structural geology, propagation mechanics and - Stanford School of ...

confining pressures produce, in my opinion, a failure phenomenon distinct from
compaction banding as observed in outcrop.
The greater value of my fledgling laboratory efforts probably lies in the collaborative
relationships developed within the experimental community pursuing compaction
localization research. I visited and worked in the labs of Bezalel Haimson (University of
Wisconsin-Madison), William Olsson and David Holcomb (Sandia National Labs) and
David Lockner (USGS-Menlo Park), and corresponded extensively with the laboratory of
Teng-fong Wong (Stony Brook University). Through these interactions and a DOE-
sponsored workshop (October 2004), which led directly to my association with co-author
John Rudnicki (Chapters 2 and 3), David Pollard and I have introduced a much-needed
field-based reality check into compaction localization experimentation. Whether this
influence will become more tangible through my own future experimental efforts remains
to be seen.
Finally, I would be remiss in not observing that, although a strong process-based
mechanics perspective and approach pervade this thesis, it is based primarily on
observations made from outcrops and samples of the Aztec sandstone. While this fact
does not detract from my results and interpretations, the issue of ubiquity is relevant from
a practical applications standpoint. That is, are CB arrays such as observed in the Aztec
common in sandstone aquifers and reservoirs, or are they a relative freak of nature? From
a fundamental physical and mechanical point of view, it is unlikely that CBs in the Aztec
represent an isolated phenomenological fluke. However, shear deformation bands have
been observed in a wide variety of clastic deposits exposed around the world, and similar
observations of CBs are needed to confirm them as a common structure in porous
sandstone.
Beyond this obvious direction for future analog reservoir-based fieldwork, a
concerted effort also is needed to develop borehole geophysical methods for detecting
and characterizing deformation bands of all types in the subsurface. The general
petrophysical attributes of bands should, in theory at least, render them visible to a
variety of imaging technologies, ranging from acoustic to electromagnetic. In conjunction
with a solid mechanical understanding of how CBs and CB arrays form—the foundations
for which are laid here in Chapters 1 through 4—such imaging techniques would provide
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