Review, analysis, and evaluation of the most recent studies dealing with the composition and environmental conditions of the lunar surface. To provide basic engineering data on the behavior of soils under lunar environmental conditions, experiments were performed to determine the properties of soils believed to be representative of materials on the lunar surface under atmospheric pressures and vacuum levels to the 10-10-torr range. Three different soil samples were used (1) silica flour having 90% of the particles between 2 and 26 μ, (2) ground olivine having 90% of the particles between 2 and 60, and (3) ground olivine having 90% of the particles between 0.7 and 15. On the basis of available data from telescopic observations, radar measurements, photometric studies, albedo and color measurements, and the most recent Ranger VII pictures, these materials are shown to be reasonably good simulations of the lunar surface. The significance of the state in which these materials might exist - loose, lightly bonded, or strongly bonded with respect to the measurements of important engineering properties - is also examined. Experiments consisted of the determination of the porosity attained by the soil when deposited under various vacuum levels and the effect of vacuum on the shearstrength parameters. For soil samples prepared in the atmosphere and then placed in the vacuum chamber, it was observed that the vacuum in the soil pores was considerably less than that recorded in the chamber. Porosities attained by soil deposited under low vacuums (1 to 10-3 torr) were less than those attained in atmosphere, but at higher vacuum levels the porosity increased with an increase in vacuum, and in the case of silica flour for vacuums of 10-7 torr or higher it was greater than when deposited in atmosphere. Direct shear tests showed that the apparent cohesion and the internal friction of the silica flour increased under vacuum. The internal friction of the olivine also increased under vacuum, but its apparent cohesion appeared to decrease. The increase in porosity in both soils and the effects on the apparent cohesion were attributed to the development of interparticle forces. These forces may be either attractive or repulsive, depending on the mineralogical composition of the soil and the vacuum level. (Author) M. F. A65-31182 # DISTRIBUTION OF CRATERS ON THE LUNAR SURFACE. Royal Astronomical Society, Monthly Notices, vol. 129, no. 5/6, Research supported by the Department of Scientific and Industrial Research. Fresh attack on the vital problem of the origin of the lunar craters by analyzing the surface distribution of craters of given diameter. The distribution shows a general clumpiness in both the lunarite (bright regions) and the lunabase (dark regions). Craters between 30 and 40 km in diameter, situated in the lunarite, are nonrandomly distributed at the 2% level of significance. This argues against the impact theory. It is found that the number-density of differently-sized craters is slightly greater in the following half of the moon than in the preceding half. This result is shown to apply equally to the lunarite and, taken separately, to the lunabase, and again argues against the theory that the craters were produced exclusively by impact. In assessing the origin of the craters on the basis of the observed frequencies and distribution of craters alone, it is concluded that the ratio of the number of impact craters to the number of endogenic craters is not very large. If only one theory is allowed, it must be that the craters are of internal origin. (Author) M. F. A65-31280 # ANGULAR SCATTERING LAW FOR THE MOON AT 6-METER WAVE- W. K. Klemperer (National Bureau of Standards, Central Radio Journal of Geophysical Research, vol. 70, Aug. 1, 1965, p. 3798- Study of the magnitude and scale of lunar surface roughness from radar data and of the effect of shadowing near the limb. Shortpulse radar echoes were obtained at a Peru facility. Because the Jicamarca 22-acre array is essentially a transit instrument, long echo-integration times were not possible. Although