Rosalind Tuthill Helz, Ph.D.
Rosalind Tuthill Helz is a Scientist Emeritus at the Florence Bascom Geoscience Center.
Rosalind Helz is a Scientist Emeritus at the Frances Bascom Center. She received her undergraduate degree in Geology from Stanford University in 1965, and graduate degrees in Geochemistry and Mineralogy from Penn State University in 1968 (M.S.) and 1978 (Ph.D). Since joining the USGS in March 1968, she has devoted her career to studying the behavior of mafic magmas, specializing in the use of petrology and chemistry to elucidate differentiation processes in mafic magmatic systems. Ongoing work includes completion of reports on the long-term study of Kilauea Iki lava lake, Hawaii and completion of reports on studies of the basal sill swarm associated with the Stillwater Complex, Montana.
Professional Experience
Smithsonian Museum of Natural History (Research Associate)
Education and Certifications
Ph.D, Mineralogy and Petrology, The Pennsylvania State University, 1978
M.Sc., Mineralogy and Petrology, The Pennsylvania State University, 1968
B.S., Geology, Stanford University, 1965
Science and Products
Compositions of glasses from the Pu'u O'o-Kupaianaha eruption of Kilauea Volcano, Hawaii January 1983 through December 1994
USGS Wildland Fire Workshop, EROS Data Center, Sioux Falls, SD, July 9-10, 1997
Differentiation and magma mixing on Kilauea's east rift zone: A further look at the eruptions of 1955 and 1960. Part II. The 1960 lavas
The Pu'u O'o-Kupaianaha eruption of Kilauea Volcano; June 1990 through August 1994 lava sample archive
The Stillwater Complex, Montana: a subvolcanic magma chamber?
Episode 49 of the Pu'u 'Ō'ō-Kūpaianaha eruption of Kilauea volcano-breakdown of a steady-state eruptive era
Whole-rock analyses of core samples from the 1967, 1975, 1979 and 1981 drillings of Kilauea Iki lava lake, Hawaii
Drilling report and core logs for the 1988 drilling of Kilauea Iki lava lake, Kilauea Volcano, Hawaii, with summary descriptions of the occurrence of foundered crust and fractures in the drill core
Differentiation and magma mixing on Kilauea's east rift zone - A further look at the eruptions of 1955 and 1960. Part I. The late 1955 lavas
Reequilibration of chromite within Kilauea Iki lava lake, Hawaii
U-Pb and Sm-Nd ages for the Stillwater Complex and its associated sills and dikes, Beartooth Mountains, Montana: Identification of a parent magma?
Diapiric transfer of melt in Kilauea Iki lava lake, Hawaii: A quick, efficient process of igneous differentiation
Science and Products
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Filter Total Items: 47
Compositions of glasses from the Pu'u O'o-Kupaianaha eruption of Kilauea Volcano, Hawaii January 1983 through December 1994
No abstract available.AuthorsRosalind Tuthill Helz, B. C. HearnUSGS Wildland Fire Workshop, EROS Data Center, Sioux Falls, SD, July 9-10, 1997
Report on the first workshop on USGS wildland fire expertise and capabilities. The workshop brought together operationaland research representatives ofthe Federal fire management agencies to initiate a more comprehensive assessmentofthe USGS's capabilities and the appropriate role(s) for USGS interaction and involvement with the fire community. Thereport discusses how the USGS can play a significaAuthorsS. G. Coloff, J. Findley, Rosalind L. HelzDifferentiation and magma mixing on Kilauea's east rift zone: A further look at the eruptions of 1955 and 1960. Part II. The 1960 lavas
New and detailed petrographic observations, mineral compositional data, and whole-rock vs glass compositional trends document magma mixing in lavas erupted from Kilauea's lower east rift zone in 1960. Evidence includes the occurrence of heterogeneous phenocryst assemblages, including resorbed and reversely zoned minerals in the lavas inferred to be hybrids. Calculations suggest that this mixing, wAuthorsT. L. Wright, Rosalind Tuthill HelzThe Pu'u O'o-Kupaianaha eruption of Kilauea Volcano; June 1990 through August 1994 lava sample archive
No abstract available.AuthorsMargaret T. Mangan, C. C. Heliker, T. N. Mattox, J. P. Kauahikaua, Rosalind Tuthill Helz, B. C. HearnThe Stillwater Complex, Montana: a subvolcanic magma chamber?
