WORKSHOP ON MOON IN TRANSITION: APOLLO 14, KREEP, AND EVOLVED LUNAR ROCKS (NASA-CR-I"'-- N90-I_02o rRAN31TION: APJLLN l_p KRFEP, ANu _VOLVFD LUNAR ROCKS (Lunar and Pl_net3ry !nst.) I_7 p C_CL O3B Unclas G3/91 0253133 LPI Technical Report Number 89-03 UNAR AND PLANETARY INSTITUTE 3303 NASA ROAD 1 HOUSTON, TEXAS 77058-4399 7 WORKSHOP ON MOON IN TRANSITION: APOLLO 14, KREEP, AND EVOLVED LUNAR ROCKS Edited by G. J. Taylor and P. H. Warren Sponsored by Lunar and Planetary Institute NASA Johnson Space Center November 14-16, 1988 Houston, Texas Lunar and Planetary Institute 330 ?_NASA Road 1 Houston, Texas 77058-4399 LPI Technical Report Number 89-03 Compiled in 1989 by the LUNAR AND PLANETARY INSTITUTE The Institute is operated by Universities Space Research Association under Contract NASW-4066 with the National Aeronautics and Space Administration. Material in this document may be copied without restraint for Library, abstract service, educational, or personal research purposes; however, republication of any portion requires the written permission of the authors as well as appropriate acknowledgment of this publication. This report may be cited as: Taylor G. J. and Warren PI H., eds. (1989) Workshop on Moon in Transition: Apo{l_ 14 KREEP, and Evolved Lunar Rocks. [PI Tech. Rpt. 89-03. Lunar and Planetary Institute, Houston. 156 pp. Papers in this report may be cited as: Author A. A. (1989) Title of paper. In W_nkshop on Moon in Transition: Ap_llo 14, KREEP, and Evolved Lunar Rocks (G. J. Taylor and P. H. Warren, eds.), pp. xx-yy. LPI Tech. Rpt. 89-03. Lunar and Planetary Institute, Houston. This report is distributed by: ORDER DEPARTMENT Lunar and Planetary Institute 330 3 NASA Road 1 Houston, TX 77058-4 399 Mail or&r requestors will he inv_,iced f, r the c,,st ,_f shipping and handling. ¢.?_l,_.rpMt,: A n,_rth-I,,+,king.,_bliqucvieu, 'tl ttlc re_i.n sum,m_dingthe Ap,,tl, ;4 tmidin.e,sit<'.The lm_<tingsite is ab,,la ¢_00I_m_<,_th _,t the Imbrium Msm, uiiich is lust l,c'.',,mlthe hori'am The t,lrgc cr<ueruc<t_Ihc <enter is Fra Maur,. 95 km i,I di,m,ctci NASA I,h,,t,, lumlherASI6.1420M Contents Preface 1 Program Summary of Technical Sessions 7 Abstracts 21 Where is the KREEP? P. E. Clark 23 Pink Spanel Troctolites in Apollo 14 Breccias D. T. Collins and A. M. Reid 26 The Problem of Lunar Initial Pb W. Comps,m, I. S. Williams, and C. Meyer 29 Apollo 14 Pristine Mare Glasses J. W. Delano, S. S. Hughes and R A. Schmitt 34 Geologic and Bombardment History of the Apollo 14 Region B. R. Hawke 38 Highly Ew_lved Liquids from the Fractionation of Mare and Nonmare Basalts P. C. Hess 46 Compositional Survey of 2-4 mm Particles from 14161 and Implications Regarding KREEP and Igneous Components in Apollo 14 Soil B. L. jolliff, R. L Korotev, and L A. Haskin 53 Fra Mauro Formation, Apollo 14: I. Composition and Frequency Distribution of Igneous and Impact Metamorphic Rocks S. Lingner, K. D. Bob< H. Palm< B. Spettel, D. St(;ffler, and H. Wdnke 58 Fra Mauro Formation, Apollo 14: III. Calculated Composition of the Primordial Lunar Crust in the Imbrium Region S. Lingner, B. Spettel, and D. St_'iffler 62 The Petrogenesis of Ew_lved Pristine Rocks J. Iamghi 66 Telescopic