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sonian Radiocarbon Laboratory for providing the bounded basins of the Balearic, Tyrrhenian, and
carbon-14 data. One radiocarbon date was pro- Ionian seas and the emerged North African and
vided by the Laboratoire de Géodynamique Ma- southern European regions bounding it. Most
rine de Villefranche-sur-Mer. workers envision this shallow area as a prolonga-
We acknowledge with gratitude the many per- tion of the Tunisian-Southern Sicilian land mass
sons with whom we have had an opportunity to an d as a link between the N orth African Atlas
discuss the various problems raised in this study. chain and the Sicilian-Italian Apennine chain.
We thank, in particular, Drs. R. Stuckenrath, The different tectonic provinces of the Strait re-
J. W. Pierce and I. Macintyre, Smithsonian In- gion have been defined and mapped by Burollet
stitution; Dr. Salvador Reguant, University of (1967) and Zarudzki (1972). Seismic reflection
Barcelona; Dr. F. W. McCoy, Lamont-Doherty exploration has provided both deep penetration
Geologica! Observatory; Dr. Charles Smith, U.S. (excellent Flexotir records of Finetti and Morelli,
Geologica! Survey, Washington; Mr. T. Durdan, 1972a, h) an d shallower subbottom coverage
University of Miami; Mr. D. Lambert, NOAA- (Woods Hole Oceanographic Institution sparker
AOML, Miami; Drs. C. Bobier, J. Poutiers and F. and air gun profiles, Zarudzki, 1972).
Fernex, all of the Station de Géodynamique de Flexotir records show that this zone, separating
Villefranche; and Mr. D. Le Boulicaut, Centre de the distinct eastern and western Mediterranean
Sédimentologie Marine of the University of Perpig- geodynamic sections, consists of thick continental
nan. crust compns1ng a generally thin Pliocene-
We thank Messrs. L. Isham and H. Sheng, Quaternary unconsolidated section above a thick
Smithsonian Institution, for their assistance with sequence of Triassic to Miocene rock units (Finetti
drafting and processing of data and samples, and and Morelli, 1972a). The reduced thickness of un-
Ms. M. J. Mann and Mr. W. R. Brown for their consolidated Pliocene and Quaternary sediments
help with the scanning electron microscopic analy- (except in some depressions such as the Malta
sis. Drs. J. W. Pierce, Smithsonian Institution, Graben where these exceed l second, penetration
R. S. J. Sparks, University of Lancaster, and T. -C. two-way travel time) can be contrasted with the
Huang, University of Rhode Island, read the thick sections in the Balearic Basin west of the
manuscript and provided helpful suggestions im- Strait. The underlying Upper Miocene units, cor-
proving the text. related with limestone and dolomite sequences in
Financial support for this investigation, part of cores and 1and sections, thicken toward Tunisia
the Mediterranean Basin (MEDIBA) Project, has (Burollet, 1967).
been provided by the Smithsonian Research Foun- There is ampie evidence of geologically recent
dation grants 450137 and 430035 to D. J. Stanley. (post-Miocene) structural displacement, and the
Support for ship-time and collection of cores and different morphological-tectonic sectors of the
photographs by the Lamont-Doherty Geologica! Strait can be related to major fault patterns. Mag-
Observatory was provided by grants number ONR netic and gravity studies reveal that the main
(N00014-67-A-0108-0004) and NSF-GA-35454. structural trends are oriented west northwest-east
This project was undertaken at the Smithsonian southeast, i.e., parallel to the major orientation of
Institution while Dr. Maldonado held a postdoc- the Sicily Channel (Allan and Morelli, 1971;
toral fellowship of the Program of Cultura! Co- Morelli, 1972; Colantoni and Zarudzki, 1973; and
operation between the United States and Spain. others). A northeast-southwest trend predominates
Travel funds for the fina! preparation of the paper at the westernmost sector of the Strait (Auzende,
have been provided to Maldonado by the Subdirec- 1971; Auzende et al., 1974). The largely vertical
ci6n Generai de Promoci6n Estudiantil (Ministerio structural displacement gives rise to a complex
de Educaci6n y Ciencia). configuration of horsts (shallow tabular-shaped
banks) and grabens (narrow, deep linear basins).
Seismic profiles clearly display the vertical and
STRUCTURAL-STRATIGRAPHIC FRAMEWORK
subvertical offset of reflectors. The intensity of
The Strait of Sicily platform occupies a geologi- structuraì 'òffset and seismicity (shallow earth-
cally strategie position between the deep, fault- quake epicenters), and the concentration of voi-