science 

uses

for a changing world

New Radiocarbon Ages 

from Haleakala Crater, 

Island of Maul, 

HawaP I

By David R. Sherrod1 and John P. McGeehin2

Open-File Report 99-143

1999

This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey 

editorial standards or with the North American Stratigraphic Code. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

U.S. DEPARTMENT OF THE INTERIOR 

U.S. GEOLOGICAL SURVEY

1 U.S. Geological Survey, Hawaiian Volcano Observatory, PO Box 51, Hawaiv i National Park, HI

96718 

2U.S. Geological Survey, Mail Stop 955, 12201 Sunrise Valley Drive, MS 955, Reston, VA 20192
New radiocarbon ages from Haleakala Crater, 

Island of Maui, Hawafi

By David R. Sherrod and John P. McGeehin

INTRODUCTION

This report describes radiocarbon ages, stratigraphic 

setting, and geographic location of ten new charcoal 

samples from East Maui (fig. 1). The results include the 

first successful dating of young lava flows from

Haleakala Crater, providing us with sufficient information to divide the crater lava flows into broad age groups 

on the basis of isotopic age, stratigraphic setting, degree 

of soil development, and vegetative contrasts. An

156°30' 

21 <

156°15' 156°

20°30'

20°

JTT.'ferr- Ke'anae Point

JktJftL'iA . A \

Haleakala 

Crater

Hana Volcanics 

Lava flows 

Cinder cones and fissure vents

Radiocarbon sample locations 

New ages 

Previously obtained ages

Hana

Figure 1. Map showing locations for new carbon-14 ages from East Maui, Hawaii. Distribution of Hana Volcanics 

from Stearns and Macdonald (1942). Previously obtained radiocarbon ages from Crane (1956), Reber (1959), Crandell 

(1983), andBergmanis (1998).
Table 1. Radiocarbon age determinations and calibrated ages for charcoal collected at Haleakala Crater and north coast 

of East Maui, Hawaii, in order of increasing age.

Calibrated age3

Age and error2 Calibrated yr B.P. 

Lab No. 1 Field No. 14CvrB.P. Maximum Intercept(s) Minimum

WW-1665

WW-1663

WW-1659

WW-1657

WW-1660

WW-1662

WW-1664

WW-1661

WW-1658

WW-1881

S97-HC265

S97-HC232C

S97-HC137

S97-HC63C

S97-HC152

S97-HC209

S97-HC242

S97-HC129

S97-HC64C

S98-HC310

330150

870140

940150

970150

1,040140

1,160150

1,870140

3,750150

4,070150

43,80011,400

506

914

951

967

1,052

1,228

1,917

4,246

4,812

428, 377, 323

785, 784, 762

910, 850, 834, 809, 799

921

950

1,060

1,821

4,141; 4,125; 4,091

4,566; 4,562; 4,529

291

689

733

743

804

956

1,709

3,930

4,418

Notes:

1 Samples processed at 14C Laboratory of the U.S. Geological Survey, Reston, Virginia. Radiocarbon ages

determined at the Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory,

Livermore, Calif.

r\

Age in radiocarbon years using Libby half-life of 5,568 years. Error is one standard deviation, in radiocarbon 

years.

Calibrated using CALIB Radiocarbon Calibration Program version 4.0, after Stuiver and Reimer (1993), in 

conjunction with decadal atmospheric 14C database (Stuiver and others, 1998). Ages reported as two-sigma 

error. CALIB software is available on the World-wide Web at the homepage for the University of 

Washington's Quaternary Isotope Laboratory (Universal Resource Locator is http://depts.washington.edu/ 

qil/).

ongoing paleomagnetic study of crater flows will further our understanding of the emplacement history of 

young lava flows at Haleakala Crater.

The ten new C ages are given in table 1. Nine ages 

are from Haleakala Crater. Of these, seven range in age 

from 870140 14C yr B.P. to 4,070150 yr B.P. and are 

thought to represent emplacement ages of lava flows. 

(All ages are in carbon-14 years before present except 

where noted as calibrated ages.) An eighth sample 

establishes a maximum age for thick lapilli tephra 

deposited against the south crater wall; its age is 3,750150 

yr B.P. The ninth sample gives an age of 330150 yr 

B.P., which appears to be too young and likely is 

erroneous in view of similar character, weathering, soil 

development, and vegetative cover of this flow and 

nearby flows that are about 1,000 yr B.P.