Thermal Infrared Measurements of the Mineralogy of Suspected Lunar Silicic Regions: Red Spots Are Not Granite P. G. Lucey and B. R. Hawke 71 Zircon-containing Rock Fragments Within Apollo 14 Breccia Indicate Serial Magmatism from 4 350 to 4000 Million Years (7. Meyer, I. S. Williams, and V_ Compston 75 Silicate Liquid Immiscibility and Crystal Fractionation in a Highly Evolved, KREEPy Magma R. W. Morris, G. J. Taylor, H. E. Newsom, and S. R. Garcia 79 Apollo14BasaltPetrogenesis:GenerationfromanOlivine-OPXDominatedMantle,FollowedbyCrustal AssimilationandFractionalCrystallization C. R. Neal and L. A. Taylor 82 Lunar Granite Petrogenesis and the Process of Silicate Liquid Immiscibility: The Barium Problem C. R Neal and L. A. Tayl_rr 89 The Splitting of KREEP into Identifiable Components: The "K-Frac" and "REEP-Frac" Hypothesis C. R. Neal and L. A. Tayl_rr 94 Elemental Abundances Around Apollo 14 and Other Selected Lunar Regions from the Apollo Gamma-Ray Spectrometer Experiment R. C. Reedy 100 Understanding Lunar Mantle Metasomatism: The Terrestrial Mantle Analogy W. I. Ridley, J. E. Nietson, and H. G. Wilshire 105 The Absence of a Heavy Eslrly Lunar Bombardment, the Prescence of a 3.85 Ga Cataclysm, and the Geological Context of Apollo 14 Rock Samples G. Ryder 107 Lunar Crustal Strength and the Large Basin-KREEPConnection H. H. Schmitt 111 An lon Microprobe Study of Trace Elements in Apollo 14 "Volcanic" Glass Beads and Comparisons to Mare Basalts G. K. Shearer, J. J. Pap&< S. B. Simon, N. Shimizu, H. Hurimoto, ,rod S. Sueno 113 Highland Crust at the Apollo 14 Site: A Review J. W. Shervais 118 Isotopic Constraints on the Petrogenesis of Apollo 14 Igneous Rocks C.-Y. Shih and L. E. Nyquist 128 Fra Mauro Formation, Apollo 14: II. 4°Ar-19 Ar Ages of Apollo 14 Rocks F. J. Stadermann, E. Heusser, and E. K. Jessberger 1_7 Brecciated Nature of the Apollo 14 Lunar Sample Suite: A Review D. St(frier 138 Fra Mauro Formation, Ap_llo 14: IV. Synopsis and Synthesis of Consortium Studies D. Stdffler, K. D. Bob< E. K. Jessberger, S. Lingner, H Palme, B. Spettel, F. Stadermann, and H. Wa'nke 145 KREEP: Major-Element Diversity, Trace-Element Uniformity (Ahnost) P. H. Warren 149 List of Workshop Participants 155 Preface This report documents the "Workshop on Moon in Transition: Apollo 14, KREEP, and Evolved Lunar Rocks," held at the Lunar and Planctary Institute on November 14-16, 1988. This workshop was one of a series of meetings organized by the Lunar and Plane- tary Sample Team (LAPST) to spur progress on various specialized topics of lunar and planetary science. The samples from Apollo I4, i.e., the Fra Mauro highlands, are entirely unlike those acquired from any other lunar site. Evolved rock types such as KREEP, alkali anorthosite, and granite are relatively abundant, and alkali-poor or ferroan anorthosite (widely suspected to be the most common type of pristine rock in the crust as a whole) is nearly absent. A subordi- nate but still abundant rock type at the site is mare basalt, the sam- ples of which also exhibit many distinctive traits. Efforts to unravel the history of the region have been complicated by the thoroughly brecciated nature of the rock