RT Journal Article
T1 Basalt Mounds and Adjacent Depressions Attract Contrasting Biofacies on a Volcanically Active Middle Miocene Coastline  (Porto Santo, Madeira Archipelago, Portugal)
A1 Santos, Ana
A1 Johnson, Markes
A1 Baarli, Gudveig
A1 Marques da Silva, Carlos
A1 Cachão, Mario
A1 Ledesma-Vázquez, Jorge
A1 Mayoral Alfaro, Eduardo
A1 Santos, ana
K1 Paleoicnología
K1 Paleontología
AB Small basalt mounds with encrusting corals and inter-mound carbonate sandy zones with abundant rhodoliths corresponding to an ancient intertidal to shallow-water sea floor areexhumed from overlying volcaniclastic deposits and basalt lava flows at Pedra de Águaon Ilhéu de Cima off Porto Santo, one of the islands of the northeastern Atlantic MadeiraArchipelago (Portugal). The mounds rise above the surrounding surface to attain a heightof about half a meter. The mounds exhibit an in situ assemblage of hermatypic corals,dominated by Tarbellastrae and Solenastrea. They formed as massive (4.2 × 1.9 m average length), isolated patches in a protected bay close to shore eroded from an uneven basalt substrate dated to the Middle Miocene (14 to 15 Ma). The slightly deeper zones between basalt mounds, which alternate with them over a distance of more than 20 m, are covered mainly by coarse carbonate sand on which rhodoliths up to 14.8 cm in diameter are preserved in situ. Many rhodoliths have grown around a basalt core, which indicates a local, nearshore source for development. Complete burial of the elevated coralsettlements and intervening low zones populated by rhodoliths occurred when volcaniclapilli and other tephra catastrophically buried this part of the rocky shore. The rhodolithsand coral assemblages exposed in an area of 12 m2 were canvassed systematically usingcensus quadrats to quantify community relationships.
PB Springer
SN 0172-9179 (Print)
SN 1612-4820 online
YR 2012
FD 2012-11-19
LK https://hdl.handle.net/10272/24839
UL https://hdl.handle.net/10272/24839
LA eng
NO Santos, A., Mayoral, E., Johnson, M.E. et al. Basalt mounds and adjacent depressions attract contrasting biofacies on a volcanically active Middle Miocene coastline (Porto Santo, Madeira Archipelago, Portugal). Facies 58, 573–585 (2012). https://doi.org/10.1007/s10347-012-0301-9
DS Repositorio Institucional de la Universidad de Huelva
RD 31 may 2026