The file: hg18.laminB1.txt.bz2 is the raw data used to encode
the laminB1 track on hg18.  This file was produced as described in
the laminB1Super track description in the hg18 browser database 
(Guelen et al. 2008). 

The format of the data is variableStep wiggle data described
at: http://genome.ucsc.edu/goldenPath/help/wiggle.html
with a "span" size of 60 bases.  Each value is for a window
size of 60 bases representing a normalized log2-ratio probe value.

Example data from chr1:

variableStep  chrom=chr1  span=60
55638   0.558
57948   -0.083
68883   0.390
76168   0.544
... etc ...