Page 17 - Maldonado_Stanley_1976

14 SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES

.tiGURE 9.-Neritic-bathyal platform (near Skerki Bank) showing topographic high (horst)
underlain by basement (B) and reduced, deformed Pliocene-Quaternary (P-Q) cover. Accumu-
lation of recent sediment is noted in small depression (arrow a).

KS 125) display a characteristic lithological uni- reflectors is readily apparent. The high-resolution
formity. No prominent sand layers are recovered 3.5 kHz profiles show that faulting has occurred
and only subtle structures are revealed in the core after deposition (Figure 7, arrow c). In some lo-
X-radiographs. Bioturbation structures are present calities tectonic displacement and sedimentation
throughout the cored sedimentary sequences. rates have occurred simultaneously, resulting in
Although the cores are generally structureless it the development of pinch-out (Figure 7, arrow a)
should be noted that some laterally continuous re- and offlap sequences (Figure 8, arrow a). The
flectors can be traced on the 3.5 kHz records; these youngest faults reveal a vertical throw of as much
reflectors are locally displaced vertically by faults. as 50 meters (Figure 7, arrow c).
The Iimited Iength of the cores has not allowed re- Neritic-Bathyal Depression (Environment 5):
covery of sediment sections forming some of these There are numerous depressions on the border-
major subbottom reflectors. However, their latera! land, and four of these have been traversed: the
continuity suggests some process which has re- gentle Malta-Linosa depression, a low between the
sulted in their regional distribution; this mech- Malta Trough and the Linosa Trough (km 365-
anism is discussed later. 470, Figures IO, 11), and three smaller, more
The importance of neotectonics affecting these marked depressions, north of Adventure Bank (km