Page 23 - Maldonado_Stanley_1976

NUMBER 16 19

FIGURE 14.-Profiles across part of Adventure Bank off southwest Sicily showing reduced uncon-
solidated cover above Neogene (A) older units (a = truncated strata, b = terrace at 107 ±3 m,
c = terrace at 140 ±10 m).

Maps of the surficial sediment based on bot- MARKED TOPOGRAPHIC HIGH (Environment 9).-
tom photographs, grab samples, and cores (i.e., The topographic highs are of two major types: (a)
AS 6-8, AS 6-7, V 14-138, V 14-140) show a mo- those showing a sedimentary cover in the 3.5 kHz
saic distribution which is not strictly depth con- records and (b) those without any kind of reflectors
trolled. Sediment types include mud to coarse- or stratification in the records. The first type is in
grained, largely bioclastic an d biogenic ( calcareous some instances strongly deformed (Figure 13AJ km
algae, bryozoans, molluscs, foraminifera, etc.) sedi- 510), or appears as an anticline (Figure 11, km
ment types (cf., Blanc, 1958; Poizat, 1970; Akal, 470). Some highs without reflectors (an acoustic
1972). However, gross texture appears to be reflector appears to pierce younger units) can be
broadly related with morphology and depth: interpreted as volcanoes (cf., Figure 6n 1 , n 2 , km
coarser sediment types are concentrated on shallow 1010; Figure 9, km 880; Figure 12, km 740), ig-
banks and mud in the somewhat deeper and de- neous intrusive masses (granite of the Galite Archi-
pressed areas. pelago, Auzende et al., 1974), strongly metamor-
Layers of cemented crusts and oxidized clasts, phosed rock, or diapiric structures (Burollet, l 967;
mostly biogenic and Pleistocene rock surfaces bare Zarudzki, l 972). The sequence of highs shown in
of sediment, are important Iocally. These horizons seismic records collected between km 775 and km
can be Iikened to "hard grounds" recorded in the 790 (Figure 13Bv n 2 ) may represent an extension
ancient sedimentary rock record (Blanc, l 958). of the Skerki Bank; this feature displays Quater-