Twentieth Lunar and Planetary Science Conference

		no.

Surface of a Terrestrial Planet Growing by Planetesimal impacts Y. Abe		1001

Scattering Properties of Venus Surface Derived from Venera-15, 16 Data A. V. Abramov, A. V. Grechischev, N. V. Zherikhin, I. A. Zheltikov, M. A. Kreslavsky, G. M. Levchenko, A. A. Morozov		1002

Paleontological Age of the Kara Impact Event A. S. Alekseev, S. B. Smirnova, M. A. Nazarov, D. D. Badjukov		1003

Carbonaceous Components in Ordinary Chondrites; Implications for Metamorphism vs. Heterogeneous Accretion C. M. O'd. Alexander, J. W. Arden, C. T. Pillinger		1004

Micron and Submicron Particle Flux Enhancement Within the Earth's Magnetosphere I: In-Situ and Laboratory Source Data W. M. Alexander, T. W. Hyde		1005

Distributions of Long-lived Cosmogenic Radionuclides in Meteorites V. A. Alexeev		1006

Periodicity of Recent Terrestrial Volcanism V. A. Alexeev		1007

Cathodoluminescence and Microscopic Lamellar Features in Quartz from the K/T Boundary and Other Experiments J. S. Alexopoulos, M. R. Owen, R. A. F. Grieve		1008

VICAR Image Processing Using Unix, X Windows, and CDROMS D. Anderson, M. Mann		1009

He, NE and AR Isotopes in the Deep-Sea Oceanic Ferromanganese Nodules: The Nodules Growth Rate G. S. Anufriev, B. S. Boltenkov, I. N. Kapitonov		1010

Further Studies on the Isotopic Composition of Interstellar Grains in Allende: I. Diamonds J. W. Arden, R. D. Ash, M. M. Grady, I. P. Wright, C. T. Pillinger		1011

Evidence of Post-accretional Alteration of CAIs in the Vigarano Carbonaceous Chondrite J. T. Armstrong		1012

Geology of Southern Guinevere Planitia R. E. Arvidson, J. J. Plaut, R. F. Jurgens, R. S. Saunders, M. A. Slade		1013

Further Studies on the Isotopic Composition of Interestellar Grains in Allende: 2. Carbon Associated with Spinels R. D. Ash, J. W. Arden, M. M. Grady, I. P. Wright, C. T. Pillinger		1014

Characteristics and Geologic/Terrain Associations of Small Dome-like Hills on Venus J. C. Aubele		1015

Beryllium-10 and Aluminium-26 Contents of Ureilites D. Aylmer, G. F. Herzog, S. Vogt, R. Middleton, D. Fink, J. Klein		1016

Grain Size Effects on Spectral Reflectance of Ol, Opx and Cpx Minerals Applied to the Hull Quotient Method H. Azuma, N. Fujii		1017

Paleomagnetism of Impactites of the Kara Impact Crater: Preliminary Results D. D. Badjukov, M. L. Bazhenov, M. A. Nazarov		1018

Impact Glasses from the Kara and Ust-Kara Structures D. D. Badjukov, M. A. Nazarov, I. V. Suponeva		1019

Gravitational Scaling of Kilauea Eruptions S. M. Baloga, J. Crisp		1020

Long Wavelength Stress Models for Mars: New and Improved W. B. Banerdt, M. P. Golombek		1021

Implications of the Inner Solar System Cratering Record for the Earth N. G. Barlow		1022

Oxidized Olivines on Mars: Spectroscopic Investigations of Heat-Induced Aerial Oxidation Products K. S. Bartels, R. G. Burns		1023

Maps of Part of the Venus Northern Hemisphere: A Joint US/USSR Mapping Project A. T. Basilevsky, G. A. Burba, R. M. Batson		1024

Areal Distribution of the Latest Volcanic Activity as a Key to Global Tectonic Style: Comparison of Northern Venus and the Pacific A. T. Basilevsky, V. P. Kryuchkov, N. N. Bobina		1025

Regolith Breccias as Precursors of Present Day Regolith on the Moon A. Basu, D. S. McKay, S. J. Wentworth		1026

Thermoluminescence of Plagioclase Feldspars and Implications for Meteorite Studies J. D. Batchelor, D. W. G. Sears		1027

Solar Wind Gases in a Metal Separate from Lunar Soil 68501 R. H. Becker		1028

Iron Oxide Mineralogy on Mars: New Results Based on High Resolution Imaging Spectroscopy During 1988 J. F. Bell III, T. B. McCord, P. G. Lucey		1029

Deimos: Hydration State from Infrared Spectroscopy J. F. Bell, J. R. Piscitelli, L. A. Lebofsky		1030

The Role of Analogy and Exclusiveness in Planetary Geology K. Benes		1031

Precision Minor Element Analyses of Silicate Minerals in Ureilites J. L. Berkley		1032

Petrogenetic Relationships Among Eucrite Clasts in LEW85313 Howardite J. L. Berkley		1033

Meteoritic Diamonds: Nature of the Amorphous Component T. J. Bernatowicz, P. Gibbons, R. Lewis		1034

Ferroan Anorthosites from an Evolving Magma Ocean M. G. Bersch, G. J. Taylor, K. Keil		1035

Martian Mantle Primary Melts: an Experimental Study of Melt Density and Viscosity and Viscosity at 23 KB C. M. Bertka, J. R. Holloway		1036

Oxygen Isotopic Fractionations in Symmetry Dependent Chemical Reactions S. K. Bhattacharya, M. H. Thiemens		1037

ISM Observations of Mars: Very First Results J. P. Bibring, M. Combes, T. Encrenaz, S. Erard, O. Forni, B. Gondet, J. Head, L. Ksanfomaliti, Y. Langevin, P. Masson, V. Moroz, C. Peters, F. Rocard, C. Sotin, A. Soufflot		1038

Formation of Tharsis and the Obliquity History of Mars B. G. Bills		1039

Models of Venus Tectonics: Evaluation and Application to Tessera Terrain D. L. Bindschadler, J. W. Head		1040

Mantle Flow Tectonics and a Weak Lower Crust: Implications for Formation of Large-scale Features on Venus D. L. Bindschadler, E. M. Parmentier		1041

Mineralogy and Chemistry of the Anomalous Chondritic Breccia ALH 85085 A. Bischoff, K. Metzler, D. Stoeffler, H. Palme, B. Spettel		1042

Comparison of Observed and Predicted Gravity Profiles over Aphrodite Terra, Venus M. T. Black, M. T. Zuber, D. C. McAdoo		1043

Identification and Characterization of a Carbonaceous, Titanium Containing Interplanetary Dust Particle D. Blake, R. H. Fleming, T. E. Bunch		1044

Telescopic Detection of Sulfur Compounds on Mars D. L. Blaney, T. B. McCord		1045

Petrology and Opaque Mineralogy of an Armalcolite-bearing Basaltic CAI from the Allende Meteorite N. Z. Boctor, I. D. Hutcheon, G. J. Wasserburg		1046

Ar39-Ar40 Ages of Eucrites: Did the HED Parent Body Experience a Long Period of Thermal Events Due to Major Impacts? D. D. Bogard, D. H. Garrison		1047

Glauconite Spherules and Shocked Quartz at the K-T Boundary in DSDP Site 603 B B. F. Bohor, W. J. Betterton		1048

Permian-Triassic Boundary Clay in China Is Volcanic, Not Impact Ejecta B. F. Bohor, W. J. Betterton, D. Jablonski, C. Z. Chen		1049

A Three-Dimensional Computer Representation of the Nucleus of Comet Halley D. C. Boice, W. F. Huebner, J. V. Lambert		1050

NMR Spectroscopic Analysis of Experimentally Shocked Quartz and the Formation of Diaplectic Glass M. B. Boslough, R. T. Cygan, R. J. Kirkpatrick, B. Montez		1051

Surface Density and Temperature Profiles in the Early Solar Nebula A. P. Boss		1052

The Dating of Impact Melt Rocks Using the Ar40/Ar39 Method R. J. Bottomley, D. York		1053

Phyllosilicate Minerals in Carbonaceous Chondrite Matrix Clasts in the Nilpena Polymict Ureilite: Evidence for a Cl-like Chondrite-Ureilite Connection A. J. Brearley, M. Prinz		1054

Variation of Martian Rampart Crater Ejecta Lobateness in Comparison to Latitude, Longitude, Terrain, and Crater Diameter N. T. Bridges, N. G. Barlow		1055

A Petrographic and Isotopic Study of Major Phases and Opaque Assemblages in an Allende FUN Inclusion C. A. Brigham, I. D. Hutcheon, D. A. Papanastassiou, G. J. Wasserburg		1056

Bidirectional Reflectance Characteristics of Black Chondrite Meteorites D. T. Britt, C. M. Pieters		1057

Relationship of C-type Asteroids to Dark Meteorites: Evidence for Optical Alteration by Asteroidal Regolith Processes D. T. Britt, C. M. Pieters, R. S. Webb, S. F. Pratt		1058

The Origin of the Breccias in the Lower Onaping Formation, Sudbury Structure (Canada): Evidence from Petrographic Observations and Sr-Nd Isotope Data P. Brockmeyer, A. Deutsch		1059

Clinopyroxene Fractionation from an Initial Lunar Magma and Some EU/EU Calculations J. G. Brophy, A. Basu		1060

Age of the Estherville Mesosiderite M. Brouxel, M. Tatsumoto		1061

Constraining Solid-State Greenhouses Using Eclipse Observations in the Thermal Infrared: A Progress Report R. H. Brown, D. L. Matson		1062

Large Mineral Grains in Interplanetary Dust D. E. Brownlee, L. S. Schramm, M. M. Whellock, M. Maurette		1063

Crater Density in the Northern Part of Venus: Areal and Topographic Patterns G. A. Burba		1064

Venera 15 and 16 Cartographic Products: A Review G. A. Burba		1065

Geologic Mapping of the Northern Venus: A Progress Report G. A. Burba, N. N. Bobina, V. P. Shashkina		1066

Olivine Alteration Phases in Shergottite ALHA 77005: Information from 4.2K Mossbauer Spectra R. G. Burns		1067

Change of Structural and Valent State of Fe Ions During Melting of Minerals (Mossbauer Study) A. M. Bychkov, A. V. Polosin		1068

Double Structural Role of Fe2+ Ions in Carbonate Glasses (Mossbauer Study) A. M. Bychkov, A. V. Polosin		1069

Morphological Variations and Evolution of Channels on Mars N. A. Cabrol		1070

Possible Scenarios Resulting from the Giant Impact A. G. W. Cameron, W. Benz		1071

The Bessel Ray Region: Preliminary Analysis of Remote Sensing Data B. A. Campbell, B. R. Hawke, J. F. Bell III, S. H. Zisk		1072

Venus: New Radar Images D. B. Campbell, A. A. Hine, J. K. Harmon		1073

New Arecibo High-Resolution Radar Images of Venus: Preliminary Interpretation D. B. Campbell, A. A. Hine, J. K. Harmon, D. A. Senske, R. W. Vor der Bruegge, P. C. Fisher, S. Frank, J. W. Head		1074

A Dune Classification Scheme for Mars: Southern Hemisphere Eolian Bedforms R. Campos-Marquetti Jr.		1075

Geologic Map of the Ulyxsis Rupes Area of Mare Australe, Mars R. Campos-Marquetti Jr., J. Robar, M. Harrington		1076

Estimating Relative Abundances of Meteorite Types W. A. Cassidy		1077

Runaway Growth of Giant Protoplanets E. Celotto, F. Marzari, V. Vanzani		1078

The Pd-Ag Systematics in IVA and IVB Iron Meteorites and in Pallasites J. H. Chen, G. J. Wasserburg		1079

