Staggered cold-water coral mound build-up on an Alboran ridge during the last deglacial (East Melilla Mound Field, western Mediterranean) - Université d'Angers Accéder directement au contenu
Article Dans Une Revue Marine Geology Année : 2022

Staggered cold-water coral mound build-up on an Alboran ridge during the last deglacial (East Melilla Mound Field, western Mediterranean)

Résumé

The start-up, build-up and demise of cold-water coral mounds are governed by environmental changes at global, regional and local scales. Whilst the formation of cold-water coral mounds across the globe is widely documented to follow interglacial-glacial cycles, less is known about their response to local environmental fluctuations during short time intervals. This study investigates the local variations in coral mound build-up along Brittlestar Ridge I (East Melilla Coral Province, Southeast Alboran Sea) by comparing three on-mound gravity cores collected ∼1 km apart, together with five previously described on-mound records, along a longitudinal transect on the ridge crest. Radiocarbon foraminiferal dating associated to U-series coral dating allowed to correlate the different records and to estimate mound aggradation rates, whilst grain-size analysis provided information on bottom current velocities. Prior to a rapid period of coral mound build-up initiated at ∼14.75 ka BP, the three cores present an occurrence of cm-thick bryozoan-dominated intervals nearly entirely consisting of the erect cheleistome Buskea dichotoma. Offsets between benthic foraminiferal and coral ages suggest that older dead allochtonous benthic foraminifera are possibly eroded from neighbouring settings, transported and deposited within the coral framework. In contrast, younger benthic foraminifera would develop on dead coral framework during periods of reef stagnation. The comparison of all cores indicates that mound build-up along the ridge did not follow the same timing during the last ∼16 kyr and that mound aggradation was marked by a staggered dynamic. Both local differences in bottom current velocities and patchiness of other key environmental actors (e.g. substrate availability) are suspected to drive the observed staggered mound build-up. Cold-water coral mound build-up shows important differences during Greenland Interstadial 1 (i.e. the Bølling-Allerød) and the Holocene, hence exemplifying how local environmental variability may overprint global and regional climate variability over short time periods.
Fichier principal
Vignette du fichier
1-s2.0-S0025322723000063-main.pdf (9.06 Mo) Télécharger le fichier
Origine : Publication financée par une institution
Licence : CC BY NC - Paternité - Pas d'utilisation commerciale

Dates et versions

hal-04277998 , version 1 (09-11-2023)

Licence

Paternité

Identifiants

Citer

R. Fentimen, Eline J Feenstra, Andres Rueggeberg, Efraim Hall, Antonietta Rosso, et al.. Staggered cold-water coral mound build-up on an Alboran ridge during the last deglacial (East Melilla Mound Field, western Mediterranean). Marine Geology, 2022, 457, pp.106994. ⟨10.1016/j.margeo.2023.106994⟩. ⟨hal-04277998⟩
7 Consultations
6 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More