19 documents found, page 1 of 2

Contourite depositional systems offshore Madeira Island: Decoding the deepwater...

There is still a great unawareness about the deep-water circulation in the NE-Central Atlantic since the Late Cretaceous. The morphology, sedimentary stacking pattern and distribution of contourite depositional systems have been widely used as paleoceanographic indicators, given clues about the relative velocity and pathways of bottom currents past-circulation. We present here evidence of a new contourite featu...

Interplay of deep-marine sedimentary processes with seafloor morphology offshor...

The deep-water sedimentary processes and morphological features offshore Madeira Island, located in the Central-NE Atlantic have been scantly studied. The analysis of new multibeam bathymetry, echo-sounder profiles and few multichannel seismic reflection profiles allowed us to identify the main geomorphologies, geomorphic processes and their interplay. Several types of features were identified below 3800 m wate...

Pleistocene coralline algal buildups on a mid-ocean rocky shore : Insights into...

Located on the northern coast of Santa Maria Island (Azores Archipelago, central North Atlantic), the Lagoinhas section preserves a carbonate buildup correlated with Marine Isotope Substage (MIS) 5e, the warmest interval of the Last Interglacial. The buildup is formed mainly by crustose coralline algae (CCA) identified as Spongites sp., and some subordinate crusts of Lithophyllum sp. and Neogoniolithon sp., as ...

Recent geospatial dynamics of Terceira (Azores, Portugal) and the theoretical i...

Ongoing work shows that species richness patterns on volcanic oceanic islands are shaped by surface area changes driven by longer time scale (>1 ka) geological processes and natural sea level fluctuations. A key question is: what are the rates and magnitudes of the forces driving spatial changes on volcanic oceanic islands which in turn affect evolutionary and biogeographic processes? We quantified the rates of...

Recent geospatial dynamics of Terceira (Azores, Portugal) and the theoretical i...

Ongoing work shows that species richness patterns on volcanic oceanic islands are shaped by surface area changes driven by longer time scale (>1 ka) geological processes and natural sea level fluctuations. A key question is: what are the rates and magnitudes of the forces driving spatial changes on volcanic oceanic islands which in turn affect evolutionary and biogeographic processes? We quantified the rates of...

Contourite drift off Madeira Island (Northeast Atlantic) and implications to Ce...

During the last decades several works have been carried out on the morphosedimentary processes driven by bottom-currents in several continental margins and abyssal plains worldwide. However these processes still remain poorly understood on deep-water settings and particularly around oceanic islands. This study is focused on the offshore of Madeira Island (Portugal), which is located in the Northeast Atlantic at...

The insular shelves of the Faial-Pico Ridge (Azores archipelago): a morphologic...

Shelves surrounding reefless volcanic ocean islands are formed by surf erosion of their slopes during changing sea levels. Posterosional lava flows, if abundant, can cross the coastal cliffs and fill partially or completely the accommodation space left by erosion. In this study, multibeam bathymetry, high-resolution seismic reflection profiles, and sediment samples are used to characterize the morphology of the...

Génese e desenvolvimento de plataformas insulares vulcânicas - o caso da Ilha d...

Assessing landslide movements in volcanic islands using near-shore marine geoph...

Morphology of the Faial Island shelf (Azores) : the interplay between volcanic,...