Guidebook - Ispra

THE APULIA CARBONATE PLATFORM-MARGIN AND SLOPE, LATE JURASSIC TO
EOCENE OF THE MAIELLA MT. AND GARGANO PROMONTORY:
PHYSICAL STRATIGRAPHY AND ARCHITECTURE P18
Figure 3.2.1 - Typical Maiolica outcrop: thin-bedded, white lime mudstones with chert lenses and layers, in places with
slump features (Testa del Gargano).
planktonic foraminifers (Turborotalia possagnoensis
Zone) occurring in the intercalated pelagic mudstones
(Bosellini et al., 1993). The unconformity separating
the Eocene deposits from the underlying deep-water
Cretaceous Scaglia Fm is not a transgressive contact,
as interpreted previously, but a submarine erosional
scar onlapped by gravity-displaced and pelagic
sediments (Bosellini et al., 1993, 1999, 2000). These
data indicate a major unconformity, associated with
an erosional hiatus of about 45 Myr, between the
Figure 3.2.3 - Breccia dyke with Tertiary clasts within the
Lower Cretaceous Maiolica Fm (Torre del Ponte).
Figure 3.2.2 - Black chert nodules in the Maiolica
Formation (Torre del Ponte).
two units. Therefore, this hiatus is more pronounced
basinward. It is not clear which mechanisms were
involved in the formation of this gap, but a huge
slump scar or prolonged activity of deep-sea currents
could explain this contact (Bosellini et al., 1993).
Stop 3.2:
The Lower Cretaceous Maiolica Formation and
its slump structures
The typical basinal deposits adjacent to the ACP
carbonates are represented by the well-known Maiolica
Fm (Figure3.2.1). It consists of white, thin-bedded,
micritic limestones with chert, rich in calpionellids
and nannoconus (Figure3.2.2). Various types of
synsedimentary deformations affect the Maiolica
Fm. Several slump features and “sedimentary dykes”
29 - P18
Volume n° 3 - from P14 to P36