Papers by Michael Stamatakis
Searching for potential marine sand resources to mitigate beach erosion in island settings
Marine Georesources & Geotechnology, 2020
This article presents the results of a marine geophysical and sedimentological study carried out ... more This article presents the results of a marine geophysical and sedimentological study carried out around Lesvos Island (NE Aegean) to investigate the potential of exploitable marine aggregate (MA) deposits that could be used for beach replenishment purposes. Sub-bottom profiler data showed a good prospect for potential coarse-grained deposits in two of the three surveyed areas around Lesvos. Grain size and mineralogical analysis of the surficial sediments revealed sands that could properly feed nourishment schemes for eroded beaches or artificial beach development. Observed MA volumes are considered adequate for renourishment operations, when the threat of projected sea-level rise is introduced. Environmental constraints, as well as human activities, are considered for the suggestion and prioritization of specific areas for detailed surveying before future exploitation.
Journal of Volcanology and Geothermal Research, 2020
Geophysical methods of analysis were applied, in order to investigate the deep structure and the ... more Geophysical methods of analysis were applied, in order to investigate the deep structure and the geothermal potential of the Methana Volcano (NE Peloponnesus, Greece). The study is based on a re-evaluation and reinterpretation of legacy magnetotelluric (MT) data with modern analysis methods, as well as 3-D inversion of aeromagnetic data constrained by in situ measurements of magnetic susceptibility. Magmatic systems are located in regions of active tectonic processes that often play a controlling role. The MT method is effective in delineating low resistivity functional elements of volcanic systems, such as magma chambers, vents, thermal fluid reservoirs and thermal fluid circulation conduits, the latter two of which are typically associated with active faults. The aeromagnetic data can assist in mapping the configuration, hence emplacement modes of volcanic rocks at depth. Accordingly, the joint interpretation of these lines of evidence, together with structural and geochemical inf...
Environmental availability of ultramafic rock derived trace elements in the fumarolic - geothermal field of Soussaki area, Greece
The geothermal degassing and fumarolic alteration occurring at Soussaki, an area in SE mainland G... more The geothermal degassing and fumarolic alteration occurring at Soussaki, an area in SE mainland Greece, facilitated a strongly acidic environment which resulted in the serpentinized ultramafic parent rock's severe weathering and a large increase of mobility of trace elements, which may be incorporated in newly formed fumarolic alteration products and secondary clays (Cr – bearing clays). We hypothesized that the fumarolic – hydrothermal alteration of ultramafic parent rock would increase the mobility and availability and would cause the distribution of Cr, Ni, Mn and Co in stream sediments and soils in labile fractions. Stream sediment and surface soil samples were collected from 46 sampling sites and the <1.8 mm grain size fraction was analyzed by Flame Atomic Absorption spectroscopy for the above mentioned elements. Evaluation of geochemical abundance and leachability of the above mentioned elements in each operationally defined geochemical fraction, was conducted by applying multi - acid digestion, single and selective sequential extraction, respectively. Mineralogical composition of the parent rock was determined by means of X – ray diffraction. The stream sediment and soil samples show significant levels of Cr: 1237 mg/kg and 1448 mg/kg, Ni: 1789 mg/kg and 1879 mg/kg, Mn: 875 mg/kg and 904 mg/kg and Co: 114 mg/kg 115 mg/kg content, respectively, in agreement with the high geochemical background of these elements in Soussaki. Our results also indicate that there is a high risk of immediate Ni, Mn and Co mobilization, reaching percentages of 17.8% and 11.3%, 67.7% and 45.2%, 44.2% and 17.6% in the surface adsorbed fraction, in stream sediments and soils, respectively. The stability of significant percentage of all trace elements found in Fe – Mn oxide fractions (Ni > Co > Mn > Cr) is controlled primarily by the Eh/pH system.
Characterization and evaluation of chabazite- and mordenite-rich tuffs, and their mixtures as soil amendments and slow release fertilizers
Archives of Agronomy and Soil Science, 2017
In the present study, zeolite tuffs of diverse chemistry, mineralogy and origin were characterize... more In the present study, zeolite tuffs of diverse chemistry, mineralogy and origin were characterized and tested for their efficiency as slow release fertilizers (SRF) through a series of leaching tests. Mixtures of zeolite tuffs were created and tested as loamy soil additives, in order to evaluate any synergistic effect on their cation exchange capacity (CEC) and SRF properties. The studied materials were a chabazite-rich tuff (SOR), a mordenite-
rich tuff (KIM), 3 mixtures of them (SOR/KIM 30/70, 50/50 and 70/30) and a commercial clinoptilolite-rich tuff (BLG). CEC (sodium acetate method) was 95.7 for BLG, 100.9 for KIM and 92.2 cmol kg−1 for SOR,
while their mixtures displayed intermediate values. SRF values vary, with the SOR/KIM 30/70 exhibiting the slowest NH4+ release in 29 days (1.7%)
compared to the control sample (19%). Zeolites promoted PO4−3 release, while their selectivity for Mg2+ and K+ was clearly affected by their different structure and chemistry. BLG exhibited the strongest selectivity
for Mg2+, having the lowest release (39%).