Five magma types occur as sills in the footwall of the Stillwater Complex, all of them coeval with the Stillwater Complex, all of them coeval with the Stillwater in age. Two of the magma types have compositions that suggest they are similar to the magmas from which the cumulates of the Stillwater's Basal and Ultramafic series crystallized. Melting experiments show that the crystallization sequenceAuthorsRosalind Tuthill HelzEpisode 49 of the Pu'u 'Ō'ō-Kūpaianaha eruption of Kilauea volcano-breakdown of a steady-state eruptive era
The Pu'u 'O'o-Kupaianaha eruption (1983-present) is the longest lived rift eruption of either Kilauea or neighboring Mauna Loa in recorded history. The initial fissure opening in January 1983 was followed by three years of episodic fire fountaining at the Pu'u 'O'o vent on Kilauea's east rift zone ∼19km from the summit (episodes 4–47). These spectacular events gave way in July 1986 to five and a hAuthorsM. T. Mangan, C. C. Heliker, T. N. Mattox, J. P. Kauahikaua, Rosalind Tuthill HelzWhole-rock analyses of core samples from the 1967, 1975, 1979 and 1981 drillings of Kilauea Iki lava lake, Hawaii
No abstract availableAuthorsRosalind Tuthill Helz, H.K. Kirschenbaum, J.W. Marinenko, Rachel QianDrilling report and core logs for the 1988 drilling of Kilauea Iki lava lake, Kilauea Volcano, Hawaii, with summary descriptions of the occurrence of foundered crust and fractures in the drill core
No abstract available.AuthorsRosalind Tuthill HelzDifferentiation and magma mixing on Kilauea's east rift zone - A further look at the eruptions of 1955 and 1960. Part I. The late 1955 lavas
The lavas of the 1955 east rift eruption of Kilauea Volcano have been the object of considerable petrologic interest for two reasons. First, the early 1955 lavas are among the most differentiated ever erupted at Kilauea, and second, the petrographic character and chemical composition of the lava being erupted changed significantly during the eruption. This shift, from more differentiated (MgO=5.0-AuthorsRosalind Tuthill Helz, T. L. WrightReequilibration of chromite within Kilauea Iki lava lake, Hawaii
Chromite mainly occurs as tiny inclusions within or at the edges of olivine phenocrysts in the 1959 Kilauea Iki lava lake. Liquilus chromite compositions are only preserved in scoria that was rapidly quenched from eruption temperatures. Analyses of drill core taken from the lava lake in 1960, 1961, 1975, 1979, and 1981 show that chromite becomes richer in Fe+2, Fe+3, Ti and poorer in Mg, Al, Cr thAuthorsP.A.H. Scowen, P.L. Roeder, Rosalind Tuthill HelzU-Pb and Sm-Nd ages for the Stillwater Complex and its associated sills and dikes, Beartooth Mountains, Montana: Identification of a parent magma?
Seven analyses from two samples of the Lower Banded series of the Stillwater Complex, Montana, yielded a U-Pb zircon-baddeleyite age of 2705 ±4 Ma. A more precise age of 2704 ±1 Ma is obtained if we regress only five of seven analyses. In either case, the age is in very good agreement with the previously reported Sm-Nd mineral isochron age of 2701 ±8 Ma for a gabbro from the Lower Banded series.NoAuthorsW. R. Premo, Rosalind Tuthill Helz, M. L. Zientek, R.B. LangstonDiapiric transfer of melt in Kilauea Iki lava lake, Hawaii: A quick, efficient process of igneous differentiation
Kilauea Iki lava lake, formed in 1959, is a large pond of picritic basalt (average MgO content = 15.34% by weight), which has cooled and crystallized as a small, self-roofed magma chamber. Repeated drilling of the upper crust of the lake, down to its molten core, and more recent (1981) drilling, through the thermal maximum and part way through the lower crust, have made it possible to monitor theAuthorsRosalind Tuthill Helz, H. Kirschenbaum, J.W. Marinenko