11
views
0
recommends
+1 Recommend
1 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      BIO-SEDIMENTARY SIGNATURES OF HIGH-FREQUENCY SALINITY/SUBAERIAL EXPOSURE CHANGES: EXAMPLES FROM THE OXFORDIAN OF PORTUGAL (CABAÇOS FORMATION)

      Read this article at

      ScienceOpenPublisherDOAJ
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          <p class="abstract-testo">The detailed sedimentary and micropalaeontological analysis of a complex association of continental to marginal-marine deposits from the Oxfordian of Portugal (Cabaços Formation) has allowed the recognition of high-frequency, subtle changes in the environmental conditions. The main factors controlling the palaeobiological responses to such minor-scale fluctuations were also identified. Two factors have shown to be especially significant: subaerial exposure duration and frequency (estimated by assigning type of features to the exposure index) and salinity trends, as suggested by the sedimentary and fossil records. In the west of the basin, salinity fluctuations were much stronger and more frequent (fresh- brackish-restricted marine-hypersaline), and subaerial exposure more marked for longer periods, than in the east of the basin. The microfossil assemblages, as a whole, but in particular the ostracod faunas, show differences in abundance, diversity, dominant species, degree of intrageneric and intraspecific variations, both along the successions and between west and east. The western populations seem to have been much less stable, which suggests that high-frequency changes in salinity (more than its absolute values) and degree of exposure were the most important controls on the palaeobiota.</p><p class="abstract-pdf"><a href="images/docs/contents/110-1/Azaredo_et_Cabral%202004.pdf"> <img style="vertical-align: middle;" src="images/icons/pdf38.jpg" alt="pdf38" width="38" height="38" /></a><a href="images/docs/contents/110-1/Azaredo_et_Cabral%202004.pdf">PDF </a></p>

          Related collections

          Author and article information

          Journal
          Rivista Italiana di Paleontologia e Stratigrafia
          Università degli Studi di Milano
          01 March 2004
          : 110
          : 1
          Article
          0267ed895e054fa9a186adf980d4eba8
          10.13130/2039-4942/6293
          39a15b4b-7cf9-48ba-8876-a709ca18669a

          RIPS is published under a Creative Commons Attribution-NonCommercial-NoDerivatives Licence 4.0 International (CC BY-NC-ND 4.0). The journal allows the author(s) to hold the copyright without restrictions. To view a copy of this license, visit https://creativecommons.org/licenses/by-nc-nd/4.0/

          History
          Categories
          Geology
          QE1-996.5
          Paleontology
          QE701-760

          Geology & Mineralogy,General geosciences,General earth science,Paleontology,Geosciences

          Comments

          Comment on this article