Rights statement: Accepted for publication in Journal of Geophysical Research: Planets. Copyright 2019 American Geophysical Union. Further reproduction or electronic distribution is not permitted. Qiao, L., Head, J. W., Ling, Z., Wilson, L., Xiao, L., Dufek, J. D., & Yan, J. ( 2019). Geological characterization of the Ina shield volcano summit pit crater on the Moon: Evidence for extrusion of waning‐stage lava lake magmatic foams and anomalously young crater retention ages. Journal of Geophysical Research: Planets, 124, 1100– 1140. https://doi.org/10.1029/2018JE005841
Accepted author manuscript, 4.91 MB, PDF document
Available under license: CC BY-NC: Creative Commons Attribution-NonCommercial 4.0 International License
Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
}
TY - JOUR
T1 - Geological Characterization of the Ina Shield Volcano Summit Pit Crater on the Moon
T2 - Evidence for Extrusion of Waning-Stage Lava Lake Magmatic Foams and Anomalously Young Crater Retention Ages
AU - Qiao, L.
AU - Head, J.W.
AU - Ling, Z.
AU - Wilson, L.
AU - Xiao, L.
AU - Dufek, J.D.
AU - Yan, J.
N1 - Accepted for publication in Journal of Geophysical Research: Planets. Copyright 2019 American Geophysical Union. Further reproduction or electronic distribution is not permitted. Qiao, L., Head, J. W., Ling, Z., Wilson, L., Xiao, L., Dufek, J. D., & Yan, J. ( 2019). Geological characterization of the Ina shield volcano summit pit crater on the Moon: Evidence for extrusion of waning‐stage lava lake magmatic foams and anomalously young crater retention ages. Journal of Geophysical Research: Planets, 124, 1100– 1140. https://doi.org/10.1029/2018JE005841
PY - 2019/5/1
Y1 - 2019/5/1
N2 - Ina, a distinctive ~2 × 3 km D-shaped depression, is composed of unusual bulbous-shaped mounds surrounded by optically immature hummocky/blocky floor units. The crisp appearance, optical immaturity, and low number of superposed impact craters combine to strongly suggest a geologically recent formation for Ina, but the specific formation mechanism remains controversial. We reconfirm that Ina is a summit pit crater/vent on a small shield volcano ~3.5 billion years old. Following detailed characterization, we interpret the range of Ina characteristics to be consistent with a two-component model of origin during the waning stages of summit pit eruption activities. The Ina pit crater floor is interpreted to be dominated by the products of late-stage, low-rise rate magmatic dike emplacement. Magma in the dike underwent significant shallow degassing and vesicle formation, followed by continued degassing below the solidified and highly microvesicular and macrovesicular lava lake crust, resulting in cracking of the crust and extrusion of gas-rich magmatic foams onto the lava lake crust to form the mounds. These unique substrate characteristics (highly porous aerogel-like foam mounds and floor terrains with large vesicles and void space) exert important effects on subsequent impact crater characteristics and populations, influencing (1) optical maturation processes, (2) regolith development, and (3) landscape evolution by modifying the nature and evolution of superposed impact craters and thus producing anomalously young crater retention ages. Accounting for these effects results in a shift of crater size-frequency distribution model ages from
AB - Ina, a distinctive ~2 × 3 km D-shaped depression, is composed of unusual bulbous-shaped mounds surrounded by optically immature hummocky/blocky floor units. The crisp appearance, optical immaturity, and low number of superposed impact craters combine to strongly suggest a geologically recent formation for Ina, but the specific formation mechanism remains controversial. We reconfirm that Ina is a summit pit crater/vent on a small shield volcano ~3.5 billion years old. Following detailed characterization, we interpret the range of Ina characteristics to be consistent with a two-component model of origin during the waning stages of summit pit eruption activities. The Ina pit crater floor is interpreted to be dominated by the products of late-stage, low-rise rate magmatic dike emplacement. Magma in the dike underwent significant shallow degassing and vesicle formation, followed by continued degassing below the solidified and highly microvesicular and macrovesicular lava lake crust, resulting in cracking of the crust and extrusion of gas-rich magmatic foams onto the lava lake crust to form the mounds. These unique substrate characteristics (highly porous aerogel-like foam mounds and floor terrains with large vesicles and void space) exert important effects on subsequent impact crater characteristics and populations, influencing (1) optical maturation processes, (2) regolith development, and (3) landscape evolution by modifying the nature and evolution of superposed impact craters and thus producing anomalously young crater retention ages. Accounting for these effects results in a shift of crater size-frequency distribution model ages from
KW - crater retention age
KW - irregular mare patches
KW - lava lake
KW - lunar/Moon
KW - magmatic foam
KW - mare volcanism
U2 - 10.1029/2018JE005841
DO - 10.1029/2018JE005841
M3 - Journal article
VL - 124
SP - 1100
EP - 1140
JO - Journal of Geophysical Research: Planets
JF - Journal of Geophysical Research: Planets
SN - 2169-9097
IS - 4
ER -