The tenth age reported here is from the north coast 

of East Maui, at the mouth of the Ke'anae Valley (fig. 

1; tables 1,2). Lava from Haleakala Crater periodically 

reaches the ocean via Kev anae. The Kev anae charcoal 

dated for this report was beneath a bench-forming 

intracanyon lava flow, an early part of the sequence of 

young volcanic rocks on East Maui. Its age is

43,80011,400 yr B.P. The youngest flow in that area, 

which forms Kev anae Point, remains undated.

STRATIGRAPHIC SETTING

The eastern part of the Island of Maui was built by 

Haleakala, one of several volcanoes in the Hawaiian 

Islands. Haleakala ("house of the sun") is the name 

used by ancient Hawaiians for a site near the volcano's 

summit and now commonly applied to the entire volcano. Haleakala completed its shield-building volcanic 

stage about 1 million years ago (mega-annums ago, or 

Ma) (Chen and others, 1991). Lavaofitsalkalic-stage 

volcanism, the Kula Volcanics, have K-Ar and 40Ar/ 

39Ar ages ranging from about 0.9 to 0.36 Ma 

(McDougall, 1964; Naughton and others, 1980; Chen 

and others, 1991 ;Baksi and others, 1992). Kula volcanism was characterized by eruptions along a rift zone 

that traverses the island from southwest to east. This rift 

zone goes by different names depending on the geographic segment discussed: southwest rift, a central 

segment (in Haleakala Crater), Hana or east rift zone 

where it traverses the east slope of the volcano, and 

Haleakala Ridge where the rift forms a prominent
bathymetric ridge on the eastern submarine flank of the 

island.

Distinctly younger volcanic rocks, the Hana 

Volcanics, lie disconformabry above the Kula Volcanics 

and are the strata of interest in this report. The Hana 

Volcanics comprise all the youthful flows on East 

Maui, including lava emplaced as recently as about 200 

years ago. Thus an accurate volcano-hazard assessment for East Maui depends on understanding the age 

and distribution of Hana Volcanics.

Radiocarbon ages from the Hana Volcanics are as 

old as 45,000±1,800 yr B.P. (F.A. Trusdell and J.P. 

McGeehin, in Bergmanis, 1998). Preliminary 40Ar/ 

Ar ages from three of the oldest Hana flows on the 

southwestriftzone are 43,000±12,000 yr, 58,00011,000 

yr, and 60,000±8,000 yr ago (one-sigma analytical 

error) (Bergmanis, 1998). Whether the 300,000-yr gap 

between published ages from the Kula and Hana 

Volcanics represents a true hiatus or only a period of 

greatly diminished volcanic flux awaits systematic sampling and dating. During the time from 0.36 to 0.06 Ma, 

however, erosional downcutting and broadening of 

large valleys modified the slopes of Haleakala. Two of 

these valleys breached the summit area and coalesced to 

form an elliptical topographic depression, Haleakala 

Crater (Stearns, 1942). Hana Volcanics coat the crater 

floor with an unknown thickness of cinder deposits and 

lava flows (Macdonald, 1978). Many of these flows are 

younger than 5,000 year in age (fig. 2).

SAMPLE PROCESSING

The charcoal samples, which ranged in weight from 

0.05 to 3.7 g, were treated physically and chemically to 

remove as many contaminants as possible. A contaminant is defined here as any carbonaceous compound 

with 14C activity that does not reflect the true 1 C 

activity of the sample. Generally this added carbon is 

the result of postdepositional effects, such as prolonged 

contact of the sample with percolating water or infiltration by modern rootlets. A standard acid-alkali-acid 

pretreatment was used for all the charcoal samples, as 

described next.

The samples were first picked clean of obvious 

surface contamination, including rootlets and sediment 

encrustation. Each sample was then soaked in a warm 

IN hydrochloric acid (HC1) solution for one hour. The 

HC1 removes inorganic carbon contaminants such as 

caliche, limestone, or shells. After neutralizing with 

distilled water rinses, each sample was soaked in a 

warm solution of 2 percent sodium hydroxide (NaOH) 

for two hours. The NaOH extracts humic acid contaminants, which are the degraded and transported byproducts 

of humus produced in active surface soils. Care was 

taken when performing the NaOH pretreatment, since 

carbon-bearing materials will exchange modern CO2 

from the atmosphere if left in an alkaline solution for an 

extended period. Therefore, a second HC1 wash of 

equal strength and duration as the first was performed 

on each sample to assure that the final pH of the sample

unpatterned

970±50

EXPLANATION 

Hana Volcanics

Lava flows and vent deposits (stippled) emplaced 0-1,000 yr B.P.

