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The markedly cyclic sedimentary successions of four late Pliocene to early Pleistocene slope turbidite systems exposed in eastern central Italy have been resolved into 31 high-frequency sequences. Chronological constraints from biostratigraphy and magnetostratigraphy indicate that these successions form a composite, partially overlapping stratigraphic record and sequence-bounding surfaces can be convincingly correlated with glacial oxygen isotope stages G2-60 (c. 2.65-1.7 Ma) inclusive. The studied successions, therefore, preserve an extraordinary and legible record of recurring, orbitally dictated glacio-eustatic sea-level fluctuations and provide an unprecedented opportunity to examine the deep-water sedimentary response to such high-frequency changes from an outcrop perspective.
Supplementary material: Sedimentological attributes of lithofacies identified in the studied successions are available at www.geolsoc.org.uk/SUP18549.
The onset of significant Northern Hemisphere glaciation from 3.0 to 2.5 Ma initiated a pattern of growth and decay of major continental ice sheets that resulted in rapid sea-level changes. Throughout the late Pliocene and early Pleistocene, these changes in sea level were dominated by the 41 ka periodicity of orbital obliquity and operated with magnitudes ranging between 25 ± 10 and 110 ± 20 m (Naish 1997). Over the last two decades, a wealth of outcrop-based studies have pointed out that, typically, the resulting shallow-marine stratigraphic record is outwardly cyclothemic, with each cyclothem representing a single Milankovitch oscillation in sea level (e.g. Clifton et al. 1988; Haywick et al. 1992; Kitamura et al. 1994; Naish et al. 1998; Massari et al. 2002; Abbott et al. 2005; Cantalamessa et al. 2005, 2006; Di Celma et al. 2005). In contrast, far fewer outcrop studies have documented the sedimentological expression of such highfrequency sea-level changes in off-shelf, slope settings (Ito & Katsura 1992; Pickering et al. 1999). One reason for this bias toward the study of unconformity-bound strata of shelf origin is the rarity of suitable late Neogene deep-water successions, which in most parts of the world underlie flooded continental margins. From this perspective, the markedly cyclic late Pliocene to early Pleistocene clastic successions exposed onland in eastern central Italy are particularly well suited, offering a unique opportunity to investigate the outcrop stratigraphy of deep-water depositional sequences deposited during glacio-eustatic changes in sea level.
The objectives of this paper are to (1) present a synthesis of the stratigraphy and chronology of these turbidite successions, which...