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A character, composed of very thin radiolar-
B ian chert beds intercalated with soft clay-
stone and mudstone. Beneath the Lykaion
C thrust fault the rocks are marked by a sys-
tem of large upright to slightly overturned
Figure 3. (A) Mythen klippe, Central Switzerland. (The author thanks H. Röst and M. Steiner for per- anticlines and synclines, which control the
mission to reproduce their Mythen image.) (B) Chief Mountain klippe, Glacier National Park, Mon- geologic map relationships (Davis, 2009,
tana. To the Blackfoot people this mountain is Ninaistako. (The author thanks Marc Adamus for 2014) (see Figs. 2 and 5).
permission to reproduce his Chief Mountain photograph.) (C) South-directed photograph of the
Agios Elias klippe, Sanctuary of Zeus, Mount Lykaion. Limestone and interbedded siltstone of
the Flysch Transition Beds Formation
the trace of this thrust fault, which I have five formations shown in the map explana- (Paleocene) crop out immediately below
named the Lykaion thrust, that is the tion (Davis, 2009) (see Fig. 2). The oldest the klippe and have eroded to an open,
archaeological boundary between the Pindos Group formation (Chert Series relatively smooth landscape forming the
upper and lower levels of the sanctuary. Beds Formation, Jurassic) rests in thrust- bedrock bench. Directly beneath is the
This thrust was identified as one among fault contact atop the youngest (Flysch Thick White Limestone Beds Formation
many within a regional system of thrust Transition Beds Formation, Paleocene). (Late Cretaceous), composed of resistant,
faults discovered during the 1:50,000 map- The Jurassic Chert Series Beds serve as a sharp weathering, brush- and bush-sur-
ping carried out by Lalechos (1973) and décollement into which the Lykaion thrust mounted limestone. In combination with
Papadopoulos (1997). soles, which is also the case for most parts the underlying Thin Platy Limestone Beds
of the Pindos fold and thrust belt (Degnan Formation (Late Cretaceous), the Thick
In carrying out geological mapping of and Robertson, 1998; Skourlis and White Limestone Beds Formation supports
the sanctuary and its surroundings Doutsos, 2003). Décollement favorability the steep imposing cliffs that mark the
(1:2500-scale), I expanded the four-unit of the Chert Series Beds derives from its west and north faces of Mount Lykaion.
Pindos Group stratigraphy of Lalechos inherent quasi-plastic mechanical Moreover, the Thick White Limestone
(1973) and Papadopoulos (1997) into the Beds Formation has been heavily attacked
by karst processes as revealed in the more
than 150 sinkholes within its map-area
distribution of just 10 km2. Today it is dif-
ficult to overstate the impenetrability of
some of this karst-modified terrain where
not agriculturally terraced.

The cone-shaped, smooth-weathering
klippe landscape above the thrust is much
different from that below because of the
presence of relatively soft sandstones of
the First Flysch Beds Formation (early
Late Cretaceous) and the mudstones and
radiolarian chert layers of the Chert Series
Beds Formations (Jurassic) (see Fig. 5).
Normal faults conspicuously cut and offset
the bedrock within the klippe (see Figs. 2
and 5), and this faulting has had a particu-
larly profound effect on the landscape
character of the top of the klippe (Davis,
2009). The normal faulting postdates the
late Cretaceous to Eocene folding and
thrusting. The clearest expression of this
faulting marks the eastern margin of the
Agios Elias klippe, where major, active,
east-dipping, NNE-striking normal faults
of the “Zeus” active fault system have cut
into the plateau-like upper surface of the
Agios Elias klippe, producing structural
platforms that step down to the east. The
edge is so precipitous that rock falls are
frequent, and a very large landslide com-
plex has accrued on the eastern flank of
the klippe (see Figs. 2 and 5). Closely asso-
ciated with the trace of this normal fault

6 GSA Today | December 2017