Lava flows and vent deposits (finer pattern) emplaced 1,000-3,000 yr B.P.

Lava flows and vent deposits (finer pattern) emplaced 3,000-5 ,000 yr B.P.

Lava flows and vent deposits emplaced prior to 5 ,000 yr B.P. Probably all 

younger than about 50,000 yr B.P.

Volcanic strata older than Hana Volcanics

Lava flows and vent deposits approximately 0.3 to 0.9 Ma. Chiefly Kula Volcanics, but includes 

some reversed-polarity strata in northern and southern crater walls that have been considered to 

predate the Kula Volcanics (Stearns and Macdonald, 1942; Macdonald, 1978)

Carbon-14 dating locality, showing age in 14C yr B.P.

Eruptive fissures

Trail

Figure 2. Explanation; see next page for map.
156°15'30" 156°12'30" 156°10' 156°07'30"

20°45

20°42'30" =5

1,870±40 i;^^rfe~ -^

in13 r~-

> 

Paliku cabin

- 4,070±50 ^ \

Base from U.S. Geological Survey, Island of Maui, 1957, scale 1:62,500

Geology mapped by 

D.R.Sherrod, 1997-98

Figure 2. Simplified geologic map of Haleakala Crater showing lava younger than 5,000 yr B.P. and recently obtained radiocarbon 

sample locations, by age. Not shown is location of S97-HC265 (330±50 yr B.P.), which is considered too young. See previous 

page for explanation of shading and symbols.
Table 2. Sample locations for charcoal collected at Haleakala Crater and north coast of East Maui, HawaTi. Coordinates referable to Old Hawaiian 

datum (Old Hawaiian Mean of some GIS software). Vertical datum is mean sea level.

Lab No. Field No.

Age and error Latitude Longitude Elevation 

"CyrB.P. (N) (W) ft Quadrangle Description

WW-1665 S97-HC265 330 ±50 20°43.958' 156°09.908' 7300 Nahiku 480 m east-southeast of Kalua Awa, on lower 

slope of north wall, north-central Haleakala" 

Crater

WW-1663 S97-HC232C

WW-1659 S97-HC137

WW-1657 S97-HC63C

870 ±40 20°43.979' 156°10.514' 7300

940 ±50 20°44.632' 156°12.391' 6840

Nahiku West wall of gully that incises foot of north

wall, 920 m southeast of rim point Hanakauhi, 

north-central Haleakala Crater

Nahiku

970 ±50 20°44.776' 156°13.201' 6820 Kilohana

1.5 km east of Holua cabin, midway across 

Ko'olau Gap, northwest Haleakala" Crater

190 m north-northeast of HoltTa cabin, 

northwest Haleakala" Crater

WW-1660 S97-HC152

WW-1662 S97-HC209

1,040 ±40 20°43.632' 156°09.456' 6720 Nahiku

1,160 ±50 20°42.995' 156°10.740' 7120 Nahiku

North side of LaMe Pux u cinder cone where banked by younger pahoehoe lava, northeast 

Haleakala Crater

Northwest side of Pu'uMaile cinder cone 

where banked by younger spiny pahoehoe, 

central Haleakala Crater

WW-1664 S97-HC242WW-1661 S97-HC129

1,870 ±40 20°44.035' 156°10.295' 7400 Nahiku

3,750 ±50 20°42.465' 156°12.119' 7320 Kaupo

200 m west of Kalua Awa, on lower slope of 

north wall, north-central Haleakala Crater

1.6 km west of Kapalaoa cabin, 220 m south of 

trail, in gully that cuts alluvial fan, southcentral Haleakala Crater

WW-1658 S97-HC64C 4,070 ±50 20°42.636' 156°10.495' 7000 Nahiku 800 m southeast of Pus u Maile cinder cone, in 

north wall of shallow canyon adjacent to Haleakala Crater's south wall

WW-1881 S9$-HC310 43,800 ±1400 20°51.315' 156°08.675' 200 Keanae Roadcut along HUna Highway, west bank of 

"Dhfa Stream, north coast of East Maui
after pretreatment was safely out of the alkaline range. 

