Sedimentary sources of the mud-breccia and mud volcanic activity in the Western Alboran Basin

Abstract

During the TTR-17 Leg 1 cruise in the West Alboran Basin, gravity cores were acquired from three mud volcanoes (MVs): Dhaka, Carmen and the recently discovered Maya. This paper presents micropaleontological and radiocarbon dating results from the three mud volcanoes, using cores containing mud breccias overlain by and interbedded with hemipelagic sediments. At Dhaka MV, the mud-breccia matrix contains very rare Holocene planktonic foraminifera associated with abundant reworked specimens of mixed Late Cretaceous to Mio-Pliocene age. At Carmen MV, the reworked assemblage is dominated by Miocene to Pliocene foraminifera occurring together with rare Late Cretaceous species while at Maya MV the mud-breccia matrix is characterized by the dominance of Santonian-Maastrichtian forms, with subordinate Tertiary species. Shallow-water benthic foraminifera such as Ammonia spp. and Elphidium spp. are generally rare and randomly distributed, but present at all studied sites. Based on these results, we suggest that the main sediment source of the mud-breccia extruded at Dhaka, Carmen and Maya MVs is possibly the lowermost overpressured olistostromic Unit VI (Aquitanian?-Burdigalian). Differences in the micropaleontological composition of the mud-breccia matrix at different sites are most likely due to differences in the main source layer and in the plumbing systems underneath the MVs. Radiocarbon dating of hemipelagic sediments associated to the mud-breccia allowed to define the age of the latest extrusion activities (>0.27 ka to > 15.6 ka BP), which seem to be episodic, short-lived and recurrent over thousands of years.

Systematic taxonomy of theTrilobatus sacculiferplexus and descendantGlobigerinoidesella fistulosa(planktonic foraminifera)

“…13, fig. 3a-c), Coccioni et al (1997), Odin et al (1997), Spezzaferri et al (2002) and Gennari et al (2013). Spezzaferri et al (2002, p. 245) listed T. subsacculifer as a warm-water planktonic indicator.…”

Mud Volcanism in a Canyon: Morphodynamic Evolution of the Active Venere Mud Volcano and Its Interplay With Squillace Canyon, Central Mediterranean

“…Visual observations of the seafloor surface may, therefore, not be able to fully resolve or ground truth backscatter variations (e.g., Paull et al, 2015) but requires sediment cores to investigate the shallow subsurface (Zitter et al, 2005). By dating of sediments overlying the mud breccia (Gennari et al, 2013) or according to the local sedimentation rate it has been possible to constrain the timing of extrusive activity of MVs on regional scales (Ceramicola et al, 2014b;Rabaute & Chamot-Rooke, 2007). Similarly, precise coring of mudflow deposits at MVs mapped by AUV, may allow to reconstruct their extrusive dynamics and to constrain their morphological evolution over time.…”

Mollusca from a species-rich deep-water <em>Leptometra</em> community in the Alboran Sea

“…The Alboran Sea contains a wide variety of ecologically interesting seafloor structures, such as submarine canyons of varying size (Baro et al 2012), carbonate mounds (Lo Iacono et al 2008, Pardo et al 2011, submarine structures caused by fluid emissions such as pockmarks and mud volcanoes (Somoza et al 2012, Gennari et al 2013, and seamounts and banks of different heights and geologic origins (Palomino et al 2011). The diverse seafloor morphology and the location and peculiar hydrodynamic features of the Alboran Sea, with the mixing of Atlantic and Mediterranean waters, promote a wide diversity of habitats and associated biota that have been little studied in specific bathyal areas, especially at a microfaunal level (Salas 1996).…”