U.S. DEPARTMENT OF THE INTERIOR GEOLOGIC INVESTIGATIONS SERIES I–2759 U.S. GEOLOGICAL SURVEY Pamphlet accompanies map 155° 20' 17'30" 15' 155 12'30" 19° 27'30" 19° 27'30" CORRELATION OF MAP UNITS 1832 Lava flows of 1832—Thin layer of tan-gray, vesicular, pähoehoe on Byron Ledge, k3n Lava flows of Kïpukanënë—Gray to orange-tan, hummocky, dense, tube-fed pähoe- m1o m4o m4o y o m1o m3 [Immediately subjacent map units are shown in actual stratigraphic sequence. now heavily masked by vegetation. Contain clear, glassy olivine phenocrysts (2 to 3 hoe and small patches of rubbly ÿaÿä erupted from unknown vent(s) in the Kïlauea m4o kpa m2 kpa W3880 m0 kpa kpa 530 m2 Not all known stratigraphic relationships can be shown] percent, 1 to 5 mm). Formerly exposed on the southwest wall of Kïlauea Iki. Loca- summit area. Flows extend from the south edge of the map to the coast. Part of y ±60 o kpa k2w AGE SURFICIAL KÏLAUEA VOLCANO MAUNA LOA VOLCANO tion of buried fissure vent approximated from sketches in Brigham (1909, p. 46–47; Kipuka Nene flows of Holcomb (1987). Weathered surface nearly white where m4y W4831 W3876 years BP DEPOSITS PUNA BASALT KAÿÜ BASALT see also Hitchcock, 1909, p. 182–185; Macdonald and Eaton, 1957, plate 1) devoid of glass. Surface glass is more intact in vegetated areas. Contain olivine phe- 2340 and 2190 1790t Keanakäkoÿi Ash Member, tephra and lava flow—Complex assemblage of gray, nocrysts (3 to 5 percent) in a feldspathic groundmass. Age estimated on the basis of kpa 0 kpa m4o ±70 ±70 m3 P 1790f bedded, primary and reworked phreatomagmatic and phreatic surge and fallout weathering and paleomagnetic data. Unit overlain by k3k, k4ok, k4ol U al t ‘U deposits (1790t) up to 12 m thick where exposed in the south caldera rim. Within k3a Lava flows of ÿÄinahou Ranch—Dense, gray-brown, aphyric tube-fed pähoehoe Ö 9/82 ‘Ö W3999 T k2w the caldera, the deposit is overlain by coarse, blocky debris from the 1924 eruption erupted from unknown vent(s) in the Kïlauea summit areas. Located in southeast m2 R W6007 A 730 y I L 580 4/82 o kpa m4o ±150 at Halemaÿumaÿu. Most of the Keanakäkoÿi Ash Member erupted over weeks or corner of map. In low-lying areas covered by prehistoric lithic ash of unknown ori- ±100 months from a source near Halemaÿumaÿu Crater (Powers, 1948; Decker and Chris- gin up to 35 cm thick. Part of Kipuka Nene flows of Holcomb (1987). Age esti- kpa kpa 1979 tiansen, 1984; McPhie and others, 1990). Approximate 1-m isopach (R.L. Christian- mated on the basis of weathering; overlain by k4ol and tube-fed pähoehoe of k4yu W5791 HISTORIC kpa UNITS (A.D. sen, unpublished data) illustrates the general distribution of the original deposit, k3h Lava flows of hornet kïpuka—Light-gray pähoehoe that has a distinctive knobby Kipuka Puaulu 1170 1975 W4367 ±150 1790 and now heavily reworked and unevenly redistributed throughout the Kaÿü Desert. Thin, surface; erupted from unknown vent(s) in the Kïlauea summit area. Flows exposed 570 k4ov y younger) 12/74 vesicular, gray-black pähoehoe flow (1790f), 1.7 km long, is interbedded with in two small kïpuka along Hilina Pali Road about 2.4 km southwest of the intersec- o W3871 kpa ±70 VOLCANO 230 W3870 tephra of the Keanakäkoÿi Ash Member south of the caldera. It erupted from an arc- tion with Chain of Craters Road. Contain equant and lath-shaped olivine phenoc- 350 9/74 ±60 m4o VILLAGE uate fissure marked by spatter and 3-m-high spatter cones, all obscured by the upper rysts (5 to 7 percent) and scattered, finely fractured, tabular olivine as much as 1 cm m1o kpa ±60 kpa VOLCANO 7/74 parts of the Keanakäkoÿi Ash Member. Flow contains olivine phenocrysts (1 to 3 across in a feldspathic groundmass. Surface glass contains visible olivine phenoc- GOLF percent, 1 to 5 mm) in an aphanitic, medium-gray groundmass rysts that display a yellowish alteration. Age estimated on the basis of outcrop COURSE k4yo m1y 1974 weathering and paleomagnetic data; overlain by k4ol W5897 Prehistoric Units y o 1973 550 Units 1,500 to 3,000 years old k4ym ±150 1972 Units 200 to 400 years old Kaoiki Fault Zone 1971 k4ys Lava flows and spatter deposits of young southwest rift zone vents—Thin, highly k2w Lava flows of Wright Road—Dense, tube-fed pähoehoe erupted from unknown y o 1969 localized, gray-brown, aphyric, vesicular pähoehoe erupted from two, small fissure vent(s) in Kïlauea summit area. Flows extend northeast of the summit caldera. Con- W4998 tain rounded olivine phenocrysts (3 to 4 percent). Outcrops are rare owing to exten- k4os k4ov vents in the upper southwest rift zone. Grouped on the basis of appearance; these W4803 ENLARGED AREA 960 9/71 sive cover of the Uwëkahuna (30 to 50 cm thick) and Keanakäkoÿi (1 to 80 cm ±60 flows probably represent separate eruptions. Mantled by the Keanakäkoÿi Ash 8740 thick) Ash Members. 14C age 2,770±150 (table 1) ±100 kpu 8/71 Member (1790t and 1790f). Overlies k4oy y k4yv Lava flow and spatter deposits of outlet vent—Gray-brown ÿaÿä and slabby pähoe- t Pleistocene and Holocene o 1968 hoe 1 to 2 m thick erupted from 1- to 3-m-high spatter rampart 2.7 km south of kpa Pähala Ash—The Pähala Ash is a general term that has been used for thick sequences Halemaÿumaÿu Crater. Heavily mantled by the Keanakäkoÿi Ash Member (1790t). 