Glide Planes to
Turbidites; Deep Water Carbonate Megabreccias,
Agar, S.1, J. Bova1,
A. Derewetzky2,
The Villajoyosa
region of the Costa Blanca of eastern
Facies range from matrix and
grain supported mega-breccias to meter scale grainstones
and wackestones; organised
into repetitive packages. These facies formed as the
result of catastrophic failure, turbidity flows and minor hemipelagic
sedimentation, respectively. Mega-breccias are laterally discontinuous, bounded
by erosional and basal glide planes. The turbidites are laterally extensive, frequently amalgamated
and up to several meters thick.
Depositional processes for mega-breccias
include seismically and/or gravitationally induced collapse of margin and slope
sediments. Turbidites represent background eustatic-controlled deposition with significant bypass of
finer-grained turbidites. Syn-
or early post sedimentary deformation is common, including compaction,
shearing, slumping and related processes. Debrite clast composition reflects the progressive erosion of the
platform from margin to interior.
Reservoir quality appears to be limited
by poor-sorting, lateral heterogeneity and a lack post-depositional meteoric
dissolution, nevertheless, the predominantly grain-dominated succession provides
a positive analogue for similar facies elsewhere in
the geological record. Fracturing observed in outcrop is another potential
mechanism to enhance the ostensibly poor reservoir potential of the section.
AAPG Search and Discover Article #90063©2007 AAPG Annual Convention, Long Beach, California