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1
FRONTIER RESEARCH ON EARTH EVOLUTION, VOL. 2
Application of core-log-seismic data integration for the high-resolution seismicstratigraphy in the Shatsky Rise
Moe Kyaw Thu and Tetsuro Tsuru
Research Program for Data and Sample Analyses, Institute for Research on Earth Evolution (IFREE)
1. Introduction
Core-log-seismic data integration method is an interdiscipli-
nary strategy, integrating core measurements, logging data and
seismic data which are in different resolution and different meas-
urement scales. The investigation by use of multiple scales of
seismic, downhole logging, and core data, contributes to improve
the confidence of each data set. With the availability of the best
combination of facilities in the IFREE, application of this unique
technique has been carried out in various studies with the datasets
taken at different geologic settings around the world.
This study is based on the successful drilling and logging in the
Shatsky Rise in the Ocean Drilling Program (ODP) Leg 198 (Fig.
1). During the two months long leg, eight sites are drilled on a
broad depth transect with six cored sites and two logged sites at all
three heights. A virtually complete section from the Holocene to
Jurassic/ Cretaceous, and first ever igneous rocks are cored from
the region [Shipboard Scientific Party, 2002]. Objective of this study
is to apply high-resolution seismic stratigraphy in the regional
scale through the core-log-seismic data integration between sites.
The results include successful establishing of onsite seismic
stratigraphy at Site 1213 in data integrated way, extension of its
stratigraphy to the Site 1214 along the high-resolution seismic pro-
file, and establishing onsite seismic stratigraphy of Site 1214 for
the lithology of its deeper section which was unknown previously.
2. Data and method
All the data sets, core lithology, well-log and reflection seismic
data, used in this study are taken from the ODP’s Leg 198 in the
Shatsky Rise. Since integration of core-log-seismic data needs
careful adjustments, synthetic seismograms are made from the
density and velocity data and are used to correlate different scales
of data in the integration process. Interpreted units are applicable
to wider area seismic profiles and have close relationship with the
representative lithology [Moe et al., 2002].
At first, high-resolution processing of the multi-channel seis-
mic data is initiated through several trials with various processing
sequences by correlating with synthetic profile. Final processing
sequence includes resampling of the data into 1 ms sampling rate,
filtering of the data within the range of 10 and 180 Hz, and spec-
tral whitening with wider frequency range. Then, onsite seismic
stratigraphic interpretation is carried out at Site 1213 due to the
availability of all data sets for the core-log-seismic data integra-
tion. In this interpretation, synthetic seismogram is modeled
through density and velocity logs and then used as basic interpre-
tation between seismic and logs, and then its equivalent lithos-
tratigraphy. After successful interpretation of seismic stratigraphy
at Site 1213, careful extension of the established stratigraphy is
carried out to the Site 1214 with the support of lithostratigraphy at
Site 1214. With the partial availability of the density and velocity
from the depth of 188 mbsf to 418 mbsf on the logs, the direct
integrated interpretation between synthetic seismogram and seis-
mic profile is based only on this depth range. Even thought litho-
logic units from the each site are used from the onboard interpre-
tations, Site 1213 units are extended to the 1214 on the final inter-
site interpretation.
3. Results
The purpose of core-log-seismic integration in Shatsky Rise is
to relate paleoceanographic events found in the core sample, to
the seismic record. By using logging data as an intermediary
between the core and seismic data, the spatial and temporal extent
of these events can be traced from the borehole location to the
whole study area along the seismic profile. During ODP Leg 198,
only two sites, Site 1207 at the northern height and Site 1213 at
the southern height, were logged. Unlike Site 1207 which is only
site drilled in the northern height, six sites are drilled in the south-
ern height. Since sediment units are cut off in the troughs between
the three heights, inter-site correlation is difficult to make between
them. After considering on the location of sites being on the same
height and reaching oldest sediments and basement, Site 1213 is
chosen to use as primary site for the data integration.
At first, onsite interpretation is followed on the onboard core
description and its lithostratigraphy due to the higher core recovery
at Site 1213. Through the process of depth and well-log properties’
correlations, similar lithostratigraphic units and its equivalent
depths are made on the seismic profile (Fig. 2B). Unit I character-
izes in medium, parallel reflectors with the lithology of nanno
ooze-rich clay. Regional unconformity of big time gap (Santonian
of Late Cretaceous to Pliocene) rest at the base of Unit I. Unit II of
Cenomanian in Late Cretaceous characterizes in weak and medium
reflectors in a thin zone where two subunits of nanno ooze with
chert at the top and chert with porcellanite at the bottom. Unit III is
subdivided into 5 units on its 607.9 m thick zone. Unit IIIA charac-
terizes the strong, parallel reflectors with weak and transparent
reflectors at the top and bottom of the unit in which chert with por-
cellanite and limestone dominates. Chert with porcellanite in unit
IIIB characterizes in weak and transparent reflectors which is sup-
ported by the stable and gradual increase of well-log density.