1959 khu of deeply weathered yellow, yellow-orange, and reddish ash over large parts of the Contain phenocrysts of olivine (1 to 3 percent) and plagioclase (2 to 4 percent) in a Island of Hawai’i. Consists of lithic and vitric fallout and possibly surge deposits medium- to dark-gray matrix. Overlie k4oy and k4oa m4o t 1954 which are widely reworked by water and wind. The Pähala Ash is often divided into k4ov k4ym —Dark-gray to purple, m4y Lava flows and spatter deposits of Kïlauea Military Camp the Main Pähala Ash, which overlies lava flows and tephras of the Hilina Basalt 1921 vesicular pähoehoe erupted from 250-m-long, 2- to 4-m-high spatter rampart that (age greater than 39 ka; Beeson and others, 1996), and the Upper Pähala Ash, which crosses the eastern access road to the Kïlauea Military Camp. Contain scattered oli- k4ov 1919 is intercalated with lava flows of the Puna Basalt as young as 3 to 5 ka (Easton, y vine phenocrysts (trace to 1 percent, generally less than 1 mm). Heavily mantled by o kul 1987). Within the map area the Pähala Ash is exposed in kïpuka on the surface of 1919 1918–19 the Keanakäkoÿi Ash Member (1790t). Overlie k4oy exposed in outer caldera fault t Mauna Loa where it is as much as 4 m thick. It consists of multiple pyroclastic units scarp just west of Volcano Golf Course access road from explosive eruptions from the late Pleistocene to middle or late Holocene. The 1892–94 k4yh —Brownish-gray shelly pähoe- Lava flows and spatter deposits of Hiÿiaka Crater source of the Pähala Ash is most likely Kïlauea Volcano (Easton, 1987; Beeson and 8/71 hoe erupted from fissure vent on the north rim of Hiÿiaka Crater. Contain scattered k4ov 1888–89 others, 1996) k4oy K I L A U E A olivine phenocrysts (trace to 1 percent). In places, fluid pähoehoe from this eruption 7/74 kpu k4oy 1882–85 poured into cracks circumferential to Hiÿiaka Crater; due to subsequent calving of MAUNA LOA VOLCANO C R A T E R the crater walls, this pähoehoe is now exposed as surface-fed dikes Kaÿü Basalt (Holocene and Pleistocene)—Within the map area, all lava flows derived 1877 kpu kul Basalt of Uwëkahuna laccolith—Dense intrusion, lenticular in shape. Fine-grained, from Mauna Loa Volcano are part of the Kaÿü Basalt, which includes all historic 1832 displays strong vertical zonation in olivine phenocryst abundance. Exposed in cal- lava flows and tephras as well as prehistoric lava flows and tephras that overlie the 1921 ? dera wall beneath Uwëkahuna Bluff (Murata and Richter, 1961; Casadevall and 25' t 1954 1832 1959 25' main Pähala Ash. The base of the Kaÿü Basalt is at least 31 ka (Wolfe and Morris, 1790t Dzurisin, 1987a). Intrudes prehistoric lavas that overlie the Uwëkahuna Ash Mem- 1996) and perhaps as old as 39 ka (Beeson and others, 1996). Lavas and tephras of 1954 Puÿu Pua‘i kpu ber but predates modern caldera collapse. Possibly originated by lateral intrusion 1975 the Kaÿü Basalt within this map area are tholeiitic in composition 8/71 1790f 1921 1921 1975 from a pre-caldera lava lake 0.5 to 2.0 ka khu 9/71 uncertain age Prehistoric Holocene Units 200+ kpu Prehistoric lava flows and tephra deposits, undivided—Prehistoric lava flows and 1975 1954 k4oy 9/71 1882–85 tephra deposits exposed in the caldera walls and walls of upper east rift zone pit cra- Units 200 to 400 years old 4/82 1954 1877 k4yh ters. Age control is poor except for Uwëkahuna Bluff section studied with paleo- m4y Younger Keamoku lava flows of Kïpukakï—Dark brown to tan, dense, massive ÿaÿä 4/82 1892–94 100 m4y magnetic techniques by Doell and Cox (1965), Holcomb and others (1986), and Halemaumau k4ol PREHISTORIC flow enclosing Kïpukakï. Erupted from a fissure vent trending obliquely across 1888–89 8/71 265±42 (2) Holcomb (1987). Casadevall and Dzurisin (1987a) conclude that lava flows in the Puÿukülua, 15 km northwest of the map area on Mauna Loa's northeast rift zone at 9/71 Crater kpu UNITS 10 Uwëkahuna Bluff section range in age from approximately 2.8 ka near the base to k4yu 9,000' elevation. Contain trace amounts of clear olivine phenocrysts (less than 1 kpu kpu k4ya 9/74 8/71 as young as 0.2 ka at the top, based on available paleomagnetic data and radiocar- percent, as large as 4 mm) and anhedra of plagioclase (generally less than 1 mm). 1892–94 8/71 bon dating of possibly correlative lava flows. Hagstrum and Champion (1995) pre- Overlain by discontinuous, thin, accretionary lapilli-rich beds of the Keanakäkoÿi 7/74 8/71 m4o kpu fer an age of about 3.0 ka for the base of the Uwëkahuna Bluff section based on Ash Member of the Puna Basalt (1790t). This is the youngest of several separate k4oa k4ys k4yck4yv k4ym k4yl 0 new paleomagnetic interpretations. We infer a 0.5 ka age for the top of the section 1918–19 k4oa ÿaÿä flows labeled the Keamoku Flows on previous maps and was termed the lobe of k4oo k4yp based on additional radiocarbon dating. No flows of Mauna Loa origin are known in 7/74 Kipuka Kekake by Peterson (1967). The flow traveled southeast down Mauna Loa's the Uwëkahuna Bluff section (Casadevall and Dzurisin, 1987b), but Rhodes and 1892–94 Holocene flank until reaching the Kïlauea shield, where it was deflected westward along the k4oo k4ol k4yk k4ya others (1989) found flows that have chemistry similar to Mauna Loa lavas in the Kïlauea-Mauna Loa boundary. 14C ages range from 230±60 to 300±60 (table 1) 1921 1790t al 9/71 375±20 (11) walls of Kïlauea Iki and Pauahi Craters and suggested that they represent Mauna ? Units 400 to 750 years old kpu Loa magma processed through the Kïlauea plumbing system. At Pauahi Crater ? m4o Older Keamoku lava flows of Kïpukapuaulu—Gray-brown to tan pähoehoe and k4yp k4yo along the upper east rift zone and at Pit Craters in the Kaÿü Desert, a portion of the k4oo ? ÿaÿä, this unit is the most widespread of the Keamoku flows. It directly underlies ? lower crater walls predate the Uwëkahuna Ash Member (Dzurisin and others, 1995) 9/82 ? k4ol 310±70 (1) al 400 k4yu —Composite unit rep- m4y and surrounds Kïpukapuaulu. Erupted from a fissure system that cuts Puÿuÿula-