there was adequate radar sensitivity to obtain echoes right out of the limb when the whole antenna was utilized, fairly serious problems arose from the huge dynamic range required to record the echo amplitude from the leading edge properly. Accordingly, only half the available antenna area and only two of the four transmitters were used in this experiment. There were two receiving systems with linear detectors, the one set at higher sensitivity for exploring the echo amplitude near the limb. Polarization was circular to avoid problems with Faraday rotation from the F region. By phasing the two halves of the antenna array to point at different points on the east-west track of the moon, the observation period could be extended to permit about 20 db of digital integration. The parameters of the system are given in a table. M. F. A65-32038 RADIO-FREQUENCY EMISSION AND DIFFERENCES IN THE (Astronomicheskii Zhurnal, vol. 42, Mar. Apr. 1965, p. 390-397; Akademiia Nauk SSSR, Plenum Komissii po Fizike Planet Astrosoveta, Jan. 1964.) Soviet Astronomy, vol. 9, Sept. -Oct. 1965, p. 307-312. 14 refs. [For abstract see Accession no. A65-26229 15-30] A65-32411 WAVELENGTH DEPENDENCE OF POLARIZATION. IV - VOL CANIC CINDERS AND PARTICLES. David L. Coffeen (Arizona, University, Tucson, Ariz.). Astronomical Journal, vol. 70, Aug. 1965, p. 403-413. 10 refs. Navy-supported research. Measurement of five laboratory samples for comparison with the moon, using a Wollaston photopolarimeter with filters near 0.36, 0.53, and 0.97, having the sun as light source. Three of the samples were porous dust layers of ground volcanic cinder particles smaller than 37, in "fairy castle" structures. The other two were a porous but solid lava fragment, and the same fragment covered with a "fairy castle" dust layer made from the same lava. The solid lava fragment, more highly polarized than the moon, has essentially no wavelength-dependence. The wavelength- and phasedependence of the lunar polarization is closely matched by the "fairy castle" structures. No dependence of polarization on sample orientation was found for the volcanic materials. Differential photometry was done with the same filters using a smoked MgO layer as comparison. All samples show a linear brightness increase (in magnitudes) from 50 to 20° phase, similar to the moon. The "fairy castle" structures show an appreciable opposition effect in the UV which, however, almost disappears in the green and IR. F.R.L. A65-32576 # PHOTOELECTRIC OBSERVATION OF THE LUNAR ECLIPSE OF J. Bouška and P. Mayer (Charles University, Astronomical Astronomical Institutes of Czechoslovakia, Bulletin, vol. 16, no. 4, 1965, p. 252-254. 8 refs. Photoelectric measurements of the moon's surface taken during a total lunar eclipse in spectral region V. The densities determined in the penumbral shadow were practically the same as the theoretical ones; in the umbral shadow they were substantially larger than the calculated densities and reached a value of D = 5. 62 near mideclipse. (Author) R. A. F. Theo Suggestion that tektites were formed by a lunar ash flow. retical calculations of pressure, temperature, and voidage (fraction of the volume not occupied by solid matter) are made for the dense phase (bulk density 0. 5 to 1. 0 g/cm2) of an ash flow, assuming a steady state with the solid particles at rest, uniform temperature, and steady emission of gas from the solid matter. The problem reduces to an ordinary nonlinear differential equation of the first order; the solution is presented in nondimensional variables, together with homology relationships for the physical parameters. For a given model of internal structure, the required gas emissivity is found to vary directly with the square of the gravity. Above the dense phase, there may be a dilute phase consisting of gas with suspended particles, having a bulk density of 0. 