New charophytes from the Upper Jurassic of the Lusitanian Basin (Portugal)

In the Lusitanian Basin (west-central Portugal), Upper Jurassic (Oxfordian) sediments were investigated in order to identify palaeontological assemblages of charophytes. Systematic studies were undertaken on specimens obtained from four field sections (Pedrógão, Vale de Ventos, Memória and Valverde). These studies revealed the presence of new forms of Porocharaceae (Porochara pedunculata n. sp) and of forms previously unknown in this region (Auerbachichara cf. saidakovskyi), as well as P. raskyae, P. minima, P. fusca, P. sulcata, P. kimmeridgensis, Aclistochara longiformis and Porochara sp. Comparison of the charophyte palaeofloras recognized in all of the studied sections has allowed the definition of three different assemblages which, coupled with other data, help to correlate these successions of Early (?) to Middle (Late?) Oxfordian age.

[1]  M. C. Cabral,et al.  BIO-SEDIMENTARY SIGNATURES OF HIGH-FREQUENCY SALINITY/SUBAERIAL EXPOSURE CHANGES: EXAMPLES FROM THE OXFORDIAN OF PORTUGAL (CABAÇOS FORMATION) , 2004 .

[2]  V. Wright,et al.  The Middle–Late Jurassic forced regression and disconformity in central Portugal: eustatic, tectonic and climatic effects on a carbonate ramp system , 2002 .

[3]  J. Colin,et al.  Sinuocythere n. gen. (Ostracoda, Limnocytheridae, Timiriaseviinae); a new genus of limnic ostracode from southern Tethyan Middle and Upper Jurassic , 2000 .

[4]  M. Schudack.  The charophytes of the Lower Saxony Basin (Upper Jurassic-Berriasian): Local zonation, supraregional correlation and paleoecology , 1996 .

[5]  M. Schudack,et al.  European Mesozoic-Cenozoic charophyte biozonation , 1996 .

[6]  M. Aurell,et al.  The Middle-Upper Jurassic ooliticironstone level in the Iberian range (Spain). Eustatic implications , 1994 .

[7]  L. Legarreta.  Evolution of a Callovian-Oxfordian carbonate margin in the Neuquén Basin of west-central Argentina: facies, architecture, depositional sequences and global sea-level changes , 1991 .

[8]  J. P. Colin,et al.  La stratigraphie sequentielle et son application aux correlations chronostratigraphiques dans le Jurassique du bassin de Paris , 1987 .

[9]  J. Colin,et al.  Taxonomie et paléoécologie de nouveaux ostracodes limniques Candonidae dans l'Oxfordien (Jurassique supérieur) du Portugal , 2002 .

[10]  R. Pereira,et al.  Overview of microfossil assemblages and palaeoecological signatures in the Middle-Upper Jurassic transitional successions from the Lusitanian Basin, Portugal , 2002 .

[11]  V. Wright,et al.  The middle-up-per Jurassic disconformity in the lusitanian basin, Portugal: preliminary facies analysis and evidence for palaeoclimatic fluctuaction , 1998 .

[12]  I. Soulié-Märsche,et al.  Fiabilité des données morphométriquesen micropaleontologie: Exemple des Charophytes , 1991 .

[13]  Raymond C. Wilson.  Mesozoic Devepelopment Of The Lusitanian Basin, Portugal , 1988 .

[14]  J. Gall,et al.  Remarquables gisements fossilifèresd'Europe occidentale (fine fossiliferous localities in Western Europe) , 1980 .

[15]  Henning Horn af Rantzien.  Morphological types and organ-genera of Tertiary charophyte fructifications. , 1959 .