Page 3 - 1332952975242153-169Slaczkaetal

Lower Pleistocene deposits in east part of the Favignana ... 155

some cases of hard interpretation because
of lacking of several diagnostic elements:
all the stratigraphic sections are incom-
plete, the basal Lower Pleistocene depo-
sits are frequently unexposed and the ero-
sion and/or faulting cut the topmost part of
the successions.

3.1 Facies Association A

This Association, whose visible

thickness is about 10 meters, is exposed

in the western margin of the Favignana

Basin between Cala Fumere and Tonnara

Florio (north of the town of Favignana, Fig.

1c). It is generally represented by coar-

sening up sequence of calcarenites and

conglomerates (Fig. 4). The bottom of the

sequence is masked by strike-slip fault. In

the lower part, fine-to-coarse grained cal-

carenites, up to several dozen cm thick,

display a variety of laminations, from pa-

Fig. 2. - a) Bioclastic sandstone with red algal clast, foraminifera and sporadic bryo- rallel to cross-bedded in lunate megarip-
zoan. Punta Burrone. Length of bar is 2 mm; b) Bioclastic sandstone with foraminife- ples and to wave ripple lamination1.
ra, bivalve shell fragments, bryozoan, red algae. Punta Fanfalo. Length of bar is
2mm; c) Fine grained bioclastic sandstone with numerous foraminifera. Area of Fras- In the upper part of the sequence,

whose thickness can reach 1.5 meters,

cia. Length of bar is 1 mm; d) Bioclastic sandstone with red algae, bivalve shell frag- predominate conglomerates (Fig. 4c) com-

ments, bryozoan and foraminifera. Madonna-Cortigliolo. Length of bar is 2 mm. posed of rounded and subrounded pebbles

a) Arenaria bioclastica con clasti di alghe rosse, foraminiferi e sporadici briozoi. Pun- derived from the erosion of the Mesozoic
ta Burrone. La lunghezza della barra è 2 mm; b) Arenaria bioclastica con foraminiferi, bedrock, as well as from other lower Pleis-

frammenti di gusci di bivalvi, briozoi ed alghe rosse. Punta Fanfalo. La lunghezza tocene deposits. The size of sporadic
della barra è 2 mm; c) Arenaria bioclastica fine con numerosi foraminiferi. Località boulders can reach dozen cm. Scattered
Frascia. La lunghezza della barra è 1 mm; d) Arenaria bioclastica con alghe rosse, fragments of bivalve shells, rhodolithes and
frammenti di gusci di bivalvi, briozoi e foraminiferi. Madonna-Cortigliolo. La lunghez- serpulite limestones also occur. The matrix
za della barra è 2 mm. consists in abraded bioclastics. Conglome-

3. DESCRIPTION OF LITHOFACIES rates show crude parallel-bedding (PETTIJHON, POTTER &
SIEVER, 1987) and low angle cross bedding seaward di-

rected; somewhere they are massive, without distinct

Several facies associations can be locally described internal structures. Parallel-bedded conglomerates in-

on the basis of coexistence of lithological features, se- clude small lenses of cross-laminated calcarenites. Incli-

dimentological structures and trace fossil assemblages. nation of lamination is generally parallel or oblique to the

Relationship between the facies associations are in coastline. Conglomerate bodies present an erosional

basal surface signed by broad shallow

channels. Trace fossils, random distributed

in the sediments, must be referred to three

ichnogenera, Thalassinoides, Planolithes

and Thenidium; somewhere vertical traces

of Skolithos-like also occur (Fig. 4c). Few

beds of calcarenites are pervasive biotur-

bated (Fig. 4d), locally limestone with bor-

ings can be observed in blocks up to tens

cm in diameter.

1 Locally there are bi-directional set of lenses

(Fig. 4a) and in places wave ripples follow

upward megaripples. On some inclined la-

minae there are lags of gravels and shells

(Fig. 4b). Also, between laminated bodies

there are lags of flat limestone pebbles and

thin (up to dozen cm) layers and/or lenses of

conglomerates, formed by rounded pebbles

of Mesozoic limestones, bioclasts and frag-

ments of molluscs and echinoids shells (Fig.

4b). Some layers (up to 50 cm thick) display

Fig. 3 - Schematic structural map of the Favignana Island showing the main faults distinct gradation from matrix supported car-

that deform the Pleistocene deposits bonate pebbles and fragment of shells in
lower part to coarse and medium grained
Carta strutturale schematica dell'Isola di Favignana che mostra le principali faglie che calcarenites topwards.
deformano i depositi del Pleistocene.