12 g/cm3 or less. The dilute phase is relatively unimportant in terrestrial flows, but in a lunar ash flow it is likely to be the predominant mode of transport. It is found to be an isothermal pseudogas, with a scale height on the moon of a few hundred meters. This concept is consistent with the recent discoveries about the petrography of the Muong Nong tektites and the morphology of the maria. A65-32672 # ACOUSTIC SIMULATION OF LUNAR ECHOES. (Author) M. F. H. S. Hayre (Kansas State University of Agriculture and Applied Grants No. NsG-129-61; No. NsG-692. Use of nonlinear modeling techniques in an attempt to model acoustically the lunar surface and other rough surfaces on a set of 16. 7-cm-diam spun-aluminum spheres. Some of the largescale lunar surface roughness features were approximately modeled using reduced wavelength scale, and the small-scale roughness was modeled by random-sized sand particles on one sphere. To investigate which type of surface roughness would simulate the lunar return, various orders of roughness and four separations of the model moon and the transducers (4-μ sec pulse at 1. 02 Mc with PRF of 20) were used to obtain experimental data. These data were reduced to give such statistical information as range of fading. The mean power vs delay time was compared with Pettengill's experimental data and found to check well. The spatial autocovariance of the wrinkle-painted surface was found to be exponential as opposed vacuum are General description of the environment of space, considering vacuum and all other significant parameters, and detailed description of the vacuum environment. The two principal effects of surface effects and internal effects (such as fatigue) discussed, together with the fatigue strength of metals in vacuum. Historical work leading up to present work on crack propagation is reviewed. Surface effects, evaporation, vapor pressure, the Langmuir equation, embrittlement of plastics, lubrication, problems of friction and wear, metal-on-metal and steel-on-diamond tests, and bearing capacity of lunar surfaces are also examined. A65-33343 (Author) R. A. F. ROCK DEGRADATION BY ALKALI METALS A POSSIBLE LUNAR EROSION MECHANISM. J. J. Naughton, I. L. Barnes, and D. A. Hammond (Hawaii, Science, vol. 149, Aug. 6, 1965, p. 630-632. 12 refs. Observation of the evolution of vapors of alkali metals from rocks melted in the laboratory under ultrahigh-vacuum conditions. These metal vapors act to comminute polycrystalline rocks to their component minerals. The resultant powder is porous and loosely packed and its characteristics may be compatible with the lunar surface as revealed by the Ranger photographs. If meteorite impact or lunar volcanism has produced vaporization or areas of molten lava, alkali erosion may have given dust of this character in adjacent solid areas. (Author) M. F. A65-33346 # THE DIRECTIONAL RADIATIVE CHARACTERISTICS OF CONICAL American Institute of Aeronautics and Astronautics, Thermophysics Specialist Conference, Monterey, Calif., Sept. 13-15, 1965, Paper 65-669. 8 p. 17 refs. Members, $0.50; nonmembers, $1. 00. Analytical study of the directional absorptivity characteristics of conical cavities, undertaken in the conviction that conical cavities would provide a reasonable thermal model of the meteor craters or other cavities to be found on the surface of the moon. A beam of parallel radiation is taken as striking a right circular conical cavity at a given angle of incidence to the cone axis. The cone is assumed to have a diffusely reflecting surface and has a given cone angle. A straightforward Monte Carlo analysis of this case is used to determine the directional reflectivity of the cone. Parameters varied are the cone angle, surface absorptivity, and angle of incidence of the solar radiation. Comparison is made with the lunar characteristics. It is concluded that the directional reflectivity of a right circular cone with 30° cone angle and a surface absorptivity of 0.500 compares well with the experimental photometric results for the lunar surface. It is inferred that the lunar surface could have many cavities with steep walls, whose structure is larger than the wavelengths of visible light, but smaller than is visible to present earth-based or lunar-probe observations. It is pointed out that results for conical cavities with cone angles near those for observed lunar craters do not correlate with observed lunar photometric results, implying that these craters, even if of considerably smaller size than those observed to date, contribute little to the reflectivity characteristics of the moon in the visible portion of the spectrum. M. M. A65-34229 NEW YORK ACADEMY OF SCIENCES, CONFERENCE ON GEOLOGICAL PROBLEMS IN LUNAR RESEARCH, NEW YORK, N. Y., MAY 16-19, 1964. New York Academy of Sciences, Annals, vol. 123, July 15, 1965. 