The Westernmost Tethys Blog

08/27/2019

Paleogene sedimentary evolution of the Alicante Trough

Filed under: Betics — Tags: , , , , — messinianalicante @ 7:52 AM

A new work to illustrate a changes in the evolution of the Alicante Trough located to the southeastern part of the sudiberian paleomargin and north to the supposed elevated sea floor forming a marine platform.  Here the link to the work in Repository of the UA.

The Paleogene Alicante Trough of the South-Iberian Margin (External Betic Zone) consists of a narrow sedimentary basin that has active margins  located to the north-northwest (active mainly during the Eocene) and to the south-southeast (active during the Oligocene). Both margins, consisting of shallow unstable platforms, were the source areas for the external-platform slope (in the opposite margins) and deep-basin (in the middle) depositional realms. The southern margin, lost under the Mediterranean Sea, is recognized only by the reconstructed Oligocene slope sediments.

Geological sketch map of the Alicante region of the study area (External Betic Zone) within the Internal Prebetic (North-Northeast sector) and Intermediate sub-Domains (south-southwest sector).

The eight successions studied, on opposites external-platform-slope margins and the deep within the central part of the basin, lead us to divide the basin into two depositional realms: the subsident Western Depositional Area (WDA) and the not subsident Eastern Depositional Area (EDA). This study has also enabled us to divide the infilling of the basin into two depositional sequences: Eocene p.p. (EDS) and Oligocene p.p. (ODS) in age, respectively, bound by two sequence boundaries (unconformities) at the Early Eocene (P6 zone) and Early Oligocene (P19 zone). The EDSand ODSare comprised of turbiditic and olisthostromic deposits and frequently slumps, evidencing an active tectonic in the margin-basin system.

Stratigraphy, correlation, sampling localization and main sedimentary cycles recognized (Eocene p.p. and Oligocene p.p.) of the studied successions in the Western (WDA) and Eastern EDA) Depositional Areas.

 

Chronostragraphy of the studied successions.

The correlation of the Paleogene sedimentary reconstructed in the Alicante Trough with other four synthetic successions throughout the External (three in the Subbetic Domain) and one in the Internal Betic Zone indicate a Paleogene generalised deformational framework.

Main Eocene and Oligocene sedimentary realms and location of the studied successions in the Internal Prebetic and Intermediate sub-Domains.

Sedimentary record and new sequential stratigraphy in the study area.

In addition, this evolution is contemporaneous to the Pyrenean, Iberian and the Nevado-Filabride Alpine deformation. The Paleogene tectonic recognised in the External Betic Zone is younger since the main orogenic deformation took place in the late Burdigalian to early Tortonian.

Correlation among synthetic Paleogene successions and main unconformities in the Betic Chain. Key: ALI, Alicante succession (Internal Prebetic-Intermediate sub-Domains); SB, Bullas succession, (Murcia province, Middle Subbetic sub-Domain); SPM, Piñar-Moreda succession, (Granada province, Middle Subbetic sub-Domain); SHC, Malaga succession (High Chain, Internal Subbetic sub-Domain); MSE, Sierra Espuña succession (Murcia province, Internal Betic Zones, Malaguide Complex).

The origin of these early tectonics is discussed in relation to the Nevado-Filabride Alpine deformation.

Palaeogeography and geodynamic model of the Western Tethys during Late Cretaceous and Late Oligocene. Numbers 1 to 5 indicate the location of the correlated successions.

Cite as: Guerrera, F., Estévez, A., López-Arcos, M., Martín-Martín, M., Martín-Pérez, J.A., Serrano, F. (2006): Paleogene tectono-sedimentary evolution of the Alicante Trough (External Betic Zone, SE Spain) and its bearing on the timing of the deformation of the South-Iberian Margin. Geodinamica Acta, 19 (2): 87-101. doi: 10.3166/ga.19.87-101

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