HR: 1340h
AN: PP43A-0655    [Abstracts]
TI: Land-Sea Correlation of Holocene Records in NW Iberian Peninsula
AU: * Gonzalez-Alvare, R
EM: raquelg@uvigo.es
AF: Dep. Xeociencias Mari¤as. Universidade de Vigo, Fac. de Ciencias do Mar. Campus Lagoas-Marcosende, Vigo, 36004 Spain
AU: Costas, S
EM: sucostas@uvigo.es
AF: Dep. Xeociencias Mari¤as. Universidade de Vigo, Fac. de Ciencias do Mar. Campus Lagoas-Marcosende, Vigo, 36004 Spain
AU: Bernardez, P
EM: pbernardez@uvigo.es
AF: Dep. Xeociencias Mari¤as. Universidade de Vigo, Fac. de Ciencias do Mar. Campus Lagoas-Marcosende, Vigo, 36004 Spain
AU: Frances, G
EM: gfrances@uvigo.es
AF: Dep. Xeociencias Mari¤as. Universidade de Vigo, Fac. de Ciencias do Mar. Campus Lagoas-Marcosende, Vigo, 36004 Spain
AU: Alejo, I
EM: ialejo@uvigo.es
AF: Dep. Xeociencias Mari¤as. Universidade de Vigo, Fac. de Ciencias do Mar. Campus Lagoas-Marcosende, Vigo, 36004 Spain
AB: Holocene climate fluctuations in the temperate region of the Northeast Atlantic have been established by comparing marine and terrestrial proxies. This work is based on suction-cores collected in the Cies Islands lagoon (NW Spain) and vibro-cores from the adjacent continental shelf. The lower Holocene marine record (9400-7000 yr BP) consists on sandy transgressive facies overlying fluvial Pleistocene deposits. During this time the continental shelf was dominated by high energy processes linked to the progressive and fast sea level rise. The rate of sea level rise sharply decelerated at 7000 yr BP and a high productive marine environment was fully established, as revealed by planktonic foraminifera assemblages and biogeochemical markers. In the terrestrial areas, peat deposits were formed beginning around 6000 yr BP in the deeper parts of the paleo-relief that was developed above the granitic basement. The peat was deposited in a fresh-water shallow coastal lake under warm and humid conditions that are brought about by prevailing SW winds. From 4800 yr BP, a progressive rainfall decrease provoked the lowering of the lake level and a weaker fluvial influence on the adjacent shelf. The prevailing eastern winds caused significantly drier conditions between 4000 and 3200 yr BP. During this period the coastal lake dried and the peat layer was covered by aeolian deposits. At the continental shelf a strong stratification of the water column induced a fall in the productivity. The end of this period is marked by the increase of storm regimes caused by a shift to prevailing SW winds. The last 3000 years are characterized by humid and warm conditions, and the enhancement of upwelling regime and terrestrial sediment supply. In Cies Islands, a sand barrier-lagoon complex was developed as a consequence of both the sea level rise and the inundation of the lower areas in the island.
DE: 4901 Abrupt/rapid climate change (1605)
DE: 4944 Micropaleontology (0459, 3030)
DE: 4964 Upwelling (4279)
SC: Paleoceanography and Paleoclimatology [PP]
MN: Fall Meeting 2005