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conditions directly affecting the seafloor changed distribution of sedimentary sequences was also con-
markedly between the late Pleistocene and the sidered in the correlation of cores (Figure 33). The
early Holocene, and that nondeposition andjor isochrons in Figures 33 to 35 reveal the thicker
erosion have prevailed since about 10,000 years sediment accumulations in the deep basins and
BP in the neritic-bathyal and shallow platform also show the truncation of Holocene sections at
environments. the top of the neritic-bathyal and shallow platform
In contrast, none of the above patterns are noted cores.
in the deep Strait basins. Rates of sedimentation The importance of volcanic activity between
approximate those on the neritic-bathyal environ- 5000 and 25,000 years BP in Linosa Trough is
ments but lower benthic populations on the basin demonstrated by the radiocarbon data on cores KS
floors have resulted in less bioturbation and better 120 and KS 118 in Figure 35. Volcanism at about
preservation of stratification. Furthermore, no ob- this time is also reported elsewhere in the Mediter-
vious changes either in lithofacies sequence pat- ranean (Keller et al., 1974).
terns or sedimentation rates are recorded in this The relation between rate of sedimentation and
deep environment between the late Pleistocene fault displacement can also be considered in light
and the recent, i.e., a period of at least 30,000 of the available carbon-14 dates. That deposition
years. and faulting are contemporaneous in the neritic-
However, other studies indicate that rates of bathyal environments is well displayed in 3.5 kHz
sedimentation in deep basins of the Mediterranean records (Figures 7, IO). The development of some
(Huang and Stanley, 1972; Rupke and Stanley, faults apparently stopped in the upper Pleistocene
1974; and others) and the Black Sea (Ross and (Figure 7, arrow B). In this area, the core tops are
Degens, 1974) have not been constant during the dated at about 10,000 years BP (core LY II-4); on
upper Quaternary. A decrease in the rate of sedi- 3.5 kHz profiles the uppermost sediment sections
mentation is reported in most Mediterranean areas are offset slightly by faults. The underlying Plio-
during the late Pleistocene to Holocene. cene and Quaternary sequences also accumulated
An anomolous reversal in the age of some core contemporaneously with fault movement as re-
samples (cf. cores KS 53 in Figure 35 and AS 6-7 · vealed by the thickening of sediments in down-
in Figure 34) may be the result of mixing by thrown fault blocks (see sparker profile in Figure
organisms. Vertical mixing of 3 to 4 m, for ex- 7, b). In some sectors faulting appears to be active
ampie, has been noted in some Holocene shelf a t present (Figures 7, c) 8, l 0), an d locally the off-
cores in the Persian Gulf (Sarnthein, 1972). set of identica! reflectors on opposite fault scarps
Another aspect that should be considered in ana- indicates a displacement rate in excess of the sedi-
lyzing radiocarbon dates is that different types of mentation rate. Thus, vertical displacement of cer-
carbonate materia! within the same sample may tain parts of the neritic-bathyal sea floor exceeds
give different radiocarbon dates (Milliman et al., 20 cm per l 000 years.
1972). An example of this is shown by two samples The nature of well-defined reflectors on 3.5 kHz
from the upper coarse calcareous layer (=== 30 cm) records is difficult to ascertain. Core analysis (LY
in core AS 6-8 (Figure 34). Here, the age of a II-4, Figure 7; Figure 34) shows that sand layers
largely shelly coarse sample (> 203 microns) is and other distinct lithologic layers are not present
slightly younger than that of the finer grade frac- in cores retrieved from this environment. As has
tion (63-203 microns) consisting primarily of been emphasized, the cores are characterized by
foraminiferal tests. A petrographic analysis of these their uniformity. Although many of the distinct
samples suggests that the fine fraction may have reflectors that appear on the 3.5 kHz records could
been more intensively reworked than the coarse not be sampled because of core length limitations,
shelly fraction. we believe that late Quaternary deposits in this
The correlation between cores based on the neritic-bathyal environment present a generai ho-
carbon-I 4 analyses is shown in Figures 34 an d 35. mogeneous pattern. Thus, the latera! continuity
Cores without available radiocarbon dates were and regional uniformity of subbottom reflectors in
correlated by extrapolation with radiocarbon dated 3.5 kHz records suggest a lithofacies change related
cores in the same environment. Lithostratigraphic to some type of regional event. We exclude a tur-