Lunar Mare-Highland Horizontal Spectral Variations from Telescopic CCD Imaging S. D. Chevrel, P. Pinet		1080

Thermal-infrared Spectral Observations of Coated Surfaces P. R. Christensen, S. L. Thliveris		1081

Depth to Unoxidized Material in the Martian Regolith C. F. Chyba, S. W. Squyres, C. Sagan		1082

The Relationship Between Orbital and Sample Data for Lunar Landing Sites P. E. Clark		1083

The Lunar Farside Revisited East of Smythii and Beyond P. E. Clark, B. R. Hawke		1084

Galileo Spacecraft Encounters with the Earth/Moon System T. C. Clarke, F. P. Fanale		1085

Origin of Xe-HL and Supernova 1987A D. D. Clayton		1086

O Anomalies in Interstellar Dust Size Fractions D. D. Clayton, K. Liftman, P. Scowen		1087

Oxygen Isotope Classification of Carbonaceous Chondrites R. N. Clayton, T. K. Mayeda		1088

The Response of an Early Martian Groundwater System to the Onset of a Colder Climate S. M. Clifford		1089

Olivine-Metal Mixtures Spectral Reflectance Properties and Phase Determinations E. A. Cloutis		1090

Some Effects of Composition on Efficiencies for Production of O and Fe from Silicate Melts by Electrolysis R. O. Colson, L. A. Haskin		1091

Use of Stationary Electrode Polarography to Measure Reduction Potentials for EU in Melt of Diopsidic Composition R. O. Colson, L. A. Haskin		1092

The Problem of Lunar Initial PB W. Compston, I. S. Williams, C. Meyer		1093

Volcanotectonic Patterns on the Southeast Flank of Alba Patera C. D. Condit		1094

Kauhako Crater and Channel, Kalaupapa, Molokai, Hawaii: A Terrestrial Analog to Lunar Sinuous Rilles C. R. Coombs, B. R. Hawke		1095

Geologic and Remote Sensing Studies of the Alphonsus Crater Region C. R. Coombs, B. R. Hawke, P. G. Lucey, J. W. Head		1096

Asymmetric Distribution of Volatiles on Mars F. M. Costard		1097

Fluvio-Thermal Erosion on Mars: A Siberian Analogy F. M. Costard		1098

Timing of Resurfacing Events in the Amenthes and Tyrrhena Cratered Highlands of Mars R. A. Craddock, T. A. Maxwell		1099

Yorktown and Lexington as Viewed by the Viking I Lander R. A. Craddock, J. R. Zimbelman		1100

Evidence for an Ancient Impact Basin in Daedalia Planum, Mars R. A. Craddock, R. Greeley, P. R. Christensen		1101

Magnetic Probing of Early-Time Impact Phenomena D. A. Crawford, P. H. Schultz, L. J. Srnka		1102

Estimating Eruption Rates of Planetary Lava Flows J. Crisp, S. Baloga		1103

Mid-infrared Spectroscopy of Palagonite J. Crisp, M. J. Bartholomew		1104

Canyon Structure in the Hebes-Juventae-Gangis Area, Mars S. K. Croft		1105

New Geologic Maps of the Uranian Satellites Titania, Oberon, Umbriel and Miranda S. K. Croft		1106

Analysis of an Ignimbrite Plateau in the Central Andes Using LANDSAT Thematic Mapper Data Implications for the Identification of Ash Deposits on Mars D. A. Crown, R. Greeley, M. F. Sheridan, R. Carrasco		1107

Minor and Trace Element Microdistributions in Angra DOS Reis and Lewis Cliff 86010: Similarities and Differences G. Crozaz, G. McKay		1108

Rare Earth Element Distribution in a Complex Type B1 Allende Inclusion, an Ion Microprobe Study (Revisited) G. Crozaz, G. J. MacPherson, L. L. Lundberg		1109

Three Vesta-like Basaltic Asteroids and the Origin of Eucrites D. P. Cruikshank, D. J. Tholen, W. K. Hartmann, J. F. Bell, R. H. Brown		1110

Eastern Aphrodite Terra, Venus: Evidence for Additional Divergent Plate Boundary Characteristics and Crustal Spreading from Diana Chasma to Atla Regio L. S. Crumpler, J. W. Head		1111

Particle-Gas Dynamics in the Protoplanetary Nebula J. N. Cuzzi, J. Champney, T. Coakley, A. Dobrovolskis		1112

Time of Crystallization of a Unique A15 Basalt E. J. Dasch, G. Ryder, C.-Y. Shih, H. Wiesmann, B. M. Bansal, L. E. Nyquist		1113

The Origin of Phosphate Minerals in the Eagle Station and Springwater Pallasites A. M. Davis, E. J. Olsen		1114

Trace Elements in Feldspathic Clasts in Polymict Ureilites A. M. Davis, M. Prinz		1115

Discontinuities in the Shallow Martian Crust P. A. Davis, M. P. Golombek		1116

Cathodoluminescence Phosphors in the Matrices of Type 3 Ordinary Chondrites J. M. Dehart, G. E. Lofgren, D. W. G. Sears		1117

The Composition and Luminescence Properties of Chondrule Olivines and Pyroxenes in the Type 3 Ordinary Chondrites J. M. Dehart, G. E. Lofgren, D. W. G. Sears		1118

Flood Surge in Martian Outflow Systems: Episodic Flow R. A. de Hon		1119

Geologic Map of Maja Valles: MTM 20057, Northern Lunae Planum, Mars R. A. de Hon		1120

A Geologic Map and Photomosaic of the Jg-15 Quadrangle of Ganymede R. A. de Hon, A. C. Leith, W. B. McKinnon		1121

The Relationship Between the Lewis Cliff Basaltic Achondrites (1985, 86 and 1987 Series) and Other Polymict Achondrites J. S. Delaney		1122

Trace Elements in Plagioclase from Three Apollo 16 Breccias J. S. Delaney, S. R. Sutton, J. V. Smith		1123

Buoyancy-driven Melt Segregation in the Earth's Moon J. W. Delano		1124

Response of U-Pb Systematics to Shock-wave Metamorphism ll:35.0-59.0 GPa Shock-Recovery Experiments on Zircon and Titanite A. Deutsch, U. Scharer, U. Hornemann		1125

Some Peculiarities of Refractory Elements Volatilization from Silicate Melts Yu. P. Dikov, M. V. Gerasimov, O. I. Yakovlev		1126

Geologic Evolution of the Highland/Lowland Transition Zone in the Ismenius Lacus Quadrangle, Mars A. M. Dimitriou		1127

On the Problem of the Magnetic Fields of Neptune and Uranus Sh. Sh. Dolginov		1128

Granulometry of the Martian Surface by Photopolarimetry A. Dollfus, M. Deschamps, J. Zimbelman		1129

The Simpson Desert Depression--An Ancient Impact Basin? M. J. Duane, W. U. Reimold		1130

Brittle and Ductile Behavior of Ice/Rock Mixtures W. B. Durham, S. H. Kirby, L. A. Stern, K. A. Ragaini		1131

The Lobate Features West of Each of the Tharsis Montes, Mars A Re-evaluation of Their Origins K. S. Edgett		1132

The Physical Properties of Dark Intracrater Materials on Mars: Examination of Photographic and Thermal Infrared Data K. S. Edgett, P. R. Christensen		1133

Large Venusian Shields: Characterization and Comparisons M. S. Edmunds		1134

Integral Photometry of PHOBOS Using Hapke's Equation N. D. Efford		1135

Regolith Thickness on Large Icy Satellites J. Eluszkiewicz, D. J. Stevenson		1136

Al-rich Pyroxenes: Metastable Formation in Supercooled Lunar Basaltic and Terrestrial Impact Melts W. V. Engelhardt, J. Arndt, H.-G. Pankau, A. Witzsche		1137

Anomalous CR Isotope Fractionation in Terrestrial Spinels Following High Temperature Distillation T. M. Esat		1138

CR Isotope Anomalies in Inclusions from Allende and Murchison Meteorites T. M. Esat, S. R. Taylor		1139

Unusual Meteorites LEW86010 and ALH85085 and Eleven Chondrites: Characterization from Cosmogenic and Trapped Noble Gases and Mineralogy O. Eugster, S. Niedermann, D. Wang		1140

Regolith Processes as Possible Reflectance Spectra Controls F. P. Fanale, B. E. Clark		1141

Highland Contamination and Subsurface Topography in Southern Mare Serenitatis W. H. Farrand		1142

Diaplectic Transformation of Hornblende from Puchezh-Katunki Astroblem, USSR S. P. Fedosova, L. V. Sazonova, S. I. Stchebletkin, V. I. Feldman		1143

MO and W Depletions in Caps in CAI's in Carbonaceous Chondrites: A Theoretical Study of the Effects of Nebular Total Pressure B. Fegley Jr., D. Kong		1144

Experimental Study of Regional Metamorphism of Impactites V. I. Feldman, Yu. B. Matveeva		1145

Neutron Signature of Carbon Dioxide and Water Ice at the Martian South Pole W. C. Feldman		1146

Laboratory Simulations of Lava Flows with Solid Crusts J. Fink, R. Griffiths		1147

Statistical Evolution of Impact Ejecta from the Earth--Implications for Transfer to Other Solar System Bodies S. A. Finney, W. B. Tonks, H. J. Melosh		1148

The Lunar Orbit in the Late Precambrian S. A. Finney, C. R. Williams, C. P. Sonett		1149

Carbon-14 Production by 155-Mev Protons in Meteorites E. L. Fireman, R. P. Beukens		1150

Thermal-Orbital History Models for a Visco-Elastic Io H. J. Fischer, T. Spohn		1151

The Assemblage of Al-rich Pigeonite with Cristobalite in the Metal Particle from the Efremovka CV Chondrite A. V. Fisenko, G. V. Baryshnikova, A. V. Guzhova, A. K. Lavrukhina		1152

Alteration of Reflectance Spectra for Dunite Processed by Laser Radiation A. V. Fisenko, N. N. Kasanova, L. F. Semjonova, E. I. Chumak, Yu. A. Surkov, A. K. Lavrukhina		1153

Acid Weathering on Mars: Spectroscopic Investigations of Sulfuric Acid-Degraded Olivines and Sulfides D. S. Fisher, R. G. Burns		1154

Implications of Folding for the Rheological Structure of the Crust of Venus R. C. Fletcher		1155

Volcanism on Mars: Experiments on CO2 Solubility in Silicic Magmas R. A. Fogel, M. J. Rutherford		1156

Incidence Angle and Resolution: Potential Effects on Interpreting Venusian Impact Craters in Magellan Radar Images J. P. Ford		1157

Large Diameter Volcanic Spatter Rings: Mechanisms of Origin and Significance for Planetary Studies P. W. Francis, S. L. de Silva, P. J. Mouginis-Mark, S. Self		1158

Lukelong Dorsa as a Zone of Underthrusting and Possible Subduction on Venus S. L. Frank, J. W. Head		1159

Spacing of Ridge Belts in the Plains-Ridge Belt Assemblage: Venus S. L. Frank, J. W. Head		1160

Resurfacing in Coprates and Thickness of the Ridged Plains H. Frey, T. D. Grant		1161

Overlapping Large Impacts and the Origin of the Northern Lowlands of Mars H. Frey, R. Schultz		1162

Estimates of Minimum Lava Flow Eruption Rates on Venus L. R. Gaddis		1163

Volcanism in NW Ishtar Terra, Venus L. R. Gaddis, R. Greeley		1164

The Abundance of Metal on S-Asteroid Surfaces: Indications from IRAS 12 and 25 Micron Flux Ratios M. J. Gaffey		1165

