9.1 Arakapas Transform Fault
Limassol Forest Complex
a.k.a Anti-Troodos Plate
Interp: Transform zone
Focus: N boundary zone against the Troodos
3 transform zone characteristics
- Extreme seafloor relief
- Def-induced unroofing of deeper o.c. levels
- Def fabrics consistent w subhorizontal shear
Extension implications
induced melt separation & emplacement
Products
- remelted depleted upper mantle
- intrusive gabbros
- Radiolarite Palaeoenvmt
Pelagic sedimentation resumes after slumping
Radiolarite - rhythmical alternation of radiolarite oozes & mudstone
--> covers up slumped seds & topog lows
Softer clays (Moni clays) overlie radiolarites
river valley erodes through them
High productivity conditions
siliceous sed unusual on highs/ridge - usually carbs above CCD
Sed cover of volcanics
E side Arakapas Transform
Topmost pillow lavas & sed cover
Umber volcaniclastics (Peripedhi Fm)
= off-axis hydrothermal black smoker activity
missing in other parts of Troodos - radiolarite instead
Brecciated pillow lavas dip SE
Radiolarites
Rhythmical alternation of radiolarite oozes & mudstone
Slumped down pillow lava palaeoslope
Material rotates downslope (SE) (fold axes converge downslope
Deformation History
Peripedhi radiolarite & umbers overlie Troodos lavas
Moni Clay atop
Lefkhara Chalk = seal
Not just one strike slip fault
series of branching faults form staircase
Sediments collect in tilted enscarpments
Radiolarites (80 Ma) younger
vs underlying lavas (90 Ma)
∴ Fault system active for long time
causing downslope slumping into grabens
Umbers & radiolarites
= tilted & slumped
∴ Extensional pulse post-transform
(rotation Troodos microplate?)
Buckling (box folds)
Layer parallel slip
radiolarite layers have differing competencies
mud horizons = weaker
Why age gap btwn lava & perapedhi seds?
High velocity currents socur away seds/prevent sedimentation (hiatus)
Planar beds
Pelagic sedimentation resumes after slumping
--> covers slumped seds & topog lows
Volcaniclastic seds vary regionally
Reflect differing seafloor topography
Enscarpments
slumped seds
Topog high
debris flows etc
Topog high nr transform
Lageia
Large, laterally continuous faults ∴ signif fault enscarpments
Height differential
= driver for energy changes & high energy reworking
Debris flows
Form on huge enscarpments at sealevel
material input from many levels
Changes in sorting/grain size
reflect changes in source material available
Poss cyclicity: debris flow - background sed - lava flow ?
Why fines toward lava?
Coarse material all reworked already/source = depleted ?
Legeia