? Lava flows and spatter deposits of the Upper East Rift Zone al ? k4oy Quaternary ÿula along the northeast rift zone about 13 km northwest of the map area. Contain ? resenting multiple eruptions. Undivided due to uncertain internal contact relations al kpu ? m4o conspicuous anhedral laths and aggregates of plagioclase (5 to 10 percent, laths * 7/74 ? in heavily vegetated terrain of the upper east rift zone. Include gray to black, dense ? generally less than 1 mm, aggregates as large as 2 mm across) and anhedral, sugary

al ? ? 577±28 (5) pähoehoe and brownish-gray shelly pähoehoe erupted from poorly exposed fissure * k4on phenocrysts of olivine (2 to 6 percent, as much as 1.5 mm across). ÿAÿä of this unit ? vents north and east of Hiÿiaka Crater. Contain scattered olivine phenocrysts (trace 9/71 k4oy EAST was mapped as one of the lower lobes of the Keamoku lava flows by Peterson * ? to 1 percent) k4oa k4oy k4os k4ol (1967). The bulk of the unit consists of pähoehoe emplaced as fast-moving, highly ? k4yc Spatter deposits and lava flows of Cone Crater—Spatter cone atop a small lava * k4yu 550±110 (1) fluid lava after most of the ÿaÿä was emplaced. This pähoehoe ponded in the saddle ? 578±57 (2) 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 between Mauna Loa and the Kïlauea shield and is characterized by pseudo-karst al * ? k4oo k4ov k4on northeast of Cone Crater erupted small fluid pähoehoe flows and two thin ÿaÿä pits caused by lateral drainage and crustal subsidence. Large tree molds and casts ? 14 k4yp ? kul occur in several places north of the map area. C ages range from 330±60 to k4ol 509±41 (3) lobes; these are similar in appearance and chemical composition and are grouped ? 830±60 (table 1) * k4yl 571±42 (6) with Cone Crater flows. Contain scattered olivine phenocrysts (trace to 1 percent, 1 * 1790f ? k4yp o y k4oa k4op to 3 mm). Flow field from main vent is cut by two collapse pits, the Pit Craters. The ? Units 750 to 1,500 years old

? kpu walls of these craters are mantled in places by red, oxidized drainback. Cone Crater 1790f m3 Lava flows of Keauhou Ranch—Dark gray, glassy (where undisturbed) tube-fed al ? k4yu flow overlies pähoehoe flow of k4yk y o pähoehoe erupted from unknown, possibly-buried vents along the northeast rift ? 9/71 k4yl Lava flows and spatter deposits of Koÿokoÿolau Crater—Gray-brown to black, RIFT k4ok zone. Unit is exposed in several grass-covered kïpuka along the north margin of the k4yl ? thin, vesicular, glassy pähoehoe erupted from spatter cone cut by Koÿokoÿolau Cra- * 627±34 (5) map area. Contain inconspicuous, sugary, anhedral olivine phenocrysts (4 to 10 per- 9/71 * ?

k4ys k4on 750 ter in the upper east rift zone. Typically contains 7 to 10 percent glassy olivine phe- cent, as much as 3 mm across) and subhedral plagioclase phenocrysts (2 to 8 per- k4oy ? kpu k4yu k4oy k4yh nocrysts. Unit is heavily vegetated and contacts are difficult to trace. Age and cent, generally less than 1 mm). Surface outcrops are similar to those of the

mapped extent differs from that in Holcomb (1987) and Wolfe and Morris (1996) al ? m3 overlying pähoehoe of the Keamoku lava flow of Kïpukapuaulu, but they can be Pu'u 760±70 (1) based on new field data. Overlie k4ol and k4ya; overlain by dense pähoehoe of k4yu. k4yp k4oy 1790f k4yv Huluhulu k3d distinguished by more dense grass cover and also by a speckled surface caused by kpu Additional outcrops southeast of its mapped extent have probably gone unrecog- 14 ? weathered olivine phenocrysts. C age 760±70 (table 1) 1979 1968 nized due to poor exposure k4oy k3d ZONE Units 1,500 to 3,000 years old k4oy 1979 k3k k4yk Lava flows and spatter deposits of Puÿukoaÿe—Gray to black, pähoehoe and ÿaÿä ? y o * o 1979 m2 971±26 (6) erupted from Puÿukoaÿe, a 35-m-tall spatter cone and two, partially buried spatter ÿAÿä flows of eastern Kaÿöiki Pali—Distinctive, dense, flinty ÿaÿä lobes that drape k4oy y 1973 22'30" * 22'30" cones about 7 km southwest of Halemaÿumaÿu Crater. Pähoehoe (mapped as sepa- the Kaÿöiki faults at the north-central edge of the map area (fig. 1). Erupted from k4oy 1973 k4op al kpu rate unit by Walker, 1969) erupted first followed by ÿaÿä. Main ÿaÿä flow traveled unknown, now-buried vents along the northeast rift zone. Contain conspicuous 1973 1979 1973 k3n nearly 9 km south. Lavas are chiefly aphyric. Small fissure vents and vesicular anhedral plagioclase phenocrysts (3 percent, as much as 0.5 mm across). Unit is 12/74 o y 1979 pähoehoe flows 1.8 km northeast of Puÿukoaÿe (Walker, 1969), mostly buried by mantled by thin, discontinuous deposits of the Keanakäkoÿi Ash Member (1790t) k3a k4oy k4ys k4yl 1974 lavas, are grouped with Puÿukoaÿe lavas. Overlie ÿaÿä flow of k4yp just west of and the upper Uwëkahuna Ash Member of the Puna Basalt, which support dense y 1973 9/71 k4oy o 1974 Puÿukoaÿe grass. Typical exposures consist of isolated blocks of ÿaÿä projecting above grass- k4yk covered areas; well-exposed in a small quarry where the Puÿu ÿÖÿö Trail crosses the k3h k4ya 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 Kaÿöiki faults. 