Carbonates on Mars: A Sedimentological Perspective S. J. Gaffey		1166

Carbonates on Mars?: Requirements for Detection and Characterization Using Reflectance Spectroscopy S. J. Gaffey		1167

Two-Dimensional Gauge Interaction Effects for Plane Shocks in Snow E. S. Gaffney		1168

Micrometeorite Impact on Thin Films: Numerical Simulation E. S. Gaffney, D. A. Hyndman		1169

Fe2-Mg Ordering in Orthopyroxenes and the Cooling Rates of Meteorites J. Ganguly, K. Bose, S. Ghose		1170

Terrain Analysis of the Meteor Crater Ejecta Blanket J. B. Garvin, J. L. Bufton, B. A. Campbell, S. H. Zisk		1171

(Os, Ru, Ir)S2 and Other Refractory Siderophile Element rich Particles in the Metamorphosed Cabonaceous Chondrites Kardoonda, Mulga (West), and PCA 82500 T. Geiger, A. Bischoff		1172

Annealing Experiments on Allende (CV3): Textural and Mineralogical Modifications T. Geiger, K. Metzler, A. Bischoff, J. Arndt		1173

Analysis of Interplanetary Dust Particles for Volatiles and Simple Molecules E. K. Gibson Jr., C. P. Hartmetz, G. E. Blanford		1174

A Layered Moldavite Containing Baddeleyite B. P. Glass, J. T. Wasson, D. S. Futrell		1175

Pristine Shatsky Rise K/T Marine Carbonates Yield Negative CE Anomalies Slightly Higher than Present Pacific Ocean, Implying a Slightly Lower pH of 8.0.; IV G. G. Goles, R. A. Schmitt		1176

Geometry of Stresses Around Tharsis on Mars M. P. Golombek		1177

Nd Isotopic Analyses of Ureilites: Evidence for Mixing of a 4.55 GA Component with a Younger Component C. A. Goodrich, P. J. Patchett, M. J. Drake		1178

Chemistry of Allan Hills 85085: Characterization of a Unique Chondrite D. C. Gosselin, J. C. Laul		1179

Nitrogen and Carbon in ALH 85085-Links with Bencubbin? M. M. Grady, C. T. Pillinger		1180

Exposure Ages of H-Chondrites and Parent Body Structure T. Graf, K. Marti		1181

The Erosional State and Style of Meteor Crater, Arizona J. A. Grant, P. H. Schultz		1182

Volcanic Geology of Tyrrhena Patera: Morphologic Similarities to Terrestrial Ash Shields R. Greeley, D. A. Crown		1183

Martian Aeolian Features: Comparison with Results from the Global Circulation Model R. Greeley, A. Skypeck, J. B. Pollack		1184

Carbonaceous Chondrite Parent Bodies, II: Results and implications of Thermal Models R. E. Grimm, H. Y. McSween Jr.		1185

Mineralogical Shock Wave Barometry: (II) Applications to Experimentally Shocked Gneiss J. Grothues, A. Deutsch, U. Hornemann, D. Stoeffler		1186

Mineralogical Shock Wave Barometry: (I) Calibration of Refractive Index Data of Experimentally Shocked a-Quartz J. Grothues, U. Hornemann, D. Stoeffler		1187

Viking Optical and Thermal Evidence for Widespread Duricrust Substrate on Mars E. A. Guinness, R. E. Arvidson		1188

The Role of Hydrothermal Circulation in the Formation of Fluvial Valleys on Mars V. C. Gulick, V. R. Baker		1189

Comparison of Mars Radar Scattering Measurements at Widely Separated Subradar Latitudes J. K. Harmon		1190

Geochronological Investigations in Superstring Cosmology C. L. Harper		1191

The H-G Asteroid Magnitude System: Mean Slope Parameters A. W. Harris		1192

Phobos: Comparison of Small Craters on PHOBOS and the Moon W. K. Hartmann		1193

"Asteroid" 2060 Chiron: Status Report on Probable Cometary Activity W. K. Hartmann, D. J. Tholen, K. J. Meech, D. P. Cruikshank		1194

In Situ Analysis of Volatile Elements and Molecules in Carbonaceous Chondrites C. P. Hartmetz, G. E. Blanford, E. K. Gibson		1195

The Natural Thermoluminescence Survey of Antarctic Meteorites- A Discussion of Methods for Reporting Natural TL Data F. A. Hasan, R. Score, D. W. G. Sears		1196

Kinetics of Evaporation of MgO, SiO2 and Mg2SiO4, and Their Effect on Isotope Mass Fractionations A. Hashimoto		1197

The Moon as a Practical Source of Hydrogen and Other Volatile Elements L. A. Haskin		1198

Pyroclastic Deposits: an Ideal Lunar Resource B. R. Hawke, C. Coombs, B. Clark		1199

Impact Structures as Crustal Probes: A Summary of Recent Progress B. R. Hawke, P. G. Lucey, P. D. Spudis, P. D. Owensby		1200

Basic Assemblages of Geologic Units in the Venus Northern Hemisphere J. W. Head		1201

Venus Tessera as Analogs to Earth Oceanic Crust Formed at Spreading Centres J. W. Head		1202

Architecture of Orogenic Belts and Convergent Zones in Western Ishtar Terra, Venus J. W. Head, R. Vorder Bruegge, L. Crumpler		1203

REE and Selected Minor and Trace Element Microdistributions in Some Pristine Lunar Highlands Rocks C. F. Heavilon, G. Crozaz		1204

Petrography of Lunar llmenite Resources G. H. Heiken, D. T. Vaniman		1205

Uranus Satellites: Albedo and Color Maps from Voyager Imaging P. Helfenstein, J. Hillier, J. Veverka, J. Moersch, C. Weitz		1206

Interesting Dynamical Aspects of 1989b, a New Short-Period Comet E. F. Helin		1207

Melting of Venusian Mantle at Spreading Centers P. C. Hess, J. W. Head, E. M. Parmentier		1208

Fractionation of Apollo 15 KREEP Basalts P. C. Hess, P. Horzempa, M. J. Rutherford		1209

Allende Olivine Chondrules, Ferroan Olivine and Oxidation R. H. Hewins, J. M. Kozul, G. C. Ulmer		1210

Influence of Melting Kinetics on the Formation of Barred Olivine Chondrules R. H. Hewins, P. M. Radomsky, H. C. Connolly Jr.		1211

Carbon and Chalcophiles at a Nonmarine K/T Boundary Joint Investigations of the Raton Section, New Mexico A. R. Hildebrand, W. S. Wolbach		1212

The Importance of an Elastic Lithosphere for Crater Retention on lcy Bodies V. J. Hillgren, H. J. McLosh		1213

A Method of Converting Reflectance Spectra into Absorption Coefficient Spectra of Mineral Mixtures for Application to Asteroidal Surface Mineralogy T. Hiroi, H. Takeda		1214

Preliminary Densities and Phase Diagram of the Water/NH3 System at P-T Conditions Relevant to the Icy Moons of the Outer Planets D. L. Hogenboom, J. Winebrake, G. J. Consolmagno, W. Dalrymple III		1215

Effects on Ambient Magnetic Fields and Plasma of the Expanding Vapor Cloud Produced in Lunar Basin-forming Impacts L. L. Hood, Z. Huang		1216

Hydrogen Extraction from Lunar Soil: Methods Applicable to a Lunar Processing Facility M. L. Houdashelt, R. Bustin, E. K. Gibson		1217

Are Shocked Minerals Unique to Impact? A. R. Huffman, N. L. Carter, C. B. Officer		1218

The Cretaceous-Tertiary Boundary at Brazos River, East Texas A. R. Huffman, J. H. Crocket, S. Gartner		1219

Trace Element Chemistries of 74241 and 79221 Mare Volcanic Glasses S. S. Hughes, J. W. Delano, R. A. Schmitt		1220

Trace Element Signatures in Mare Volcanic and Impact-Melt Glasses from Apollo 14, 15, 16 and 17 S. S. Hughes, J. W. Delano, R. A. Schmitt		1221

MG Isotopes and Rare Earth Abundances in Plagioclase from Ordinary Chondrites: A Search for 26Al I. D. Hutcheon, R. Hutchison, A. Kennedy		1222

Shock Effects in H-Group Chondrites M. L. Hutson		1223

Micron and Submicron Particle Flux Enhancement Within the Earth's Magnetosphere II: Transport Mechanisms and Particle Dynamics in Cislunar Space T. W. Hyde, W. M. Alexander		1224

Micron and Submicron Particle Flux Enhancement Within the Earth's Magnetosphere III: Charged Particle Trapping and Enhanced Lifetime Criteria Between L Values 1.7 and 3.0 T. W. Hyde, W. M. Alexander		1225

Isotopic and Chemical Constraints on the Formation of HAL-type Refractory Inclusions T. R. Ireland, A. J. Fahey, E. K. Zinner		1226

The Kaidun Meteorites: Estimation of the Impact Velocity of the Meteorite Parent Bodies A. V. Ivanov, B. A. Ivanov		1227

Z-Model with Shear Bulking and Gravity Anomalies Above Impact Craters B. A. Ivanov		1228

Resonance Trapping of Comet and Asteroid Dust Particles by the Earth and Mars A. A. Jackson, H. A. Zook		1229

Is the Shergottite EETA 79001 a Breccia? E. Jagoutz		1230

Studies of the Distribution of Rare-Earth Elements in the Minerals of Lunar Ferroan Anorthosites O. B. James, M. M. Lindstrom, J. J. McGee		1231

Planetary Response of Thick Lithospheres to Loading D. M. Janes, H. J. McLosh		1232

Spectrophotometric Analysis of the Lunar Plinius/Apollo 17-Region R. Jaumann, G. Neukum		1233

Search for Debris of the Tunguska Meteor Analytical Study of Spherules from the Explosion Site C. Jehanno, D. Boclet, J. Danon, E. Robin, R. Rocchia		1234

Pristine Shatsky Rise K/T Marine Carbonates Yield Fe NET/Ir NET-CI Chondritic Ratio: No Evidence for Fe from Terrestrial Crater Ejecta Rules Out Direct Asteroid-Comet Impact, I. Observations G.-Y. Jin, R. A. Schmitt		1235

Pristine Shatsky Rise K/T Marine Carbonates Yield FeNET/FeNET-CI Chondritic Ratio: No Evidence for Fe from Terrestrial Crater Ejecta Rules Out Direct Asteroid-Comet Impact; II. G.-Y. Jin, R. A. Schmitt		1236

Pristine Shatsky Rise K/T Marine Carbonates Exhibit Anomalous Mn/Al Ratios Relative to Normal Pacific Ocean Carbonates III G.-Y. Jin, R. A. Schmitt		1237

Volcanic and Impact Classes from Mare Fecunditatis Y. Jin, L. A. Taylor		1238

Dark Inclusions in Allende, Vigarano, and Leoville: Implications for Oxidation Prior to Final Accretion of CV3 Parent Bodies C. A. Johnson, M. Prinz, M. K. Weisberg, R. N. Clayton, T. K. Mayeda		1239

Results of a Training Exercise in Geological Mapping and Interpretation of Venus: Venera Map 12 J. R. Johnson		1240

Experimental Study of Igneous Kaersutite Stability with Application to SNC Petrogenesis M. C. Johnson, M. J. Rutherford, P. C. Hess		1241

Lithologic Distribution and Classification of 2-4 MM Particles from Apollo 14 Soil 14161 B. L. Jolliff		1242

Geochemistry of 2-4 MM Particles from 14161 and Implications Regarding Compositional Systematics B. L. Jolliff, L. A. Haskin, R. L. Korotev		1243

Experimental Constraints on the 205Pb- 205TI Chronology of Iron Meteorites J. H. Jones		1244

