The emergence of volcanic oceanic islands on a slow-moving plate: The example of Madeira Island, NE Atlantic

In oceanic islands, well age-constrained deposits containing arthropod somatofossils (body fossils) are rare. However, when available, these are important for providing empirical and independent minimum ages for molecular phylogenetic dating and complementary data on taxonomy, evolution and palaeobiogeography information of the biological groups found as fossils. This is especially important for taxa that speciated within oceanic islands, many becoming single island endemics (SIE). Recently, associated with a 1.3 Ma (Calabrian) fluvial and lacustrine sedimentary deposit from Porto da Cruz in Madeira Island (Fig. 1), a wing, putatively identified as Hymenoptera, was found. Here we describe this wing fossil as belonging to Ichneumonidae, a group with ca. 30% of SIE in Madeira Island. Moreover, this is the first somatofossil of ichneumonid parasitic wasps found in Madeira Island and in Macaronesian islands (i.e. Azores, Madeira, Canaries and Cabo Verde).

Download Full-text

Spatial and temporal characterization of the exposure of island-associated cetacean populations to whale-watching in Madeira Island (NE Atlantic)

Regional Studies in Marine Science ◽

10.1016/j.rsma.2021.102084 ◽

2021 ◽

pp. 102084

Author(s):

Annalisa Sambolino ◽

Filipe Alves ◽

Marc Fernandez ◽

Anja Badenas Krakauer ◽

Rita Ferreira ◽

...

Keyword(s):

Ne Atlantic ◽

Whale Watching ◽

Madeira Island

Download Full-text

Interplay of deep-marine sedimentary processes with seafloor morphology offshore Madeira Island (Central NE-Atlantic)

Marine Geology ◽

10.1016/j.margeo.2021.106675 ◽

2021 ◽

pp. 106675

Author(s):

C. Roque ◽

F.J. Hernández-Molina ◽

P. Madureira ◽

R. Quartau ◽

V. Magalhães ◽

...

Keyword(s):

Ne Atlantic ◽

Sedimentary Processes ◽

Seafloor Morphology ◽

Madeira Island

Download Full-text

Hotspot volcanism close to a passive continental margin: the Canary Islands

Geological Magazine ◽

10.1017/s0016756898001447 ◽

1998 ◽

Vol 135 (5) ◽

pp. 591-604 ◽

Cited By ~ 216

Author(s):

J. C. CARRACEDO ◽

S. DAY ◽

H. GUILLOU ◽

E. RODRÍGUEZ BADIOLA ◽

J. A. CANAS ◽

...

Keyword(s):

Mantle Plume ◽

Canary Islands ◽

Continental Margin ◽

Structural Evolution ◽

Oceanic Islands ◽

Lithospheric Deformation ◽

Igneous Activity ◽

Slow Moving ◽

Rift Zones ◽

Canarian Archipelago

The Canarian Archipelago is a group of volcanic islands on a slow-moving oceanic plate, close to a continental margin. The origins of the archipelago are controversial: a hotspot or mantle plume, a zone of lithospheric deformation, a region of compressional block-faulting or a rupture propagating westwards from the active Atlas Mountains fold belt have been proposed by different authors. However, comparison of the Canarian Archipelago with the prototypical hotspot-related island group, the Hawaiian Archipelago, reveals that the differences between the two are not as great as had previously been supposed on the basis of older data. Quaternary igneous activity in the Canaries is concentrated at the western end of the archipelago, close to the present-day location of the inferred hotspot. This is the same relationship as seen in the Hawaiian and Cape Verde islands. The latter archipelago, associated with a well-defined but slow-moving mantle plume, shows anomalies in a plot of island age against distance which are comparable to those seen in the Canary Islands: these anomalies cannot therefore be used to argue against a hotspot origin for the Canaries. Individual islands in both archipelagoes are characterized by initial rapid growth (the ‘shield-building’ stages of activity), followed by a period of quiescence and deep erosion (erosion gap) which in turn is followed by a ‘post-erosional’ stage of activity. The absence of post-shield stage subsidence in the Canaries is in marked contrast with the major subsidence experienced by the Hawaiian Islands, but is comparable with the lack of subsidence evident in other island groups at slow-moving hotspots, such as the Cape Verdes. Comparison of the structure and structural evolution of the Canary Islands with other oceanic islands such as Hawaii and Réunion reveals many similarities. These include the development of triple (‘Mercedes Star’) rift zones and the occurrence of giant lateral collapses on the flanks of these rift zones. The apparent absence of these features in the post-erosional islands may in part be a result of their greater age and deeper erosion, which has removed much of the evidence for their early volcanic architecture. We conclude that the many similarities between the Canary Islands and island groups whose hotspot origins are undisputed show that the Canaries have been produced in the same way.

Download Full-text