  The Chamaeleon I dark cloud (Cha I} has been mapped in C18O J=1-0 with an
angular resolution of 1 arcmin using the SEST telescope. The large scale
structures previously observed with lower spatial resolution in the cloud turn
into a network of clumpy filaments. The automatic Clumpfind routine developed
by Williams et al. 1994 is used to identify individual clumps in a consistent
way. Altogether 71 clumps were found and the total mass of these clumps is 230
Mo. The dense 'cores' detected with the NANTEN telescope (Mizuno et al. 1999)
and the very cold cores detected in the ISOPHOT serendipity survey (Toth et al.
2000) form parts of these filaments but decompose into numerous 'clumps' The
filaments are preferentially oriented at right angles to the large-scale
magnetic field in the region. We discuss the cloud structure, the physical
characteristics of the clumps and the distribution of young stars. The observed
clump mass spectrum is compared with the predictions of the turbulent
fragmentation model of Padoan & Nordlund 2002. An agreement is found if
fragmentation has been driven by very large-scale hypersonic turbulence, and if
it has had time to dissipate into modestly supersonic turbulence in the
interclump gas by the present time.
