  The relationship between observed structures in the solar atmosphere and the
magnetic fields threading them is known only for the solar photosphere, even
then imprecisely. We suggest that some of the fine structure in the more
tenuous chromosphere and corona- specifically some populations of spicules and
fibrils- correspond to warps in 2D sheet-like structures, as an alternative to
conventional interpretations in terms of tube-like structures. The sheets are
perhaps related to magnetic tangential discontinuities, which Parker has argued
arise naturally in low-beta conditions. Some consequences of this suggestion,
if it can be confirmed, are discussed.
