THE MEDITERRANEAN LOWER CRETACEOUS

Table 2
The Early Cretaceous Time Scale
Epoch Age
Late Cretaceous Cenomanian .
retaceous
U
Early
Albian
Aptian
Barremian
Hauterivian
Valanginian
Berriasian
Late Jurassic Tithonian
after Casey,
1964
б
-100-
6
-106-
6
-112-
6
118-
6
124-
6
130-
6
136-
Boundary and duration in m. y.
after Van H i n t e,
1976
8
-100-
-108-
7
-115-
6
-121-
5
-126-
5
-131^
К: Alb
KA Pt
К
4 KBer
-135
after H a r 1 a n d
et al., 1982
According to the different authors, the duration of the Early Cretaceous is
between 36 and 46 million years. The average duration of the Early Cretaceous is
about 6 million years, the maximum duration being 15.5 million years (for the Albian
Age).
Irrespective of some difficulties connected with the application of radiometric
methods, they define along general lines the time interval of the Early Cretaceous
and provide data for a number of interpretations. For example, according to the
studies of P о 1 e v a y a et al. (По л е в а я et al., 1960), in the section of the
Lower Cretaceous along the Bolshaya Laba river the glauconite from two samples
(samples 2603 and VIII) is divided by a marl formation about 300 m thick. These
samples differ by 3 million years in age, which suggests sedimentation rate of about
0.1 mm/year.
12