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
Filter Total Items: 47
The character of long-term eruptions: Inferences from episodes 50-53 of the Pu'u 'Ō'ō-Kūpaianaha eruption of Kīlauea volcano
The Pu'u 'Ō'ō-Kūpaianaha eruption on the east rift zone of Kīlauea began in January 1983. The first 9 years of the eruption were divided between the Pu'u 'Ō'ō (1983–1986) and Kūpaianaha (1986–1992) vents, each characterized by regular, predictable patterns of activity that endured for years. In 1990 a series of pauses in the activity disturbed the equilibrium of the eruption, and in 1991, the outp
USGS 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 significa
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
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, w
Episode 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 h
The 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 sequence
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Filter Total Items: 47
The character of long-term eruptions: Inferences from episodes 50-53 of the Pu'u 'Ō'ō-Kūpaianaha eruption of Kīlauea volcano
The Pu'u 'Ō'ō-Kūpaianaha eruption on the east rift zone of Kīlauea began in January 1983. The first 9 years of the eruption were divided between the Pu'u 'Ō'ō (1983–1986) and Kūpaianaha (1986–1992) vents, each characterized by regular, predictable patterns of activity that endured for years. In 1990 a series of pauses in the activity disturbed the equilibrium of the eruption, and in 1991, the outpUSGS 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 significaDifferentiation 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, wEpisode 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 hThe 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 sequence