891 p. CONTENTS: I - INTRODUCTION AND HISTORICAL REVIEW. INTRODUCTORY REMARKS. James Q. Gant, Jr. (International Lunar Society, Washington, D. C.), p. 371, 372. HOOKES AND SPURRS IN SELENOLOGY. J. Green (North American Aviation, Inc., Downey, Calif.), p. 373-402. II VOLCANIC AND IMPACT MECHANISMS AND ORIGINS. TIDAL AND GRAVITY EFFECTS INTENSIFYING LUNAR DEFLUIDIZATION AND VOLCANISM, Jack Green (North American Aviation, Inc., Downey, Calif.), p. 403-469. 118 refs. [See A6534230 22-30] LUNAR DIFFERENTIATION PROCESSES. (NASA, Goddard Space Flight Center, Md.), p. [See A65-34231 22-30] Louis S. Walter 470-480. 12 refs. MELTING TEMPERATURE OF COMPLEX SILICATES. Emanuel Azmon (Northrop Corp., Hawthorne, Calif.), p. 481-494. 14 refs. [See A65-34232 22-30] A. PALEOVOLCANIC ORIGINS OF THE LUNAR SEAS. Dauvillier (Collège de France, Paris, France), p. 516-523. [See A65-34234 22-30] THE ORIGIN OF LUNAR CRATERS. N. Boneff (Sophia, University, Sophia, Bulgaria), p. 524, 525. CONVECTIVE ORIGIN OF LUNAR CRATERS. H. Tazieff (Institute of Volcanology, Paris, France), p. 526, 527. [See A6534235 22-30] PROOF OF THE VOLCANIC ORIGIN OF MOST LUNAR CRATERS AND OF TECTONIC MARIA. Kurd von Bülow (Rostock, University, Rostock, Germany), p. 528-531. BALANCE OF ENDOGENIC TO EXOGENIC ENERGY IN THE CRUST OF THE MOON. Robert Enzmann (Avco Corp., Wilmington, Mass.), p. 532-542. 22 refs. [See A65-34236 22-30] THE ORIGIN OF LUNAR FEATURES. Ralph B. Baldwin (Oliver Machinery Co., Grand Rapids, Mich.), p. 543-546. [See A65-34237 22-30] CRATER FREQUENCY EVIDENCE FOR VOLCANISM IN THE LUNAR HIGHLANDS. Robert T. Dodd, Jr., Vern G. Smalley, John W. Salisbury, and Joel E. M. Adler (USAF, Office of Aerospace Research, Bedford, Mass.), p. 555-561; Discussion, A. Marcus (California, University, Berkeley, Calif.), p. 561, 562. [See A65-34238 22-30] GRAVITATIVE EFFECTS ON LUNAR IMPACT STRUCTURES. William L. Quaide, Donald E. Gault, and Richard A. Schmidt (NASA, Ames Research Center, Moffett Field, Calif.), p. 561, 562. 10 refs. [See A65-34239 22-30] A COMPARISON OF FEATURES CHARACTERISTIC OF NUCLEAR EXPLOSION CRATERS AND ASTROBLEMES. Nicholas M. Short (California, University, Livermore, Calif.), p. 573-616. 30 refs. [See A65-34240 22-30] LUNAR AND TERRESTRIAL STRUCTURAL MODELS ON A COMMON SPHERE. B. B. Brock (Anglo American Corporation of South Africa, Ltd., Johannesburg, Republic of South Africa), p. 617-630. [See A65-34241 22-30] EARTH AND MOON - TECTONICALLY CONTRASTING REALMS. Robert S. Dietz and John C. Holden (U. S. Coast and Geodetic Survey, Washington, D. C.), p. 631-640; Discussion, G. J. H. McCall (Western Australia, University, Perth, Australia), P. 640. 15 refs. [See A65-34242 22-30] PRINCIPAL STRUCTURAL ELEMENTS OF THE MOON AND THE SIGNIFICANCE OF THE GEOGRAPHIC-GEOLOGICAL AP PROACH. Iu. A. Khodak, p. 641-655. 76 refs. [See A65-34243 22-30] IV SURFACE PROPERTIES AND RADIATION EFFECTS. THERMAL PROPERTIES OF POSTULATED LUNAR SURFACE MATERIALS, P. E. Glaser, A. E. Wechsler, and A. E. Germeles (Arthur D. Little, Inc., Cambridge, Mass.), p. 656-670. 44 refs. [See A65-34244 22-30] THE CASE FOR A COHESIVE LUNAR SURFACE MODEL. J. D. Halajian (Grumman Aircraft Engineering Corp., Bethpage, N. Y.), p. 671-710; Discussion, B. W. Hapke (Cornell University, Ithaca, N. Y.), p. 710. 37 refs. [See A65-34245 22-30] EFFECTS OF A SIMULATED SOLAR WIND ON THE PHOTOMETRIC PROPERTIES OF ROCKS AND POWDERS. Bruce Hapke (Cornell University, Ithaca, N. Y.), p. 711-721. 17 refs. [See A65-34246 22-29] RADIOMETRIC AND PHOTOMETRIC MAPPING OF THE MOON THROUGH A LUNATION. Richard W. Shorthill and John M. Saari (Boeing Co., Seattle, Wash.), p. 722-739. 