(17) ... kreta 2.pdf · aan het eind van de presentatie staat een lijst van de literatuur en de...
TRANSCRIPT
door: Rob Hekkenberg 2019-02
https://upload.wikimedia.org/wikipedia/commons/thumb/0/0b/Crete_relief_map.svg/3370px-Crete_relief_map.svg.png
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Aan het eind van de presentatie staat een lijst van de literatuur en de figuren die gebruikt zijn voor deze presentatie.De referenties staan in de presentatie aangegeven tussen haakjes.
Deze presentatie mag niet commercieel gebruikt worden.
http://ontheworldmap.com/greece/islands/crete/crete-road-map.html
Schematisch overzicht van het oostelijke Middellandse-Zeegebied met daarin aangegeven de
positie van de belangrijkste plaatgrenzen. De pijlen op de plaatgrenzen geven de huidige
onderlinge bewegingsrichting en relatieve bewegingsnelheid aan (naar McClusky et al., 2003).
De grootte van de pijlen is een maat voor de relatieve bewegingssnelheid tussen de
begrenzende platen. De pijlgrootte is voor 1 cm/jr beweging.
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Crete´s location above a subduction zones makes it vulnerable to earthquakes, map from PLATT et al. 2007
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-500 mj-250 mj Er was Tethys ocean,PK (5km plattenkalk) tot 30km diep
daarna: Exhumeren (opheffen)
-200 mj Pangea breekt
-50 mj Vardar ocean sluit, Apulië botst met EuraziëDelen hiervan zijn te vinden op Kreta: Tripolitza en Pindos dekbladen
-30 mj, laatste delen van Apulië schuiven op “pre-Kreta”: Phylliet-Kwartsiet en Plattenkalk (kern van Apulië). (hoge druk lage temperatuur metamorfose)
-12 mj Het Grieks continent met Kreta breekt los,
- 5 mj Kreta los van Peloponnesia
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assemblages with variable amounts of the stable ZTR group (zircon, tourmaline, rutile) and apatite, found at all the other localities. The garnet assemblage is assumed to have been derived from mica schist complexes existing at the western margin of the Pelagonian microcontinent,
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(-2,5mj)
(-7mj)
(-11mj)
(-20mj)
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(Kreta WestZ-N)
(Plakias Z-N)
(Agia Galini Z-N)
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Verschil tussen Anticline en Antiform
Met een anticline of anticlinaal wordt in de geologie
een plooi bedoeld met naar beneden wijzende
flanken, waarbij de aardlagen aan de binnenzijde
het oudst zijn. Binnen de structurele geologie wordt
met een antiform een plooi met naar beneden
wijzende flanken bedoeld.
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Fig.9. Schematic drawing of the evolution of the detachment system
of southern Greece. Note that the position of Crete with respect to
the outcrop of the detachment varied through time. The hanging
wall to the Cretan detachment became fragmented from south to
north, leading to the formation of extensional klippen. In between
the seen, sedimentary basinsd eveloped, floored by the Lower
Sequence. Around N-S extension ceased and E-W extension,
combined with approximately N-S compression, deformed the
Cretan detachment.
A klippe (German for cliff or crag) is a geological feature of thrust
fault terrains. The klippe is the remnant portion of a nappe after
erosion has removed connecting portions of the nappe. This
process results in an outlier of exotic, often nearly horizontally translated strata overlying autochthonous strata.
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The Cretan grounds hosts rocks that were formed during the phase of Tethys Sea and
were layered during the raising of the land. There are at least 7 types of these layers in
Crete, with the three of them dominating. Sorting these three according to the lowest
position they are Platy limestone, the formation of Tripoli (limestone) and Phyllite-
quartzite. Quite rare formations are Asterousia formations and ophiolites(volcanic rocks).
Limestone may be crystalline, clastic, granular, or massive, depending on the method
of formation. Crystals of calcite, quartz, dolomite or barite may line small cavities in the
rock. When conditions are right for precipitation, calcite forms mineral coatings that cement the existing rock grains together, or it can fill fractures.
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PS
PK
PLK
TP
Diep water
BD
Pindos trog van NeoTethysbots met Eurazië
(Wiki)
Plattenkalk is een zeer fijnkorrelige kalksteen, neergeslagen in water onder
omstandigheden waar bioturbatie zich niet voor doet. De afwezigheid van bioturbatie
draagt bij tot de creatie van dunne, fijn gelamineerde, ongestoorde kalksteen.
Chert is a hard, fine-grained sedimentary rock composed of crystals of quartz that are
very small. Chert is often of biological origin but may also occur inorganically as a
chemical precipitate or a diagenetic replacement. Geologists use chert as a generic
name for any type of microcrystalline or cryptocrystalline quartz.
