Integrated
CHIRP and Water Bottom Sediment Sampling Across a Modern Carbonate Platform,
Turks and Caicos, BWI
Ruf, Amy S.1, Jason W. Eleson2,
Bryan Motzel3, Timothy S. Dulaney4, Gregory S. Benson5,
Stephen Kaczmarek6, Lisa K. Meeks4, Sean A. Guidry5,
Eugene C. Rankey7, Stacy L. Reeder8, Humberto Guarin6,
James R. Markello5, Jim Weber9 (1) ExxonMobil Upstream
Research Company, Houston, TX (2) ExxonMobil Development Company, Houston, (3)
ExxonMobil Production Company, Houston, (4) ExxonMobil Exploration Company,
Houston, (5) ExxonMobil Upstream Research Company, Houston, (6) N/A, N/A, (7)
University of Miami, Miami, FL (8) University of Miami, Miami, (9) ExxonMobil,
Houston, TX
Marine 2D CHIRP sub-bottom profile data
and collocated water bottom sediment samples were collected along several
transects on the Caicos Platform, Turks and Caicos, BWI, to evaluate roles of
antecedent topography and present day physical conditions on distribution of
Holocene carbonate sediments. Approximately 200 km of CHIRP data were collected
over platform interior, tidal pass, tidal delta, reef lagoon, and beach to
fore-reef environments. The top Pleistocene surface and intra-Holocene
stratigraphy are imaged on unprocessed CHIRP lines. Reflection strength of the
water bottom is strongly correlated to sediment induration, providing an
indicator of surface hardness conditions along CHIRP lines. Shoals, patch
reefs, channels, margins, and possible structural deformation features can be
interpreted and calibrated to sediment sampling observations. Initial results
show minimal correlation between Pleistocene topography and Holocene
sedimentation across the platform interior and reef lagoon. Approximately 300
sediment samples were collected along CHIRP transects and from beach and platform
interior shoal environments not accessible by marine CHIRP equipment. At each
sample location, water depth and GPS coordinates were recorded, and detailed
descriptions of biota, environment, and physical conditions were documented.
Sediment sample observations were compiled into a database linked to a GIS to
provide spatial context to distribution of grains, sedimentary structures,
biota, and physical conditions. Evaluation of trends and spatial distribution
of these features, integrated with CHIRP observations, provides insights on
facies prediction and controls of carbonate sedimentation on the Caicos
platform and may be used to more accurately characterize porosity and
permeability trends in carbonate geomodels.
AAPG Search and Discover Article #90063©2007 AAPG Annual Convention, Long Beach, California