there is block level corruption.
if this is production system, open a TAR with OSS and proceed.
DONT Attempt to do anything, UNLESS YOU HAVE valid Backup.

to determine which object is corrupted, issue
SELECT SEGMENT_NAME, 
       SEGMENT_TYPE, 
       OWNER
FROM   SYS.DBA_EXTENTS
       WHERE FILE_ID = < f >  AND   --f=your file# , b=block#        
       < b > BETWEEN BLOCK_ID AND BLOCK_ID + BLOCKS - 1;