14C ages range from 2,190±70 to 2,340±70 (table 1) k4ok 1,500 Crater. Lava flows in the map area include the youngest flows from the ÿAilaÿäu Units 3,000 to 10,000 years old k4yc k4oy vent (fig. 3), the source of voluminous lava flows containing large lava tubes m1y ÿAÿä flow west of Kïpukakï—Distinctive ÿaÿä west of Kïpukakï. Erupted from al k4oy 1972 m2 extending to the east coast of Kïlauea (Holcomb, 1981; 1987). The youngest ÿAila- k4yp 1969 unknown, now-buried vents along the northeast rift zone. Contains clear, euhedral * 2,265±49 (2) ÿäu flows are well exposed along Crater Rim Drive near Thurston Lava Tube (Kea- olivine phenocrysts (6 to 8 percent, as much as 6 mm across) and subhedral plagio- k4yc nakakina). Typically contain semi-equant and acicular olivine phenocrysts (5 to 15 al k4oy k3h clase phenocrysts (3 to 5 percent, generally less than 1 mm) in a dense, medium- k4yc k4yu percent). Age estimated on the basis of superposition and multiple radiocarbon k4ya k4yu 1971 gray matrix. The flow is as much as 9 m thick and forms bold, brush-covered out- al dates from beneath surface flows correlated with the ÿAilaÿäu shield northeast of k4oy 1974 crops above adjoining grass-covered older flows. Unit is mantled by discontinuous 14C ages range from <200 to 620±70 (table 1). Some or all of these dated o k4oy k2w map area. deposits of the Uwëkahuna Ash Member of the Puna Basalt, but overlies the Pähala y flows may actually be older than k4ya k3h 2,770±150 (1) Ash. Its age is estimated by outcrop weathering at 4,000 to 5,000 years WW308 3,000 ? k4yp Lava flows and spatter deposits of Cone Peak—Gray-brown vesicular pähoehoe, m1o Lava flows of Puÿuÿulaÿula—Deeply weathered pähoehoe along the northwest boun- k4yk 400 k4op slabby pähoehoe, and ÿaÿä erupted from Cone Peak, a 900-m-long spatter rampart 2 ±50 dary of the map area. On the basis of chemical and paleomagnetic data, the likely k4yk k4ol m1y km southwest of Halemaÿumaÿu Crater. Unit includes thin, vesicular pähoehoe o k4yc System source of this flow is Puÿuÿulaÿula, about 13 km northwest of the map area at y flows from fissure vents extending as much as 5 km downrift. Initial fissure may k4yc Koa'e Fault 10,000’ elevation on the northeast rift zone. Typically aphyric but contains scattered, have extended uprift to the southwest margin of the caldera. Pähoehoe is denser in k4oy inconspicuous, anhedral, olivine phenocrysts (1 to 2 percent, generally 1 mm exposures on caldera side of Cone Peak vent. Contain scattered olivine phenocrysts m1o across). Unit is buried by as much as 2 m of the Uwëkahuna Ash Member of the k4op (trace to 1 percent; generally less than 1 mm) in a dark-gray matrix. Overlies k4oy 8,645±71 (2) Puna Basalt and upper units of the Pähala Ash in the map area, and it is exposed 10,000 and underlies k4yk k4yu only in deep gullies, where it overlies thick older units of the Pähala Ash. The sizes al k4yo Older lava flows of ÿAilaÿäu—Black, glassy, dense tube-fed pähoehoe erupted from khu k3k of ash-free exposures have been exaggerated on the map. At higher elevations this k4yu kpa WW302 unknown vent(s) in the Kïlauea summit area. Contain scattered olivine phenocrysts k4yc flow has an orange-weathered surface. 14C ages range from 8,550±100 to 650 (trace to 1 percent, generally less than 1 mm). Poorly exposed in heavily vegetated 8,740±100 (table 1) k4oy ±60 terrain. Underlie olivine-rich flows of k4ya. 14C age 310±70 (table 1) k3n Pleistocene Unit 12/74 Units 400 to 750 years old m0 ÿAÿä flow northeast of Volcano Golf Course—Distinctive, plagioclase-rich ÿaÿä at al 1971 Pleistocene k4oy Younger lava flows of the Observatory vent—Tan-gray, chiefly dense, tube-fed the north edge of the map. Erupted from unknown vents on the northeast rift zone. k3k k4ya ? pähoehoe and five prominent ÿaÿä lobes erupted from unknown vent(s) near Uwëka- Generally covered by as much as 2.5 m of the Uwëkahuna Ash Member of the Puna k4oy huna Bluff (Observatory vent of Holcomb, 1987). Flows extend southwest from the Basalt and the upper part of the Pähala Ash. Where artificially exposed, the surface summit caldera and typically contain phenocrysts of olivine and intergrown clino- is deeply weathered to orange clay around ÿaÿä clasts and along fractures. Fresh k4yk WW370 m0 pyroxene (3 to 10 percent) and conspicuous plagioclase (1 to 5 percent). Large tree rock contains subhedral plagioclase phenocrysts (15 to 18 percent, as much as 5 * 460 k3a W5785 ±60 k3n molds are preserved in this flow 1 km west of the Kïlauea Military Camp. In the mm in length) and clear, euhedral olivine phenocrysts (5 to12 percent, as much as 8 600 upper southwest rift zone and southwest caldera wall, the uppermost flow (or flows) mm across). Its age is unknown but almost certainly is pre-Holocene k4ok ±100 WW301 AA10602 of this unit is a vesicular to dense picritic pähoehoe (indicated by small v pattern), k4oy 970 400 in places only a few cm thick, that contains olivine phenocrysts up to 7 mm across. ÿAÿä lava flow k4oy ±60 ±70 DESCRIPTION OF MAP UNITS southwest), 12 km from the summit. Contain scattered olivine phenocrysts (trace to This flow is characterized in places by strong vertical zonation in olivine abundance k3n y o 1 percent, generally less than 1 mm) in a dark-gray to black groundmass (Duffield (scattered outcrops indicated by asterisk) and is correlative with the patches of pic- Cinder or spatter cone 12/74 k3k SURFICIAL DEPOSITS ritic basalt mapped by Walker (1969) and the regional prehistoric pähoehoe picrite y o W4337 and others, 1982) Picrite—Picritic lava flow of unit k4oy. Scattered outcrops of picrite indicated by aster- al Alluvium (Holocene)—Chiefly sand redistributed by running water; mixed with aeolian complex of Wright (1971). It may represent a late, olivine-rich phase from the 1973 620 8/71 Lava flows and spatter deposits of August 14, 1971—Black, glassy, pähoehoe isk ( ). Correlative with llkp of Walker (1969) 1973 ±70 sand. Derived principally from the Keanakäkoÿi Ash Member of the Puna Basalt Observatory vent (fig. 3) or a separate eruption possibly fed by a dike exposed in k3a erupted from fissures on the caldera floor southeast of Halemaÿumaÿu and from fis- k3a (1790t) the southwest caldera wall (dike 5S; see fig. 14.1 in Casadevall and Dzurisin, Uwëkahuna Ash—Shown where greater than approximately 30 cm in thickness. 