High-resolution sequence stratigraphy of stacked fan delta sequences, Corinth Rift, Greece
Zusammenfassung der Projektergebnisse
The objectives of this study was to get information about external mechanisms which influence the internal depositional architecture of a Gilbert-type fan delta. Here, the focus is on the Pliocene-Pleistocene lllias delta complex which is situated on the southern coastline of the Gulf of Corinth on the Peloponnese, Greece. The methods applied in this study include a closer inspection of the local geology in the field, sedimentological logging of selected sections, gamma ray spectroscopy, X-ray powder diffraction (XRD) and analysis of palynofacies particles. Based on observations, four lithological sections were logged and sampled in detail and total of 35 samples were taken at the continental-marine transition zone bottomsets). The results show a correlation of specific facies types with analogous palynofacies findings and mineralogical compositions. The distribution of the mineralogical constituents reflects mostly the petrography of the source rocks in the hinterland of this llias delta. This similarity in composition suggests only minor influence of chemical weathering but supports physical weathering and mechanical breakdown of source rocks under arid climates. The analysis of organic particles reflects no significant fluctuations of the climate conditions during deposition of the investigated llias delta sequence. A final comparison and interpretation provides a correlation of the interstratified bottomsets with the continental vs. marine (+lacustrine) ratio of organic particles. Opaque particles and amorphous organic material are the predominaht particles groups in nearly all slides (80 - 90%). Terrestrial and lacustrine palynomorphs as well as structured phytoclasts are only sparse abundant in all samples. Marine palynomorphs (dinoflagellate cysts) are only abundant in 5 of 35 samples. The XRD analysis show high contents of quartz and calcite as well as of different mica modifications. Feldspar minerals are only spars in stock.
