Publication Date:
2021-01-25
Description:
Continuous marine successions covering the Middle Miocene Climate Transition (MMCT;
-15-13.7 Ma) are scarce and the lack of a high-resolution magnetobiostratigraphic
framework hampers the construction of astronomically tuned age models for this time
interval. The La Vedova High Cliff section, exposed aiong the coast of the Cònero Riviera
near Ancona (Italy), is one of the few Mediterranean sections covering the critica1
time interval of the MMCT. Starting from an initial magnetobiostratigraphic age model,
a robust astronomica1 tuning was constructed for the intewal between 14.2 and 13.5
Ma, using geochemical element data and time series analysis. A shift in 6180 of bulk
sediment occurs between -13.92 and 13.78 Ma and can be related to the Mi3b oxygen
isotope event, reflecting the rapid expansion of the East Antarctic Ice Sheet in the
Middle Miocene. The onset of the 6°C CM6 carbon excursion is dated at -13.86 Ma. OUr
results confirm the proposition that these events coincide with a 405-kyr minimum in
eccentricity and a node in obliquity related t0 the -1.2 Myr cycle. From 13.8 Ma onwards,
distinct quadruplet cycles containing sapropelitic sediments are observed, suggesting a
causa1 connection between the main Middle Miocene cooling step and sedimentation and
circulation in the Mediterranean.
Description:
Published
Description:
19-36
Description:
2.2. Laboratorio di paleomagnetismo
Description:
reserved
Keywords:
Middle Miocene
;
Mediterranean
;
astronomical tuning
;
paleomagnetism
;
biostratigraphy
;
environmental changes
;
orbital forcing
;
sapropels
;
04. Solid Earth::04.04. Geology::04.04.10. Stratigraphy
;
04. Solid Earth::04.05. Geomagnetism::04.05.06. Paleomagnetism
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
book chapter
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