SITE GEOPHYSICS
Geophysical Data near
Site 901
Only one multichannel
seismic-reflection profile passes through
Site 901 (Fig. 4).
It is the east-west Lusigal Line 12 (see "Background
and Scientific Objectives" section,
Fig.
2 and Fig. 3, this chapter). Site
901 is located over a
basement high that is 15 km wide on Lusigal Line
12 (west to east).
The high is triangular in west-east cross section (Fig.
2). Site 901 is
located over the top of the high. Basement was estimated
to lie about 110 ms
two-way traveltime below the seafloor or 100 mbsf
at its shallowest
known point. An 80-m seafloor fault scarp (Fig. 5) is
located over the
basement high. This steps down to the west and is
almost certainly related to recent fault movement along the western
side of the high.
Site 901 is located about 500 m to the east of the fault
scarp. Beslier et
al. (1993) and Whitmarsh, Miles, and Mauffret (1990)
interpreted regional seismic and magnetic data, respectively, to indicate
that Site 901 is
located over extended continental crust.
