Rights statement: This is the author’s version of a work that was accepted for publication in Icarus. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Icarus, 319, 2019 DOI: 10.1016/j.icarus.2018.09.038
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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
}
TY - JOUR
T1 - Late-stage intrusive activity at Olympus Mons, Mars
T2 - summit inflation and giant dike formation
AU - Mouginis-Mark, Peter J.
AU - Wilson, Lionel
N1 - This is the author’s version of a work that was accepted for publication in Icarus. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Icarus, 319, 2019 DOI: 10.1016/j.icarus.2018.09.038
PY - 2019/2
Y1 - 2019/2
N2 - By mapping the distribution of 351 lava flows at the summit area of Olympus Mons volcano on Mars, and correlating these flows with the current topography from the Mars Orbiter Laser Altimeter (MOLA), we have identified numerous flows which appear to have moved uphill. This disparity is most clearly seen to the south of the caldera rim, where the elevation increases by >200 m along the apparent path of the flow. Additional present day topographic anomalies have been identified, including the tilting down towards the north of the floors of Apollo and Hermes Paterae within the caldera, and an elevation difference of >400 m between the northern and southern portions of the floor of Zeus Patera. We conclude that inflation of the southern flank after the eruption of the youngest lava flows is the most plausible explanation, which implies that intrusive activity at Olympus Mons continued towards the present beyond the age of the youngest paterae ~200 – 300 Myr (Neukum et al., 2004; Robbins et al., 2011). We propose that intrusion of lateral dikes to radial distances >2,000 km is linked to the formation of the individual paterae at Olympus Mons. Two specific dikes to the SE of the volcano are inferred to have volumes of ~4,400 km3 and ~6,100 km3, greater than the volumes of individual calderas and implying triggering of both caldera collapse and lateral dike injection by the arrival of large inputs of magma from the mantle. A comparable disparity between lava flow direction and current topography, together with a tilted part of the caldera floor, has been identified at Ascraeus Mons.
AB - By mapping the distribution of 351 lava flows at the summit area of Olympus Mons volcano on Mars, and correlating these flows with the current topography from the Mars Orbiter Laser Altimeter (MOLA), we have identified numerous flows which appear to have moved uphill. This disparity is most clearly seen to the south of the caldera rim, where the elevation increases by >200 m along the apparent path of the flow. Additional present day topographic anomalies have been identified, including the tilting down towards the north of the floors of Apollo and Hermes Paterae within the caldera, and an elevation difference of >400 m between the northern and southern portions of the floor of Zeus Patera. We conclude that inflation of the southern flank after the eruption of the youngest lava flows is the most plausible explanation, which implies that intrusive activity at Olympus Mons continued towards the present beyond the age of the youngest paterae ~200 – 300 Myr (Neukum et al., 2004; Robbins et al., 2011). We propose that intrusion of lateral dikes to radial distances >2,000 km is linked to the formation of the individual paterae at Olympus Mons. Two specific dikes to the SE of the volcano are inferred to have volumes of ~4,400 km3 and ~6,100 km3, greater than the volumes of individual calderas and implying triggering of both caldera collapse and lateral dike injection by the arrival of large inputs of magma from the mantle. A comparable disparity between lava flow direction and current topography, together with a tilted part of the caldera floor, has been identified at Ascraeus Mons.
KW - Ascraeus Mons
KW - Mars
KW - Olympus Mons
KW - Volcanic dikes
U2 - 10.1016/j.icarus.2018.09.038
DO - 10.1016/j.icarus.2018.09.038
M3 - Journal article
VL - 319
SP - 459
EP - 469
JO - Icarus
JF - Icarus
SN - 0019-1035
ER -