In Italy, the cyclostratigraphy observed in the Aptian-Albian
marly limestones [ De Boer, 1982; Schwarzacher and
Fischer, 1982; Herbert and Fischer, 1986; Herbert et
al., 1994] does not generally continue into the underlying
Maiolica Formation, which is a less marly, thin bedded, pelagic
limestone. As the top of the Maiolica coincides closely with
polarity chron CM0, the young M-sequence polarity chrons are within
the Maiolica. In two sections in the top of the Maiolica (Cismon
and Gorgo a Cerbara), Herbert [1992] has shown that bedding
bundles and individual beds correspond closely to orbital
eccentricity (100 kyr) and precession (
20 kyr) cycles,
respectively. This has provided a means of determining the duration
of polarity chrons in the CM0-CM3 interval.