caa a22 4500 463216342 CHVBK 20180405153157.0 cr unu---uuuuu 170326e20070601xx s 000 0 eng 10.1007/s00367-007-0078-y doi (NATIONALLICENCE)springer-10.1007/s00367-007-0078-y Palynological characterization of gassy sediments in the inner part of Ría de Vigo (NW Spain). New chronological and environmental data [Elektronische Daten] [C. Muñoz Sobrino, S. García-Gil, J. Diez, J. Iglesias] Palynological characterization of the pollen assemblages from core ZV-01 offers a reliable age record of shallow ‘gas seal' and ‘gas reservoir' sediments from the Ría de Vigo (NW Spain). Gassy sediments show a direct correspondence with the palynological assemblage zones (LPAZ) 2, 3 and 4, which range in age from 950 to 1510a.d. for the interval 81-176cm where gas is found. The facies acting as a seal would correspond to the sedimentation in the ria starting from 1510a.d. These assemblages also provide significant data which make it possible to reconstruct the palaeoenvironmental changes recorded in the sedimentary infill of the Ría de Vigo. The gassy horizon corresponds to the phase when riparian and mesophilous forest were better represented. This coincides with a relative high abundance of Lingulodinium machaerophorum, which indicates that the waters of the ria had been less renewed by oceanic waters and had a plentiful supply of continental nutrients. At that time, anoxic conditions resulted from restricted vertical circulation of seawater and/or high biological productivity. The dinocyst assemblages overlying and underlying the gassy horizon in core ZV-01 are clearly different from those concomitant with the accumulation of the gassy sediments. This suggests that oceanographic conditions in the Ría de Vigo may have changed several times during the time interval covered by our record. The weaker relationship between L. machaerophorum/Spiniferites spp., and simultaneous significant increases in Impagidinium spp. and Bitectatodinium tepikiense may indicate a greater intrusion of colder, more oceanic waters into the Ría de Vigo, which may have provoked intensification in upwelling during two periods, ca. 700-850a.d. and ca. 1500-1750a.d. Springer-Verlag, 2007 Muñoz Sobrino C. Departamento Bioloxia Vexetal e Ciencias do Solo, Universidade de Vigo, 36200, Vigo, Spain aut García-Gil S. Departamento Xeociencias Mariñas e Ordenación do Territorio, Universidade de Vigo, 36200, Vigo, Spain aut Diez J. Departamento Xeociencias Mariñas e Ordenación do Territorio, Universidade de Vigo, 36200, Vigo, Spain aut Iglesias J. Departamento Xeociencias Mariñas e Ordenación do Territorio, Universidade de Vigo, 36200, Vigo, Spain aut Geo-Marine Letters Springer-Verlag 27/2-4(2007-06-01), 289-302 0276-0460 27:2-4<289 2007 27 367 https://doi.org/10.1007/s00367-007-0078-y text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00367-007-0078-y text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Muñoz Sobrino C. Departamento Bioloxia Vexetal e Ciencias do Solo, Universidade de Vigo, 36200, Vigo, Spain aut NATIONALLICENCE 700 1- García-Gil S. Departamento Xeociencias Mariñas e Ordenación do Territorio, Universidade de Vigo, 36200, Vigo, Spain aut NATIONALLICENCE 700 1- Diez J. Departamento Xeociencias Mariñas e Ordenación do Territorio, Universidade de Vigo, 36200, Vigo, Spain aut NATIONALLICENCE 700 1- Iglesias J. Departamento Xeociencias Mariñas e Ordenación do Territorio, Universidade de Vigo, 36200, Vigo, Spain aut NATIONALLICENCE 773 0- Geo-Marine Letters Springer-Verlag 27/2-4(2007-06-01), 289-302 0276-0460 27:2-4<289 2007 27 367 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer