Ina pit crater on the Moon: Extrusion of waning-stage lava lake magmatic foam results in extremely young crater retention ages

Research Article| May 01, 2017 Ina pit crater on the Moon: Extrusion of waning-stage lava lake magmatic foam results in extremely young crater retention ages Le Qiao; Le Qiao 1State Key Laboratory of Geological Process and Mineral Resources, Planetary Science Institute, School of Earth Sciences, China University of Geosciences, Wuhan 430074, China2Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, Rhode Island 02912, USA Search for other works by this author on: GSW Google Scholar James Head; James Head 2Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, Rhode Island 02912, USA Search for other works by this author on: GSW Google Scholar Lionel Wilson; Lionel Wilson 3Lancaster Environmental Centre, Lancaster University, Lancaster LA1 4YQ, UK Search for other works by this author on: GSW Google Scholar Long Xiao; Long Xiao 1State Key Laboratory of Geological Process and Mineral Resources, Planetary Science Institute, School of Earth Sciences, China University of Geosciences, Wuhan 430074, China Search for other works by this author on: GSW Google Scholar Mikhail Kreslavsky; Mikhail Kreslavsky 4Earth and Planetary Sciences, University of California Santa Cruz, California 95064, USA Search for other works by this author on: GSW Google Scholar Josef Dufek Josef Dufek 5School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Le Qiao 1State Key Laboratory of Geological Process and Mineral Resources, Planetary Science Institute, School of Earth Sciences, China University of Geosciences, Wuhan 430074, China2Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, Rhode Island 02912, USA James Head 2Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, Rhode Island 02912, USA Lionel Wilson 3Lancaster Environmental Centre, Lancaster University, Lancaster LA1 4YQ, UK Long Xiao 1State Key Laboratory of Geological Process and Mineral Resources, Planetary Science Institute, School of Earth Sciences, China University of Geosciences, Wuhan 430074, China Mikhail Kreslavsky 4Earth and Planetary Sciences, University of California Santa Cruz, California 95064, USA Josef Dufek 5School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, USA Publisher: Geological Society of America Received: 13 Sep 2016 Revision Received: 21 Dec 2016 Accepted: 30 Dec 2016 First Online: 28 Jun 2017 Online Issn: 1943-2682 Print Issn: 0091-7613 © 2017 Geological Society of America Geology (2017) 45 (5): 455–458. https://doi.org/10.1130/G38594.1 Article history Received: 13 Sep 2016 Revision Received: 21 Dec 2016 Accepted: 30 Dec 2016 First Online: 28 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Le Qiao, James Head, Lionel Wilson, Long Xiao, Mikhail Kreslavsky, Josef Dufek; Ina pit crater on the Moon: Extrusion of waning-stage lava lake magmatic foam results in extremely young crater retention ages. Geology 2017;; 45 (5): 455–458. doi: https://doi.org/10.1130/G38594.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract The enigmatic Ina feature on the Moon was recently interpreted to represent extrusive basaltic volcanic activity within the past 100 m.y. of lunar history, an extremely young age for volcanism on the Moon. Ina is a 2 × 3 km D-shaped depression that consists of a host of unusual bleb-like mounds surrounded by a relatively optically fresh hummocky and blocky floor. Documentation of magmatic-volcanic processes from shield volcano summit pit craters in Hawai'i and new insights into shield-building and dike evolution processes on the Moon provide important perspectives on the origin of Ina. We show that the size, location, morphology, topography, and optical maturity of Ina are consistent with an origin as a subsided summit pit crater lava lake on top of a broad ∼22-km-diameter, ∼3.5-b.y.-old shield volcano. New theoretical treatments of lunar shield-building magmatic dike events predict that waning-stage summit activity was characterized by the production of magmatic foam in the dike and lake; the final stages of dike stress relaxation and closure cause the magmatic foam to extrude to the surface through cracks in the lava lake crust to produce the mounds. The high porosity of the extruded foams (>75%) altered the nature of subsequent impact craters (the aerogel effect), causing them to be significantly smaller in diameter, which could bias the crater-derived model ages. Accounting for this effect allows for significantly older model ages, to ∼3.5 b.y., contemporaneous with the underlying shield volcano. Thus extremely young volcanic eruptions are not required to explain the unusual nature of Ina. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.