Geochemical Modeling of Igneous Fractional Crystallization J. H. Jones		1245

Petrology and Conditions of Crystalization of Type II FeO-rich Chondrules in Semarkona (LL3.0) J. H. Jones		1246

Belts of Embryonic Collisional Mountain Ranges in the Vicinity of the TaNoVa-Updoming, Mars? H.-P. Jons		1247

Suspected Block/Plate Boundaries Within the MEGA - Aureole of the TaNoVa - Updoming on Mars H.-P. Jons		1248

Trends in Carbon-14 Terrestrial Ages of Antarctic Meteorites from Different Sites A. J. T. Jull, P. A. J. Englert, D. J. Donahue, T. W. Linick		1249

Cosmogenic Nuclide Production Rates: Carbon-14 from Neutron Spallation A. J. T. Jull, P. A. J. Englert, D. J. Donahue, R. C. Reedy, D. Lal		1250

Dual polarization Radar Cross Sections of Mercury and Venus at 3.53 CM Wavelength R. F. Jurgens, R. M. Goldstein, W. Greiner		1251

Nickel and Cobalt Partitioning Between Silicate and Metal Liquids in the Presence of Graphite at Ten Kilobars A. A. Kadik, J. R. Holloway		1252

Geochemistry of the LEW86010 Angrite G. W. Kallemeyn, P. H. Warren		1253

Can We Radiometrically Date Cryovolcanic Flows on Icy Satellites? J. S. Kargel		1254

Rheological Extremes of Cryogenic Liquids on Icy Satellites J. S. Kargel, S. K. Croft		1255

Regolith Stage of Meteorites: Track Studies of Pesyanoe Achondrite L. L. Kashkarov, L. I. Genaeva		1256

Track Studies in Olivines from Chondrules and Matrix for the Ordinary Chondrites Tieschitz H3, Saratov L4 and Elenovka L5 L. L. Kashkarov, G. V. Kalinina		1257

Investigation of Nikol'skoe L4-5 Chondrule Olivines by Thermoluminescence Method L. L. Kashkarov, N. N. Korotkova, V. G. Kashkarova, Ya. A. Skripnik		1258

Thermoluminescence Characteristics of Kaidun Carbonaceous Chondrite Minerals L. L. Kashkarov, N. N. Korotkova, V. G. Kashkarova, Ya. A. Skripnik		1259

Was the Moon Formed from the Mantle of a Martian-sized Planetesimal? T. Kato, A. E. Ringwood		1260

Alteration of Ca-and Al-rich Inclusions in Allende: A Transmission Electron Microscope Study L. P. Keller, P. R. Buseck		1261

Chemical and Isotopic Constraints on the Formation and Evolution of SA-I, a Basaltic CAI from Allende A. K. Kennedy, I. D. Hutcheon, G. J. Wasserburg		1262

Deuterium Enrichments and Synthesis of Meteoritic Organic Matter J. F. Kerridge		1263

Nitrogen, Xenon and Argon in Lunar Regolith Breccia 60016: A Study of Solar-wind Nitrogen and Measures of Antiquity J. F. Kerridge, K. Marti		1264

The Role of Mantle Convection in the Formation of Highland Regions on Venus W. S. Kiefer, B. H. Hager		1265

Identification of Solar Nebula Condensates in Interplanetary Dust Particles, Unequilibrated Ordinary Chondrites and Carbonaceous Chondrites W. Kloeck, K. L. Thomas, D. S. McKay		1266

Particle Emission from Artificial Cometary Surfaces: Material Science Aspects H. Kochan, L. Ratke, H. Hellman, K. Thiel, E. Grun		1267

Morphological Distinction of Sapping-and Runoff-Dominated Valley Networks on Earth and Mars R. C. Kochel, S. M. O. Miller		1268

Extraterrestrial Spherules from Glacial Sediment in Antarctica: Internal Structure, Mineralogy, and Chemical Composition C. Koeberl, E. H. Hagen, G. Faure		1269

New Mineralogical and Chemical Data on the Machinga (L6) Chondrite, Malawi C. Koeberl, H. E. Horsch, R. K. W. Merkle, W. U. Reimold		1270

Geochemical Stratigraphy of the 60009/60010 Core, Apollo 16 R. L. Korotev		1271

Mars: Gravity Field and Deep Structure of the Olympus Mons E. D. Koryakin		1272

Clotho Tessera, Venus: A Fragment of Fortuna Tessera? R. C. Kozak		1273

Iron Redox Characteristics and Chemical Oxygen Diffusion in the System Anorthite-Diopside S. J. Kozak, H. D. Schreiber, M. W. Riethmiller, S. E. Bienert, J. W. Webb		1274

Comparison of the Thermal Emission Spectra from the Surfaces of Mercury and the Moon R. W. H. Kozlowski, A. L. Sprague, L. A. Lebofsky		1275

Tentative Analysis of Reflectivity Map of Venus Surface Based on Venera-15, 16 Measurements: Comparison with Pioneer Venus Data M. A. Kreslavsky, A. T. Basilevsky		1276

Tentative Analysis of RMS Map of Venus Surface Based on Venera 15, 16 Measurements: Comparison with Pioneer Venus Data M. A. Kreslavsky, A. T. Basilevsky		1277

A System of Conjugate Strike-Slip Faults in the Ridge Belts on Venus V. P. Kryuchkov		1278

Radar-bright Flow-like Features as Possible Traces of the Latest Volcanic Activity on Venus V. P. Kryuchkov, A. T. Basilevsky		1279

Non-equilibrium Trace Element Partitioning and RELICT Grains in a Type BI CAI S. M. Kuchner, J. R. Laughlin, L. Grossman		1280

Origin of Chondrules G. Kurat, H. Palme		1281

Martian Cryolithosphere: Mapping of Vertical Section Types R. O. Kuzmin, G. A. Burba, N. N. Bobina, V. P. Shashkina, F. V. Zabalueva		1282

Preliminary Estimates of Sediment Volume in the North Polar Sand Seas of Mars N. Lancaster, R. Greeley		1283

The Bholghati Consortium Chemical Study of the Bholghati Howardite J. C. Laul, D. C. Gosselin, M. R. Smith		1284

Intact Capture of Hypervelocity Particles in Aerogels M. R. Laurance		1285

The Nature of Low Albedo Asteroids from 3 micron Spectrophotometry L. A. Lebofsky, T. D. Jones		1286

Earth-based Radio Observations of the Planet Mercury M. J. Ledlow, J. O. Burns, J. H. Zhao, G. Gisler, M. Zelik, D. Baker		1287

Viking IRTM Observations Regional Albedo and Photometric Studies of Mars S. W. Lee, R. T. Clancy		1288

On the Formation of Valhalla Basin (Callisto) G. A. Lejkin, A. N. Sanovich		1289

Computer Simulation of Dust Grain Evolution K. Liffman		1290

The First Meteoritic Silver Minerals in Pena Blanca Springs Enstatite Achondrite: Assemblages, Compositions and Silver Isotopes Y. T. Lin, A. El Goresy, I. D. Hutcheon		1291

Procedures for Instrumental Neutron Activation Analysis of Individual Cosmic Dust Particles D. J. Lindstrom, M. E. Zolensky, R. M. Lindstrom		1292

Geochemistry and Petrology of Recrystallized Gabboric Breccias from the Apollo 15 Site M. M. Lindstrom, U. B. Marvin, B. B. Holmberg, D. W. Mittlefehldt		1293

Geochemistry of 15205 KREEP Basalt Clasts M. M. Lindstrom, B. Moss, D. W. Mittlefehldt		1294

Discovery of Neogene Tektites Layer in the Core Collected from North Pacific Z. Liu, H. Peng		1295

Dynamic Crystallization Experiments on Pyroxene-rich Chondrule Melts: Comparison of Experimentally Produced and Natural Textures and Mineral Compositions G. E. Lofgren		1296

Fractionation Trends of Evolved Lunar Magmas J. Longhi		1297

Is Natural Silicate Liquid Immiscibility Metastable? J. Longhi		1298

A Search for Zinc lsotope Anomalies in CAIs: First Results R. D. Loss, G. W. Lugmair		1299

Interior Structures of Valles Marineris, Mars B. K. Lucchitta, L. M. Bertolini		1300

An Enstatite Crustal Composition for Mercury? P. G. Lucey, J. F. Bell		1301

Imaging Spectroscopy of the Central Highlands from 7 to 1.00 microns P. G. Lucey, B. R. Hawke		1302

Telescopic Thermal Infrared Measurements of the Silicate Mineralogy of Lunar Red Spots P. G. Lucey, B. R. Hawke		1303

High Spectral Resolution Spectroscopy of the Martian Moons P. G. Lucey, J. F. Bell, J. R. Piscitelli		1304

A Spectral Mixing Model Approach to the Analysis of the Spectra of Lunar Soils P. G. Lucey, J. Granahan, M. L. Nelson, B. R. Hawke		1305

The Dependence of Near-infrared Spectral Parameters on Lunar Rock Type Composition P. G. Lucey, M. Nelson, J. Granahan, B. R. Hawke		1306

Rb-Sr and Other Isotopic Studies of the Angrite LEW 86010 G. W. Lugmair, S. J. G. Galer, R. Loss		1307

Derivation of an Average Single Particle Phase Function for the Lunar Regolith K. Lumme, J. I. Peltoniemi, W. M. Irvine		1308

Preplanetary Evolution and Protomatter of Venus A. B. Makalkin, V. A. Dorofeyeva		1309

Intact Planetoid Capture: Application to Planets Venus and Earth R. J. Malcuit, D. M. Mehringer, R. R. Winters		1310

Microprobe Analysis of Chondrite Yefremovka (C3): New Data and their Genetic Interpretation A. A. Marakushev, L. B. Granovsky, N. G. Zinovyeva, O. B. Mitreikina		1311

The Model of Heat and Mass Transfer in the Cometary Atmosphere M. Ya. Marov, A. V. Kolesnichenko, Yu. V. Skorov		1312

Cold Welding of Aeolian Materials in the Venusian Environment: Experimental and Theoretical Considerations J. R. Marshall, G. Fogleman, R. Greeley		1313

A New Xenon Component in Chondritic Metal K. Marti, J. S. Kim, B. Lavielle, P. Pellas, C. Perron		1314

A Granite Fragment from the Apennine Front--Brother of QMD? R. Martinez, G. Ryder		1315

Parameters of Excavation and Melting Zones of Kara Crater V. L. Masaitis, M. S. Mashchak, T. V. Selivanovskaya		1316

High Energy Spallation Xenon Spectrum from Barium Targets K. J. Mathew, M. N. Rao, R. Michel		1317

Production of Stable Xenon Isotopes from Barium by Low-Energy Protons K. J. Mathew, M. N. Rao, R. Michel, K. Presher		1318

Noble Gases in DARWIN Glass: Anomalous Neon Enrichment J. Matsuda, H. Yajima		1319

Fractionation of Noble Gases in Vapor-Growth Diamonds J. Matsuda, K. Fukunaga, K. Ito		1320

Allende Chondrules: Further Demonstration of Fractionated and Unfractionated REE and Alkali Metals H. Matsuda, N. Nakamura, S. Noda		1321

Coupled Evolution of the Atmosphere-Ocean, Continent, and Interiors T. Matsui, E. Tajika		1322

Giant Micrometeorites from Antarctic Blue Ice M. Maurette, D. E. Brownlee, L. S. Schramm		1323

Electron Microscope Studies of Carbon-rich Grains in a New Collection of Antarctica Micrometeorites M. Maurette, C. Jouret, Ph. Bonny, J. P. Bradley, M. S. Germany, Y. Kihn		1324

Noble Gas Measurements of Extraterrestrial Particles from Polar Sediments M. Maurette, C. Olinger, R. Walker, C. Hohenberg		1325

