Archaeoseismology and Palaeoseismology in the Alpine ... - Tierra

Within the FBFZ, the Eşen Basin is formed as a ca. 15 km
wide and 30 km long, NNE‐trending extensional graben
behind the Lycian Nappes front close to the contact with
the Beydağları autochthon. The Lycian Nappes basement
consists of ophiolitic rocks, limestones and turbiditic
sandstones. The basin is bounded and transected by a
series of N‐ to NE‐ trending faults that had exhorted
important control on the character and distribution of
sedimentary facies since the Late Miocene.
Historical and recent seismic reports show a density of
earthquake‐clustering in the FBFZ comparable to regions
located along the NAF and EAF, suggesting it represents a
significant seismic hazard. In spite of this the FBFZ is
seismically defined by weak to moderate (M ≤ 6)
earthquakes only. Important exceptions include the
northeastern extremity and the off‐shore southwestern
extremity (Rhodes 1957, off‐shore Turkey 1926, 1969,
1975, 1980, and 2001) were large earthquakes have
occurred.
PINARA SITE
The ancient Lycian City of Pınara is located along the fault‐
controlled western border of the Eşen Basin, near the
modern village of Minare. The archaeological site is
spread over a 3 – 4 km 2 area that includes a variety of
exposed geological units (Fig. 2A). The basement along
the basin margin is characterized by a pre‐Late Miocene
thrust contact between two limestone nappes. This
contact is demarcated by a relatively thin flysch unit with
exotic limestone blocks up to 50 m width. From the Late
Miocene onward, the thrust contact was down‐faulted to
the east along a series of sub‐parallel normal faults (Fig.
2B). Just south of Pınara, strongly tilted Upper Miocene
fluvial deposits with intermixed breccia levels abut against
the marginal fault and are unconformably overlain by
Pleistocene terrace deposits.
Fig. 2: Geological map (A) and cross section (B) of Pınara ancient
city. 1 – Roman Theatre, 2 – Bath, 3 – Odeon, 4 – Temple, 5 –
Tomb, 6 – Agora, 7 – Necropolis, 8 – Rock Tombs
The largest part of the city was built on a down‐faulted
limestone basement block, whereas tombs of the
Acropolis were mainly carved in a ~80 m high NE‐SW‐
trending fault face to the west (Fig. 2B). No archaeological
1 st INQUA‐IGCP‐567 International Workshop on Earthquake Archaeology and Palaeoseismology
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remains are present on the basement flysch, which
probably was used for agricultural purposes. The Roman
Theatre was built on a slightly westward‐tilted
Pleistocene terrace that rests on top of the flysch.
According to the ancient records, the city of Pınara was
founded by colonists from Xantos between the 5th and
4th century BC. It was one of the largest cities in the
powerful Lycian league and located along the main Lycian
road (Akurgal, 1978). In the course of time the city was
under both Roman and Byzantine control. The city was
destroyed by three earthquakes in 141 AD (Guidoboni,
1994; Lang, 2003; Akşit, 2006), ~240 AD (Lang, 2003;
Akşit, 2006) and 1851 (Soysal et al., 1981). Pınara received
financial aid for the reconstruction of the city after the
first two earthquakes (Guidoboni, 1994; Lang, 2003; Akşit,
2006). Eventually, the city lost its financial and geographic
importance and at the end of the 9th century AD the city
was abandoned
The observations in Pınara ancient city reveal several
different kinds of damages (Fig. 3). The vertical cracks and
joints of numerous beams, door and window frames and
the undulated wall relict between Temple to the Odeon
indicate horizontal and vertical oscillations. The
reconstructed temple wall close to the tomb building
shows that this structure has been destroyed and rebuild
at least two times. The sliding of blocks of masonry arch
close to Odeon shows a typical deformation, which has
been interpreted as resulting from an earthquake (Marco,
2008; Kamai and Hatzor, 2008). Moreover, the southern
collapsed edge of the Roman theatre shows a
characteristic earthquake related U shape gap. The
imbricate arrangements of collapsed blocks indicate rapid
collapse due to seismic activity (Sintubin and Stewart,
2008). Likewise, the rotated blocks of the northern wing
of the theatre are strong indication that the damage is
earthquake related.
The detailed assessment of the archaeological relicts
indicates that various kinds of damages are of
seismogenic origin. Investigations show also that the city
was destroyed several times (Yerli et al., submitted).
A B
C D
E F
Fig. 3: Examples of probably seismic‐related damage in Pınara; A‐
rebuild temple wall, B‐ sinuously deformed wall with ejected
blocks, C‐ opened vertical joints, D‐ “U” shape collapse of
southern wall of Roman Theatre, E‐ vertical undulation structure