12 refs. [See A6534247 22-30] SOME RESULTS OF PHOTOMETRIC AND COLORIMETRIC COMPARISON OF TERRESTRIAL VOLCANIC CRUSTS WITH THE LUNAR SURFACE. V. V. Sharonov, p. 740-750. 7 refs. [See A65-34248 22-30] V LUNAR SURFACE FEATURES AND CHANGES. VI LUNAR AND TERRESTRIAL ANALOGS. RHYOLITE ASH-FLOW PLATEAUS, RING-DIKE COMPLEXES, CALDERAS, LOPOLITHS, AND MOON CRATERS. Wolfgang E. Elston (New Mexico, University, Albuquerque, N. Mex.), p. 817842. 84 refs. [See A65-34255 22-30] THE CALDERA ANALOGY IN SELENOLOGY. G. J. H. McCall (Western Australia, University, Perth, Australia), p. 843-875. 47 refs. [See A65-34256 22-30] TECTONIC AND PETROGRAPHIC OBSERVATIONS ON POLYGONAL STRUCTURES IN MISSOURI. G. C. Amstutz (Missouri, University, Rolla, Mo.), p. 876-894. ASTROBLEMES, LUNAR CRATERS, AND MARIA, Robert S. Dietz (U. S. Coast and Geodetic Survey, Washington, D. C.), p. 895, 896. [See A65-34257 22-30] THE LARGEST SO-CALLED METEORITE SCARS IN THREE CONTINENTS AS DEMONSTRABLY TIED TO MAJOR TERRESTRIAL STRUCTURES. Walter H. Bucher, p. 897-903. [See A65-34258 22-30] THE IDENTIFICATION OF ANCIENT CRATERS. C. S. Beals (Department of Mines and Technical Surveys, Ottawa, Ontario, Canada), p. 904-914. ANALOGUES OF LUNAR CRATERS ON THE CANADIAN SHIELD. K. L. Currie (Geological Survey of Canada, Ottawa, Canada), p. 915-940. 33 refs. [See A65-34259 22-30] THE EXTRATERRESTRIAL ORIGIN OF CANADIAN CRATERS. M. R. Dence (Dominion Observatories, Ottawa, Canada), p. 941969. 39 refs. [See A65-34260 22-13] POSSIBLE METEORITE CRATERS - WOLF CREEK, AUSTRALIA AND ANALOGS. G. J. H. McCall (Western Australia, University, Perth, Australia), p. 970-998. 39 refs. [See A6534261 22-13] INTERPRETATION OF RANGER VII PHOTOGRAPHS. Jack Green (North American Aviation, Inc., Downey, Calif.), p. 9991002. [See A65-34262 22-30] VII SHATTER CONING. POSSIBLE SHATTER CONES IN A VOLCANIC VENT NEAR ALBUQUERQUE, NEW MEXICO. Wolfgang E. Elston and Paul Wayne Lambert (New Mexico, University, Albuquerque, N. Mex.), p. 1003-1016. 20 refs. [See A65-34263 22-13] THE ORIENTATION AND ORIGIN OF SHATTER CONES IN THE VREDEFORT RING. W. I. Manton (Witwatersrand, University, Johannesburg, Republic of South Africa), P. 1017-1048; Discussion, B. B. Brock (Anglo American Corporation of South Africa, Ltd., Johannesburg, Republic of South Africa), p. 1048, 1049. 29 refs. [See A65-34264 22-13] A MORPHOLOGICAL COMPARISON OF DIAGENETIC CONEIN-CONE STRUCTURES AND SHATTER CONES. G. C. Amstutz (Missouri, University, Rolla, Mo.), p. 1050-1056. 14 refs. [See A65-34265 22-13] TEKTITE ORIGIN. DISCUSSION ORIGIN OF TEKTITES FROM THE MOON. Green (North American Aviation, Inc., Downey, Calif.), p. 1057. ON THE COSMIC ORIGIN OF TEKTITES. Alexandre Dauvillier (Collège de France, Paris, France), p. 1058-1060. 7 refs. [See A65-34266 22-30] THE LUNAR ORIGIN OF TEKTITES. J. J. Gilvarry (General Dynamics Corp., San Diego, Calif.), p. 1061-1081. 71 refs. [See A65-34267 22-30] ASPECTS OF LUNAR SULFUR TECHNOLOGY. Marion D. THE CAST BASALT INDUSTRY. Lubomir Kopecky (Geological SELECTION OF ROCK STANDARDS FOR LUNAR RESEARCH. Jack Green (North American Aviation, Inc., Downey, Calif.), p. 1123-1147. 9 refs. [See A65-34270 22-30] INVESTIGATION OF WATER EXTRACTION PROCESSES FOR USE ON THE MOON. A. E. Wechsler, P. E. Glaser, and A. E. Germeles (Arthur D. Little, Inc., Cambridge, Mass.), p. 11481159. 19 refs. [See A65-34271 22-05] X - GEOPHYSICAL PROGRAMS. USE OF GEOPHYSICAL MEASUREMENTS IN LUNAR SURFACE ANALYSIS. Richard A. Geyer and Jack R. Van Lopik (Texas Instruments, Inc., Dallas, Tex.), p. 1160-1174. 9 refs. [See A6534272 22-30] AEROMAGNETIC SURVEY OF METEOR CRATER, ARIZONA. Roy G. Breereton (California Institute of Technology, Pasadena, Calif.), p. 1175-1181. 13 refs. [See A65-34273 22-13] MAGNETIC RECONNAISSANCE OF SIERRA MADERA, TEXAS, AND NEARBY IGNEOUS INTRUSIONS. Paul D. Lowman, Jr. (NASA, Goddard Space Flight Center, Md.), p. 1182-1197. 18 refs. [See A65-34274 22-13] LUNAR EXPLORATION FROM ORBITAL ALTITUDES. Peter C. Badgley (NASA, Ames Research Center, Moffett Field, Calif.), p. 1198-1219. 