Scatter Plots of Elemental Abundances in Micrometeorites: A Non Statistical Interpretation M. Maurette, D. E. Passoja		1326

A New Collection of Micrometeorites, Extracted from 100 Tons of Artificially Melted Blue Ice, Near Cap-Prudhomme in Antarctica M. Maurette, M. Pourchet, Ph. Bonny, M. de Angelis, P. Siry		1327

Mechanisms of Resurfacing in the Amenthes and Tyrrhena Cratered Highlands of Mars T. A. Maxwell, R. A. Craddock		1328

Oxygen Isotopes in the Bholghati Howardite T. K. Mayeda, R. N. Clayton		1329

Geologic and Structural Features of the Elysium Mons Caldera K. McBride		1330

Evidence of Pyroclastic Activity near Elysium Mons, Mars K. McBride, J. R. Zimbelman		1331

The Oxygen Fugacity of the Stillwater Complex Magma I. S. McCallum, G. W. Rattray		1332

Homogenization of Chondrule Silicates in Ordinary Chondrites: Constraints on Asteroidal Metamorphism T. J. McCoy, E. R. D. Scott, R. H. Jones, K. Keil		1333

A Description of a Possible Coupling Between Dust Grains and Water Based on Ions in Comet P/Halley R. A. McDonald, W. G. Tanner Jr., W. M. Alexander		1334

The comet Nucleus: Ice and Dust Morphological Balances in a Production Surface of Comet P/Halley J. A. M. McDonnell, G. S. Pamloewocz, S. F. Green, C. H. Perry		1335

Mars' Global Color and Albedo A. S. McEwen, L. A. Soderblom, J. D. Swann, T. L. Becker		1336

Partitioning of Ni, Co, Sc, La, and other Elements Between Olivine and Natural Basaltic Melt at 75 Kbars and 1800 deg C, and Implications for the Early Thermal History of the Earth E. A. McFarlane, M. J. Drake, T. Gasparik		1337

Mineralogy of the Ferroan Anorthosite Suite: Clues to the Parent Magma Puzzle J. J. McGee		1338

Martian Outflow Channel Formation by Water Erosion Under Nonequilibrium Conditions K. A. McGeehan, S. A. Schumn, R. S. Robinson		1339

Geologic Evidence Supporting an Endogenic Origin for the Martian Crustal Dichotomy G. E. McGill		1340

Influence of Volatile Loss on the Mantle Temperature of Venus P. J. McGovern, S. C. Solomon		1341

Shock Production of Organics During Cometary Impact C. P. McKay, W. R. Borucki, D. R. Kojiro, F. Church		1342

Impact Glasses in Apollo 14 Regolith Breccias and the Origin of Soils D. S. McKay, S. J. Wentworth		1343

Is Unique Achondrite LEW 86010 a Crystallized Melt? G. McKay, L. Le, J. Wagstaff		1344

Redox Conditions During the Crystallization of Unique Achondrite LEW 86010 G. McKay, L. Le, J. Wagstaff		1345

Origin of Ithaca Chasma, Tethys, II: The Importance of the Lithosphere W. B. McKinnon, L. A. M. Benner		1346

Carbonaceous Chondrite Paent Bodies, I: Constraints and Formulation of Thermal Models H. Y. McSween Jr., R. E. Grimm		1347

The Geomorphology of Eastern Gangis Chasma Within Valles Marineris, Mars D. E. Melendrez		1348

Giant Impact Theory of the Moon's Origin: First 3-D Hydrocode Results H. J. Melosh, M. E. Kipp		1349

Gamma-ray Methods for the Measurement of Atmospheric Thickness and Surface Pressure at Mars A. E. Metzger, E. L. Haines		1350

Accretionary Dust Mantles in CM Chondrites as Indicators for Processes Prior to Parent Body Formation K. Metzler, A. Bischoff		1351

Pb207/Pb206 Ages of Zircon-containing Rock Fragments Indicate Continuous Magmatism in the Lunar Crust from 4350 to 3900 Million Years C. Meyer, I. S. Williams, W. Compston		1352

On the Production of Cosmogenic Nuclides in Meteoroids by Galactric Protons R. Michel, P. Cloth, P. Dragovitsch, D. Filges		1353

Rare Earth Element Abundances in Individual Magnetic, Stony Spherules from Deep-sea Sediments K. Misawa, S. L. Ma, K. Yamakoshi, K. Nogami, N. Nakamura		1354

Diogenite Petrogenesis: Geochemistry and Petrology of Whole Rocks and Coarse-grained Separates D. W. Mittlefehldt, M. M. Lindstrom		1355

Geochemistry and Petrogenesis of Mesosiderite Whole Rock Silicates D. W. Mittlefehldt, M. M. Lindstrom		1356

Geochemistry of LEW86010 and Angra DOS Ries and Constraints on the Genesis of the Angrites D. W. Mittlefehldt, M. M. Lindstrom, D. J. Lindstrom		1357

Different Densities of Diaplectic Plagioclase Crystals Among Meteorites, Lunar Rocks and Terrestrial Impact Craters Y. Miura, T. Kato		1358

Identification of Planetary Surfaces by Remote Secondary-Ion Method Y. Miura, S. Sasaki, N. Kawashima, A. Yamori		1359

Carbonates in Some Meteorites: Information from Absorption Bands near 7 μm M. Miyamoto		1360

Raman Spectra of Ureilite Diamonds M. Miyamoto, Y. Nishimura, J. Matsuda, K. Ito		1361

Martian and Terrestrial Lava Flows H. J. Moore, J. A. Ackerman		1362

Martian Quasi-Specular Echoes: Preliminary 1986 Results H. J. Moore, T. W. Thompson		1363

The Average Relative Velocity and Average RMS Relative Velocity of the Meteoroid Population T. H. Morgan, D. J. Kessler		1364

Degree of Chemical Homogeneity of Carbonaceous Chondrites as Possible Analogs of PHOBOS Material L. V. Moroz, N. G. Zinovyeva, A. T. Basilevsky		1365

Reflectivity Spectra (350-2200 nm) of SNC Meteorites R. V. Morris		1366

Effect of Matrix Properties on the Reflectivity of Dispersed Nanocrystalline Hematite: Implications for Martian Spectral Data R. V. Morris, H. V. Lauer Jr.		1367

Mossbauer Backscatter Spectrometer: A New Approach for Mineralogical Analysis on Planetary Surfaces R. V. Morris, D. G. Agresti, T. D. Shelfer, T. J. Wdowiak		1368

Geologic Rationale for a Mars Rover/Sample Return Mission to Northern Elysium Planitia P. J. Mouginis-Mark		1369

Recent Water Release in the Tharsis Region of Mars P. J. Mouginis-Mark		1370

Statistical Photoclinometry and Surface Topography of Atmosphereless Bodies K. Muinonen, K. Lumme, W. M. Irvine		1371

New High P-T Experimental Results on Orthopyroxene-Chrome Spinel Equilibrium and a Revised Orthophroxene-Spinel Cosmothermometer A. B. Mukherjee, V. Bulatov, A. Kotelnikov		1372

Possible Composition of Halley Comet Dust (Si-poor Particles) According to the Data Obtained by Mass-Spectrometer Puma-2 L. M. Mukhin, Yu. P. Dikov, E. N. Evlanov, M. N. Fomenkova, M. A. Nazarov, O. F. Prilutsky, R. Z. Sagdeev, B. V. Zubkov		1373

Possible Composition of Halley Comet Dust (Si-rich Particles) According to the Data Obtained by Mass-Spectrometer Puma-2 L. M. Mukhin, Yu. P. Dikov, E. N. Evlanov, M. N. Fomenkova, M. A. Nazarov, O. F. Prilutsky, R. Z. Sagdeev, B. V. Zubkov		1374

Hypervelocity Impacts of Planetesimals as a Source of Organic Molecules and of Their Precursors on the Early Earth L. M. Mukhin, M. V. Gerasimov, E. N. Safonova		1375

Simultaneous Positional Observations of the System of Faint Satellites of Jupiter J. D. Mulholland, O. Calame, J.-L. Heudier, A. Maury, C. Pollas		1376

Chemical Signatures of the Infratrappean Sediments of Deccan Traps, India and Their Implications to the K-T Boundary Scenario A. V. Murali, Y.-G. Liu, R. A. Schmitt, S. Chatterjee		1377

The Volcanic and Tectonic History of Ganymede S. L. Murchie		1378

Morphologic Classes of Grooves on PHOBOS S. L. Murchie, J. W. Head, J. B. Plescia		1379

The Cratering Record of Ganymede and Callisto: Evidence for the Character of the Crater-forming Impactor Populations S. L. Murchie, J. W. Head		1380

Early Outgassing of the Earth's Mantle: Implications of Mineral/Melt Partitioning of 1 D. S. Musselwhite, M. J. Drake, T. D. Swindle		1381

Systematics of the 1.0 micron Absorption Band in Reflectance Spectra of Actinolite J. F. Mustard, C. M. Pieters, S. F. Pratt		1382

Formation of Chondrules and Matrix Materials in the Heterogenous Solar Nebula H. Naghara		1383

Vaporization in the System Plagioclase Solid - Hydrogen H. Naghara, I. Kushiro		1384

Experimental Investigation of Vaporization and Fractionation of Alkali Metals During Melting of a Chondritic Material and Their Bearing on Chondrule Formation N. Nakamura, T. Shimaoka		1385

Numerical N-Body Simulation of the Accretion Process of the Terrestrial Planets N. Namiki, T. Matsui		1386

Vacuum-Weathered Sulfur: Calorimetric Evidence for Unusual Phase Composition D. N. Nash, J. L. Gooding		1387

Morphology of the Kara and Ust-Kara Impact Craters, USSR M. A. Nazarov, D. D. Badjukov, A. S. Alekseev		1388

Geology and Chemistry of the Kara and Ust-Kara Impact Craters M. A. Nazarov, L. D. Barsukova, D. D. Badjukov, G. M. Kolesov, I. V. Nizhegorodova, A. A. Alekseev		1389

Potassium-Argon of the Kara Impact Event M. A. Nazarov, E. M. Kolesnikov, D. D. Badjukav, V. L. Masaitis		1390

Apollo 14 High-Alumina Basalt Petrogenesis: Isotopic Evidence for Assimilation and Fractional Crystallization (AFC) C. R. Neal, L. A. Taylor		1391

The Barium Problem in Silicate Liquid Immisciblity: Influence of Melt Composition and Structure on Elemental Partitioning C. R. Neal, L. A. Taylor		1392

Definition of Pristing, Unadulterated urKREEP Composition Using the "K-FRAC/REEP-FRAC" Hypothesis C. R. Neal, L. A. Taylor		1393

Unique Isotopic Signatures of Eclogite Xenoliths as Evidence of Ancient Plate Tectonic Processes C. R. Neal, L. A. Taylor, P. Holden, J. P. Davidson, A. N. Halliday, R. N. Clayton, T. K. Mayeda		1394

Apollo 17 High-Ti Basalt Petrogenesis: an Integrated Approach Using Whole-Rock Major and Trace Element Analyses C. R. Neal, L. A. Taylor, S. S. Hughes, R. A. Schmitt		1395

The "K-FRAC/REEP-FRAC' Hypothesis Evidence for Both KREEP Components in 12033 Felsite with Post-SLI Fractionation of the REEP-FRAC C. R. Neal, L. A. Taylor, A. D. Patchen		1396

Mineralogy and Petrography of 28 New Apollo 17 Basalts C. R. Neal, L. A. Taylor, A. D. Patchen, M. Ballington		1397

High Resolution Stereo Camera (HRSC) Experiment Proposal for the Soviet Mars 94 Mission G. Neukum, A. Drescher, G. Enderlein, M. Gonano, K. Hiller, H. Hoffmann, R. Jaumann, M. Lehner, P. Regner, E. Ress, R. Richter, K. Schmidt, G. Schwarz, J. Albertz, H. Ebner		1398