The results demonstrate that mixtures of zeolite tuffs could have a potential use in agricultural processes, by improving parameters like: chemistry, mineralogy, CEC and SRF efficiency, and resulting in the production of a competitive and functional soil additive.
The main objective of the present study is the identification of the potential marine aggregates ... more The main objective of the present study is the identification of the potential marine aggregates deposits in Kissamos Bay. The survey uses existing information and primary data, such as bathymetric maps, sub-bottom profiles and surface sediments, in order to map the seabed morphology, reveal the stratigraphy of the uppermost substrate, and determine the granulometric properties of sediments.
The scope of the present contribution is to contrast two different marine environments in two dif... more The scope of the present contribution is to contrast two different marine environments in two different Greek Islands (Afantou Bay_Rhodes Island and Kissamos Bay -Crete Island), in order to be characterized as marine aggregates environments or not. Marine aggregates (MA) are sands and gravels dredged from the sea bed and are used in: concrete and mortar manufacture, asphalt and coated products, block making, drainage and fill materials, leisure and sport facilities and beach replenishment (
Thermally Induced Silica Transformation in Pliocene Diatomaceous Layers from Aegina Island, Greece
Siliceous Deposits of the Tethys and Pacific Regions, 1989
Exhumed hydrocarbon-seep authigenic carbonates from Zakynthos Island (Greece): Concretions not archaeological remains
In Zakynthos Island (Greece), authigenic cementation of marine sediment has formed pipe-like, dis... more In Zakynthos Island (Greece), authigenic cementation of marine sediment has formed pipe-like, disc and doughnut-shaped concretions. The concretions are mostly composed of authigenic ferroan dolomite accompanied by pyrite. Samples with >80% dolomite, have stable isotope compositions in two groups. The more indurated concretions have δ18O around +4‰ and δ13C values between −8 and −29‰ indicating dolomite forming from anaerobic oxidation of thermogenic methane (hydrocarbon seep), in the sulphate-methane transition zone. The outer surfaces of some concretions, and the less-cemented concretions, typically have slightly heavier isotopic compositions and may indicate that concretion growth progressed from the outer margin in the ambient microbially-modified marine pore fluids, inward toward the central conduit where the isotopic compositions were more heavily influenced by the seep fluid. Sr isotope data suggest the concretions are fossil features, possibly of Pliocene age and represent an exhumed hydrocarbon seep plumbing system. Exposure on the modern seabed in the shallow subtidal zone has caused confusion, as concretion morphology resembles archaeological stonework of the Hellenic period.
Bulletin of the Geological Society of Greece, 2016
The aim of this study is to examine the effectiveness of natural and synthetic zeolitic materials... more The aim of this study is to examine the effectiveness of natural and synthetic zeolitic materials as potential amendments for the rehabilitation of mine degraded areas. Two types of natural zeolite tuffs, clinoptilolite-and mordenite-rich originating from Samos Island, Greece, were used as low cost modifiers. In addition, the synthetic zeolite Na-P1, produced from lignite fly ash of the Meliti Lignite fired Power Station (Florina, Greece), was used. Fly ash was converted into synthetic zeolite via a low temperature alkaline hydrothermal treatment. In order to evaluate the aquatic solubility and potential bioavailability of heavy metals in contaminated soils of the mining area of Lavrion, specific soil amendments were used in leaching experiments. The Na-P1zeolite proved to be the most effective among the tested amendments for in situ de-contamination of mining soils. Comparing the two natural zeolites used, the mordenite-rich tuff exhibited better results than the clinoptilolite-rich, for the reduction of the potential bioavailability of almost all the studied heavy metals. Despite the high trace element content of the specific soils, it was observed that the Glaucium flavum, a plant that grows in the contaminated soils of Lavrion, does not accumulate high concentrations of metals; therefore the high toxic element content of soils does not always influence the physiology of the plants.