14 refs. [See A65-34275 22-30] PROGRESS IN SELENODESY. Mahlon S. Hunt (USAF, Office of Aerospace Research, Bedford, Mass.), p. 1220-1235. 18 refs. [See A65-34276 22-30] SUMMARY, p. 1236-1257. A65-34230 TIDAL AND GRAVITY EFFECTS INTENSIFYING LUNAR DEFLUIDIZATION AND VOLCANISM. Jack Green (North American Aviation, Inc., Space and Information Systems Div., Space Sciences Laboratory, Downey, Calif.). (New York Academy of Sciences, Conference on Geological Problems in Lunar Research, New York, N. Y., May 16-19, 1964, Paper.) New York Academy of Sciences, Annals, vol. 123, July 15, 1965, p. 403-469. 118 refs. Survey of the evidence to date supporting a defense of defluidization as a generally operative terrestrial and lunar process. Defluidization is defined as the release of fluids from the interior of a cosmic body at any given rate or place, manifesting itself by intrusive activity and volcanism. The differences in time and place that could make the moon more susceptible to outgassing are taken into account. Tidal effects, thermal considerations, gravitative effects, mantle-volume-to-surface-area relationships, defluidization products and sequence of escape, luminescence, and the surface morphology supporting defluidization are discussed. The significant differences that exist between the earth and the moon that would enhance lunar defluidization, and a comparison of the defluidization versus impact models are summarized point by point. De fluidization is thought to be a generally operative cosmogonic process which was intensified on the moon because of tidal, gravity, and vacuum effects; furthermore, meteoritic impact is considered to be a trivial process in affecting both the genesis and development of almost all major lunar surface structures. Two appendices are included; they contain expressions for calculating lunar body tides raised by the earth and a summary of reports of lunar surface changes. Theoretical study of the processes of igneous rock differentiation as applied to the moon. Four major assumptions form the basis of the study: (1) the increase in lithospheric pressure as a function of depth is less for the moon than the earth; (2) the moon has been hot enough, at some time in its history and at least locally, to melt the silicate material of which it is composed; (3) although local at any one time, this melting has taken place in most areas of the upper part of the moon, so that presently there are few places that have escaped igneous activity since the moon was formed; and (4) because of the ubiquitous nature of the melting and the gravitative attraction of the moon, the moon's rocks have lost much of the material, which at standard temperature and pressure are considered volatile (particularly water and oxygen). The assumptions are discussed in the light of effects of total pressure and water and oxygen deficiencies. It is concluded that igneous activity has differentiated a lunar crust (if it did not at the time of the moon's formation) and that such differentiation also served to concentrate the radioisotopes in the more acidic crustal fraction tending to increase the amount of volcanic activity at the surface and further degassing and dehydrating the superficial rocks. However, loss of water is considered to have the opposite effect. M. L. A65-34232 MELTING TEMPERATURE OF COMPLEX SILICATES. (New York Academy of Sciences, Conference on Geological Problems Experimental study of the melting of complex silicates, related to research on lunar geology. The melting point of dunite, a rock composed of some of the highest melting rock-forming minerals (mostly SiO2 and MgO), is investigated as a function of time pressure. It is found that dunite melts instantaneously above 1750°C, under the pressure proposed to exist within the moon's core (47 kbars), but that melting could also occur if a lower temperature were maintained for a longer time. Several theories of the moon's composition are briefly discussed, including Kuiper's, Urey's and Hoyle's. It is shown that volcanic melting of dunite may be expected to occur several hundred degrees centigrade below impact melting. M. L. A65-34233 BEHAVIOR OF LAVA ON THE LUNAR SURFACE. Walter I. Dobar (Bendix Corp., Systems Div., Ann Arbor, Mich.). (New York Academy of Sciences, Conference on Geological Problems in Lunar Research, New York, N. Y., May 16-19, 1964, Paper.) New York Academy of Sciences, Annals, vol. 123, July 15, 1965, p. 495-515. 