The Nickel Content of the Lunar Core H. E. Newsom		1399

Pre-compraction Irradiation of Individual Grains from Meteoritic Breccias: Exceedingly Long Regolikth Histories or an Active Early Sun? R. H. Nichols Jr., C. M. Hohenberg, C. T. Olinger, J. N. Goswami		1400

Terrestrial KR and Xe Contamination in Lunar Anorthosite 60018: Evidence for an Anomalous Adsorption Process S. Niedermann, O. Eugster		1401

Helium and Neon Isotopes in Stratospheric Particles A. O. Nier, D. J. Schlutter		1402

In Situ 10Be-26Al Exposure Ages at Metor Crater, Arizona K. Nishiizumi, C. P. Kohl, E. M. Shoemaker, J. R. Arnold, D. Lal, J. Klein, D. Fink, R. Middleton		1403

REE, Sr, BA and Alkali Metal Characteristics of Fine-grained Rims from Allende Chondrules S. Noda, N. Nakamura		1404

Tectonic Features on Ariel: Evidence for Collapse of a Tidal Bulge P. A. Nyffenegger, G. J. Consolmagno		1405

Rb-Sr Age of an Eucritic Clast in the Bholghati Howardite and Initial SR Composition of the Lewis Cliff 86010 Angrite L. E. Nyquist, H. Wiesmann, B. Bansal, C.-Y. Shih		1406

On the Possibility of Life on Early Mars V. R. Oberbeck, G. Fogleman		1407

A New Estimate of the Meteoroid Impact Flux on the Moon J. Oberst, Y. Nakamura		1408

Magnetic Characterization of Lunar Soils R. R. Oder, L. A. Taylor, R. Keller		1409

Carbonate Composition and Stability in the Martian Mantle: Preliminary Results M. I. Odezynskyi, J. R. Holloway		1410

Numerical Accuracy in Solving Coagulation Equation for Planetary Accumulation K. Ohtsuki, Y. Nakagawa, K. Nakazawa		1411

Planetary Impacts: The Effects of Gravity, Size, and Velocity on the Scaling of Crater Geometry and the Transition from Simple to Complex Craters J. D. O'Keefe, T. J. Ahrens		1412

Post-eclipse and Darkside Brightness Variations on Io M. O'Shaughnessy, P. Helfenstein, J. Veverka		1413

The Bulk Composition of "Fremdlinge" from a Ca, Al-rich Allende Inclusion H. Palme, I. D. Hutcheon, B. Spettel		1414

Asteroid Collisional Evolution: The Holistic Approach P. Paolicchi, A. Cellino, D. Davis, P. Farinella, V. Zappald		1415

Trace Element Characteristics of Apollo 14 Volcanic and Impact-Generated Glass Beads J. J. Papike, C. K. Shearer, S. B. Simon, K. C. Galbreath, N. Shimizu, H. Yurimoto, S. Sueno		1416

Diapiric Walls as a Model for Ridge and Trough Terrain on Icy Satellites R. Pappalardo, R. Greeley		1417

Vanadium-rich Refractory Platinum Metal Nuggets from a Fluffy Type A Inclusion in Allende J. M. Paque		1418

Theoretical Constraints on the Location of Eruptions and Intrusions of Planetary Volcanoes: Data from Kilauea Volcano, Hawai'i E. A. Parfitt		1419

Channels and Valley Networks Associated with Argyre Planitia, Mars T. J. Parker		1420

Gravitational Stirring of Planetesimals by a Planet Embryo: Implications for Runaway Growth C. W. Patterson		1421

Carbonaceous Chondrites from Queen Maud Land, Antarctica: Glimpses of New Parents R. L. Paul, M. E. Lipschutz		1422

Volatile/Mobile Trace Elements in the Bholghati Howardite R. L. Paul, M. S. Wang, M. E. Lipschutz		1423

Discovery of a Peculiar Flanged Microtektite in Sediment Collected from North Pacific H. Peng, Z. Liu		1424

A Discovery of Impact Craters on Deep-Sea Cosmic Spherule H. Peng, Z. Liu		1425

Inclusions in Chondritic Metal Grains: A Clue to the Origin of FVM Xe? C. Perron, M. Bourot-Denise, P. Mellas, K. Marti, J. S. Kim, B. Lavielle		1426

1/500,000 Geomorphological Mapping of Mars: Melas Chasma, Valles Marineris J. P. Peulvast, F. M. Costard		1427

Tectonic Response to Mantle Dynamics in Venus R. J. Phillips		1428

REE Distribution Coefficients for Plagioclase: Implications for Anorthosite Melts W. C. Phinney, D. A. Morrison		1429

Erosional Landforms at Alba Patera D. Pieri, D. Schneeberger		1430

Compositional Stratigraphy of the Lunar Highland Crust C. M. Pieters		1431

Seeing Through the Dust and Alteration Products of Mars C. M. Pieters		1432

A Ground Probing Radar Survey at Meteor Crater Arizona: First Results J. Pilon, R. A. F. Grieve, V. L. Sharpton, J. Kennedy, J. Coderre		1433

Earthbased Telescopic Near-infrared Probing of Mars by CCD-Imaging P. C. Pinet, S. Chevrel		1434

Comparison of 26 AL and Initial 87 Sr/86Sr Systematics in Allende CAIs F. A. Podosek, J. C. Brannon, G. J. MacPherson, A. Fahey, L. Lundberg, E. Zinner		1435

Temperature-Induced Changes of the Structural State of Iron Ions in Silicate Melts (Mossbauer Study) A. V. Polosin, A. M. Bychkov, A. A. Barisov		1436

Yield Strengths of Martian Complex Craters S. B. Posin		1437

Effect of Eruptive Conditions on Volcano Morphology S. B. Posin, R. Greeley		1438

The Tectonic and Igneous Evolution of Enceladus S. Pozio, J. S. Kargel		1439

PB Isotopes in Anorthositic Breccia 67075, Revisited: Evidence of a Mare Basalt-Age Component W. R. Premo, M. Tatsumoto		1440

The Distribution and Origin of Duricrust on Mars M. A. Presley, P. R. Christensen		1441

Petrologic and Stable Isotope Study of the Kakangari (K-Group) Chondrite: Chondrules, Matrix, CAI's M. Prinz, M. K. Weisberg, C. E. Nehru, G. J. MacPherson, R. N. Clayton, T. K. Mayeda		1442

Sm-Nd Chronology of Differentiation of Small Planets A. Prinzhofer, D. A. Papanastassiou, G. J. Wasserburg		1443

Arachnoids on Venus: Plausible Mechanism of Formation A. A. Pronin, V. K. Borozdin		1444

Regionalization of the Moon's Surface Based on the Thermal Radiation in the IR Region of the Spectrum (10-12 Microns) S. G. Pugacheva		1445

Unusual Mantle Xenoliths from Southeast China Q. Qi, L. A. Taylor, X. Zhou		1446

Lavas, Calderas and Magma Chambers of Alba Patera on Mars J. Raitala, K. Kauhanen		1447

Coronae Chain on Venus-A Hot SPOT Under a Moving Plate? J. Raitala, T. Tormanen		1448

Identification of Iron Meteorites in the Prairie Network Fireball Data R. S. Rajan, D. O. Revelle		1449

Proton to Neon Ratio in Ancient Solar Flares Based on Fayetteville and Kaopeta M. N. Rao, J. T. Padia		1450

Cosmogenic-Nuclide Production Rates in Interstellar Grains R. C. Reedy		1451

Solar Cosmic Rays: Fluxes and Reaction Cross Sections R. C. Reedy, K. Nishiizumi, J. R. Arnold		1452

The Bholghati Howardite: Petrography and Mineral Chemistry A. M. Reid, P. Buchanan		1453

The Bronzite-Granophyre from the Vredefort Structure - A Review W. U. Reimold, H. Horsch, R. J. Durrheim		1454

Evaluation of Initial Properties of Iron Meteoroids Using Terrestrial Crater Signatures D. O. Revelle, R. S. Rajan		1455

The Geology of the Maja Valles Region, Mars (MTM 20052) J. W. Rice Jr.		1456

Preparation of Cosmic Dust Analogs for Shock Metamorphism F. J. M. Rietmeijer, A. Albrecht		1457

Grain Size Distributions of Magneli Phases and Metallic Titanium in Chondritic Porous Interplanetary Dust Particles F. J. M. Rietmeijer, I. D. R. MacKinnon		1458

Layer Silicate Chemistry in P/Comet Halley from Puma-2 Data F. J. M. Rietmeijer, L. M. Mukhin, M. N. Fomenkova, E. N. Evlanov		1459

Redox Equilibria in Pallasite Meteorites and the Eucrite Parent Body (EPB) K. Righter, R. J. Arculus, J. W. Delana		1460

Non Mass Dependent Isotopic Fractionation: A Survey of Various Experimental Conditions F. Robert, J. Halbout, M. Javoy		1461

Lakshmi Planum Volcanism: Style, Origin, and Relation to Other Volcanic Deposits on Venus K. M. Roberts, J. W. Head		1462

Hydrology of a Flow Event in Kasei Valles, Mars M. S. Robinson, K. L. Tanaka		1463

On the Existence of Several Iridium-enriched Layers at the K-T Boundary and in a Jurassic Sequence R. Rocchia, D. Boclet, Ph. Bonte, A. Castellarin, V. Courtillot, C. Jehanno, F. C. Wezel		1464

Experimental Impacts: Analysis of Ejected Debris O. D. Rode, O. I. Yakovlev, T. V. Romashova		1465

Distribution of Craters with Central Peaks and with Hills and Ridges at Bottom over the Lunar Surface Zh. F. Rodianova, V. V. Shevchenko		1466

A Model Comet Made from Mineral Dust and H2O-CO2 Ice: Sample Preparation Development K. Roessler, P. Hsiung, H. Kochan, H. Hellmann, H. Duren, K. Thiel, G. Kozler		1467

Tidal Despinning and the History of Mercury M. N. Ross, P. J. Thomas		1468

Chromium Isotopic Systematics in Carbonaceous Chondrites: 54Cr Deficits in Acid Soluble Phases of Murchison and Urgueil M. Rotaru, J. L. Birck, C. J. Allegre		1469

Faulting History of the Alba Patera-Ceraunius Fossae Region of Mars S. L. Rotto, K. L. Tanaka		1470

CO2/3- and SO2/4- bearing Anionic Complexes Detected in Martian Atmospheric Dust T. L. Roush, J. Pollack, C. Stoker, F. Witteborn, J. Bregman, D. Wooden, D. Rank		1471

A Unique Chondrite Grouplet: Petrology and Chemistry of Carlisle Lakes 001 and Allan Hills 85151 A. E. Rubin, G. W. Kallemeyn		1472

Collisional Distruption Experiments: Impact Strength Analysis and Velocity Distributions E. V. Ryan, D. R. Davis		1473

Bombardment in the Moon-Earth System 4.5-3.8 GA Ago: The Lunar Record of Early Quiet and Late Cataclysm G. Ryder		1474

Petrogenesis of Apollo 15 KREEP Basalts G. Ryder		1475

Mineralogical Study of LEW 85328 Ureilite J. Saito, H. Takeda		1476

Measurement of Christiansen Frequencies in Spectra of Particulate Samples for Determination of Rock Composition J. W. Salisbury, D. M. D'Aria		1477

A Preliminary Compositional Study of Anorthosite and Related Rocks from the Lower Banded Series of the Stillwater Complex P. A. Salpas, B. Moss		1478

Gas Capture of Outer Jovian Planets - Critical Mass for Core Instability S. Sasaki		1479