Below this unit is thin and strong reflecting unit which covers
clayey and porcellanite sediments including thin black shale layer.
Higher restivity, and gamma values are assumed to be the reason
of strong reflectors around black shale layer. Unit IIID is mixed
medium and weak reflector zones which may have caused from the
compact and hard porcellanite and soft nanno chalk. The lower-
most unit IIIE characterizes strong, parallel seismic reflectors at
the upper half and weak reflectors at the lower half of chert, por-
2
FRONTIER RESEARCH ON EARTH EVOLUTION, VOL. 2
cellanite, claystone lithology. The age of this unit ranges from
Berriasian (early Cretaceous) to possibility of Late Jurassic.
Extended interpretation of the onsite seismic stratigraphy from
the Site 1213 reached to the Site 1214 with some difficulties due
to the stratigraphic complexity at small trough between two sites
(Fig. 2C). Those difficulties are 1) two topographic troughs
between two sites at which unit II of Cenomanian age is truncat-
ing (Fig. 2C), and 2) thinner sediment layers at the high-angel
slope near Site 1214. Primary interpretations were in doubt
between two seismic patterns, onlapping and truncation.
Thorough investigations concluded it as erosional truncation
which cut off the Unit II at the Height B, not continuing to the
Site 1214. Sediments layers in the Site 1214 changed to thinner in
thickness to the Trough A and caused difficulties in making inter-
pretations. Moreover, unit thicknesses are in big difference
between two sites. Unit I covers thin layer of clayey nanno ooze
in Pleistocene age which are in medium, parallel reflectors.
Cenomanian aged Unit II has been missing at the Site 1214, hence
sediments in the area jumped to the Albian aged bioturbated chert
to porcellanite with strong, parallel seismic reflectors as Unit IIIA.
Unit IIIB mixes weak and strong seismic reflectors of chert, por-
cellanite and limestone lithology. Black shale layer appears in the
Unit IIIC of claystone to clayey porcellanite with strong reflectors
as in Site 1213. ODP drilling at the Site 1214 ended at the top of
the Unit IIID of porcellanite and chert lithology. Extended inter-
pretation from there is the result of the inter-site correlation along
the seismic. This thick unit characterizes strong reflectors at upper
half and semitransparent reflectors at the lower half. The last Unit
IIIE is interpreted as chert, porcellanite and claystone with mix-
ture of strong and medium reflectors.
4. Conclusions
Successful application of the core-log-seismic data integration
in the Shatsky Rise benefited inter-site correlation of the seismic
stratigraphy and lithostratigraphy of the area in wider scale and
higher resolution. Further study is carrying on in the process of
interpretation in depositional and paleoceanographic history of the
region in combination with micropaleontologic and geochemical
results. Final results will have detailed understanding on the depo-
sitional and paleoceanographic history of the area.
Acknowledgements. We thank the captain, crew and technicians of
the JOIDES Resolution from Ocean Drilling Program for the core and
downhole logging data acquisition, A. Klaus and W. Sager from the
Texas A & M University for the seismic data.
References
Moe K. T., K. Tamaki, S. Kuramoto, R. Tada and S. Saito, High-reso-
lution seismic stratigraphy of the Yamato Basin, Japan Sea and its
geological application, The Island Arc, 11/1, 61-78, 2002.
Shipboard Scientific Party, Leg 198 Initial Report, ODP Init. Repts.,
198, 2002.
3
FRONTIER RESEARCH ON EARTH EVOLUTION, VOL. 2
Figure 1. Location and bathymetric map illustrating seismic track lines in the southern height of the ShatskyRise. ODP Sites 1213 and 1214 (red circles) and other sites (black and white circles) are shown on the map.
Figure 2. Core-log-seismic data integrated stratigraphic correlation at Sites 1213 and 1214. (A) Onsite lithostratig-raphy and seismic stratigraphy of the Site 1214 in its depth in meters below seafloor, core numbers and their recov-ery, lithologic symbols, units, their geologic age and lithology, their equivalent seismic units are shown from left toright. (B) Onsite lithostratigraphy and seismic stratigraphy of the Site 1213 with additional well-logs and syntheticprofile. (C) Regional seismic stratigraphy of the southern height of the Shatsky Rise through core-log-seismic dataintegrated correlation between Sites 1214 and 1213. Vertical scales are in two-way travel time in seconds.