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to place a minimum size limit when measuring clasts (Blenkinsop, 1991; Clark<br />
and James, 2003; Barnett, 2004).<br />
CSD data are commonly presented with respect to 3-dimensional space. If<br />
an object is fractal in 2-dimensions, it is also fractal in 3-dimensions, and<br />
(5.5)<br />
This conversion is validated by the fact that D s refers to the line, surface, or<br />
space that dissects the object. An increase in Euclidean dimension requires the<br />
same increase in D s (e.g. Sammis et al., 1987). This conversion is justified for a<br />
breccia made <strong>of</strong> a homogeneous, isotropic material, but error can be introduced<br />
if this assumption is used on anisotropic materials (e.g. Barnett, 2004; Farris and<br />
Paterson, 2007). To reduce this potential error, outcrops with 3 dimensional<br />
exposures can be used. Clast distribution can also be expressed as a function <strong>of</strong><br />
clast frequency versus mass (e.g. Hartmann, 1969; Blenkinsop, 1991), or percent<br />
sample by weight versus diameter (see Schoutens, 1979), both <strong>of</strong> which are<br />
directly related to a 3-dimensional distribution. These results also pertain to<br />
power law distributions and therefore their slopes are proportional and can be<br />
converted to D s (Blenkinsop, 1991; Perfect, 1997).<br />
5.3.2. The Fractal Dimension-Brecciation Mechanism Link for Clast<br />
Size Distribution (CSD)<br />
Understanding the brecciation mechanism will provide important<br />
information on the mechanical response to subsurface volcanic eruption. As CSD<br />
results are a function <strong>of</strong> the self-similar manner by which fractures proliferate<br />
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