The final step was overnight drying in a convection 

oven at 80°C.

Carbon was extracted from the pretreated samples 

as CO2 and then reduced to graphite (100 percent 

carbon). Approximately 4 mg of pretreated charcoal 

was selected from each sample and combusted in a 

sealed Vycor glass tube with copper oxide and silver at 

900°C for six hours. The tubes were placed on a highvacuum extraction line and cracked in a break-seal 

apparatus. The resulting CO2 was purified of volatile 

gases and sent through a cold trap to remove water. The 

purified and dried CO2 was reduced to graphite by 

placing a measured volume (equivalent to 1 mg carbon) 

in a chamber with approximately 4 mg of 63-mesh 

spherical iron, hydrogen, and zinc as a catalyst at 575°C 

for ten hours. The sample carbon (precipitated on the 

iron) was pressed into aluminum targets for accelerator 

mass spectrometry analysis.

Lawrence Livermore Lab's Center for Accelerator 

Mass Spectrometry did the actual 14C dating using their 

FN tandem accelerator. Ages are reported as radiocarbon years before present (B.P.) using the Libby half-life 

of 5,568 years (table 1). Analytical error is reported as 

one standard deviation. No measurements were made 

for 613C fractionation effects in these charcoal samples; 

the assumed value for terrestrial charcoal of-25 per mil 

was used for purpose of the age calculations.

In table 1, ages are also shown as calibrated years

20°44'30"

B.P. using the radiocarbon calibration software of Stuiver 

and Reimer (1993) in conjunction with the decadal 

atmospheric 14C database (Stuiver and others, 1998).

SAMPLE SITES

Sample sites are described on the basis of age from 

youngest to oldest. Each description includes a sketch 

showing the strata that bound the charcoal sample and 

a geologic map with topographic base.

Samples from Haleakala Crater

S97-HC265: 330±50 yr. B.P. (probably too young 

for emplacement age)

Kalua Awa fissure, north-central crater wall

Charcoalized stems or twigs (sample weight 0.8 g) 

were collected from beneath porphyritic pahoehoe that 

plastered a gully wall downslope from its vent (figs. 3, 

4). Exposure was obtained by peeling away the gullywall lava (a rind only 10 cm thick) to expose underlying, 

variably developed soil less than 10 cm thick. The 

charcoal was in vegetative litter beneath the flow, with 

largest fragments 4-5 mm in diameter. The zone is 

heavily rooted by modern plants.

This age is thought too young for the following 

reasons. The vent that produced the flow is an uprift 

extension of the Kalua Awa fissure, which produced 

flows that are petrographically similar to this dated 

flow, have similar soil cover, and support similarly

156°9'

20°43'30"

Base from U.S. Geological Survey, 

Nahiku, 1957, scale 1:24,000

Geology mapped by 

D.R.Sherrod, 1997-98

Lighter pattern, Hanakauhi flows (labeled "h"). Carbon-14 age 870±40 yr B.P. Vent deposits shown stippled 

Approximate fissure alignment shown by hachured lines for closed depressions or gaping cracks

Darker pattern, Kalua Awa flows. Carbon-14 age 1,040±40 yr B.P. Vent deposits shown stippled. Contacts within 

unit show areas of pahoehoe (labeled kap) and "a"a (labeled kaa)

Alluvium labeled "a"; other units unlabeled. Age of 1,870±40 yr B.P. from fissure vent that predates Kalua Awa 

deposits. See text for discussion of youngest age, 330±50 yr B.P., which is interpreted as too young

Figure 3. Location and geologic setting for samples from north-central part of Haleakala Crater.
S97-HC265, Charcoal stems 

or twigs, to 5 mm diameter

Gully-coating 

lava flow

Charcoal found by 

peeling back lava

Tephra deposits

Talus deposits

Figure 4. Stratigraphic sketch for sample S97-HC265: 

33Q±50 yr. B.P.

sparse vegetation. Another flow in the sequence yielded 

an age of 1,040±40 yr B.P. Vegetation on these ~ 1,000- 

yr-old flows is denser than on a nearby flow that yielded 

an age of 870±40 yr B.P. For these reasons, the 330-yr 

age is considered too young, and the gully-plastering 

flow is thought to be more closely related to the 1,040- 

yr-old flow. Preliminary paleomagnetic data place the 

HC265 lava in a period of steep inclination (-40°) that 

characterizes much of the paleomagnetic secular variation curve from 1,000 to 300 yr B.P., preventing definitive challenge, on that basis alone, to the seemingly tooyoung radiocarbon age (D.E. Champion, oral commun., 

1998).

