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)

(k)

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)

(k)

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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