Oligocene carbonate ramps and platforms are widespread and though they are important carbonate reservoirs, detailed studies on the facies organization, platform type and internal architecture are scarce. Within this context, the Chattian carbonate units cropping out in Salento (southern Italy) allow detailed study of the distribution of skeletal components and facies architecture. The lower Chattian Castro Limestone, previously considered as a fringing reef, is reinterpreted as a distally steepened ramp with a distal talus induced by a paleo-escarpment in the substrate. Epiphytic biota and sediment dweller organisms thriving in seagrass meadows dominated production in the shallow-water euphotic zone. Seawards, large rotalid foraminifers dominated a detritic mesophotic zone. Near the edge of the escarpment, also in the mesophotic zone, luxurious growth of corals built discrete mounds with no evidences of wave-resistant growth fabrics. Basinward, 25° to 30° dipping clinobeds abut against the escarpment where coral rudstone/floatstone textures resulted from downfall of corals and sediments. The upper Chattian Porto Badisco Calcarenite represents a homoclinal ramp dominated by packstone textures. In the euphotic inner ramp, autochthonous biota suggests the occurrence of extensive seagrass meadows. Basinward, large rotalid packstone and small coral mounds developed in mesophotic conditions, and rhodolithic floatstone to rudstone and large lepidocyclinid packstone characterize the sediments of the deeper oligophotic zone. Comminuted skeletal debris, depleted of light-dependent organisms, typifies deposition in the dysphotic/aphotic zone. In both examples, the middle ramp (meso-oligophotic zones) was the most prolific in terms of carbonate production, whereas shallow-water seagrass-related production (euphotic) was much less important. Corals built mounds, also in the mesophotic zone but never reached sea level. Hydrodynamic conditions in the meso-oligophotic zone are better explained by breaking of internal waves, and their induced up- and down-slope currents, instead of the surface storm waves. © 2014 Elsevier B.V.

Carbonate ramp evolution during the Late Oligocene (Chattian), Salento Peninsula, southern Italy / Pomar, Luis; Guillem Mateu, Vicens; Michele, Morsilli; Brandano, Marco. - In: PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY. - ISSN 0031-0182. - STAMPA. - 404:(2014), pp. 109-132. [10.1016/j.palaeo.2014.03.023]

Carbonate ramp evolution during the Late Oligocene (Chattian), Salento Peninsula, southern Italy

BRANDANO, Marco
2014

Abstract

Oligocene carbonate ramps and platforms are widespread and though they are important carbonate reservoirs, detailed studies on the facies organization, platform type and internal architecture are scarce. Within this context, the Chattian carbonate units cropping out in Salento (southern Italy) allow detailed study of the distribution of skeletal components and facies architecture. The lower Chattian Castro Limestone, previously considered as a fringing reef, is reinterpreted as a distally steepened ramp with a distal talus induced by a paleo-escarpment in the substrate. Epiphytic biota and sediment dweller organisms thriving in seagrass meadows dominated production in the shallow-water euphotic zone. Seawards, large rotalid foraminifers dominated a detritic mesophotic zone. Near the edge of the escarpment, also in the mesophotic zone, luxurious growth of corals built discrete mounds with no evidences of wave-resistant growth fabrics. Basinward, 25° to 30° dipping clinobeds abut against the escarpment where coral rudstone/floatstone textures resulted from downfall of corals and sediments. The upper Chattian Porto Badisco Calcarenite represents a homoclinal ramp dominated by packstone textures. In the euphotic inner ramp, autochthonous biota suggests the occurrence of extensive seagrass meadows. Basinward, large rotalid packstone and small coral mounds developed in mesophotic conditions, and rhodolithic floatstone to rudstone and large lepidocyclinid packstone characterize the sediments of the deeper oligophotic zone. Comminuted skeletal debris, depleted of light-dependent organisms, typifies deposition in the dysphotic/aphotic zone. In both examples, the middle ramp (meso-oligophotic zones) was the most prolific in terms of carbonate production, whereas shallow-water seagrass-related production (euphotic) was much less important. Corals built mounds, also in the mesophotic zone but never reached sea level. Hydrodynamic conditions in the meso-oligophotic zone are better explained by breaking of internal waves, and their induced up- and down-slope currents, instead of the surface storm waves. © 2014 Elsevier B.V.
2014
corals; facies analysis; large benthic foraminifera; seagrass; carbonate ramp; oligocene
01 Pubblicazione su rivista::01a Articolo in rivista
Carbonate ramp evolution during the Late Oligocene (Chattian), Salento Peninsula, southern Italy / Pomar, Luis; Guillem Mateu, Vicens; Michele, Morsilli; Brandano, Marco. - In: PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY. - ISSN 0031-0182. - STAMPA. - 404:(2014), pp. 109-132. [10.1016/j.palaeo.2014.03.023]
File allegati a questo prodotto
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/570797
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 78
  • ???jsp.display-item.citation.isi??? 73
social impact