Ophiolite, Ophio is Greek for snake, and lite means stone. It is a section of the
Earth's oceanic crust and the underlying upper mantle that has been uplifted and exposed above sea level and often emplaced onto continental crustal rocks.
Crystalline schist, with clusters of granite, granitic gneiss and phyllite (a metamorphic
rock). Such rock formations are chiefly to be met with in western Crete, west of the
White Mountains, and only sporadically in other parts of the island.
The Olonos-Pindos zone: An extension of the zone that extends down the length of
the Pindos range and into the central Peloponnese, consisting of limestone, dolomite,
flysch and schist, which form the majority of rock types on Crete.
Neogenic rock strata: Formed from the erosion of older strata, these are chiefly found
in central Crete, with some scattered examples in the rest of the island.
Igneous rocks: Peridolites and diabase (a kind of basalt) exist south of Rethymnon.
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High Pressure
metamorph
(ong -170mj)
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Maar ook vanuit het westen
Langs weg vlak
voor Hora Sfakion
(weg langs Imbros)
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(sediment - kalksteen)
(weg Plakias-Rethimnon)
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(broos)
(buigzaam)
Transform fault
(17-15 mj)(24-19 mj)
(-14 mj)
(-10 mj)
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(e-h)
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stress (force per unit area)
strain (resulting compression/stretching
(ductile)
(brittle)
(ductile)
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Rose diagram
This is a visually attractive way of representing the
orientation of fractures and lineaments as they
appear on the surface of the Earth, and can also be
used to represent the trend distribution of linear
structures
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a. Large scale anticlinic structure
(dashed line) at the face of
Limnakaro fault, Lassithi mts.
b. Close, similar folding in
Psiloritis Mountains (south of
Anogia village),
c. Recumbent, asymmetric fold in
Vossakos area Note thickening
and buckle-folding at the inverted
limb.
d. Isoclinal folding and axial plane
schistosity in Vossakos area
illustrating a hinge zone thickened
by flexural slip.
e. Open angular folding at the
inverted limb in Samaria gorge
(Portes); axial plane
approximately horizontal.
f, Propagating deformation
forming open-similar and
asymmetric, drag folds in Samaria
gorge.
All pictures in platy marbles.
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(a) Structural map of the Omalos
transverse zone and the Paleochora
salient showing L1 stretching lineations
(white lines) and D1 sense of shear
(black arrows). The three major ductile
thrust fault zones defining the
Paleochora salient are also highlighted.
(b-d) Stereoplots (lower hemisphere e
equal area projections) of L1 lineation
data from the threedistinctsegments of
the Paleochorasalient;starsymbol:
orientation ofmeanL1 lineation in each
segment; number of measurement
is indicated.
(e) Map of L1 lineation trend lines
defined by trace of 792 stretching
lineations, with polarity indicating the
transport direction as determined by a
range of shear sense indicators. See
text for details.
(f) Frequency distribution histogram of
sense of shearing for the analyzed
stations in the study area. Numbers in
the bars reflect the amount of stations
recording the corresponding kinematic
pattern.
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Map of the Omalos transverse zone and the
Paleochora salient showing major D2 brittle
thrust faults and fold axial traces of meso-
scale and major map-scale brittle F2 folds.
Map of compression (double arrows) and
transport (single arrows) directions for the
younger (Late Miocene early Pleistocene)
paleostress fieldMap of compression and transport directions for the older
(Middle-Late Miocene) paleostress field
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Fig.9. Photographs of D2 brittle thrust faults. (a) View of the Tripolitsa thrust fault, which carries Mesozoic carbonaceous
rocks of the cover thrust sheets on Middle Carboniferouse Late Triassic siliciclastic rocks of the PQ thrust sheet. Photo
taken looking subparallel to the transport direction; field of view is ca. 400 m wide. (b) Close-up view of the area in the box
of (a) showing deformation style in the footwall of the Tripolitsa thrust fault. N-dipping thrust faults with a well-defined
ramp-flat geometrycause imbrication of the HP-rocks (rear part of the Paleochora salient; 352604300N, 233405200E). (c)
View of the Tripolitsa thrust fault. Photo taken looking subparallel to the transport direction; field of view is ca. 200 mwide.
(d) Close-up view of the area in the box of (c). S/C structures in the immediate footwall of the Tripolitsa thrust fault,
compatible with top-to-the-S sense of shear (rear part of the Paleochora salient; 352704300N, 233600200E).