26 refs. Experimental investigation of a simulated magma in vacuum and a determination of selected physical properties of terrestrial rocks in a simulated lunar environment. Samples of molten silica, basalt, and granite, allowed to upwell and solidify in vacuum, are shown to yield photometric curves closely resembling the mean lunar curve. During the vacuum upwelling, such samples produced color changes resembling those recently observed on the lunar surface (the Aristarchus event). A brief review of the study's results as compared with published reports defining the nature of is presented, and it is emphasized that many of these reports are based on material forming under atmospheric pressure, unlike the moon. It is concluded that the results tend to indicate that lava is present on the lunar surface and that earth-moon correlations can be made if the physical properties of the materials are determined in similar environments. M. L. the lunar surface (New York Academy of Sciences, Conference on Geological Problems in Lunar Research, New York, N. Y., May 16-19, 1964, Paper.) New York Academy of Sciences, Annals, vol. 123, July 15, 1965, p. 526, 527. Brief summary of the arguments in favor of the convective origin of large lunar craters. It is pointed out that the only acceptable mechanism that simultaneously accounts for (1) the polygonal shape of the large craters, (2) their flat bottom, (3) their juxtaposition, (4) the fact of a non-overlap of a larger crater over a smaller one, and (5) the presence of a single peak in many craters is that convection currents occurred in the outer layer of the moon prior to its solidification. Thus, it is concluded, the craters are in fact convection cells, the size of which had been decreasing with time. A65-34236 M. L. BALANCE OF ENDOGENIC TO EXOGENIC ENERGY IN THE CRUST OF THE MOON. Robert Enzmann (Avco Corp., Research and Advanced Development Div., Wilmington, Mass.). (New York Academy of Sciences, Conference on Geological Problems in Lunar Research, New York, N. Y., May 16-19, 1964, Paper.) New York Academy of Sciences, Annals, vol. 123, July 15, 1965, p. 532-542. 22 refs. Theoretical investigation of the balance of endogenic to exogenic energy in the moon's crust. Nine orders of geomorphic features are proposed, in parallel, for the earth and moon, and a table listing the features of the proposed geomorphic orders, and suggestions for the energies and forces tending to create, maintain, and destroy them, is given. It is pointed out that on the earth, attrition of objects the size of sand grains is dominated by transport mechanisms, but that on the moon, transport mechanisms are weaker or absent. It is thought conceivable that attractive forces may dominate objects as large as sand grains. A65-34237 THE ORIGIN OF LUNAR FEATURES. M. L. Ralph B. Baldwin (Oliver Machinery Co., Grand Rapids, Mich.). (New York Academy of Sciences, Conference on Geological Problems in Lunar Research, New York, N. Y., May 16-19, 1964, Paper.) New York Academy of Sciences, Annals, vol. 123, July 15, 1965, p. 543-546. Brief summary of the arguments for a meteoritic-impact theory of the origin of lunar craters. While evidence supporting the presence of igneous activity on the moon is considered strong, it is argued that meteoritic impact must also be a very likely process on the moon. The major evidences cited are statistical analyses of crater dimensions as functions of size; in particular, the relationship between rim-to-rim diameter and rim-to-bottom depth, expressed on a log-log scale as a simple quadratic that is equally valid for tiny, explosive craters on earth, through terrestrialmeteoritic-crater range, and up to the large lunar craters. diameter-vs-rim-height curve and the rim-width-vs-diameter