samples, but recent years have seen much work aimed at isolating individual clasts within the breccias. Mare glasses from regolith samples are also targets of considerable ongoing research. The purpose of this workshop was to utilize the latest constraints for a new evaluation of the history of the Fra Mauro highlands, a new evaluation of the nature and history of KREEP, granite, and other evolved lunar rock types, and ultimately a fresh evaluation of the transition of the Moon from its early anorthosite-forming (magma ocean?) period to its later stages of KREEPy, granitic, and mare magmatism. The Organizing Committee appointed by LAPST consisted of G. Jeffrey Taylor, University of New Mexico, and Paul H. Warren, University of California, Los Angeles, chairmen; B. Ray Hawke, University of Hawaii; Graham Ryder, Lunar and Planetary Institute; Paul Spudis, U.S. Geological Survey, Flagstaff; and Lawrence A. Taylor, University of Tennessee. Logistics and administrative sup- port were provided by the Projects Office of the Lunar and Plane- tary Institute--we are deeply grateful to Pam Jones, LeBecca Turner, and their coworkers for their usual diligent and efficient organizational work. G. Jeffrey Taylor and Paul H. Warren ,2 ' Program Monday Morning, November 14, 1988 8:00 a.m. Registration 9:00 a.m. Introduction to Workshop: G J. Taylor and P. ft. Warren Topic 1 - REGIONAL GEOLOGY AND THE ROLE OF IMPACTS Chairman: P. Spudis Summarizer: B. R. Hawke Geological and Bombardment History of the Apollo 14 Region B. R. Hawke Telescopic Measurements of SiO2 Abundances of Suspected Lunar Silicic Regions: Red Spots Are Not Granite P. Lucey and F;. R. Hawke Elemental Abundances Around Apollo 14 and Other Selected Lunar Regions from the Apollo Gamma-Ray Spectrometer Experiment R. Reedy Where is the KREEP? P. E. Clark The Absence of a Heavy Early Lunar Bombardment, the Presence of a 3.85 Ga Cataclysm, and the Geological Content of Apollo 14 Rock Samples G. Ryder Monday Afternoon, November 14, 1988 Topic 2 - BRECCIATED NATURE OF THE APOLLO 14 SUITE Chairman: W. C. Phinney Summarizer: O. B. James Brecciatcd Nature of the Apolh, 14 Suite t). Sff;ffler 4°At - _'_Ar Ages of Apollo 14 Rocks F. J. Suldermann, E. Heusser, and E. K. Jessberger Fra Mauro Formation, Apollo 14: I. Composition and Frequency Distribution of Igneous and hnpact Metamorphic Rocks S. Lingner, K. Bob< H. Palme, B. Speuel, D. Su';ffler, and H Wa'nke Fra Mauro Formation, Apollo 14: Ill. Calculated Composition of the Primordial Lunar Crust in the Imbrium Region S. LiTwwr, B. Speuel, and D. Stg;ffler Fra Mauro Formation, Apollo 14: IV, Synopsis and Synthesis of Consortium Studies D. St(;ffler, K. Bob< E. K. Jessberger, S. I.ingner, H. Palme, B. Speuel, F. Su_dermann, and H. Wiinke Topic 3 - WHAT IS KREEP? Chairman: G. J. Taylor Summarizer: P. H. Warren KREEP: Major-Element Diversity, Trace-Element Uniformily (Almost) P. ft. Wanen High[,,' Ew_lved Liquids from the Fractionation of Mare and Nonmare Basalts P. C. Hess PRECEDING PAGE BLANK NOT FILMED P,Nit. _ r _'_' _' __U_L' _ 4 _qrrkshop on Moon in Transiri.n The Splitting of KREEP into Identifiable Components: The "K-Frac" and "REEP-FRAC" Hypothesis C.