Stamatakis M.G., Fragoulis D., Papageorgiou A. & E. Chaniotakis (1998): Zeolitic tuffs from Greece and their commercial potential in the cement industry. World Cement, V. 29, No. 7, p. 97¬-102
T he famous Acropolis in Athens is an ancient temple site located high up on a rocky cliff in the... more T he famous Acropolis in Athens is an ancient temple site located high up on a rocky cliff in the middle of Athens. Its turbulent history is long -in human life-span terms -and dates back to 6000 BC. It has been the focus of a myriad of texts written by all types of authors, but oddly enough, the rock that bears the site has scarcely been mentioned. This paper intends to fill that gap, to pro-vide readers and visitors alike with a view of another much longer history, dating back to the Upper Cretaceous age, some 70 million years ago, when the rocks that underlie the rocky crest of the sacred hill were deposited in the delta of a mighty river. How much the geological composition and geological structure of the hill affects its human-related history, and why this par-ticular hill has been – and for some, still is – considered sacred, might be a matter of intense debate. So first let us briefly address that glimpse of time. After all, a rock is only a rock, at least for us geologists. ...
Characterization of lightweight aggregates produced with clayey diatomite rocks originating from Greece
Materials Characterization, 2004
... levels of thick Tertiary, lacustrine deposits located in central Greece containing, besides o... more ... levels of thick Tertiary, lacustrine deposits located in central Greece containing, besides opal ... LWAs of natural and artificial origin are currently used in lightweight structural concrete, in precast ... Laboratory investigations on the behaviour of the laboratory LWAs during their thermal ...
Testing Dioscorides’ Medicinal Clays for their Antibacterial Properties: the case of Samian Earth
Journal of Archaeological Science
ABSTRACT
Stamatakis M., Samantouros K. Koukouzas N., Vassilatos Ch. And Kamenou E. 2000. The zeolites from Evros region: A potential use as cultivation substrate in hydroponics. Acta Horticulturae 548, 93-¬103
Acta horticulturae
Modern sands derived from the Vertiskos Unit of the Serbomacedonian Massif (N. Greece): a preliminary study on the weathering of the Unit
Open Geosciences, 2012
ABSTRACT Modern sand samples were collected from the Vertiskos Unit of the Serbomacedonian Massif... more ABSTRACT Modern sand samples were collected from the Vertiskos Unit of the Serbomacedonian Massif, northern Greece, and were examined for their texture and mineralogical composition. They were collected from active channels and torrents. The textural study demonstrated that these modern sands are moderately to very-poorly sorted, often polymodal in grain size distribution, texturally and mineralogically immature to submature, and consist of coarse-grained gravelly sands to slightly-gravelly muddy sands. The dominant composition is quartzofeldspathic. All samples contain detrital minerals of metamorphic origin, mainly amphibole and garnet, in addition to minor amounts of pyroxene and detrital calcite. These sediments were deposited rapidly and close to their source, the metamorphic basement of the Vertiskos Unit. The mineral constituents of the samples indicate that the Vertiskos Unit is undergoing rapid physical weathering due to the temperate and seasonal climate. The results of this study suggest that these modern sands constitute one sedimentary petrologic province comprised of primarily of amphibole-garnet.
Central European Journal of Geosciences, 2009
Two bulk samples of clayey diatomite of Upper Miocene age originated from Western Macedonia, nort... more Two bulk samples of clayey diatomite of Upper Miocene age originated from Western Macedonia, northern Greece and Thessaly central Greece were examined for their efficiency to be used as industrial absorbents. The samples were characterized using X-Ray Diffraction, Thermo-Gravimetric and Fourier Transform Spectroscopy, Scanning Electron Microscopy and ICP-MS analytical methods. The absorption capability of the clayey samples in oil and water were also examined. The mineralogy of both samples is predominated by the presence of clay minerals and amorphous silica. The clay minerals prevailed in the Klidi (KL) bulk sample, with muscovite being the dominant phase, and kaolinite and chlorite occurring in minor amounts. In the Drimos (DR) bulk sample, vermiculite was the predominant clay phase. Smectite was not found in either sample, whereas detrital quartz and feldspars were present in significant amounts. The amorphous silica phase (opal-A) occurs mainly with the form of disck-shaped diatom frustules. The chemistry of the samples is characterized by the predominance of silica, alumina, and iron, whereas all the other major and the trace elements are in low concentrations. Both clayey diatomite rocks exhibited sufficiently good oil and water absorption capacity, ranging between 70 to 79% in the clay-rich sample KL and 64 to 70% in the opal-A-rich sample DR. Comparing the properties of the rocks studied with other commercial absorbents, it is concluded that they may find applications as absorbents in industrial uses.