S97-HC232c: 870140 yr B.P.

Hanakauhi fissure, north-central crater wall

A charcoalized root(?) was found beneath aphyric 

v av a erupted from a fissure system that traverses the 

north crater wall near Hanakauhi, a prominent peak on 

the north rim (fig. 3). The exposure is in a gully that has

6-8 m

S97-HC232C, 2 -cm-long 

charcoal root (?)

Soil, some tephra

2-cm-lpng charcoalized 

root in soil 10 cm 

below lava

Tephra sequence

lava on gully floor

Base not exposed

eroded the edge of the flow and carved into underlying 

lapilli tephra deposits (fig. 5). The charcoal, weighing 

2.4 g, was 3-4 mm in diameter and at least 2 cm long; it 

lay near the top of a 50-100-cm-thick soil, and from a 

depth 10 cm below the base of the overlying lava flow. 

The bake zone is 8 cm thick, so the charcoal was 

collected from just beneath the bake zone.

The Hanakauhi fissure system is the youngest volcanic feature in the eastern crater and may be the 

youngest in all of Haleakala Crater. Its 870-yr age is the 

youngest dated lava (discounting the 330-yr age from 

S97-HC265). No charcoal has been found beneath 

potentially younger flows in the western crater area (fig. 

2 or 6, youngest flows from Ka Luv u o ka v CTo), and 

preliminary paleomagnetic results (D.E. Champion, 

unpub. data, 1998) are ambiguous when comparing the 

relative ages of the Ka Luv u flows and Hanakauhi 

fissure flows. The Hanakauhi flows are essentially 

unvegetated.

S97-HC137: 940±50yrB.P.

Likely erupted from HalalTi vent, central crater floor 

This charcoal sample (3.7 g) was a lengthy root as 

much as 7 mm in diameter, one of several that lie at a 

soil-ash interface buried beneath a pahoehoe toe of 

slightly porphyritic lava (fig. 7). The thin reddishbrown soil is overlain by coarse black ash 8-10 cm 

thick; some roots in the soil project up into the ash. 

Exposure was created by pick and shovel. The charcoal 

age likely is the emplacement age of lava, but no chill 

features are found in the lava to indicate a connection 

between the roots and the once-subaerial part of the 

plant beneath the flow.

The dated lava, in the central part of Kov olau Gap 

(fig. 6), is underlain by ankaramite from Puv u o Maui. 

Thus Puu o Maui is older than 940 yr B.P. The dated 

lava is overlain upslope by lava that issued from a vent

Slightly porphyritic 

lava flow

Coarse-grained 

black ash

Fine black ash 

Reddish-brown soil

-S97-HC137,

charcoalized root to 

7 mm in diameter

Figure 5. Stratigraphic sketch, sample S97-HC232c: 

870±40yrB.P.

Figure 7. Stratigraphic sketch for sample S97-HC137: 

940±50yrB.P.

8
on the northwest flank of Halali" i cinder cone, so some 

eruptions from Halali"i are younger than 940 yr B.P. 

Given the configuration of older flows and possible 

vents, it seems likely that the dated flow also issued 

from Halali" i, possibly all part of eruptions about 900- 

1,000 yrB.P.

S97-HC63c: 970±50yrB.P.

Holua flows, likely erupted from vent near or at Ka Lu"u 

o ka "D"o

Charcoalized twigs (0.3 g) 3-8 mm across were 

recovered from a thin black ash that underlies the edge

156°12'30"

of" a" a where it ramps down a steep slope a few hundred 

meters north (downslope) from Holua Cabin (figs. 6,8). 

Exposure was created by pick and shovel. Three 

discrete samples were collected at increasing distance 

from the flow front as lava was pried away (a, b, c on fig. 

8); dated sample c was 58 cm from the front.