19 20' 19 20' sure vents on the southeast caldera rim north of Keanakäkoÿi Crater. Lava flooded 155° 20' 17'30" 15' INTERIOR—GEOLOGICAL SURVEY, RESTON, VA—2003 155 12'30" t Talus (Holocene)—Angular blocks of basalt forming steep rubble aprons along the base the eastern part of the caldera floor. Contain olivine phenocrysts (1 to 3 percent, 1 to 1987a). Contacts between the picrite and earlier, less olivine-rich flows of k4oy are Deposits are typically yellow-brown in contrast to the gray Keanakäkoÿi and yel- and lower walls of Kïlauea caldera, much of which formed during the surface wave obscured by the Keanakäkoÿi Ash Member (1790t). In a caldera-wall exposure just low-orange Pähala Ash 1 4 mm) in a dark-gray to black groundmass (Duffield and others, 1982) Base from U.S. Geological Survey, Kilauea Crater, Volcano, 9 /2° SCALE 1:24 000 Geology mapped by C.A. Neal (1987–1989, 1997), J.P. Lockwood magnitude (M ) 6.6 Kaÿöiki earthquake of November 16, 1983 (Buchanan-Banks, east of BM 3724 in unit k4yp, the picrite is overlain by olivine-rich scoria, ash, and —Shown where greater than approximately 1.5 m in thickness Kau Desert, Makaopuhi Crater, 1981 (1978–1993), and modified from Holcomb (1987) S 1968 Lava flows of August 22, 1968—Black, glassy pähoehoe pad less than 1 m thick and Pähala Ash 11/ 2 0 1 MILE 1987) reticulite of unknown origin. 14C ages range from 410±100 to 960±60 (table 1) Universal Transverse Mercator projection Digital cartography by P.E. Bruggman, D. Dutton, T.J. Felger, J.P. Lock- covering about 5,000 m2 erupted from fissure vent 1 km east-northeast of Pauahi RTH HAWAIIAN k4os Dikes—Located in walls of Kïlauea and Kïlauea Iki Craters. Bars represent approximate 1.50 1 KILOMETER wood, Ellen Lougee, Sandy Margriter, and Patrick Showalter; cartogra- Crater; additional spatter emitted from a second fissure 0.5 km northeast of Pauahi Lava flows of Steaming Bluff—Dense, tube-fed pähoehoe erupted from unknown ISLANDS KÏLAUEA VOLCANO location and strike; solid circles denote variable or unknown orientation. Size exag- phy by D.A. Ryan; edited by J.L. Zigler Crater is not shown owing to limited extent (these are vents 3 and 2, respectively, of vent(s) in the Kïlauea summit area. Flows extend north of the summit caldera and TRUE NORTH TRUE Manuscript approved for publication December 10, 2001 PUNA BASALT contain conspicuous plagioclase, olivine, and clinopyroxene phenocrysts in a crys- gerated for clarity. From Casadevall and Dzurisin (1987a) CONTOUR INTERVAL 20 METERS MAP LOCATION Jackson and others, 1975). A third fissure vent just north of Pauahi Crater emitted MAGNETIC NO NATIONAL GEODETIC VERTICAL DATUM OF 1929 Puna Basalt (Holocene)—All units on this map derived from Kïlauea Volcano are part only hot gasses. Contain scattered olivine phenocrysts (trace to 1 percent) talline groundmass. Overlie k4ov in road cuts along Highway 11. Heavily mantled Contact—Dashed where approximately located; dotted where concealed; queried where APPROXIMATE MEAN inferred and highly uncertain. Internal contacts distinguish ÿaÿä or cinder or spatter of the Puna Basalt, which includes all historic and prehistoric lava flows and tephras 1959 Lava flows, spatter deposits, and reticulite of November 14 to December 20, by the Keanakäkoÿi Ash Member (1790t; see isopach on map). May be correlative DECLINATION, 2002 cones of same map unit that overlie the main Pähala Ash. The base of the Puna Basalt is not precisely 1959—Black, glassy pähoehoe in Kïlauea Iki Crater capping a solidified lava lake with k4oy defined and may be as old as 39 ka (Beeson and others, 1996). Lavas and tephras of 135 m thick (Richter and others, 1970). Surface is generally smooth but is broken k4ol Lava flows of Luamanu—Gray to black, dense pähoehoe and vesicular surface-fed Fault—Dashed where approximately located; dotted where concealed. Bar and ball on the Puna Basalt within this map area are tholeiitic in composition. into large polygonal plates related to cooling and subsidence of the lake. Contain pähoehoe erupted from unknown vent(s) in the Kïlauea summit area. Flows extend downthrown side south-southeast from the caldera. Contact relations with adjacent units are approxi- Historic Units abundant olivine phenocrysts (15 to 20 percent). Puÿu Puaÿi, a 70-m-high cinder and Crack or non-eruptive fissure k4ym mate due to vegetation, cover by Keanakäkoÿi Ash Member (1790t; see isopach on k4os k4ov A.D. 1790 and younger spatter cone on the southwest rim of Kïlauea Iki was built by fallout from lava foun- tains reaching 580 m in height. The vent is visible as a rubble-choked opening at the map), and indistinct lithologic contrasts. Part of Kokoolau Flows of Holcomb 1959 Kïlauea Iki isopachs—Isopachs represent thickness, in cm, of tephra-fall depos- 9/82 —Black, glassy, pähoehoe y kpu Lava flows