(a-d)
(e-h)
(k)
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(e) SE-directed, moderately to steeply dipping foliation parallel thrust faults and duplex structures in the PQ thrust sheet
(Omalos transverse zone; 352400800N, 235604900E). (f) Steeply dipping back thrust fault affecting Neogene sediments
(Omalos transverse zone; 352201800N, 235304500E). (g) Thrusting of the carbonaceous rocks of the Trypali thrust sheet
on Neogene sediments (Omalos transverse zone; 352203700N, 235302400E). (h) S/C fabric used for the determination of
the transport direction in the metasiliciclastic rocks of the PQ thrust sheet (Omalos transverse zone; 352404200N,
235604000E).
(a-d)
(e-h)
(k)
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Fig.10. Photographs of F2 folds. (a) S-verging margin-distal fold deforming rocks of the Trypali thrust sheet (western
margin of Paleochora salient; 351601800N, 233603000E). (b, c) SE-verging margin-parallel folds deforming rocks of the
Plattenkalk thrust sheet (Omalos transverse zone; Samaria gorge). (d) SW-verging margin-normal map-scale fold
corresponding to net 16 in Fig. 8(a, e); field of view is ca. 2 km wide (Omalos transverse zone; 35180N, 23500E).
(k)(a-d)
(e-h)
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Block diagrams showing the structural and kinematic evolution of the Omalos oblique ramp
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Deel vd Asomatos breuk bij Kakomouri rock, Plakias
Mesozoische kalksteen van het Tripolitza dekblad
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Deel vd Asomatos breuk bij Kakomouri rock, Plakias
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West Crete from space - White Mountains and its many gorges © Sfakia-Crete.com
The geological upheavals of the early Miocene, 25 million years ago, led to the emergence from the sea of Aegeis, a continuous stretch of land which linked south-east Europe and Asia Minor. In the middle Miocene, Aegeis had high mountains and also dips filled with water. The flora grew to such an extent that by the late Miocene (14 million years ago) Aegeis was inhabited by large herbivorous mammals.In the late Tertiary (10 million years ago) the waters of the Mediterranean began to inundate Aegeis, forming the islands of the Aegean and Crete. Eight million years ago Crete was already surrounded by water.In the Pliocene epoch (1-3 million years ago) there was a constant process of rise and fall of land, and a deep tectonic rift was created in the Cretan sea, approximately in the same position as it is today.Geological upheavals in the area once occupied by Aegeis continued throughout the Pleistocene (1 million to 25.000 years ago) in which there were successive warm and cool periods caused by the gradual spreading and retreat of the glaciers. As a result, the level of the sea rose and fell, creating bridges between Crete and the adjacent lands over which the island was colonised by animal and plant species.
Since the late Miocene period, 5 to 10 million years ago, the
intense uplift of the whole Cretan area, due to plate tectonics,
accelerated karstic weathering, forming many gorges and caves
and plateaus.
The gorges are formed mainly in carbonate rocks, i.e. limestone
and marble, as a result of continuous land uplift and erosion by
water of the rivers. The land uplift is usually caused by faults, or
'cracks in the earth':
But here is the interesting observation. The Iron Gate looks more like
a relatively rapid breach in a rock wall, and not the result of a slow
erosion process. The other gates to the south – a relatively narrow
cleft in a larger structure – also shares this feature. So, something
different has been happening at different time periods.
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Early stage: Coastal limestone planes crossed by a river
Middle stage: The fault or crack is breaking, due to geological uplift and pressureNote that the lower end of the gorge is not yet open widely
Final stage: Immense erosion by the river and rising of the stone floor continues, widening the gorge Ha gorge
SE Crete
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Kust tussen Agia Roumeli
en Hora Sfakion
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The Samaria gorge was created during the Quaternary period. The dolomite beds of which the rock formations of the area are composed have been fractured by a variety of factors (glacial action, karstic phenomena etc.) which are particularly marked in the Gingilos area as well as around the 'Gates'.
Plattenkalk plooien in het Oligoceen (-25mj)
Dolomiet met kwarts lagen
Rivier afzetting
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Afwisselend kwarts / kalken??
Druipsteen,
Calciumcarbonaat: het
koolzure zout van calcium.
Calciet of Aragoniet
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Plakias
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Dunne pelagische kalken met donkere vuursteen
pelagische zone (de pelagische sedimenten). men heeft het dan over de diepe oceaanbodem, die buiten het bereik ligt van de kusten, de invloed van rivieren
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Zandsteen duinen
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Een unieke ligging, aan het einde van de Messara-vlakte, tussen de krijtrotsen, waarbij
talrijke gaten deze plaats een karakteristiek gezicht
geven.