The dated "a" a lava is from a sequence of flows that 

mantle the west crater floor. The map pattern of its 

extent suggests that the Holua lava came from Ka Luu 

o ka "D"o, a youthful cinder cone, although the direct 

connection of lava and vent is obscured by younger, 

petrographically similar lava from the same vent (fig.

156°12'30"

20°45'

20°44'

20°43'

Base from U.S. Geological Survey, 

Kilohana and Nahiku, 1957, scale 1:24,000

Geology mapped by 

D.R.Sherrod, 1997-98

Lighter pattern, Holua flows. Carbon-M age 970±50 yr B.P. from beneath lava near Holua Cabin. Vent deposits 

shown stippled at Ka Lif u o ka *O*O and from fissure (hachured line) that traverses north flank of Kamoaln 

cone

Darker pattern, Halali'i flows. Carbon-14 age 940150 yr B.P. from flow at ~6800-ft elevation. Vent deposits shown 

stippled.

Blanket of thick tephra deposits labeled "t". Alluvium labeled "a". Pu'u o Maui lava labeled "pm". Other units 

unlabeled.

Figure 6. Location and geologic setting for samples from western part of Haleakala Crater.

9
S97-HC63c, 3-8 mm charcoalized

twigs found by peeling

back lava __ , 58 cm ,

Figure 8. Stratigraphic sketch for sample S97-HC63c: 

970±50yrB.P.

6). The younger lava is the youngest lava flow in the 

west crater area and must be younger than the dated 

Holua flow on the basis of superposition.

S97-HC152: 1,040±40 yr B.P.

Kalua Awa fissure, north-central crater wall

Sample is from a thin soil that underlies ankaramite 

pahoehoe on the east side of Lav ie Puu, a substantially 

older cinder cone in the east crater area (fig. 3). 

Charcoalized stems and twigs (0.2 g) were found after 

digging back 30 cm from the face of a low, natural 

exposure (fig. 9). The overlying lava flow was 5-10 cm 

thick at initial edge and 30 cm thick where excavation 

ceased.

The dated pahoehoe was an early-erupted lava 

from the Kalua Awa fissure system. Younger products 

of the fissure are v av a. Expansive pahoehoe flows are 

an uncommon eruptive product in Haleakala Crater; 

the Kalua Awa pahoehoe is perhaps the best known,

S97-HC152, charcoal stems 

collected^ in soil 30 cm in from 

end of pahoehoe toe

30cm

Thin soil

Cinder deposit of 

weathered orangebrown lapilli 2-10 

mm across

owing to a trail crossing eastward fromN CT ili Puv u in the 

eastern crater area (fig. 3).

Alluvium masks the connection between pahoehoe 

near Lav ie Pu u and the adj acent broad field of pahoehoe 

near vDv ili Puv u, so the dated lava is correlated on the 

basis of petrographic similarity. Additional correlation 

is provided by paleomagnetic studies, which indicate 

nearly coincident inclination and declination of magnetic pole for samples from the disparate areas of 

pahoehoe (D.E. Champion, unpub. data, 1998).

The Kalua Awa flows are older than the 870-yr-old 

lava from Hanakauhi fissure (S97-HC232c). For this 

reason the 330-yr age (S97-HC265) from an aforementioned flow that issued from the northeastern vent in the 

Kalua Awa fissure is discounted as erroneously young.

S97-HC209: 1,160±50 yr B.P.

Erupted from Puv u Nole, central crater floor.

Charcoalized stems and twigs (0.1 g) were collected from a thin sandy soil underlying a short pahoehoe 

lobe that oozed from v av a or spiny pahoehoe (fig. 10). 

Exposure is in a gully floor at the edge of Puv u Maile 

cinder cone (fig. 11), but the sample was obtained by 

peeling lava back 30 cm from the natural cut.

The Puv u Nole ankaramite flows are the youngest 

crater lava to reach the ocean southward through Kaupo 

Gap, building Lapehu and Apole Points (fig. 1). The 

dated flow is youngest of the sequence. Slightly older 

flows in the sequence, probably similar in age, are 

exposed successively down the Kaupo lava fan; phenocryst abundance diminishes as relative Stratigraphic 

age increases.

S97-HC242: 1,870±40 yr B.P.

Spatter rampart along fissure parallel to but slightly 

north of Kalua Awa fissure.