Off-Disk Implantation of the Solar Wind and the Origin of Venusian AR S. Sasaki		1480

Covariance and Harmonic Analysis of the Interaction of Lunar Gravity and Its Surface Characteristics L. A. Savrov, E. K. Kuchik		1481

Orthopyroxene of Impact Melts - Indicator of Impact Melt Cooling (Boltysh Astrobleme, USSR) L. V. Sazonova		1482

Plagioclase Crystallization Peculiarities in Impact Melts of Boltysh Astrobleme (USSR) L. V. Sazonova, V. I. Feldman, N. N. Korotaeva		1483

Morphologies of Ten Venusian Shields Between LAT 30 deg and 90 deg N G. G. Schaber, R. C. Kozak		1484

Response of U-Pb Systematics to Shock-wave Metamorphism I: Accessory Minerals in the Haughton Impact Structure, Devon Island, Arctic Canada U. Scharer, A. Deutsch		1485

Fluid Volcanism on Miranda and Ariel P. M. Schenk		1486

Mimas Grooves, the Herschel Impact, and Tidal Stresses P. M. Schenk		1487

Cometesimal Explosions in Earth's Atmosphere (CEEA) and Steep Angle Cometesimal Cratering (SACC) Events Cause Cretaceous/Tertiary (L/T) Extinction Phenomena R. A. Schmitt		1488

Episodic Channel Activity at Ma'adim Vallis, Mars D. M. Schneeberger		1489

Mantle Convection and the Thermal Evolution of Mars G. Schubert, D. Bercovici, G. Glatzmaier		1490

Venus Coronae: Formation by Mantle Plumes G. Schubert, D. Bercovici, P. J. Thomas, D. B. Campbell		1491

Protracted Global Catastrophes from Oblique Impacts P. H. Schultz, D. E. Gault		1492

Styles of Eject Emplacement, Meteor Crater P. H. Schultz, J. A. Grant		1493

Structural Mapping and Interpretation of Valles Marineris, Mars R. A. Schultz		1494

Chronology and Global Distribution of Fault and Ridge Systems on Mars D. H. Scott, J. M. Dohm		1495

Planetary Compositions-Clues from Small Bodies and the Sun E. R. D. Scott, H. E. Newsom		1496

Analysis of Aeroballistically Dispersed Glass Samples from Wabar Crater, Saudi Arabia T. H. See, D. W. Mittlefehldt, F. Hoerz		1497

VLT-LT Basalts of Luna 16 and Luna 20: Petrography, Mineralogy, and Petrogenesis A. S. Semenova, L. S. Tarasov, N. N. Kononkova, N. V. Solovieva		1498

Synthesis of Venus Equatorial Geology: Variations in Styles of Tectonism and Volcanism and Comparison with the Northern High Latitudes D. A. Senske, J. W. Head		1499

Venus Equatorial Geologic Units D. A. Senske, J. W. Head		1500

Examination of Radar-bright Deposits Associated with the Crater Voynich Using Venera 15/16 and Pioneer Venus Roughnees, Reflectivity, Altimetry, and Imaging Data D. A. Senske, A. T. Basilevsky, D. B. Campbell, A. V. Abramov, A. V. Grechishchev, G. M. Levchenko		1501

Subaqueous Landslides on Mars? P. J. Shaller, B. C. Murray, A. L. Albee		1502

On Reported Occurrences of Shock-deformed Clasts in the Volcanic Ejecta from Toba Caldera, Sumatra V. L. Sharpton, B. C. Schuraytz		1503

Is Plagioclase Removal Responsible for the Negative EU Anomaly in the Source Regions of Mare Basalts? C. K. Shearer, J. J. Papike		1504

A Comparison of Trace Element Characteristics of Picritic Glass Beads from the Apollo 14 and Apollo 17 Sites: Implications for Basalt Petrogenesis and Compositional Variability in the Lunar Mantle C. K. Shearer, J. J. Papike, S. B. Simon, K. C. Galbreath, N. Shimizu		1505

The Olivine-Fassaite Liquidus: Experiments and Implications for Angrite Achondrites and Ca-Al Chondrules S. B. Sherman, A. H. Treiman		1506

Melt Rock Components in KREEPy Breccia 15205-Petrography and Mineral Chemistry of KREEP Basalts and Quartz-Normative Mare Basalts J. W. Shervais, S. K. Vetter		1507

Isotopic and Chemical Constraints on Models of Aluminous Mare Basalt Genesis C.-Y. Shih, L. E. Nyquist		1508

Ages of Pristine Lunar Plutonic Rocks and Their Petrogenetic Implications C.-Y. Shih, L. E. Nyquist, E. J. Dasch, B. M. Bansal, H. Wiesmann		1509

Lunar Albedo-Color Diagram: Survey of South-West Part of Lunar Disk Yu. G. Shkuratov, N. V. Bondarenko, Yu. V. Kornienko, N. P. Stankevich		1510

Geology of the Connolly Basin Impact Structure, Western Australia E. M. Shoemaker, C. S. Shoemaker		1511

Gravity Investigation of the Connolly Basin Impact Structure, Western Australia E. M. Shoemaker, C. S. Shoemaker, J. B. Plescia		1512

Interaction of Lithosphere and Biosphere: Some Evidences from Early Metazoa and Metaphytes from India M. Shukla, B. S. Venkatachala, M. Sharma		1513

Comparative Petrology and Chemistry of Apollo 17 Regolith Breccias and Soils S. B. Simon, J. J. Papike, J. C. Laul, S. S. Hughes, R. A. Schmitt		1514

Radarclinometry: Implications for the Morphology of Small Dome-like Hills on Venus V. P. Sinilo, E. N. Slyuta		1515

Cold VS Hot Accretion of Tieschitz and Other Chondrites W. R. Skinner		1516

Compaction and Lithification of Chondrites W. R. Skinner		1517

The Relic Structure of Rotational Stress Field on Venus? E. N. Slyuta, L. V. Kudrin		1518

Isolation of Compositional Variance from Viking Lander Multispectral Images M. O. Smith, J. B. Adams		1519

Direct Analysis of Terrestrial and Meteorite Samples Using Laser - Ablation Inductively Coupled Plasma/Mass Spectrometry M. R. Smrekar, D. W. Koppenall, D. C. Gosslin, J. C. Laul		1520

Implications of Gravity Modeling for a Thermal Isostasy Hypothesis for Bell Regio, Venus S. E. Smrekar, R. J. Phillips		1521

Estimating Lithospheric Thermal Gradient on Mars from Elastic Lithosphere Thickness: New Constraints on Heat Flow and Mantle Dynamics S. C. Solomon, J. W. Head		1522

Lithospheric Flexure Beneath the Freyja Montes Foredeep, Venus: Constraints on Lithospheric Thermal Gradient and Heat Flow S. C. Solomon, J. W. Head		1523

Analysis of Topography and Line of Sight (LOS) Accelerations over Western Aphrodite: Evaluation of a Spreading Center Model C. Sotin, D. A. Senske, J. W. Head, E. M. Parmentier		1524

Planetesimal Accretion Studies: Effects of Numerical Parameters D. Spaute, D. R. Davis, S. J. Weidenschilling		1525

Sample Thermal History Models of KOSI Comet Nucleus Simulation Experiments T. Sphon, J. Benkhoff		1526

A Diffusion Source Mechanism for the Atmospheres of Mercury and the Moon A. L. Spudis		1527

The Lunar Crisium Basin: Geology, Rings, and Deposits P. D. Spudis, B. R. Hawke, P. G. Lucey		1528

Early Mars: Warm and Wet, or Just Wet? S. W. Squyers		1529

Photochemical Haze on Triton J. A. Stansberry, M. G. Tomasko, J. I. Lunine		1530

Rb-Sr and Sm-Nd Signatures from the Montagnais and Popigai Impact Craters O. Stecher, H. H. Ngo, D. A. Papanastassiou, G. J. Wasserburg, L. F. Jansa		1531

Appollo 15 Green Glass: The Range of Chemical Compositions in Individual Formational Events A. M. Steele, L. A. Haskin		1532

Cathodoluminescence Mineralogy of Meteorites I. M. Steele		1533

Forsterite in CI Meteorites and Interplanetary Dust: Minor Elements and Comparison with Other Meteorite Types I. M. Steele		1534

The Effects of Stellar Perturbations on the Orbits of the Outer Planets and Objects in the Kuiper-Duncan Disk S. A. Stern		1535

The Thermodynamic Desitruction of Ice Grains in Planetary Rings S. A. Stern		1536

Planetesimal Swarms Perturbed by a Distant Protoplanet G. R. Stewart		1537

Coronae of Mnemosyne Regio, Venus: Morphology and Origin E. R. Stofan, J. W. Head		1538

Major Characteristics of the Plains-Corona Assemblage, Venus E. R. Stofan, J. W. Head		1539

Degradation of Organic Compounds Under Simulated Martian Conditions C. R. Stoker, R. Mancinelli, F. D. Tsay, S. S. Kim, J. Sculley		1540

Magnesium and Silicon Isotopic Compositions of Individual Oxide Grains from a Murchison Acid Residue: A Search for Exotic Material J. Stone, I. D. Hutcheon, S. Epstein, G. J. Wasserburg		1541

Geology of Mimas P. J. Stooke		1542

Tethys: Volcanic and Structural Geology P. J. Stooke		1543

Volcanism on Callisto P. J. Stooke		1544

Physical Interpretation of Thermal and Reflected Data on Martian Surface Units E. L. Strickland III		1545

Physical Properties of Meridiani Sinus-type Units in the Central Equatorial Region of Mars E. L. Strickland III		1546

Physical Properties of Oxia/Lunae Planum and Arabia-type Units in the Central Equatorial Region of Mars E. L. Strickland III		1547

Surface Photometric Properties and Albedo Changes in the Central Equatorial of Mars E. L. Strickland III		1548

Are Asteroids the Source of the Period of Late Heavy Bombardment in the Inner Solar System? R. G. Strom		1549

Tectonics of North Polar Plains on Venus A. L. Sukhanov		1550

Mathematical Deconvolution of Mineral Absorption Bands J. M. Sunshine, C. M. Pieters, S. F. Pratt		1551

Neutron Spectroscopy for Investigation of Small Bodies and Asteroids Yu. A. Surkov, O. P. Shcheglov, M. L. Ryvkin, O. A. Vinogradova		1552

Trace Element Compositions of Interplanetary Dust and Terrestrial Particles Collected from the Stratosphere S. R. Sutton, G. J. Flynn		1553

Location of Small SiC Crystals in Meteorites Using a Low-Voltage X-Ray Mapping Technique P. S. Swan, R. M. Walker, J. Yuan		1554

Parentless Fission Xenon in the Meteorite Bholghati? T. D. Swindle, C. M. Hohenberg, R. H. Nichols Jr., C. T. Olinger		1555

Noble Gases in the Nakhlite Governador Valadares T. D. Swindle, R. H. Nichols Jr., C. T. Olinger		1556

Pyroxene Chemical Variations of Heavilyl Shocked Ureilites and the Planetesimal-scale Collision Model for the Ureilite Genesis H. Takeda		1557

Discovery of Two Antarctic Eucrites with Reference to the HED (Howardite-Eucrite-Diogenite) Association H. Takeda, T. Tagai		1558

Mineralogical Resemblance of the Y86032-type Lunar Meteorites to Feldspathic Fragmental Breccia 67016 H. Takeda, M. Miyamoto, H. Mori		1559

Geochemical Identification of VLT-LT Basalts from Mare Fecunditatis and Apollonius Region L. S. Tarasov, A. F. Kudryashova, A. S. Semenova, V. B. Baryshev, K. V. Zolotarev		1560

