Calcareous nannoplankton from the Neogene of the NW-Peloponnes, Greece

Frydas, Dimitris

doi:10.1127/njgpm/1987/1987/274

Cited by 14 publications

(7 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Currently the southern margin of the Corinth Rift consists of an array of active north-dipping normal faults (Fig. 1), the oldest of which are known to have activated in the mid-Pleistocene based on synsedimentary delta deposits and seismic sections (Kontopoulos and Doutsos, 1985;Frydas, 1987;Ori, 1989;Leeder et al, 2008;Ford et al, 2016).…”

Section: Calibrating Bedrock Erodibilitymentioning

confidence: 99%

New constraints on bedrock erodibility and landscape response times upstream of an active fault

et al. 2020

View full text Add to dashboard Cite

Considerable progress has been made in modelling the response of rivers to tectonic perturbation in order to decode the tectonic signals embedded in river long profiles and planform geometry. Whilst studies have showed the importance of rock type on the morphology of rivers responding to tectonics on a local scale, these effects are often not captured in landscape evolution models. In fact, current models of fluvial response to tectonic perturbation such as active faulting require carefully collected data sets to fully constrain or calibrate key parameters, including the effect of bedrock lithology on substrate erodibility and timescales for tectonic signal propagation in bedrock river systems. Here we constrain the role of bedrock in controlling fluvial incision for a 240 km 2 catchment draining into the Gulf of Corinth, which has excellent tectonic constraints and a variety of bedrock lithologies. An active normal fault at the downstream end of the catchment (the East Eliki Fault) is known to have initiated at 0.7 Ma, with average Quaternary uplift and incision rates of 1.00-1.25 mm/yr. The initiation of the East Eliki Fault is recorded in the river as a prominent knickzone 7-16 km upstream of the fault. Detailed field data collected within this catchment at 500 m intervals along the main channel length at this tectonically wellconstrained field site show an order of magnitude increase in river channel slopes (y/x = 0.02 to 0.18) and stream powers (1 kWm -2 to 27 kWm -2 ) at the lithological boundary between weak and resistant bedrock. The weak conglomerates and strong limestones have Schmidt hammer compressive strengths of ca. 30 and 50 respectively, based on in-situ rock strength measurements. Consequent erodibility values of 1.8 ± 0.3 × 10 -14 and 5 -6 ± 2 × 10 -15 ms 2 kg -1 show a factor of three to four decrease in erodibility for a two-fold increase in rock strength. A simple simulation of tectonic signal propagation through the river catchment based on these erodibility values indicates that the observed plan view position of the knickpoint is consistent with our calculated knickpoint positions based on erodibility values derived from incision rate and stream power data. However, the tectonic signal associated with faulting would have propagated completely through the catchment within 1 Ma if it were entirely composed of weak rock for similar climatic and tectonic conditions, indicating that lithology has a major control on landscape response times.Our results help constrain the effect of lithology on river channel geometry and allow erosional parameters to be derived that are crucial for effective modelling of tectonic rates from topography.

show abstract

Section: Calibrating Bedrock Erodibilitymentioning

confidence: 99%

New constraints on bedrock erodibility and landscape response times upstream of an active fault

et al. 2020

View full text Add to dashboard Cite

show abstract

“…As in the Corinth graben, deposition in the Rio graben has occurred in two separate sedimentary cycles. T h e older one consists of alternating sand silt, silty clay and massive clay or laminated beds, deposited during the upper Pliocene (Frydas 1987) into a lacustrine to shallow marine environment. As can be seen from a borehole in the Patras Gulf these sediments attain a thickness of about 1800 m. T h e younger sedimentary cycle comprises coarse sediments which cover the older sediments unconformably.…”

Section: Sedimentary Fariesmentioning

confidence: 99%

The Corinth‐Patras rift as the initial stage of continental fragmentation behind an active island arc (Greece)

1988

View full text Add to dashboard Cite

During the migration of the back arc extension from central to western Greece the Corinth and Patras grabens are being formed. Orthogonal opening of these graben zones is accomplished by WNW listric normal faults and NNE transfer faults which produce an along-axis fragmentation. The listric faults show an increase in the dip of the fault plane westwards as well as a decrease in the maximum extension rate from 50% to the east in the Corinth graben, to 10% to the west in the Patras graben. Similarly, towards the west, P l i e u a t e r n a r y deposits become thinner whereas Pliocene sediments thin-out indicating a westward rift propagation. another orthogonal fault system consisting of NNW and ENE normal faults. These faults have been formed during general uplift behind the orogenic front which has been migrating from western Greece to the Ionian islands. T h e ENE-trending Rio graben which belongs to his orthogonal system connects the Patras graben to the Corinth graben and has subsequently been active as a transfer fault between them.Plio-Quaternary geodynamic processes in central continental Greece are quite similar to those earlier processes observed in the central Aegean region which reflect the initial stage of continental break-up behind a migrating orogenic front.As the back arc extension migrates westwards it is interacting or is being superimposed above

show abstract

“…Το λιγνιτικό κοίτασμα της Μαγούλας (12,4 Mt) εντοπίζεται στο ανατολικό τμήμα της λεκάνης του Πύργου, 12 km ΒΑ της πόλης του Πύργου (Βάγιας 1994). Οι Νεογενείς σχηματισμοί, οι οποίοι εξα πλώνονται στη λεκάνη ανήκουν στο Ανώτερο Πλειόκαινο έως Πλειστόκαινο και συνίστανται από άμμους, ιλύες, αργίλους, λιγνίτες και ψαμμίτες (Hageman 1977, Frydas 1987, Kamberis et al 1992, Tsaila-Monopolis et al 1993. Στη λεκάνη της Ζαχάρως δύο λιγνιτικές εμφανίσεις εντοπίζονται σε δύο μικρά ορυχεία κοντά στα χωριά Τρύπες και Κουμουθέκρας με πάχος 1 m και 2 m, αντίστοιχα.…”

Section: γεωλογικο πλαισιοunclassified

Quantitative Mineral Matter Determination in Lignites Using X-Ray Dlfractometry and Position Sensitive Detector (Xrd-Psd)

Παπαζησίμου

Καλαϊτζιδησ

2004

geosociety

View full text Add to dashboard Cite

Thirty lignite samples from western Péloponnèse (Greece) were examined in the Department of Mineralogy, Natural History Museum, London, using an X-Ray Diffractometer equipped with a Position Sensitive Detector (Enraf-Nonius PSD 120). Diffraction patterns acquisition time was only 5 min with the minimum interference of the organic matter. Qualitative and quantitative evaluation of the mineral matter present performed using GUFI5 Enraf-Nonius software and involved a pattern-fit stripping technique. The prevailing minerals in all the studied samples are the mixed layers of illite/smectite, quartz, muscovite and K-feldspars. The weight percentages of the mineral matter as it was calculated from the diffraction patterns display high correlation coefficient (>0.85) with the respective wt.-% of ash in 750°C for most of the samples. The low correlation coefficient (0.65) of some samples may be attributed to the very small size of the mineral crystalline particles and/or the presence of inorganic amorphous phases.

show abstract

Calcareous nannoplankton from the Neogene of the NW-Peloponnes, Greece

Cited by 14 publications

References 0 publications

New constraints on bedrock erodibility and landscape response times upstream of an active fault

New constraints on bedrock erodibility and landscape response times upstream of an active fault

The Corinth‐Patras rift as the initial stage of continental fragmentation behind an active island arc (Greece)

Quantitative Mineral Matter Determination in Lignites Using X-Ray Dlfractometry and Position Sensitive Detector (Xrd-Psd)

Contact Info

Product

Resources

About