Key Engineering Materials, 2002
The use of selected secondary materials for improving the reactivity of cement raw mix, is a chal... more The use of selected secondary materials for improving the reactivity of cement raw mix, is a challenging subject. It is known that certain foreign elements exert a considerable effect on the cement raw mix burnability and clinker structure, even at low concentration. This work is part of a project on the use of selected minerals as a source of elements having a positive effect on the burnability of cement raw mix. The minerals, iron rich wolframite, stibnite and a wolframitestibnite assemblage, were selected in order to introduce W, Sb and S in the cement raw mix. One reference and twelve modified mixtures, prepared by mixing the reference sample with 0.5, 1.0, 1.5 and 2.0 % w/w of the above minerals, were studied. Their effect on the burnability is discussed in Part I. The subject of this paper is their effect on the structure of the produced clinker. The XRD studies, performed in samples that were burned at 1450 o C, showed that the diffraction patterns correspond to a structure of a typical clinker, obtained at the above temperatures. In addition, samples sintered at lower temperature (1200-1400 o C) were examined in order to investigate the effect of the additives on the intermediate products. It is concluded that the added compounds affect mainly the structure of calcium aluminate and calcium aluminoferrite phases, due to their dissolution in the melt formed during the sintering. Scanning Electron Microscopy was used in order to examine the structure of the clinker and the distribution of the foreign elements in its main phases. It is shown that W and Sb are mainly concentrated in the solidified melt. In addition, bigger and more roundish alite crystals are found in these samples. These modifications are attributed to the effect of the added elements on the properties of the melt.
Sedimentary Geology, 2001
Irregular masses, veins and leaf replacements composed of the phosphate minerals vivianite, mitri... more Irregular masses, veins and leaf replacements composed of the phosphate minerals vivianite, mitridatite, anapaite and hydroxylapatite occur in the Sarantaporo±Elassona Upper Miocene lacustrine basin, Thessaly, central Greece. They are hosted in clayey diatomite. Grey to dull green irregular veins of anapaite up to 40 cm thick and spherical concretions up to 2 cm in diameter sporadically occurred at shallow depths. Minor hydroxylapatite rims anapaite masses. Mitridatite occurs in the near surface as greenish-brown veins 5 cm thick, cutting the diatomite or oriented sub-parallel to bedding. The mitridatite veins are rimmed by, and grade into, iron oxides±hydroxides at the surface. In borehole samples, at depths greater than 40 m, bluish vivianite frequently replaces leaves and faecal pellets up to 2 cm in diameter.
Mineralium Deposita, 1996
Zeolites are present in altered pyroclastic rocks at many localities in Greece, and large deposit... more Zeolites are present in altered pyroclastic rocks at many localities in Greece, and large deposits o f potential economic interest are present in t hree areas: (1) the Evros region of the province of Thrace in the no rtheastern pa rt of the Greek mainland; (2) the islands of Kimolos and Po liegos in the western Aegean; and (3) the island of Samos in the eastern Aegean Sea. The deposits in Thrace are of Eocene-Oligocene age and are rich in heulandite and/o r clinoptilolite. Those of Kimolos and P oliegos a re mainly Quaternary a nd are rich in mo rd enite. Those of Samos are Miocene, and are rich in clinoptilo li te and/ or analcime. The d eposits in Thrace are believed to have formed in an open hydrological system by the actio n of meteoric wa ter, and those of the western Aegean islands in a similar way but under conditions of high heat fl ow, whereas the d eposits in Samos were fo rmed in a saline-alkaline lake.
Journal of Paleolimnology, 2011
The Mytilinii Basin,
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Papers by Michael Stamatakis
rich tuff (KIM), 3 mixtures of them (SOR/KIM 30/70, 50/50 and 70/30) and a commercial clinoptilolite-rich tuff (BLG). CEC (sodium acetate method) was 95.7 for BLG, 100.9 for KIM and 92.2 cmol kg−1 for SOR,
while their mixtures displayed intermediate values. SRF values vary, with the SOR/KIM 30/70 exhibiting the slowest NH4+ release in 29 days (1.7%)
compared to the control sample (19%). Zeolites promoted PO4−3 release, while their selectivity for Mg2+ and K+ was clearly affected by their different structure and chemistry. BLG exhibited the strongest selectivity
for Mg2+, having the lowest release (39%).
The results demonstrate that mixtures of zeolite tuffs could have a potential use in agricultural processes, by improving parameters like: chemistry, mineralogy, CEC and SRF efficiency, and resulting in the production of a competitive and functional soil additive.