I
or sheet
In geology, a tabular igneous intrusion emplaced parallel to the bedding of the enclosing rock.
Although they may have inclined orientations, nearly horizontal sills are most common. Sills may range from a few inches to hundreds of feet thick and up to hundreds of miles long. They include rock compositions of all types.
II
[c mediumvioletred] (as used in expressions)
{{link=balance sheet">balance sheet
Greenland Ice Sheet
Laurentide Ice Sheet
sheet erosion