Η παρούσα διπλωματική εργασία με τίτλο «Ιζηματολογική, γεωχημική μελέτη και παλαιογεωγραφική εξέλιξη - Δυναμικό γένεσης υδρογονανθράκων των Μειοκαινικών αποθέσεων στη Βορειοδυτική πλευρά του νησιού της Κέρκυρας», εκπονήθηκε στα πλαίσια του μεταπτυχιακού προγράμματος με τίτλο «Γεωλογικές Διεργασίες στη Λιθόσφαιρα και Γεωπεριβάλλον», του τμήματος Γεωλογίας της σχολής Θετικών Επιστημών του Πανεπιστημίου Πατρών. Η περιοχή μελέτης ανήκει στη λεκάνη της Κέρκυρας και αποτελεί τμήμα ενός συγκλίνου, γνωστό ως Λεκάνη Καρουσάδων, το οποίο αναπτύσσεται στη βορειοδυτική πλευρά του νησιού, και δημιουργήθηκε εξαιτίας της δράσης της Ιόνιας επώθησης. Με βάση τον γεωλογικό χάρτη του Ι.Γ.Μ.Ε., φύλλο Βόρειος και Νότιος Κέρκυρα 1962, 1:50.000, τα μελετηθέντα ιζήματα αναφέρονται ως μολασσικές αποθέσεις ηλικίας Μέσου - Ανώτερου Μειοκαίνου. Για την ιζηματολογική ανάλυση συλλέχθηκαν 88 δείγματα, εκ των οποίων τα 8 από το Βόρειο τμήμα της Κέρκυρας, και τα υπόλοιπα 80 από τον κόλπο του Αγίου Γεωργίου Πάγων. Για την γεωχημική έρευνα, πραγματοποιήθηκε μια σειρά από χημικές αναλύσεις σε όλο των αριθμό των δειγμάτων, προκειμένου να υπολογιστεί η περιεκτικότητα των ιζημάτων σε Corg και CaCO3. Ο υπολογισμός της περιεκτικότητας σε Corg έγινε με τη μέθοδο τιτλοδότησης, που πρόκειται για την τροποποιημένη μέθοδο Walkley - Βlack σύμφωνα με τον Gaudette et al., 1974 και ο υπολογισμός της περιεκτικότητας σε CaCO3 έγινε με τη μέθοδο διάσπασης του CaCO3 με την χρήση οξικού οξέως CΗ3CΟΟΗ (Varnavas, 1979). Στόχος της παρούσας διπλωματικής εργασίας είναι η μελέτη των ιζηματολογικών και γεωχημικών χαρακτηριστικών των νεογενών σχηματισμών της βορειοδυτικής Κέρκυρας, με έμφαση στην περιοχή του κόλπου του Άγιου Γεώργιου Πάγων. Ειδικότερα, η λεπτομερής ανάλυση των ιζημάτων θα μας βοηθήσει στον προσδιορισμό των περιβαλλόντων ιζηματογένεσης τους και στον εντοπισμό πιθανών μητρικών πετρωμάτων υδρογονανθράκων, που σε συνδυασμό με την κατακόρυφη και πλευρική τους ανάπτυξη θα μας δώσει τη δυνατότητα δημιουργίας του εξελικτικού μοντέλου της περιοχής μελέτης. Τα αποτελέσματα που προέκυψαν από την ιζηματολογική ανάλυση μας οδήγησαν στην κατασκευή δύο σεναρίων για την παλαιογεωγραφική εξέλιξη της περιοχής. Η διαφορά των δύο σεναρίων εστιάζεται στο χρόνο έναρξης της μετανάστευσης της τεκτονικής δραστηριότητας προς τα δυτικά και συνεπώς στο πότε η πίεση μετανάστευσε δυτικά και έξω από την περιοχή μελέτης. Το γεγονός ότι μεγάλο μέρος των αναλυθέντων ιζημάτων χαρακτηρίζεται από ικανοποιητικό έως υψηλό ποσοστό Corg μας έδωσε τη δυνατότητα να χαρακτηρίσουμε τα ιζήματα της περιοχής ότι έχουν καλή έως και πολύ καλή δυνατότητα γένεσης υδρογονανθράκων. Τέλος, έγινε μελέτη της ανθρακικής σειράς της Κέρκυρας, με βάση μόνο βιβλιογραφικά δεδομένα και με σκοπό την εκτίμηση της πιθανότητας γένεσης υδρογονανθράκων. Προσδιορίστηκε ότι κύριο μητρικό πέτρωμα μπορούν να αποτελέσουν οι σχιστόλιθοι Ιουρασικής ηλικίας, με τους υπερκείμενους ασβεστόλιθους να μπορούν να αποτελέσουν το ταμιευτήριο πέτρωμα. / The present thesis, «Sedimentological, Geochemical analysis and Palaiogeographic evolution – Prospectivity of the Miocene deposits of the Northwestern part of Corfu island», was conducted as part of a postgraduate program in Geology. The study area is extended in the basin of Karousades, located at the northwestern part of Corfu Island and constitutes part of a syncline, which was created by the activity of the Ionian thrust. The sedimentological units were classified based on the geological map of I.G.M.E., North and South Corfu sheet 1962, 1:50.000, as Molasse formation of Middle-Upper Miocene. In order to determine the sedimentological parameters, a total of eighty-eight (88) samples were collected of which eight (8) samples were from the Northern part of Corfu Island and eighty (80) samples were from the gulf of Agios Giorgos Pagon. In addition, a series of geochemical analysis was accomplished in order to calculate the calcium carbonate (CaCO3) and organic carbon (Corg) content. The analysis of Organic Carbon (Corg) content was based on the method of titration according to a modified Walklet – Black method (Gaudette et al., 1974) and the analysis of calcium carbonate was based on decomposition of CaCO3 using CH3COOH (Varnavas, 1979). The objective of this thesis is the study of sedimentological and