Sedimentology and distribution of late quaternary calciturbidites and calcidebrites in the Mozambique Channel (Southwest Indian Ocean) - Université de Bretagne Occidentale Access content directly
Journal Articles Facies Year : 2021

Sedimentology and distribution of late quaternary calciturbidites and calcidebrites in the Mozambique Channel (Southwest Indian Ocean)

Lawrence Amy
  • Function : Author
Ewen Dennielou
  • Function : Author
Gwenael Jouet
  • Function : Author
  • PersonId : 847391

Abstract

Submarine gravity flow processes on carbonate platform slopes can lead to the deposition of calciturbidite and calcidebrite beds on the adjacent deep-water seafloor. Such deposits have been previously found to occur more frequently during sea-level highstands, leading to increased export of carbonates to the deep sea during interglacial periods. Here, we document a new occurrence of these types of event beds in cores near a series of volcano-cored carbonate platforms in the Mozambique Channel (SW Indian Ocean), describing them from a sedimentological perspective and analyzing the controls on their distribution. 32 event beds, located near four isolated platforms, are composed primarily of uncoated skeletal grains from primarily shallow-water and planktic taxa. Compositional analysis shows that planktic foraminifera are hydrodynamically sorted such that they form a greater proportion of the upper parts of event beds. Age models based on foraminifer δ18O isotope data allow for precise (ky-scale) dating of each gravity flow event; results show that events occurred with frequencies ranging from 2 to 4 events per 100,000 years over the past ~ 800 kyr regardless of the phase within the sea-level cycle (i.e., transgressive, regressive, highstand or lowstand). However, events were most frequent during periods, both relative and absolute, of highest sea level, and are therefore interpreted to be controlled in part by sea-level status or change, though additional causes are also possible.

Dates and versions

hal-03205876 , version 1 (22-04-2021)

Identifiers

Cite

John Counts, Stephan Jorry, Natalia Vazquez-Riveiros, Lawrence Amy, Ewen Dennielou, et al.. Sedimentology and distribution of late quaternary calciturbidites and calcidebrites in the Mozambique Channel (Southwest Indian Ocean). Facies, 2021, 67 (2), ⟨10.1007/s10347-021-00624-1⟩. ⟨hal-03205876⟩
45 View
0 Download

Altmetric

Share

Gmail Mastodon Facebook X LinkedIn More