EVALUATION OF THE GEOLOGIC RELATIONS AND SEISMOTECTONIC STABILITY OF THE YUCCA MOUNTAIN AREA NEVADA NUCLEAR WASTE SITE INVESTIGATION (NNWSI) PROGRESS REPORT 30 SEPTEMBER 1995 CENTER FOR NEOTECTONIC STUDIES MACKAY SCHOOL OF MINES UNIVERSITY OF NEVADA, RENO DISTRIBUTION OF ?H!S DOCUMENT IS UKLMTED DISCLAIMER Portions of this document may be illegible in electronic image products. Images are produced from the best available original document CONTENTS SECTION I. General Task Steven G. Wesnousky SECTION II. Task 1: Quaternary Tectonics John W. Bell Craig M. dePolo SECTION III. Task 3: Mineral Deposits Volcanic Geology Steven I. Weiss Donald C. Noble Lawrence T. Larson SECTION IV. Task 4: Seismology James N. Brune Abdolrasool Anooshehpoor SECTION V. Task 5: Tectonics Richard A. Schweickert Mary M. Lahren SECTION VI. Task 8: Basinal Studies Patricia H. Cashman James H. Trexler, Jr. DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsi- bility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Refer- ence herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recom- mendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. o SECTION I O o Annual Progress Report-—General Task Prepared by Steven G. Wesnousky October 1,1994 to September 30,1995 Introduction This report provides a summary of progress for the project "Evaluation of the Geologic Relations and Seismotectonic Stability of the Yucca Mountain Area, Nevada Nuclear Waste Site Investigation (NNWSI)." A similar report was previously provided for the period of 1 October 1993 to 30 September 1994. The report initially covers the activities of the General Task and is followed by sections that describe the progress of the other ongoing Tasks which are listed below. Task 1: Quaternary Tectonics Task 3: Mineral Deposits, Volcanic Geology Task 4: Seismology Task 5: Tectonics Task 8: Basinal Studies General Task Staff Steven G. Wesnousky, Project Director, Nina G. Krob, Administrative Assistant Administrative Activities The General Task continued the (1) coordination and oversight of the research of Tasks 1,3,5, and 8, the (2) oversight of budgets and (3) the collation and preparation of required monthly reports. As well, Dr. Wesnousky has continued to represent NWPO at meetings with the National Academy of Sciences, the Nuclear Regulatory Commission, and the Department of Energy. Steven G. Wesnousky attended the following meetings and provided the following seminars for NWPO: January 26,1994, NRC/DOE Technical Exchange on Seismic Hazard Assessment and Seismic Design, Las Vegas, NV February 2-5,1995, NWPO field trip to examine faults in the Yucca block, precarious rocks, and the Rock Valley fault May 5-6,1995, Examine Crater Flat and Rock Valley Trenches. May 16-17,1995, NRC-DOE technical exchange atFOC, Yucca Mountain. June 15,1995, Technical Contractors Meeting at Carson City. 0.1 Technical Activities Projects Completed: Scaling Laws relating earthquake size, fault slip rate, and earthquake magnitude: This project was implemented in the preceding fiscal year, completed during this fiscal year, and submitted and accepted for publication this fiscal year. Estimation of the size of expected earthquakes along mapped faults is generally determined from empirically derived relationships between fault length and seismic moment or magnitude for historical earthquakes. There are numerous of these compilations, including a most recent by Wells and Coppersmith (BSSA, v.84,974-1003,1994). Many of these compilations and resulting regressions of earthquake size versus fault length tend to ignore an observation that has been in the seismological literature for some time, which is that the relationship of earthquake size versus rupture length in earthquakes is a function of the repeat time or fault slip rate on which the earthquake occurs (e.g. Scholz et al, BSSA, v. 76,65-70,1986; Kanamori and Allen, in Earthquake Source Mechanics, v. 6, 1985; Wesnousky, JGR, v. 91, 12,587-12,631, 1986). We show that slow slipping faults will generally produce a larger moment- magnitude earthquake man a faster slipping fault, by as much as .3 to .4 magnitude units when considering faults slipping at .01 to 10 mm/yr, respectively. Earthquake Frequency Statistics: Whether or not seismicity on a particular fault satisfies the Gutenberg-Richter or characteristic earthquake distribution is important to seismic hazard analysis at Yucca Mountain. Study of the question is hampered by limited