geochemical characteristics of the Neogene formations in northwest Corfu, with emphasis in the gulf of Agios Georgios Pagon. Specifically, detailed analysis of sediments will help us to identify the depositional environments and identify potential source rocks, which in combination with the vertical and lateral development will enable us to reconstruct the evolutionary model of the study area. The results obtained from our sedimentological analysis led to the construction of two scenarios for the paleogeographic evolution of the region. The difference between the two scenarios focuses on the start time of tectonic activity migration to the west and therefore, in when the pressure migrated west and outside the study area. The fact that many of the analyzed sediments are characterized by high Corg rate suggests that the studied samples have a good to very good source rocks potential. Finally, the study of carbonate formations of Corfu was based only on bibliographic data in order to assess the probability of finding potential source rocks. It was determined that the main source rock is constituted by shales of Jurassic age, with overlying limestone as the reservoir rock.

[Tuncated abstract] Soil is a relatively low cost and robust geochemical sampling medium and is an essential part of most mineral exploration programs. In areas of covered terrain, however, soils are less reliable as a sampling medium because they do not always develop the geochemical signature of the buried mineralisation; possibly a result of limited upward transport of ore related elements into the surficial overburden. As economic demands on the resources industry grow, mineral exploration continues to expand further into areas of covered terrain where the rewards of finding a new deposit relative to the risks of finding it may be comparatively low. Thus, improving the costeffectiveness of a geochemical exploration program requires a sound understanding of the mechanisms by which soil geochemical anomalies form in transported overburden. This thesis examines the deep biotic uplift of ore related elements by deep rooting vegetation as a mechanism for the development of soil geochemical anomalies within transported overburdens, in semi-arid and arid regions. '...' Vegetation and soils were analysed at two Au prospects in Western Australia: Berkley, Coolgardie and Torquata, 210 km south-east of Kambalda, in semi-arid Western Australia to complement both the mass balance and the differential modelling. At Berkley, both the vegetation and soils located directly over the mineralisation showed high concentrations of Au. There may be indirect evidence for the operation of the deep plant uptake flux taking effect from the field evidence at Berkley. Firstly, anomalous concentrations of Au were found in the surface soils, with no detectable Au in the transported overburden. Secondly, the trace element concentrations in vegetation showed correlation to the buried lithology, which to our knowledge has not been reported elsewhere. The results from the samples at Torquata, in contrast, were less conclusive because the Au is almost exclusively associated with a surficial calcrete horizon (at <5 m soil depth). Strong correlations of Ca and Au in leaf samples however, suggest that the vegetation may be involved in the formation of calcrete and the subsequent association of Au with the calcrete. Among the vegetation components, the litter and leaf samples gave the greatest anomaly contrast at both prospects. Finally, three main drivers for the deep biotic uplift of elements were identified based on the results from the mechanistic numerical modelling exercise: i) the deep uptake flux; ii) the maximum plant concentration and; iii) the erosional flux. The relative sizes of these three factors control the rates of formation and decay, and trace element concentrations, of the soil anomaly. The main implication for the use of soils as exploration media in covered terranes is that soil geochemical anomalies may only be transient geological features, forming and dispersing as a result of the relative sizes of the accumulative and loss fluxes. The thesis culminates in the development of the first quantitative, mechanistic model of trace element accumulation in soils by deep biotic uplift.

