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7.2.1.2 lithozone b2
Turbiditic calcarenites and calcirudite (Fig. 13C).
A1 A1 7.2.1.3 lithozone b3
Calcilutites with minor intercalations of nodular or
lenticular cherts black or brown coloured (Fig. 13B).
A2 7.2.1.4 lithozone b4
Millimeter surface of oxides of iron and manganese.
A2 The fine lithologies vary greatly in composition, rang-
ing from fully siliciclastic to almost fully calcareous, in
Fig. 12 - Sezione stratigrafica della Litofacies A che mostra la millimetric to centimetric beds. Carbonate clays can be
relazione con i depositi di detrito di versante cemen- classified as Wackestone (Dunham, 1962) or Biomi-
tati. crite (Folk, 1962) with uniserial foraminifera and bi-
valves. According to the present study, report that the
Fig. 12 - Stratigraphic section of Litofacies A tht show its turbidite events are frequent, with erosive basal sur-
relationship with the cemented talus slope deposit. faces and thicknesses ranging from a few centimeters
to three decimetres. Each of turbidites in the lithozone
che sono precipitati con un cambiamento delle con- B2 presents the facies a, b and sometimes c of the of
dizioni chimico-fisiche, formando dei livelli ce- Bouma sequence (Fig. 13D). A few turbidites include
mentati di detrito. Questi sono correlabili ad un pa- deformed mudstone clasts in the basal massive facies,
leoclima umido. Infatti, in climi aridi, i processi di clearly derived from the underlying eroded fine-grained
weathering e la cementazione, sono molto limitati. layers (Fig. 13C). One layer in lithozone B1 presents
limivore bioturbation. The normal polarity of this suc-
7.2 unità litostratigrafica cession is inferred from the normal gradation and the
di punta troia basal erosive surface of facies a of Bouma sequence
of the turbidites (Fig. 13D). The lower stratigraphic
7.2.1 litofacies b boundary is characterized by an angular unconformity
La litofacies B costituisce la parte som- of about 20° with the lithofacies C (that will be subse-
mitale dell’unità litostratigrafica di Pun- quently described). The maximum observable thickness
ta Troia ed è costituita da n.4 litozone. is about 15 m. The lithofacies B can be related to Fm.
Buccheri (Malm), which in Foglio 604 Isole Egadi in
7.2.1.1 litozona b1 C.A.R.G. project is interpreted by D’Angelo et al. as
Argilliti varicolori ben stratificate e marne (Fig. 13A). slope deposit. The observations made on outcrops sug-
gest, instead, a sea bottom basin environment proximal
7.2.1.2 litozona b2 to the slope. This is supported by the onlap on litho-
Calcareniti e calciruditi torbiditiche (Fig. 13C). facies C and depositional characteristics (alternance
between lithozone B2 and lithozone B3). The work of
7.2.1.3 litozona b3 Nigro & Renda (2005) identifies several similar situ-
Calcilutiti con intercalazioni minori di selci nodulari ation in other sites in western Sicily, where Middle Ju-
o lenticolari di colore nero o marrone (Fig. 13B). rassic pelagic strata onlap and lie on the carbonate
platform faulted strata. The facies of the pelagic strata
7.2.1.4 litozona b4 involved in the strike-slip faulting range from hemipe-
Superficie millimetrica di ossidi di ferro e manganese. lagic to condensed (Nigro & Renda, 2005). According
to this study, the lithofacies B is intersected by several
normal faults dipping to the south-west with small dis-
placements. The latter may be interpreted as the ar-
rangement of the wedge of sediment to the lithostatic
load induced by the weight of overlying sediments that
creates compaction and then subdsidence (Fig. 14).
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