Lunar mare regions Bruce Ferguson Phil Oakley Richard Urata Kyle Willett ASTR 5835 October 17 2006 1 Outline Observations of the lunar maria and their environment Geochemical makeup of the maria Geophysical processes of mare emplacement Tectonic features and evolution through time 2 Ground based observations Naked eye observations and mythology Telescopic views Nomenclature Oceanus Mare Lacus Palus Sinus 3 Controversy dust vs lava Early attempts to determine physical distribution of mare material Pettit and Nicholson experiment 1958 Measured thermal emission from surface during lunar eclipse Conclusion lunar surface is covered almost completely by layer of dust pumice Gilvarry 1958 4 Orbital observations Early programs Luna Surveyor Ranger Lunar Orbiter Manned non landers Apollo 8 9 10 13 Modern Clementine Lunar Prospector SMART 1 Spectroscopy imaging and sample return http nssdc gsfc nasa gov planetary lunar lunarussr html 5 Orbital observations Early programs Luna Surveyor Ranger Lunar Orbiter Manned non landers Apollo 8 9 10 13 Modern Clementine Lunar Prospector SMART 1 Spectroscopy imaging and sample return http www lpi usra edu resources ranger 6 Lunar landing Sources of Moon rock Apollo missions Luna probes Lunar meteorites Absolute age dating of maria Chemical and physical analysis of surface http www jpl nasa gov history hires 1968 moon landing map jpg 7 Composition and geochemistry Isotopic studies have shown ratios of elements vary across lunar surface Common minerals FeO K Th Closely associated with mare indicative of KREEP 8 Individual features 9 Lava plains in the Solar System Mars Venus Mercury Satellites NASA Milkovich 2002 McGill 2004 10 Key features Geographical distribution of mare Association with impact basins cause e ect Hemispheric asymmetry Composition Maria vs highlands Composition variation within impact basins Tectonics Dark mantle Pinori 2000 11 Origin of the Mare Magmas Overview of magma processes Bowen s reaction series reprocessing Brief magmatic history of the Moon Mare compositional characteristics timing of eruptive ux geophysical models for the origin of the mare 12 Magma processes Fractional Crystallization di erent minerals solidify out of the magma at di erent temperatures In the 1920 s Bowen gures it all out Discontinuous Series Ma c high in Mg and Fe low Si Continuous series Felsic high in Ca and Na higher Si 13 Magma processes cont d Magma reprocessing mixing of primitive magmas to form more evolved melts like basalts ma c felsic driven by upwelling convection of melt at depth transferring its heat to the intruded solid rock partial melting di erent parts of solid rock melt at di erent temperatures e g peridotite olivine and pyroxene pyroxene melts rst changes chemical composition 14 Brief Magmatic History of the Moon a Felsic stu rises Ma c sinks b Catastrophic overturning c Mg suite KREEP basalts d Formation of the mare basalts 15 Characteristics and timing Cover 17 of lunar surface only 1 of the crust High Mg relative to Fe deep source Wide range in TiO2 with increasing REE abundance Negative Eu anomaly well explained by magma ocean model 16 The Models 17 Evaluating the models Model Pros Cons Stratified source region Eu anomaly differentiated saturation pressure formed at same depth Mg Ca similar One deep source w assimilation at shallow depths Eu anomaly one source one depth different mare have wide range of trace elements Catastrophic overturning mixing of cumulates transports incompatible requires a large scale radioactive elements overturning downwards for heating No magma ocean differentiation and serial magmatism simpler picture compares well with terrestrial picture most evidence regarding Eu goes against this 18 Volcanic Processes http www discoverourearth org student volcanoes cascades 2 html 19 Mare Volcanism http encarta msn com encnet refpages RefMedia aspx re d 461532559 artre d 761570122 sec 1 pn 1 http volcanoes usgs gov Products Pglossary pahoehoe ropy html 20 http harrimanrocks rutgers edu igneous 3 CSgranite htm 21 How Do You Melt Magma http earthsci org education teacher basicgeol igneous igneous html 22 Lunar Thermal Evolution Hiesinger and Head 2006 23 Transport of Magma to Surface Hiesinger and Head 2006 24 Mare Features Craters 25 Mare Features Rilles Sinuous and Linear 26 Rilles Rimae 1 Cut by owing water 2 Tectonic activity 3 Lava channels collapsed lava tubes 27 Hadley Rille 28 Mare Serenitatis Moon Idaho 29 Rima Ariadaeus 30 31 Mare Features Wrinkle ridges 32 Mare Ridge Formation 1 Volcanic intrusive extrusive activity 2 Structural deformation of the crust 33 34 Unusual Features Spearhead shaped depressions 35 Unusual Features Secondary impact Volcanic eruptions 36 Unusual Features Torricelli Crater 37 Unusual Features 38 39 References Vaucher J 2006 Cerberus Plains Mars Chronology of Volcanic Event and Evidence of Recent Tectonic Activity 2006LPI 37 1851V Werner C and D Loper 2002 On lunar asymmetries 2 Origin and distribution of mare basalts and mascons JGRP 107 E6 12 1 Pentecost A and J Arkani Hamed 2000 Origin of the lunar mare basalt 2000LPI 31 1984P Gilvarry J 1958 The Nature of the Lunar Maria ApJ 127 pp 751 762 Canup R and K Righter eds 2000 Origin of the Earth and Moon Univ of Arizona Press Tucson Pinori S and G Bellucci 2001 Imaging spectroscopy of selected regional dark mantle deposits of the Moon Planetary and Space Science 49 487 500 Milkovich S J W Head III and L Wilson 2002 Identi cation of mercurian volcanism resolution e ects and implications for MESSENGER Meteoritics and Planetary Science 37 pp 1209 1222 McGill G 2002 Tectonic and stratigraphic implications of relative ages of venusian plains and wrinkle ridges Icarus Volume 172 Issue 2 p 603 612 Apollo 11 Lunar Landing Mission press kit NASA 1969 Ranger VII Photographs of the Moon Part I 1964 NASA JPL Caltech Hiesinger H and J W Head III New Views of Lunar Geoscience An Introduction and Overview Reviews in Mineralogy Geochemistry Vol 60 pp 1 81 2006 Head J W III et al in Moon and Mercury Volcanism in Early Planetary History Environmental E ects on Volcanic Eruptions From Deep Oceans to Deep Space eds James R Zimbelman and Tracy K P Gregg New York Kluwer Academic Plenum Publishers 2000 pp 143 178 Head J W Solomon S C 1981 Science July 3 213 Whitford Stark J L 1979 Proc Lunar Planet Sci Conf 10 2975 2994 Comer R P et al 1979 Proc Lunar Planet Sci Conf 10 2441 2463 Sharpton V L Head J W 1988 LPSC 18 307 http www laputanlogic com http denali