<p>Predmet&nbsp; istraživanja ove&nbsp; doktorske&nbsp; disertacije&nbsp; su srednje&nbsp; i&nbsp; gornje&nbsp; pleistocene&nbsp; lesno-paleozemlji&scaron;ne sekvence&nbsp; (LPS)&nbsp; u&nbsp; dolini&nbsp; Južne Morave&nbsp; na&nbsp; profilima&nbsp; ciglana&nbsp; u&nbsp; Stalaću i Belotincu.&nbsp; Ove&nbsp; LPC&nbsp; predstavljaju jedinstven&nbsp; kontinentalni&nbsp; arhiv&nbsp; paleoklimatskih&nbsp; i paleoekolo&scaron;kih promena&nbsp; tokom&nbsp; pleistocena&nbsp; u&nbsp; ovom&nbsp; delu&nbsp; Balkanskog&nbsp; poluostrva.&nbsp; Nakon detalʁnihterenskih istraživanjai uzorkovanja na pomenutim lesnim profilima, razmatrano je vi&scaron;e istraživačkihproblema.&nbsp; Izvr&scaron;eno&nbsp; jepedo- i lito-stratigrafsko opisivanje&nbsp; naoba profila.&nbsp; Na njima je&nbsp; zapaženo nekoliko&nbsp; metara&nbsp; moćnih glacijalnih&nbsp; lesnih&nbsp; horizonata&nbsp; i nekoliko&nbsp; interglacijalnih<br />pedokomleksa,&nbsp; koji&nbsp; se vizuelno&nbsp; jasno&nbsp; razlikuju.&nbsp; Izvr&scaron;ena&nbsp; je rekonstrukcija&nbsp; relʁefa na&nbsp; osnovu prostornih odnosa LPS. Ukupna deblʁinaanalizirananih LPS iznosi:&nbsp; u&nbsp; Stalaću&nbsp; približno20,5 m, gde&nbsp; je&nbsp; zapaženo po&nbsp; sedam&nbsp; pedokompleksa&nbsp; i&nbsp; lesnih&nbsp; horizonata,&nbsp; dok&nbsp; je&nbsp; deblʁina u&nbsp; Belotincu analiziranih LPS 8 m. Vrednosti magnetnog susceptibiliteta (MS)&nbsp; u&nbsp; Stalaćuukazuje da poreklo pra&scaron;kastog fluvijalnog materijala&nbsp; potiče&nbsp; izdva nezavisna izvora.&nbsp; Veće vrednosti&nbsp; MS prisutne&nbsp; su u materijalu koji&nbsp; potiče&nbsp; iz sliva Zapadne Morave. Dok manje vrednosti ukazuju da&nbsp; je poreklo materijala iz JužneMorave. U Belotincu manje vrednosti MS ukazuju da je poreklo materijala iz<br />sliva&nbsp; Južne Morave.&nbsp; Tumačenjem rezultata apsolutnog luminescentnog datiranja&nbsp; na oba profila ukazuju da&nbsp; su LPS nastajale tokom poslednjih ~ 350.000 godina u&nbsp; Stalaću i ~ 35.500 godina u Belotincu. Granulometrijski sastav LPS u Stalaću&nbsp; je&nbsp; sačinjen od pet različitih frakcija&nbsp; &lt; 2,0 &mu;m, 2,0-6,2&nbsp; &mu;m,&nbsp; 6,2-20,0&nbsp; &mu;m,&nbsp; 20,0-63,0&nbsp; &mu;mi&nbsp; &gt;63,0&nbsp; &mu;m.&nbsp; Dok,&nbsp; su u&nbsp; Belotincu&nbsp; najvi&scaron;e&nbsp; zastupljene krupne&nbsp; čestice od&nbsp; 51&nbsp; %&nbsp; do&nbsp; 66&nbsp; %&nbsp; i&nbsp; grube&nbsp; frakcije,&nbsp; koje&nbsp; ukazuju&nbsp; na&nbsp; neposrednu&nbsp; blizinu&nbsp; izvora porekla&nbsp; materijala.&nbsp; Boja&nbsp; LPS&nbsp; na&nbsp; profilima&nbsp; u&nbsp; Stalaću i&nbsp; Belotincu&nbsp; menja&nbsp; se i&nbsp; kovarira&nbsp; sa&nbsp; MS. Kolorimetrijski rezultati ukazuju, slično MS rezultatima, da lesni sedimenti potiču jednim delom iz&nbsp; Južne Morave,&nbsp; a&nbsp; drugim&nbsp; delom&nbsp; iz Zapadne&nbsp; Morave.&nbsp; Geohemijske&nbsp; analize&nbsp; ukazuju&nbsp; na dominantno&nbsp; silikatno&nbsp; raspadanje&nbsp; čestica,&nbsp; slično dunavskom&nbsp; lesu.&nbsp; Geohemijski&nbsp; sastav&nbsp; LPS Belotinc&nbsp; pokazuje&nbsp; da&nbsp; pedokompleks&nbsp; je&nbsp; obogaćen organskog&nbsp; ugljenika,&nbsp; dok&nbsp; su u&nbsp; lesnim slojevima&nbsp; primećene&nbsp; niže vrednosti&nbsp; organskog&nbsp; ugljenika.&nbsp; Generalno&nbsp; tumačenje svih&nbsp; rezultata ukazuje na dominantan mediteranski klimatski uticaj na LPS u srednjem pleistocenu, dok&nbsp; je u gornjem i mlađem pleistocenu bio dominantan uticaj kontinentalne klime.