and spatter deposits of September 25, 1982 base of the southwest wall of Kïlauea Iki. Continuous blanket of cinders extends (1987). Flows contain scattered olivine phenocrysts (trace to 1 percent, generally its. Outer isopach represents approximate limit of continuous cover. Dotted where o t erupted from vents near the southern caldera wall where the high stand of ponded southwest 4 km (Richter and others, 1970) less than 1 mm) in a light- to medium-gray, well-crystallized groundmass. May be concealed. Adapted from Richter and others (1970) and new field data lava produced a 2- to 3-m-high terrace. A 1.5-km-long tongue that exited the caldera 14 1954 Lava flows and spatter deposits of May 31 to June 3, 1954—Dark-gray to black closely related in age to k4ov and k4oo. C age 550±110 (table 1) Keanakäkoÿi Ash Member isopach—Isopach shows 1-meter thickness. Dotted where and flowed south is locally slabby pähoehoe and ÿaÿä. Lava also spilled across Cra- k4ov pähoehoe erupted from fissure vents on the central Kïlauea caldera floor. Contain k4oo Older lava flows of Observatory vent—Gray to black, dense, low-relief, tube-fed concealed. From R.L. Christiansen, unpublished data ter Rim Drive and into the main caldera depression. Low spatter ramparts and open pähoehoe erupted from unknown vent(s) in the Kïlauea summit area. Flows exposed olivine phenocrysts (1 to 3 percent, 1 to 3 mm; Macdonald and Eaton, 1957) —Shows limits of spatter rampart where mappable. Dotted where con- t fissures mantled by drainback mark the eruptive vents. Contain scattered olivine only locally in summit region several km southwest of Halemaÿumaÿu Crater as Fissure vent 1921 Halemaÿumaÿu overflows of January to March, 1921—Light gray, dense pähoehoe phenocrysts (trace to 1 percent, generally less than 1 mm) in a medium-gray cealed k4ov near Halemaÿumaÿu Crater. Surface is flat to undulating, broken in places into thin, vesicular, surface-fed pähoehoe beneath k4oy. Many small patches unmappa- groundmass (Banks and others, 1983) —Hachures shown inward facing. Not shown on caldera walls and some small blocky piles and patches of slabby and spiny pähoehoe. A 2- to 4-cm-thick glass ble on the western flank of the Observatory shield (fig. 3). Unit is areally extensive Crater 4/82 Lava flows and spatter deposits of April 30 to May 1, 1982—Black, glassy, shelly craters for clarity. Dotted where concealed rind is locally preserved. Contain olivine phenocrysts (3 to 5 percent) in a sugary southwest of map area as far as the coast. Lavas are chiefly aphyric but occasionally pähoehoe, slabby pähoehoe, and ÿaÿä. Erupted from fissure vents surrounded by groundmass (U.S. Department of Agriculture, 1921). Surface is littered with coarse contain scattered olivine phenocrysts (trace to 1 percent, generally less than 1 mm) o y Age relations—Shows older (o) and younger (y) age relations between units. Indicated spatter ramparts 2 to 4 m high on the central caldera floor and northeast wall of in a light- to medium-gray feldspathic groundmass. Closely related in age to k4ol kul blocky debris from the 1924 eruption at Halemaÿumaÿu where contact is well exposed and age relations are certain 1919 Halemaÿumaÿu Crater. Contain scattered olivine phenocrysts (trace to 1 percent, and k4ov. 14C ages range from 450±60 to 590±100 (table 1) 1919 Halemaÿumaÿu overflows of March to December, 1919—Dark-gray to black, flat- 14 t generally less than 1 mm) in a light- to medium-gray groundmass (Banks and oth- W4367 Radiocarbon sample locality—Shows Lab Number and C age in years BP (table 1) lying to undulating pähoehoe north of Halemaÿumaÿu Crater. Marked by prominent k4ov Lava flows of Volcano village—Dense, hummocky tube-fed pähoehoe and small 570 ers, 1983) tumuli as much as 3 m high. Collapsed lava tubes and rubble-filled pits occur north patches of rubbly ÿaÿä erupted from unknown vent(s) in the Kïlauea summit area. ±70 1979 Lava flows and spatter deposits of November 16, 1979—Black, glassy, shelly Flows extend northeast from the summit caldera beneath Volcano village. Heavily 8/71 and northwest of Halemaÿumaÿu. The northern margin of this flow field is flat and pähoehoe, slabby pähoehoe, and ÿaÿä. Erupted from fissures west of, within, and has a thick glass rind. Contain olivine phenocrysts (1 to 3 percent, generally less mantled by Keanakäkoÿi Ash Member (1790t; see isopach on map). Lavas are kpu east of Pauahi Crater. Contain scattered olivine phenocrysts (trace to 1 percent; K I L A U E A than 1 mm) in a feldspathic groundmass. Surface near Halemaÿumaÿu Crater is lit- chiefly aphyric but occasionally contain scattered olivine phenocrysts (trace to 1 k4ov Banks and others, 1981) 7/74 tered with coarse blocky debris from the 1924 eruption (U.S. Department of Agri- percent, generally less than 1 mm) in a light- to medium-gray feldspathic ground- 1975 Lava flows and spatter deposits of November 29, 1975—Black, glassy, shelly mass. Closely related in age to k4oo and k4ol. 14C ages range from 350±60 to Telephoto view to the south across Kïlauea Caldera from the U.S. Geological Survey culture, 1919) C R A T E R pähoehoe erupted from fissure vents on the central caldera floor and small spatter 1,170±150 (table 1) Hawaiian Volcano Observatory, July 19, 1974, 1:25 p.m. Lava fountains as high as 25 m 1918–19 Halemaÿumaÿu overflows of February 23 to March 3, 1918 and February 25 to kpu cone at the base of the northeast wall of Halemaÿumaÿu Crater. Contain scattered k4on ÿAÿä flow and spatter deposits of