See Inside for GSA 2004 Annual Meeting Technical Program VOL. 14, NO. 10 A PUBLICATION OF THE GEOLOGICAL SOCIETY OF AMERICA OCTOBER 2004 Inside: Dilational fault slip and pit chain formation on Mars DAVID A. FERRILL, DANIELLE Y. W YRICK, ALAN P. MORRIS, DARRELL W. SIMS, AND NATHAN M. FRANKLIN, p. 4 Section Meetings: South-Central, p. 42 Cordilleran, p. 44 VOLUME 14, NUMBER 10 OCTOBER 2004 Cover: The southeastern part of Alba Patera, a massive shield volcano in the western hemisphere of Mars, is cut by a dense network of normal faults, producing a horst and graben terrain. This normal fault system, along with GSA TODAY publishes news and information for more than 18,000 GSA members and subscribing libraries. GSA Today many others on Mars, also hosts pit crater chains. lead science articles should present the results of exciting new In the image, these pit chains appear as north- research or summarize and synthesize important problems or northeast trending lines of depressions occurring issues, and they must be understandable to all in the earth within deep grabens (e.g., northeast corner) and science community. Submit manuscripts to science editors associated with smaller-displacement normal Keith A. Howard,
[email protected], or Gerald M. Ross, faults. The image was created by draping a color
[email protected]. coded digital elevation map (total relief in image GSA TODAY (ISSN 1052-5173 USPS 0456-530) is published 11 is 4218 m; blue is low, brown is high) from Mars times per year, monthly, with a combined April/May issue, by The Orbiter Laser Altimetry (MOLA) data over a Viking Geological Society of America, Inc., with offices at 3300 Penrose photomosaic (illumination is from the west).