historical, geological, and instrumental data. We initially used a well-defined data set in southern California and extended the research to a global data set of faults to empirically examine the question. The results are published or now in press in Wesnousky (1994), Stirling et al, (1995), and Wesnousky (1995). Meetings and Abstracts: 1994 AGU Annual Fall Meeting, San Francisco, CA Adams, K. D. and S. G. Wesnousky, Isostatic Rebound of the Pluvial Lake Lahontan Basin, Nevada and California: Progress Report, EOS supplement, Nov 1,1994, p.581. Kumamoto, T. and S. G. Wesnousky, Review of Japanese Paleoearthquake Data: Observations Bearing on the Characteristic of Earthquake Recurrence along Japanese Intraplate Faults, EOS supplement, Nov 1,1994, p. 452. Stirling, M., S. G. Wesnousky, and K. Shimazaki, Fault Trace Complexity, Cumulative Slip and the Shape of the Magnitude- Frequency Distribution fort Strike-Slip Faults: A Global Survey, EOS supplement, Nov 1,1994, p. 437. 1995 SSA Annual Meeting, El Paso, TX 0.2 Anderson, J. G., S. G. Wesnousky, M. W. Stirling, M. P. Sleeman, and T. Kumamoto, Regressions for Magnitude of Earthquakes incorporating fault slip rate as an independent parameter. 1995 Cordilleran Section of the Geological Society of America, Boise, Idaho. Adams, K. D., and S. G. Wesnousky, The age and synchroneity of the Highest Lake Lahontan Shoreline Features, Northwestern Nevada and Northeastern California. 1995 Int. Union. Quaternary Research (INQUA), 14th Congress, Aug 3-10, Berlin, 1995 Johnson, D. L., S. G. Wesnousky, and L. Abbott, Rapid, time-constrained pedogenesis and diagenesis following natural (1811-12 Earthquakes) and human-caused (1916 Watertable lowering) events, New Madrid Seismic Zone, Midcontinental USA. Wesnousky, S. G., Johnson, D. L., and L. Abbott, Paleosol and C-14 evidence for two pre-1811 large magnitude earthquakes in the New Madrid Seismic Zone, Midcontinental USA. 1995 Y. M. Goldschmidt Conference, Penn State University, University Park, PA. May 24-26 Johnson, D. L., and S. G. Wesnousky, Origins and ages of iron concretions formed in sand, New Madrid seismic zone, Midcontinental USA. Publications Wesnousky, S. G., The Gutenberg-Richter or Characteristic Earthquake Distribution, Which is it? (1994) Bulletin of the Seismological Society of America, 84,1940-1959. Working Group on California Earthquake Probabilities (Contributor), Seismic Hazards in Southern California: Probable Earthquakes, 1994 to 2024 (1995), Bulletin of the Seismological Society of America, 85,379-439. Kumamoto, T., S. G. Wesnousky, M. Okamura, H. Tsutsumi, N. Chida, K. Shimazaki, and T. Nakata (1995), Active Faults in Lake Tahoe, Western Part of the United States-a Preliminary Report, Active Fault Research, v. 13,47-53. Caskey, S. J., S. G. Wesnousky, P. Zhang, and D. B. Slemmons, Surface Faulting and Mechanical Aspects of the 1954 Fairview Peak (Ms = 7.2) and Dixie Valley (Ms=6.9) Earthquakes, Central Nevada, accepted for publication in the Bulletin of the Seismological Society of America. Caskey, S. J., Geometric relations of dip slip to a faulted ground surface: new nomograms for estimating components of fault displacement, Journal of Structural Geology, 17,1197-1202,1995. 0.3 Anderson, J. G., S. G. Wesnousky, M. W. Stirling, M. P. Sleeman, and T. Kumamoto, Earthquake Size as a Function of Fault Slip Rate, submitted to Bulletin of the Seismological Society of America. Stirling, M. W., S. G. Wesnousky, Fault trace complexity, cumulative slip, and the shape of the magnitude-frequency distribution for strike-slip faults: a global survey, accepted for publication in the Geophysical Journal of the Royal Astronomical Society. Hirabayashi, C. K., T. K. Rockwell, S. G. Wesnousky, M. W. Stirling, and F. Suarez-Vidal, A Neotectonic Study of the San Miguel- Vallecito fault, Baja California, Mexico, accepted for publication in the Bulletin of the Seismological Society of America. 0.4 o SECTION II O o TASK1 QUATERNARY TECTONICS PROGRESS REPORT 1 October 1994 to 30 September 1995 John W. Bell Principal Investigator Craig M. dePolo Co-Investigator SUMMARY OF ACTIVITIES CONDUCTED DURING THE CONTRACT PERIOD During the contract period, the following activities were conducted by Task 1: ** J.W. Bell completed and published with F.F. Peterson, R.I. Dorn, A.R. Ramelli, and T.L. Ku the paper "Late Quaternary geomorphology and soils in Crater Flat, Yucca Mountain area, southern Nevada" in the Geological Society