Keanakäkoÿi—ÿAÿä erupted from 300-m-long on the skyline south of Keanakäkoÿi Crater feed lava cascading into the crater. Three en Photograph showing night view (time exposure) of Hale- April 17, 1919—Gray-brown, flat-lying pähoehoe south of Halemaÿumaÿu Crater. olivine phenocrysts (trace to 1 percent, generally less than 1 mm). Eruption fol- spatter rampart 600 m south of Keanakäkoÿi Crater. Weathered surface is orange- echelon fissure fountains are active north of Keanakäkoÿi. Low fountains at the crater's maÿumaÿu Crater, taken about 1967–68. Contain olivine phenocrysts (5 to 7 percent, 1 to 5 mm) visible as white specks in lowed a M 7.2 earthquake located on Kïlauea Volcano’s south flank (Tilling and gray. Contain phenocrysts of olivine (2 to 4 percent, generally less than 1 mm) and 1921 north rim feed flows that have just cut the Crater Rim Road, middle fountains feed fluid surface glass. Distinguished from the 1894 flow by its darker surface and lower t 1954 1832 1959 others, 1976) rare phenocrysts of plagioclase. Heavily mantled by the Keanakäkoÿi Ash Member pähoehoe lavas into a gully on the right. High fountains on the floor of Kïlauea Crater relief. Surface is littered with coarse, blocky debris from the 1924 eruption at Hale- 12/74 Lava flows and spatter deposits of December 31, 1974—Black, glassy, shelly (1790t; see isopach on map) and 1959 tephra. Overlie k4oa and is overlain by k4ol 1954 Puÿu Pua‘i (foreground) mark the easternmost extent of the caldera-floor fountains that extend more maÿumaÿu (HVO Research Association, 1918; U.S. Department of Agriculture, 1919) kpu pähoehoe near eruptive vents; slabby pähoehoe and ÿaÿä in distal areas. Erupted k4op Lava flows and spatter deposits of Pu’uhuluhulu—Dense, tube- and surface-fed 1975 than a kilometer west of this photo. (Photograph by J.C. Forbes.) 1892–94 Halemaÿumaÿu overflows of 1892 to 1894—Gray, hummocky pähoehoe and small 1921 1921 8/71 from left-stepping en echelon fissure vents in the upper southwest rift zone. Contain pähoehoe and vesicular, glassy spatter erupted from Pu’uhuluhulu at the east margin khu 1975 JPL patches of slabby pähoehoe and ÿaÿä east and southeast of Halemaÿumaÿu Crater. 9/71 conspicuous olivine phenocrysts (5 to 7 percent, 1 to 5 mm) in glassy matrix (Peter- of the map. The surface of the pähoehoe is poorly exposed beneath 10 to 20 cm of Altered locally to whitish-yellow. Several collapse pits up to 5 m across and hollow 1954 son and others, 1976) tephra from Mauna Ulu (fig. 1; lava shield off map area southeast of Pu’uhuluhulu), 1975 1882–85 tumuli characterize the surface. Contain phenocrysts of olivine (5 to 10 percent) and 9/71 khu Historic Kïlauea lavas, undivided—Chiefly pähoehoe from former overflows and a few cm of the Keanakäkoÿi Ash Member, and 5 to 10 cm of reddish-brown lithic 4/82 plagioclase (1 to 3 percent), commonly intergrown and visible in the surface glass, 1954 1877 subsidence terraces from lava lakes, now exposed in the walls of Halemaÿumaÿu ash from unknown source(s). Contain glassy olivine phenocrysts (5 to 12 percent, 1 4/82 imparting a speckled appearance. Surface is littered with coarse, blocky debris from 1892–94 100 Crater. Includes lavas from eruptions as recent as September, 1974 and possibly as to 8 mm) k4ol the 1924 eruption at Halemaÿumaÿu. Overflows were recorded in April to Septem- Halemaumau E 8/71 A old as 1832. Also includes gray-black, aphyric, shelly pähoehoe erupted from 4-m- k4oa Lava flows of Ähua—Dense, hummocky tube-fed pähoehoe erupted from unknown 1888–89 S Crater T ber 1892 and February to April 1894. Other overflow events probably went unre- 9/71 R high, conical spatter cone 800 m southwest of Puÿukoaÿe. This lava flow covers vent(s) in the Kïlauea summit area. Flows extend south from the summit caldera. kpu 10 IF corded (Brigham, 1909, p. 184–191; Volcano House Register, 1891–1898) T 2 ZONE about 500 m and overlies 1790t. Surface is characterized by numerous tumuli. Part of Kalue flows of Holcomb kpu kpu ZON 1888–89 Halemaÿumaÿu overflows of 1888 to 1889—Orange-brown, fluid pähoehoe and 8/71 SOUTHWEST RIFT E 9/74 Lava flows and spatter deposits of September 19, 1974—Black, glassy, shelly (1987). Contain scattered phenocrysts of olivine (trace to 1 percent, generally less 9/74 Photograph showing discontinuous row of lava CAN shelly pähoehoe with numerous small, hollow lava tubes, exposed east of Halema- 8/71 pähoehoe erupted from fissure vents on the floor of the summit caldera west of and than 1 mm) in a light- to medium-gray groundmass characterized by abundant, con- 1892–94 8/71 fountains 50–100 ft high during the 1971 ÿumaÿu Crater. Contain scattered olivine phenocrysts (trace to 1 percent, 1 to 2 mm) 7/74 within Halemaÿumaÿu Crater. Contain scattered olivine phenocrysts (trace to 1 per- spicuous, plagioclase microlites. Overlie k4ok kpu Kïlauea Summit eruption. (National Park Serv- in a feldspathic groundmass. Surface is littered with coarse, blocky debris from the k4oa cent, generally less than 1 mm) in a medium- to dark-gray groundmass (Peterson k4ok Younger lava flows of Käluÿe—Tan-gray, tube-fed pähoehoe with abundant tumuli k4yp 0 ice photograph.) 