Deze holen werden in de tijd van de Minoïsche cultuur (-3000 - -1200 jr) gebruikt als graftombes
Plakias
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The Dikteon Cave and the Ideon Cave in central Crete are the most important ancient
sacred caves in Crete, and they share many myths. The most famous myth is obviously
the birth of Zeus, which Hesiod tells us took place near the city of Lyktos in east-central
Crete, i.e. at the Dikteon Cave.
1. De geologie van Kreta, De ontwikkeling van een stuk plaatgrens gedurende de laatste 35 miljoen jaar. A.R. Fortuin, GEA, september 2007, 3, 101-108.
2. Neogene supradetachment basin development on Crete(Greece)duringexhumationoftheSouth Aegeancorecomplex Douwe J. J. van Hinsbergenn,w and Johan E. Meulenkampn, BasinResearch (2006) 18, 103–124, doi: 10.1111/j.1365-2117.2005.00282.
3. https://www.cretanbeaches.com/en/facts/geology-of-crete4. From orogenic hinterlands to Mediterranean-style back-arc basins: a
comparative analysis, J.P. PLATT,Journal of the Geological Society, 164, 297-311, 1 March 2007, https://doi.org/10.1144/0016-76492006-093
5. A Geological companion to Greece and the Aegean. Higgins MD, Higgins R (1996) Duckworth Publishers, London, Chapter 2 and 16.
6. https://www.tripadvisor.nl/Attractions-g189413-Activities-c57-t59-Crete.html
7. Gondwana breakup and the Western Tethys (regional view), AVI by Seton et al, 2012
8. https://commons.wikimedia.org/wiki/File:Tectonic_plates_boundaries_detailed-en.svg, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=40016114
9. The paleogene history of the pelagonian zone s. L. (Hellenides, greece): heavy mineral study from terrigenous flysch sediments, P. Faupl, a. PAVLOPOULOS and G. Migiros, Geologica Carpathica, 50, 6, Bratislava, 1999 -12
10.https://www.slideshare.net/WilliamSzary/global-tectonics-evolution-plate-tectonics-the-oceans-part-i
11.Structure and tectonics of subophiolitic me ´langes in the western Hellenides (Greece): implications for ophiolite emplacement tectonicsC. Ghikasa, Y. Dileka and A.E. Rassiosb, International Geology Review Vol. 52, Nos. 4–6, April–June 2010, 423–453
12.Comparison of the Late Triassic carbonate platform evolution and Lofercyclicity in the Transdanubian Range, Hungary and Pelagonian Zone, Greece, J. Haas et al, Central European Geology, Vol. 52/2, pp. 153–184 (2009)
13.Patterns and conditions of deformation in the plattenkalk nappe cretegreece- a preliminary study, Fassoulas C., Rahl J.M., Ague J., and Henderson K., Bulletin of the Geological Society of Greece vol. XXXVI, 2004
14.Carbonatitic dykes during Pangaea transtension Pelagonian Zone Greece-F L Schenker et al, Lithos 302–303 (2018) 329–340
15.Tectonics of the Aegean Anatolian region Glenn Simonelli - Indiana University 2002
16.The Aegean plate tectonic evolution in Mediterranean M. Reith 2014-0917.https://upload.wikimedia.org/wikipedia/commons/d/da/Hellenic_arc.png18.Crete, a continent in an island, http://www.nhmc.uoc.gr/en/exhibition-
halls/gift-shop/products/2874119.http://www.crete-kreta.com/crete-geology20.New geological conceptual model in western Crete (3) E Manoutsoglou
Conf Prot. and rest. of the environment XI, Thessaloniki, Volume Proc. 2012
21.The_geothermal_occurrence_of_Kapistri_Ierapetra_ar (1) Geol. Soc of Greece, vol. XLVII 2013 Proceedings of the 13th Int. Congress, Chania
22.https://www.sfakia-crete.com/sfakia-crete/gorges.html23.The Dikteon Cave or Dikteon Andron,
http://www.explorecrete.com/archaeology/dikteon-andron-cave.html
24.Tectonic evolution of a crustal-scale oblique ramp, Hellenides thrust belt, Greece, V. Chatzaras et al, ournal of Structural Geology 57:16-37 · October 2013
25.https://www.sfakia-crete-forum.com/read.php?7,63326.Samaria Gorge www.sfakia-crete-forum.com27.Fieldguide to the Geology of Crete, Univ. Of Crete, 2004, ISBN 960-267-
008-128.https://www.zorbas.nl/kloven-op-kreta-griekenland.htm29.http://geologylearn.blogspot.com/2016/11/stereographic-
projection.htmlrh: Foto van rob hekkenberg