This sample consists of 0.6 g of charcoalized stems 

or twigs 2-4 mm in diameter collected from the upper 10

S97-HC209, loose 

stems in 3-cm-thick soil

* a* a from PiTu Nole

Charcoal in sandy 

soil horizon

/Sandy soil, probably 

reworked tephra

Tephra #1: reddish to 

black tindery lapilli 

(<1 cm in diameter)

Tephra #2: black 

lapilli (0.2-0.8 mm)

Figure 9. Stratigraphic sketch for sample S97-HC152: 

l,040±40yrB.P.

Figure 10. Stratigraphic sketch for sample S97-HC209: 

l,160±50yrB.P.

10
cm of peaty baked soil on buried talus beneath spatter 

(fig. 12). Overlying aphyric spatter deposits are less 

than 2 m thick and surround a pit that formed during 

eruption. Sloughing of the pit walls has exposed the 

spatter-soil contact.

The spatter deposit lacks phenocrysts, in contrast to 

the adjacent, younger Kalua Awa fissure (age 1,040 yr 

B.P.; S97-HC152). It is uncertain whether the 1,870- 

yr-old vent erupted lava flows. None is found near the 

vent, but some aphyric lava flows that may correlate are 

found downslope in the upper part of Kaupo Gap, where 

they project from beneath the Kalua Awa lava.

S97-HC129: 3,750±50 yr. B.P.

Beneath tephra deposits of south crater wall

Charcoal flecks (0.06 g total) originating as twigs 

or other wood were recovered from the upper part of a 

paleosol formed in windblown ash and silt that underlies thick fallout deposits of black glassy lapilli (less 

than 2 cm in diameter) (fig. 13). Presumably the 

charcoal was created by the heat from the lowest tephra 

deposit. The natural exposure was found in a narrow 

gully cut into the tephra and talus adjacent to the south 

wall of Haleakala Crater (fig. 11).

The tephra is fallout accumulated from numerous 

cinder-vent eruptions on the crater floor. Prevailing 

winds disperse most fallout southwestward, where it 

lands on the south and west crater walls and upper 

southwestern flanks of Haleakala. Between eruptive 

episodes, colluvium is deposited downslope across the

S97-HC242, Charcoalized 

stems 2-4 mm diameter

Spatter rampart

2-4-cm-long 

charcoalized stems in 

upper 10 cm of soil

Talus deposit

Base not exposed

156°12'30"

Figure 12. Stratigraphic sketch for sample S97-HC242: 

1,870±40 yr B.P.

tephra. Likely other tephra sequences are present at 

depth, but this exposure was too shallow to reveal them 

(base not exposed). Elsewhere in the crater walls, 

tephra and colluvial wedges are interbedded.

S97-HC64c: 4,070±50 yr B.P.

Lava from Puv u Maile cinder cone, south-central crater 

area

The Puu Maile charcoal sample is from black, ashrich soil beneath v av a (fig. 14). The site is a natural 

exposure created by a prominent gully along the contact

156°10'

20°43'30"

20°42'30"

Base from U.S. Geological Survey, 

Nahiku and Kaupo, 1957, scale 1:24,000

Geology mapped 1997-98

Lighter pattern, Pif u Nole flows. Carbon-14 age 1,160150 yr B.P. Vent deposits shown stippled 

Darker pattern, Pif u Maile flows. Carbon-14 age 4,070±50 yr B.P. Vent deposits shown stippled.

Blanket of thick tephra deposits labeled "t"; carbon-14 age 3,750±50 yr B.P. from base of 6-m-thick sequence 

of tephra near south crater wall. Alluvium labeled "a"; other units unlabeled.

Figure 11. Location and geologic setting for samples from south-central part of Haleakala Crater.

11
As thick 

as 5 m

S97-HC129, 4- mm flakes 

of charcoal from twigs

Black lapilli tephra 

and ash from several 

cinder-cone building 

eruptions

Flecks of charcoal 

in top of compacted 

paleosol (wind-blown 

accumulated ash, soil). 

Base not exposed.

Figure 13. Stratigraphic sketch for sample S97-HC129: 

3,750±50 yr. B.P.

between Pif u Maile lava and an older cinder vent that 

plastered the south crater wall (fig. 11). Sample "c," 

which consists of charcoalized twigs or roots (1.1 g), 

was collected by digging 35 cm back from the gully 

face.

