A SeqStrat 2
seqstrat
seqstrat
Hierarchy of cycles
1st order 10-200 Myr Tectonic reconfiguration 2nd order 5-?30 Myr Major tectonic events 3rd order 0.5-5 MyrTectonic or major climatic events 4th order 100-400 kyr Milankovitch cycles, climatically forced 5thorder 20-40 kyr Milankovitch cycles, climatically forced
FRST
Forced regressive/falling stage systems tract
SMST
Shelf margin systems tract
Exmple of systems tracts in outcrop
Book Cliffs
falling limb systems tract diagram
.
what generates parasequences
sea level change OR autocyclic switching of delta or fan lobes at this scale
how to tell if parasequences are progradtional, retrogradtional or aggradational from log data?
there will be an overall trend (fining/coarsening upwards)
(L4)
ravinement surface
flat erosional surface
flooding surface vs. sequence boundary at log scale
flooding surface: abrupt deepening
sequence boundary: abrupt shallowing
carbonate ramp lithologies and envirnoments
.
carbonate vs. siliclastic falling stage
.
carbonate vs. siliclastic lowstand
.
carbonate vs. siliclastic transgressive
.
carbonate vs. siliclastic highstand
.
MFS can be recognised with downlap how?
.
describtors for reflector configuration
geometry
continuity
amplitude
frequency
different ways to pick flooding boundaries, which one is Exxons?
Exxon/Vail/Van Wagoner: Classic sequence stratigraphic approach, picking sequence boundaries at unconformities marked by the downward shift in the position of landwards onlap.
Alternatives:
Galloway (1989): Maximum flooding surface used as the sequence boundary Collier, Alkyonides Gulf study: Maximum regressive surface (initial flooding surface at base of each transgressive systems tract) picked as sequence boundaries
apparent lateral variations in systems tracts caysed by
delta lobe switching.
how are faults relevent
uplift etc.
what is the shelf margin systems tract
lowest point of sea level (lump of sediment at the bottom of the shelf break)
in transgressive systems tract why does onlap go up and back.
often each sea level rise is higher than the one before it as there is often background subsidence
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Cartes-fiches
Hierarchy of cycles
1st order 10-200 Myr Tectonic reconfiguration 2nd order 5-?30 Myr Major tectonic events 3rd order 0.5-5 MyrTectonic or major climatic events 4th order 100-400 kyr Milankovitch cycles, climatically forced 5thorder 20-40 kyr Milankovitch cycles, climatically forced
FRST
Forced regressive/falling stage systems tract
SMST
Shelf margin systems tract
Exmple of systems tracts in outcrop
Book Cliffs
falling limb systems tract diagram
.
what generates parasequences
sea level change OR autocyclic switching of delta or fan lobes at this scale
how to tell if parasequences are progradtional, retrogradtional or aggradational from log data?
there will be an overall trend (fining/coarsening upwards)
(L4)
ravinement surface
flat erosional surface
flooding surface vs. sequence boundary at log scale
flooding surface: abrupt deepening
sequence boundary: abrupt shallowing
carbonate ramp lithologies and envirnoments
.
carbonate vs. siliclastic falling stage
.
carbonate vs. siliclastic lowstand
.
carbonate vs. siliclastic transgressive
.
carbonate vs. siliclastic highstand
.
MFS can be recognised with downlap how?
.
describtors for reflector configuration
geometry
continuity
amplitude
frequency
different ways to pick flooding boundaries, which one is Exxons?
Exxon/Vail/Van Wagoner: Classic sequence stratigraphic approach, picking sequence boundaries at unconformities marked by the downward shift in the position of landwards onlap.
Alternatives:
Galloway (1989): Maximum flooding surface used as the sequence boundary Collier, Alkyonides Gulf study: Maximum regressive surface (initial flooding surface at base of each transgressive systems tract) picked as sequence boundaries
apparent lateral variations in systems tracts caysed by
delta lobe switching.
how are faults relevent
uplift etc.
what is the shelf margin systems tract
lowest point of sea level (lump of sediment at the bottom of the shelf break)
in transgressive systems tract why does onlap go up and back.
often each sea level rise is higher than the one before it as there is often background subsidence
