Group presentation made on tectonics of sedimentary basin to present in a class where I was a team leader.

1. TECTONICS OF SEDIMENTARY BASINS
Ziaul Haque
Josh Poole
Morgan Shuman
DevonVerellen
David Adrian
Cheryl Coker
Phillip Daymond

2. Major Subdivisions of Basin Settings
1. Divergent
2. Convergent
3. Transform
4. Hybrid
Primary Controls on basin evolution
 Type of substratum
 Proximity to plate boundary
 Type of nearest plate boundary
Subsidence of the crust is induced by:
 Attenuation of crust due to stretching and erosion.
 Contraction of lithosphere during cooling.
 Depression of crust and lithosphere by sedimentary or
tectonic loads.

3. Classification of Sedimentary Basin
Basin Related to Convergent Setting:
 Back-arc basins (e.g., Black Sea)
 Intra-arc basins
 Fore-arc basins (e.g., Trakya basin)
 Trenches (e.g., many trenches in the Pacific Ocean)
 Foreland basins
Basins related to divergaent plate:
 Rift basins (e.g., Red Sea)
 Failed-rift basins (aulacogens; e.g., North Sea, Rhine Graben, Baikal
 Rift, East African Rift). These form as a result of crustal tension.
Transform boundaries:
 Along strike-slip faults there are transtensional and transpressional zones.
Strike-slip basins, Pull-apart basins develop along the transtensional
segments
Basins unrelated to plate boundaries:
 Cratonic and epicratonic basins

4. Formation mechanisms of basins

6. A) proto-oceanic stage
B) end of proto-
oceanic stage
C) Continental terrace
stage
D) continental-
embankment stage

8. Intracratonic Basins
 Most have formed above ancient failed rifts
 Many experience renewed subsidence during orogeny in adjacent
orogenic belts
Oceanic Basins
 Increases in depth with age.
 Depends on sediment type with depth of water
 Carbonate Compensation Depth (CCD)
 No carbonate below this depth
 Depressed near equator
 Silica Compensation Depth (SCD)
 less well defined than CCD
 Deeper than CCD
 Below SCD
 only nonbiogenic clay accumulates

9. Arc-Trench Systems
 Extensional
 formation of oceanic crust
behind magmatic arcs due to
trench rollback being faster than
trenchward migration of the
overriding plate
 Compressional
 continental margin advances
trenchward faster than trench
rollback
 Neutral
 trench rollback = trenchward
advance of overriding plate
Trenches
 Accretion and preservation of
trench deposits
A. Low sediment supply, mostly
oceanic crust
B. Moderate sediment supply,
mixture of trench and oceanic
facies
C. High sediment supply, mostly
trench facies

10. Trench-Slope Basins
• Small ponded basins along
inner trench walls
• Irregular bathymetry
• Turbidites pond behind
ridges subparallel to trench
• Model appropriate for
sediment-rich areas
Moore and Karig, 1976

11. Forearc Basins
 Geometry controlled by (1) initial setting, (2) sediment
thickness on subducting plate (3) rate of sedimentation
(4) rate and orientation of subduction (5) time since
subduction occurred
 Prograde accretion at trenches and retrograde
migration of magmatic arcs after subduction
 5 types of forearc basins

12. Forearc Basins

13. Intra-arc Basins
 Associated with active volcanoes
 Depositional environments can be oceanic, shelfal, or
mountainous
 Composition depends on underlying crust
 Form from tectonomagmatic collapse in or around
eruptive centers
 Intra-arc basins may evolve into Interarc Basins during
backarc spreading, collapse as calderas, or be uplifted
and destroyed

14. Backarc basin evolution
 Stage 1: Early rifting
 Stage 2: Basin widening
with active volcanism
and spreading
 Stage 3: Basin maturity
 Stage 4: Basin inactivity,
spreading stops

15. Foreland Basin
 Pre Plate Tectonic term used
to describe a basin between
an orogenic belt and a craton
 Compressional tectonics
behind the arc trench system
is the driving force
 Retroarcs used with
compressional arcs

16. Remnant Ocean Basins and Suture Belts
• “Most sediment shed from orogenic
highlands formed by continental collisions
pours into remnant ocean basins as
turbidites that are subsequently deformed
and incorporated into the orogenic belts as
collision sutures lengthen.” (Graham and
other, 1975)
• Synorogenic flysch and molasse deposits
Peripheral Foreland Basin
• Forms as the elastic lithosphere flexes
under encroaching dynamic load
• Modified Speed and Sleep Model
(Stockmal and others, 1986)
• Demonstrated effects of rifted-margin
age and topography of lithospheric
flexure and basin development

17. Piggyback Basins
• Formed and have been filled while being
carried on the top of moving thrust sheets
• Majority of sediment is derived from
associated fold-thrust belts
• Low preservation potential; young orogenic
systems
Foreland Intermontae Basins
1. Green River type
• Large, equidimensional/elliptical,
bounded on 3 + by uplifts, lakes common
2. Denver type
• Elongate, open, asymmetric synclinal
downwarps with uplift on 1 side
3. Echo Park Type
• Narrow, highly elongate, fault bounded,
through drainage, strike-slip origin

18. Strike-Slip Setting
1. Transtensional Basin – (pull-apart) form at left-stepping sinistral fault
junctures and right-stepping dextral fault junctures
2. Transpressional Basin
• Ridge Basin – deformed and over thrust margins that creates flexural
subsidence from tectonic load
• Fault-Wedge Basin – Uplift of blocks at restraining bend but down drop
once block is past bend
3. Transrotational Basin – Block along restraining bend rotate

19. 1. Intracontinental Wrench Basins - failed rifts from
intracontinental rifts
• Aulacogen – Form at high angle to orogenic
belt and has a rifted history of ocean basin
formation prior to collision
• Impactogens – Same as aulacogen but does
not have pre-collisional history
• Random Rifts – unrelated to ocean formation
or collision and deformed during suturing
2. Successor Basin – deeply subsiding troughs with
limited volcanism associated with narrow uplifts
• Form on top of inactive fold-thrust belts, suture
belts, transform belts, and noncratonal failed
rifts
• Presence indicated end of orogenic activity
Hybrid Setting

20. Thank You!