Aphyric lava from Pif u Maile poured through 

Kaupo Gap and reached the ocean. Petrographically 

similar lava from vCTili Puv u also flowed southward. 

These two lava sequences have similar vegetative cover 

and are thought to be similar in age. More precise 

correlation may result from additional paleomagnetic 

studies.

The 4,070-yr-old lava from Pifu Maile is the oldest 

of the conspicuous lava sequences exposed on the floor 

of Haleakala Crater. Scattered older vents drape the 

crater walls and form hills poking through the younger 

lava of the crater floor. As seen in figure 2, most of the

crater floor has been covered at least once in the past 

5,000 years.

Sample from north coast of East Maui, 

neaKe'anae Point

S98-HC310: 43,800±1,400 yr B.P.

An early Haleakala Crater flow that reached coast via 

Kev anae Valley

The sample that produced this unexpectedly old 

age was a charcoalized stick or twig (0.5 g) from a 

roadcut along the Hana Highway. It lay about 2 cm 

below the base of v av a and near the top of an 8-10-cmthick bake zone in fine-grained sedimentary strata that 

cap conglomerate (fig. 15). The stick, nearly 1 cm in 

diameter and 3 cm long, may have been as long as 6 cm 

judging from the path of white discoloration in adjacent 

bake zone.

Several lava flows from Haleakala Crater have 

reached the coast via Kev anae Valley. The dated flow, 

part of the Piv inav au Basalt of Stearns and Macdonald 

(1942) (fig. 16), lies at an elevation of about 200 ft, 

where it forms one of several exposures along a prominent topographic bench. Nearby Kev anae Point, which 

is only a few feet above sea level, likely formed about 

1,000 yr B .P. by the emplacement of the Kev anae Basalt 

(fig. 16). (Older flows elsewhere around East Maui 

commonly develop prominent cliffs as the ocean erodes 

landward.) Previously published mapping (Stearns and 

Macdonald, 1942) shows the Kev anae Basalt filling the 

middle valley floor, and our mapping from Haleakala 

Crater shows that much of the upland valley floor is

S97-HC64C, 35 cm from 

face of stream bank

massive core 

rubble base

charcoal in 

black ash-rich soil

Cinders, pebbles 

cobbles in colluvium

Cinders, bedrock

S98-HC310, Charcoalized 

stick or twig, 3 cm long

2m charcoalized stick or 

/twig within 2 cm of 

clinkery base of * a* a

Crumbly paleosol; 

upper 8 cm baked

Sandy conglomerate

Road bed

Figure 14. Stratigraphic sketch for sample S97-HC64c: 

4,070±50yrB.P.

Figure 15. Stratigraphic sketch for sample S98-HC310: 

43,800+1,400 yr B.P.

12
mantled by petrographically similar lava (for example, 

S97-HC137, 940±50 yr B.P.). Our work in the lower 

Kev anae Valley is ongoing.

ACKNOWLEDGMENTS

The figures showing stratigraphic position of charcoal samples were prepared by Jenda Johnson, who also 

assisted in collecting samples S97-HC63c and 64c. 

(She dug a few holes into forlornly barren paleosols,

20°52'30"

156°10'

too.) Permission to work in Haleakala Crater came 

from Ron Nagata, chief of Resources Management at 

Haleakala National Park, who provided much additional assistance stemming from his deep knowledge of 

Haleakala Crater. We thank Nagata and other park staff 

who made our time at Haleakala both pleasurable and 

effective. The manuscript was reviewed and improved 

by Christina Heliker and Willie Scott (both of U.S. 

Geological Survey).

156°07'30"

20°50'

Base from U.S. Geological Survey, 

Keanae, 1957, scale 1:24.000

EXPLANATION

Hana Volcanics (Holocene and Pleistocene)

Ke'anae Basalt (Holocene)

vOhiv a Basalt (Holocene or Pleistocene)

Pauwalu and Waiokamilo Basalts (Holocene or Pleistocene)

Prina"au Basalt (Pleistocene) 

Conglomerate and sandstone (Pleistocene)

Geology mapped by H.A. Powers, 

in Stearns and Macdonald, 1942

unpatterned Kula Volcanics (Pleistocene)

43,800±1,400 \ Carbon-14 sampling locality, showing age in 14C yr B.P.

Figure 16. Location and geologic setting for sample from north coast of East Maui.

13
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14