</p> / <p>The&nbsp; research&nbsp; subject&nbsp; of&nbsp; this&nbsp; dissertation&nbsp; are&nbsp; Middle&nbsp; and&nbsp; Upper&nbsp; Pleistocene&nbsp; loesspaleosol&nbsp; sequences&nbsp; (LPS)&nbsp; in&nbsp; the&nbsp; South&nbsp; Morava&nbsp; valley,&nbsp; at&nbsp; brickyards&rsquo; profiles&nbsp; in&nbsp; Stalac&nbsp; and Belotinac. These LPS represent a unique continental record of paleoclimate and paleoecological changes during Pleistocene in this part of the Balkan Peninsula. After detailed terrain researches and&nbsp; samplings&nbsp; at&nbsp; the&nbsp; two&nbsp; loess&nbsp; profiles,&nbsp; several&nbsp; research&nbsp; problems&nbsp; were&nbsp; discussed.&nbsp; Pedostratigraphic and litho-stratigraphic descriptions were done for both profiles. There were found several&nbsp; meters&nbsp; of&nbsp; powerful&nbsp; glacial&nbsp; loess&nbsp; horizons&nbsp; and&nbsp; several&nbsp; interglacial&nbsp; pedocomplexes&nbsp; that were visually distinctive. A relief reconstruction was carried out based on spatial LPS ratios. The total&nbsp; thickness&nbsp; of&nbsp; the&nbsp; analyzed&nbsp; LPS&nbsp; is:&nbsp; approximately&nbsp; 20.5&nbsp; m&nbsp; in&nbsp; Stalac,&nbsp; where&nbsp; seven pedocomplexes&nbsp; and&nbsp; seven&nbsp; horizons&nbsp; were&nbsp; observed,&nbsp; whereas&nbsp; thickness&nbsp; of&nbsp; analyzed&nbsp; LPS&nbsp; in Belotinac was 8 &nbsp; m. The magnetic susceptibility (MS) values in Stalacpoint at two independent sources of dusty fluvial materials. The higher MS values are observed in materials originating from the West Morava basin, while lower MS values indicate that materials originate from the South&nbsp; Morava&nbsp; basin.&nbsp; Interpretations&nbsp; of&nbsp; absolute&nbsp; luminescent&nbsp; dating&nbsp; results&nbsp; at&nbsp; both&nbsp; profiles indicate&nbsp; that&nbsp; the&nbsp; LPS&nbsp; were&nbsp; formed&nbsp; during&nbsp; last&nbsp; ~&nbsp; 350.000&nbsp; years&nbsp; in&nbsp; Stalac&nbsp; and&nbsp; ~&nbsp; 35.500&nbsp; in Belotinac. The LPS in Stalac is granulometrically consisted of five different fractions: &lt; 2.0 &mu;m, 2.0-6.2 &mu;m, 6.2-20.0&nbsp; &mu;m, 20.0-63.0&nbsp; &mu;mand &gt;63.0&nbsp; &mu;m. In Belotinac the most frequent particles are&nbsp; the&nbsp; large&nbsp; ones&nbsp; varying&nbsp; from&nbsp; 51%&nbsp; to&nbsp; 66%&nbsp; and&nbsp; rough&nbsp; fractions,&nbsp; which&nbsp; indicates&nbsp; that&nbsp; the material source was in its immediate proximity. The LPS colours both in Stalac and Belotinac covariate with the MS. Similarly to the MS results, the colorimetric results indicate that a part of the loess sediments originates from the South Morava, and the other part from the West Morava. Geochemical analyses point at a dominant silicate particle decomposition, which is similar to the Danube&nbsp; loess.&nbsp; Geochemical&nbsp; composition&nbsp; of&nbsp; BelotinacLPS&nbsp; shows&nbsp; an&nbsp; organic-carbon-enriched pedocomplex,&nbsp; while&nbsp; lower&nbsp; values&nbsp; of&nbsp; the&nbsp; organic&nbsp; carbon&nbsp; are&nbsp; observed&nbsp; in&nbsp; the&nbsp; loess&nbsp; layers.&nbsp; The general interpretation of the results points at dominant Mediterranean climate influence on the LPS&nbsp; in&nbsp; the&nbsp; Middle&nbsp; Pleistocene,&nbsp; while&nbsp; in&nbsp; the&nbsp; Upper&nbsp; and&nbsp; Younger&nbsp; Pleistocene&nbsp; a&nbsp; continental climate influence was dominant.</p>

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