1924 eruption at Halemaÿumaÿu. Overflows occurred between July 1888 and May 1918–19 k4oa and others, 1976) and small patches of ÿaÿä from unknown vent(s) in the Kïlauea summit area. Flows RTH 1889; activity was particularly vigorous on February 8, 1889 (Dana, 1890; Volcano 7/74 —Erupted in the summit cal- extend south from the caldera. Part of Kalue flows of Holcomb (1987). Contain 7/74 Lava flows and spatter deposits of July 19 to 22, 1974 House Register, 1885–1891) dera and upper east rift zone. Summit lavas are chiefly black, glassy, flat-lying, fluid phenocrysts of olivine (5 to 7 percent) and plagioclase (3 to 5 percent) that are often 1892–94 CAN C.A. Neal (1987–1989, 1997) 1882–85 Halemaÿumaÿu overflows of 1882 to 1885—Light-gray to brown-gray pähoehoe 14 k4ol JPL J.P. Lockwood (1978–1993) pähoehoe, local slabby pähoehoe, and ÿaÿä fed from fissure vents on the floor of the intergrown. C ages range from 460±60 to 740±100 (table 1) 1790t RTH modified from R.T. Holcomb (1987) exposed on the central caldera floor. Generally smooth but cut by open cracks and 9/71 1921 k4ya summit caldera southeast of Halemaÿumaÿu to just north of Keanakäkoÿi. Contain large (4 by 20 m) elongate tumuli. Contain olivine phenocrysts (3 to 5 percent) in a Units 750 to 1,500 years old The Board of Geographic Names determines official names of places, ? INDEX MAP SHOWING SOURCES scattered olivine phenocrysts (trace to 1 percent, 1 to 4 mm) in a dark-gray ground- feldspathic groundmass. Plagioclase phenocrysts are conspicuous in glassy samples. k3d Lava flows and spatter deposits of Devil’s Throat—Red, oxidized, aphyric cinder, features, and areas in the United States and its territories. The Board kpu OF GEOLOGIC MAPPING mass. Upper east rift zone vents cross the south edge of Keanakäkoÿi Crater and recently approved use of diacritical marks in written forms of geographic ? Surface is littered with coarse, blocky debris from the 1924 eruption at Halemaÿu- spatter, and vesicular to dense pähoehoe erupted from small cone exposed in road- continue across the Chain of Craters Road near Luamanu Crater. Lavas erupted near names derived from the Hawaiian language. The authors choose to use ? maÿu. Overflows from September 1882 to late 1885 covered most of the caldera cut along Chain of Craters Road adjacent to northwest margin of Hiÿiaka Crater and Hawaiian spellings of place names following Pukui and Elbert (1986) Luamanu Crater contain phenocrysts of olivine (3 to 5 percent, 1 to 3 mm) and pla- and Pukui and others (1986) in the text of this publication, and they are ? floor. A hornito called Little Beggar formed March 3, 1884 and continued to be 150 m southeast of Devil’s Throat. Most of the pähoehoe flows originated as agglu- 9/82 ? k4ol gioclase (1 to 2 percent, 2 to 3 mm; Peterson and others, 1976) responsible for accuracy. Note that some place names appear without active for several years. It was buried during the 1954 eruption (Brigham, 1909, p. tinated spatter, which is visible on some flow surfaces. Overlain by k4ya and shelly correct Hawaiian spelling to be consistent with the original usage in cited ? ? 1969 Lava flows and spatter deposits of the Mauna Ulu eruption—Black, glassy pähoe- publications. In addition, place names on the topographical map base k4oy Geologic Map of the Summit Region of 156–158; Hitchcock, 1909, p. 221–226; Volcano House Register, 1873–1885) pähoehoe of k4yu. Age assignment is older than that of Holcomb (1980; 1981) and remain uncorrected. ? 1971 hoe and ÿaÿä from fissure vents in the upper east rift zone and from overflows of kpu 1877 Spatter deposits and lava flows of 1877—Gray-brown, oxidized, vesicular spatter Wolfe and Morris (1996) based on new field data Any use of trade, product, or firm names in this publication is for ? k4oa 1972 * 7/74 ? Mauna Ulu (located just off map southeast of Pu’uhuluhulu). Most lavas contain and remobilized spatter deposits on the east caldera wall. Deep pit 1 m across at the k3k Older lava flows of Käluÿe—Gray to orange-tan, dense, tube-fed pähoehoe and small descriptive purposes only and does not imply endorsement by the U.S. 9/71 Kïlauea Volcano, Hawaii 1973 scattered olivine phenocrysts (trace to 1 percent; Peterson and others, 1976; Swan- Government. * ? k4on base of the wall may mark a vent. Contain scattered olivine phenocrysts (trace to 1 patches of ÿaÿä erupted from unknown vent(s) in the Kïlauea summit area. Flows k4oy 1974 son and others, 1979; Tilling and others, 1987) For sale by U.S. Geological Survey, Information Services, Box 25286, By percent, 1 to 3 mm). Additional deposits on south caldera wall, at base of south exposed along Hilina Pali Road at the south edge of map. Part of Kalue flows of Federal Center, Denver, CO 80225, 1–888–ASK–USGS Figure 2. Enlarged map of Kïlauea summit area showing extent of historic and prehistoric lava flows. Prin- 9/71 Lava flows and spatter deposits of September 24 to 29, 1971—Black, glassy, wall, and on the floor of Keanakäkoÿi Crater (Peterson, 1967) have been largely Holcomb (1987). Flows of this unit reach the coastline south of map area. Contain Available on World Wide Web at http://pubs.usgs.gov/imap/i2759 cipal faults, cracks, dikes, and areas where deposits from the Keanakäkoÿi Ash Member of the Puna Basalt Christina A. Neal and John P. Lockwood vesicular pähoehoe from fissure vents on the caldera floor and along the upper covered by younger lavas. Probably erupted in May of 1877 (Brigham, 1909, p. phenocrysts of olivine (2 to 4 percent) and minor equant plagioclase (trace to 2 per- obscure underlying lava flows also shown. 2003 southwest rift zone as far as the southwest flank of Mauna Iki (fig. 1; off map to 131–132; Hitchcock, 1909, p. 217; Volcano House Register, 1873–1885) cent) in fine-grained groundmass. 14C ages range from 320±50 to 1150±70 (table 1) Printed on recycled paper