
t (éboulis)al (alluvions)k4ypk4ylk4yak4ysk4yvk4ymk4oyk4ook4osk4ovk4olk4onk4oak3dk2wkpukpam4o
Holocène
Holocène
Mauna Loa
Coulées de lave historiques
Autres roches
Faille / faille enfouieLimite des cendres de KeanakākoʻiCendres du Kīlauea Iki (isolignes en cm)Fissure éruptive, rebord de cratère