Geochemistry of Rare Elements in Various Types of Basaltic Rocks from Apollo 17 Samples L. S. Tarasov, A. F. Kudryashova, A. A. Ulyanov, V. B. Baryshev, K. V. Zolotarev		1561

Metal Segregation in Asteroids G. J. Taylor		1562

Contrasting Pb-Pb Ages of the Cemulate and Non-Cumulate Eucrites F. Tera, R. W. Carlson, N. Z. Boctor		1563

Crustal Evolution and Dust Emission of Artificial Cometary Nuclei K. Thiel, G. Kolzer, H. Kochan, E. Grun, H. Kohl		1564

Formation of Ganymede's Crater Palimpsests P. J. Thomas, S. W. Squyres		1565

Impact Delivery of Organic Molecules to the Early Earth and Implications for the Terrestrial Origins of Life P. J. Thomas, C. F. Chyba, L. Brookzhaw, C. Sagan		1566

Goldstone Radar Observations of Mars: The 1986 Opposition T. W. Thompson		1567

Fe-S-Ca-Al-bearing Carbonaceous Veins in the Yamato-74130 Ureilite: Evidence for the Genetic Link to Carbonaceous Chondrites K. Tomeoka, H. Takeda		1568

A Possible Impact Structure in Tunisia W. D. Tomlinson		1569

Crystal Settling in a Vigorously Convecting Magma Ocean W. B. Tonks, H. J. Melosh		1570

Chaotic Motion in the Kuiper Belt of Comets: The Delivery of Short Period Comets M. V. Torbett		1571

Alteration of Campo Del Cielo Soil by Meteorite Impact: Implications for the Surface of Mars S. G. Traub-Metlay, W. A. Cassidy		1572

Origin of Olivine in the Nakhla Achondrite, with Implications for Distribution of Fe/Mg Between Olivine and Augite A. H. Treiman		1573

Effectiveness of Intact Capture Media P. Tsou, J. Aubert, D. E. Brownlee, L. Hrubesh, J. Williams, A. Albee		1574

Nondestructive Cosmic Dust Positioning and Velocity Sensor P. Tsou, J. G. Bradley, D. E. Brownlee, A. L. Albee		1575

Condensation Experiments in the System Mg-Si-O-H A. Tsuchiyama		1576

Thermal Evolution of Mars and Venus Including Irreversible Fractionation D. L. Turcotte		1577

Volatile Enriched Mantle Fluids in Diamond G. Turner, R. Burgess		1578

Hydrogen Isotopic Fractionation During Impact: Serpentine, Isotopically Enriched Serpentine, and Murchison J. A. Tyburczy, R. V. Krishnamurthy, S. Epstein, T. J. Ahrens		1579

Hydrogen Isotope Abundances in Early Solar System Materials A. A. Ulyanov, A. L. Devirts, E. P. Lasutina, M. A. Korovkin, Yu. A. Shukolyukov		1580

Oxygen Isotopic Anomaly in Metasomatically Altered Refractory Inclusions of Carbonaceous Chondrites A. A. Ulyanov, V. I. Ustinov, N. N. Kononkova, Yu. A. Shukolyukov		1581

The Distribution of Meteoritic Material in Impactites from the Terny Astrobleme (Krivoi Rog, Ukr.Ssr) A. A. Valter, G. M. Kolesov, D. Yu. Sapozhnikov, A. Z. Miklishansky		1582

A New Ca, Al-Silicate Mineral from the Moon D. T. Vaniman, D. L. Bish, S. J. Chipera		1583

A Dynamic Melting Model for the Origin of Apollo 15 Olivi ne-Normative and Quartz-Normative Mare Basalts S. K. Vitter, J. W. Shervais		1584

Jetting and the Origin of Tektites A. M. Vickery		1585

Weak Fe2+ -Fe3+ Charge Transfer Absorption Features Seen in CM2 Carbonaceous Chondrites and Narrowband Reflectance Spectra of Primitive Asteroids F. Vilas, M. J. Gaffey		1586

Isotopic Compositions of H, C, and N in C Diamonds from the Allende and Murray Carbonaceous Chondrites A. Virag, E. Zinner, R. S. Lewis, M. Tang		1587

Cosmogenic Radionuclides in the Antarctic H5-Chondrites LEW 85319 and LEW 85320 S. Vogt, P. A. J. Englert, J. Klein, D. Fink, R. Middleton		1588

Multi-stage Tectonic Evolution of Eastern Ishtar Terra, Venus R. W. Vorder Bruegge, J. W. Head		1589

Petrology and Chemistry of Probable Impact Melt Rocks at the Sevetin Crater S. Vedna		1590

Preliminary Geologic Map of the Etana Region Quadrangle (JG-1) of Ganymede R. Wanger, R. Jaumann, G. Neukum		1591

The Nexus of the Flexus A. S. Walker		1592

Preliminary Investigation of Empirical and Model Relationships Between Surface Roughness and HH and VV SAR Returns: Implications for Magellan Data Analysis S. D. Wall, J. J. van Zyl, R. S. Saunders		1593

Multielement Analyses of Interplanetary Dust Particles with PIXES and SYXFA R. Wallenwein, Ch. Antz, E. K. Jessberger, A. Buttlewitz, A. Knochel, K. Traxel, M. Bavdaz		1594

Evolution of the Lunar Magma Ocean As Recorded by the Composition of Plagioclase H. Waenke, G. Dreibus, H. Palme, S. Seifert, B. Spettel, D. Stoeffler		1595

Disc Tides and the Formation of Grant Planet Cores W. R. Ward		1596

Volumes and Compositions of Crusts Stable over Primordial Silicate Magmaspheres: Effects of Planet Size and FeO Content P. H. Warren		1597

Effects of Megaregolith Insulation on Sm-Nd Cooling Ages of Deep-Crustal Cumulates from the Moon and Large Asteroids P. H. Warren, H. Haack, K. L. Rasmussen		1598

Antarctic Meteorites Anomalous Abundance of Ungrouped Irons J. T. Wasson		1599

Formation of Antipodal Terrains on Icy Satellites A. Watts, R. Greeley, H. J. Melosh		1600

Sputtering of Mo: Light Isotope Enrichment and Cosmochemical Implications D. L. Weathers, I. D. Hutcheon, H. Gnaser, T. A. Tombrello, G. J. Wasserburg		1601

Oxygen-Isotopic Compositions of Individual Forsteritic Grains, Fayalitic Rims, and Matrix Olivines from the Allende Meteorite S. Weinbruch, E. Zinner, A. El Goresy, H. Palme		1602

Evidence for a Relationship Between Bencubbin, ALH85085 and CR Chondrites M. K. Weisberg, M. Prinz, C. E. Nehru		1603

ALH85151 and Carlisle Lakes 001: Members of a New Chondrite Group M. K. Weisberg, M. Prinz, C. E. Nehru, R. N. Clayton, T. K. Mayeda		1604

Calcium Carbonate and Silicate "Rust" in the Nakhla Meteorite S. J. Wentworth, J. L. Gooding		1605

INAA of Glass Spheres from Ancient Apollo 16 Regolith Breccias S. J. Wentworth, D. J. Lindstrom, M. E. Zolensky, M. M. Lindstrom, D. S. McKay		1606

Application of Remote Sensing Techniques to Alkaline Volcanic Rocks: Trans-Pecos, Texas J. L. Whitford-Stark		1607

Loss of Large Craters in the Terrestrial Impact Record R. W. Wichman, P. H. Schultz		1608

Planetary Noble Gases in "Phase Q" of Allende: Direct Determination by Closed System Etching R. Wieler, H. Baur, P. Signer, R. S. Lewis, E. Anders		1609

Streaking on Earth and Mars M. J. Wilkinson		1610

Stress Distribution on Tellus Regio, Venus, Inferred from Gravity and Topography D. R. Williams, R. Greeley		1611

Structure in the Themis, Eos, and Koronis Families J. G. Williams, E. M. Shoemaker, R. F. Wolfe		1612

Origin of Debris Flow Material: Ismenius Lacus, Mars S. H. Williams, J. R. Zimbelman		1613

Dynamics of Groove Formation on PHOBOS by Ejecta from Stickney L. Wilson, J. W. Head		1614

The Influence of Gravity on Planetary Volcanic Eruption Rates: A Reappraisal L. Wilson, E. A. Parfitt		1615

Chondrules as Near-equilibrium Assemblages That Formed in Fractionated Systems J. A. Wood, A. Hashimoto, B. B. Holmberg		1616

Finite Element Simulation of Intact Capture of Hypervelocity Particles in Multiple Films L. Wu, P. C. Chou		1617

Geologic Feature of the Duolun Impact Crater, China S. Wu		1618

Sulfur Isotope Ratio Measurements (33S, 34S) in Meteoritic Components G. Xia, M. H. Thiemens		1619

Noble Gases in Shock-produced Diamond H. Yajima, J. Matsuda		1620

Eucrite Pomozdino: Chemical and Mineral Composition of Clasts and Matrix: A Correction A. A. Yaroshevsky, L. F. Migdisova		1621

Carbon Isotopic Measurements of Deep Sea Spherules P. D. Yates, I. P. Wright, C. T. Pillinger, R. Hutchison		1622

Anticipating Magellan: Interpreting Radar Images of Geological Features S. B. Yewell		1623

The Effect of Albedo on Sublimation-driven Flow of SO2 on Io A. P. Zent		1624

Tetrataenite in the Plessite of the Iron Meteorite Carlton J. Zhang, D. B. Williams, J. I. Goldstein		1625

Masses on Preplanetary Bodies at the Final Stage of Accumulation Evaluated from the Eccentricities and Inclinations of Orbits of the Terrestrial Planets I. N. Ziglina		1626

Erosional Outliers of Dust Along the Southern Margin of the Tharsis Region, Mars J. R. Zimbelman		1627

Geologic Mapping of Southern Mangala Valles, Mars J. R. Zimbelman		1628

Estimates of Rheologic Properties for Flows on the Martian Volcano Olympus Mons J. R. Zimbelman, J. H. Fink		1629

A Possible Pyroclastic Deposit near Elysium Mons, Mars J. R. Zimbelman, K. M. McBride		1630

Mg- and O-Isotopic Compositions of Periclase, Spinel, and Melilite from Vigarano CAI 477B E. K. Zinner, C. Caillet, A. El Goresy		1631

C11, C12, and CM2 Clasts in the Bholghati Howardite and the AI RAIs Chondrite M. E. Zolensky, R. A. Barrett, J. L. Gooding		1632

Matrix and Rim Compositions Compared for 13 Carbonaceous Chondrite Meteorites and Clasts M. E. Zolensky, R. A. Barrett, J. L. Gooding		1633

The Utility of Silica Aerogel as a Cosmic Dust Capture Medium on the Space Station M. E. Zolensky, R. A. Barrett, F. Hoerz, F. Cardenas, W. Davidson, G. Haynes, W. Carswell, S. L. Koontz		1634

Petrography, Mineralogy, and Matrix Composition of Yamato-82162, a New C12 Chondrite M. E. Zolensky, R. A. Barrett, M. Prinz		1635

Trace Element Compositions of Six "Chondritic" Stratospheric Dust Particles M. E. Zolensky, D. J. Lindstrom, K. L. Thomas, R. M. Lindstrom, M. M. Lindstrom		1636

Water-bearing Minerals in the Martian Soil (Thermodynamic Prediction of Stability) M. Yu. Zolotov		1637

On the Meteoroid Flux Striking the Solar Max Satellite H. A. Zook, B. G. Cour-Palais, J. H. Allton		1638

Lithospheric Control in the Development of the Martian Plains Ridges M. T. Zuber, L. L. Aist		1639

Twentieth Lunar and Planetary Science Conference

TABLE OF CONTENTS