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Nutrients, sea level and tectonics: constrains for the facies architecture of a Miocene carbonate ramp in central Italy.
- Source :
-
Terra Nova . Aug2002, Vol. 14 Issue 4, p257-262. 6p. - Publication Year :
- 2002
-
Abstract
- ABSTRACT In the western part of the central Apennines, Lower–Middle Miocene carbonates were deposited on a tropical–subtropical carbonate ramp. They record two long-term cycles, the first of which is illustrated in this paper. Between 21 and 17.5 Ma, Miocene carbonates, paraconformably overlying the Cretaceous limestones, record a transgressive event during a time of global (2nd order) sea-level lowstand. It is postulated that this deviation is related to an increase in tectonic subsidence. Between 17.5 Ma and 16–15 Ma, with a progressive relative sea-level rise, the inner–middle ramp facies belt stepped back, whereas the bryozoan-dominated outer ramp facies belt stepped back but simultaneously prograded. This bloom of suspension-feeding organisms is interpreted to reflect an increased nutrient availability, hence a change from oligotrophic to eutrophic conditions. Strontium-isotope dates constrain correlation of the second phase with a eutrophic event possibly linked to the influence of the neighbouring Apenninic accretionary wedge and foredeep system. [ABSTRACT FROM AUTHOR]
- Subjects :
- *STRATIGRAPHIC geology
*FACIES
Subjects
Details
- Language :
- English
- ISSN :
- 09544879
- Volume :
- 14
- Issue :
- 4
- Database :
- Academic Search Index
- Journal :
- Terra Nova
- Publication Type :
- Academic Journal
- Accession number :
- 7122776
- Full Text :
- https://doi.org/10.1046/j.1365-3121.2000.00419.x