APPENDIX








The digital data is available from the following U.S.G.S. URL:





http://wrgis.wr.usgs.gov/open-file/of99-383/





	


************DATA CONTENTS





The digital dataset consists of one file:  lines representing major extensional faults in the Paleozoic surface topography beneath Yucca Flat.





The file  is an ASCII data file, created by the Arc/Info (Environmental Systems Research Institute, inc.) UNGENERATE command, with the vertices for each line bracketed by the line ID and the key word END.  There are two types of information stored in the ASCII file in addition to the location of the lines which represent faults. The first is the line ID, which distinguishes between certain and approximately located faults.  Faults that are certain are coded with ID numbers below 100, and faults that are approximately located are coded with ID numbers above 100.  The ID numbers are arbitrary within these groupings.  The second type of information stored in the ASCII file is line direction.  The lines are stored as vectors, which have a starting point and an ending point.  The lines represent normal faults, which have an up-thrown and a down-thrown side.  The lines are coded using a right-hand rule: that is, if one were to stand on the line near where it begins and face along the line towards the end, the down-thrown side


(where the bar-and-ball symbol would be on a geologic map representation) is on the right, and the up-thrown side is on the left.





	


faults.asc	ASCII data file of the major extensional faults in the Paleozoic surface topography beneath Yucca Flat, coded as follows:


		


		id, longitude,latitude


		    longitude,latitude


		    longitude,latitude


		    longitude,latitude


		    etc.


		END


		id, longitude,latitude


		etc.


		


		The longitude and latitude are in projected coordinates and represent the vertices of the line.  The end of each line is defined by the word END.  The projection for the coordinates is:





UTM meters, zone 11, NAD27, Clarke 1866 spheroid