relationship are also noted. It is concluded that both the volcanic and impact processes are necessary to explain the lunar surface features. A65-34238 CRATER FREQUENCY EVIDENCE FOR VOLCANISM IN THE LUNAR HIGHLANDS. The M. L. Robert T. Dodd, Jr., Vern G. Smalley, John W. Salisbury, and Joel E. M. Adler (USAF, Office of Aerospace Research, Cambridge Research Laboratories, Bedford, Mass.). (New York Academy of Sciences, Conference on Geological Problems in Lunar Research, New York, N. Y., May 16-19, 1964, Paper.) New York Academy of Sciences, Annals, vol. 123, July 15, 1965, p. 555-561; Discussion, A. Marcus (California, University, Berkeley, Calif.), p. 561, 562. Consideration of the possibility that cratering might be interrupted by deposition of a thick blanket of material, as part of a continuing statistical study of the crater frequency in the lunar highlands. The surface area considered lies in the Cratered Plain Province. Details of the crater measurements are presented. Results are obtained by submitting the data to a least-squares fit, using an IBM 7090. The plotted frequency-diameter data are found to suggest two curves of the form F = AD+B, intersecting at a diameter in the vicinity of 10 to 20 km. It is concluded that the simple relationship between crater diameter and frequency for the mare surfaces deteriorates in the highlands where, evidently, several processes have been at work. It is noted that there is a complexity in the geologic history of these areas that is not generally appreciated. The criteria by which the boundaries of the Cratered Plain Province were determined are outlined. A65-34239 GRAVITATIVE EFFECTS ON LUNAR IMPACT STRUCTURES. William L. Quaide, Donald E. Gault, and Richard A. Schmidt (NASA, Ames Research Center, Space Sciences Div., Moffett Field, Calif.). M. L. (New York Academy of Sciences, Conference on Geological Problems in Lunar Research, New York, N. Y., May 16-19, 1964, Paper.) New York Academy of Sciences, Annals, vol. 123, July 15, 1965, p. 563-572. 10 refs. Study of the relationship between crater morphology and dimension. It is considered that any explanation must be based on a probable mode of origin of the craters. It is shown that although the lunar cratering rate is considerable, in view of the moon's age, the rate is not reliable enough to account for all the lunar craters, but it is assumed that most of the craters have had their origins in hypervelocity impacts. The radii of 169 selected young lunar craters are considered, and several cratering mechanisms are discussed: (1) large craters (diameters more than 10 km) are produced mostly by cometary impact, and smaller craters by dense projectiles; (2) all craters produced by dense projectiles; and (3) postcratering events have modified crater shapes, in particular, isostatic rebound, gravitative effects, and impact-triggered volcanism. It is concluded that if large craters are assumed to originate by hypervelocity impact, then one process that can account for most of their observed features is gravity sliding, probably along ring fractures produced during impact. A major implication of this conclusion is noted - namely, that it is not possible to determine the mass of the cratering projectile from diameter-depth relations of large lunar craters. A65-34241 LUNAR AND TERRESTRIAL STRUCTURAL MODELS ON A COMMON SPHERE. M. L. B. B. Brock (Anglo American Corporation of South Africa, Ltd., (New York Academy of Sciences, Conference on Geological Problems Theoretical comparison of lunar and terrestrial surface features, by means of a transparent, plastic dome used to study the repetitive patterns on a geological globe. In addition to the dome, earth and moon globes of identical size are used. The nautical manner of distance measurement, in terms of angle of arc subtended at the center of the sphere, is used because it is applicable to any heavenly body and allows a comparison of those structural patterns which, it is believed, are a function of the body itself. It is tentatively concluded that the coarser tectonic patterns of the earth and moon |