-
8/9/2019 17156896 Sedimentary Basins Petroleum Geology
1/24
Sedimentary Basins &Sedimentary Basins &
Petroleum GeologyPetroleum Geology
-
8/9/2019 17156896 Sedimentary Basins Petroleum Geology
2/24
Controls on largeControls on large--scalescale
sedimentationsedimentation Sedimentary processes are controlled, on large scales,Sedimentary processes are controlled, on large scales,
by:by:
ClimateClimate determines:determines:
weathering rates,weathering rates, precipitation & runprecipitation & run--off (sed. transportation),off (sed. transportation),
environmentsenvironments
Tectonic settingTectonic setting determines:determines:
reliefrelief
time for sed. transporttime for sed. transport
types of environmentstypes of environments
types of sedimentary basinstypes of sedimentary basins
source rock typesource rock type
-
8/9/2019 17156896 Sedimentary Basins Petroleum Geology
3/24
What is a sedimentary basin?What is a sedimentary basin?
A low area on the Earths surface relative to surroundingsA low area on the Earths surface relative to surroundings e.g. deep ocean basin (5e.g. deep ocean basin (5--10 km deep), intramontane basin (210 km deep), intramontane basin (2--3 km3 km
a.s.l.)a.s.l.)
May be ofMay be oftectonictectonic (or(orerosionalerosional origin)origin)
A receptacle for sedimentation; erosion may also be importantA receptacle for sedimentation; erosion may also be important
Sedimentation may be interruptedSedimentation may be interrupted -- unconformitiesunconformities Basins may be small (kms2) or large (106+ km2)Basins may be small (kms2) or large (106+ km2)
Basins may be simple or composite (subBasins may be simple or composite (sub--basins)basins)
Basins may change in size & shape due to:Basins may change in size & shape due to: erosionerosion
sedimentationsedimentation tectonic activitytectonic activity
eustatic seaeustatic sea--level changeslevel changes
Basins may overlap each other in timeBasins may overlap each other in time
-
8/9/2019 17156896 Sedimentary Basins Petroleum Geology
4/24
The Evolution of SedimentaryThe Evolution of Sedimentary
BasinsBasins The evolution of sedimentary basins mayThe evolution of sedimentary basins may
include:include:
tectonic activity (initiation, termination)tectonic activity (initiation, termination)
magmatic activitymagmatic activity
metamorphismmetamorphism
as well as sedimentationas well as sedimentation
all may be contemporaneousall may be contemporaneous Basins may develop on oceanic crust,Basins may develop on oceanic crust,
island arc crust, or continental crustisland arc crust, or continental crust
-
8/9/2019 17156896 Sedimentary Basins Petroleum Geology
5/24
Basins may be sedimentary basinsBasins may be sedimentary basins
sedimentary fill is relatively undeformed,sedimentary fill is relatively undeformed,
basin margin facies are preservedbasin margin facies are preserved OR,OR, structuralstructural (remnants of)(remnants of) basinsbasins
sedimentary fill is deformedsedimentary fill is deformed
dips > original depositional slopesdips > original depositional slopes basin margin facies are erodedbasin margin facies are eroded
-
8/9/2019 17156896 Sedimentary Basins Petroleum Geology
6/24
Components of a basinComponents of a basin
Axial elements of sedimentary basins:Axial elements of sedimentary basins:
Basin axisBasin axis is the lowest point on theis the lowest point on the
basement surfacebasement surface
Topographic axisTopographic axis is the lowest point on theis the lowest point on the
depositional surfacedepositional surface
DepocentreDepocentre is the point of thickest sedimentis the point of thickest sediment
accumulationaccumulation
-
8/9/2019 17156896 Sedimentary Basins Petroleum Geology
7/24
What type of basin do we have?What type of basin do we have?
Depends on the structural setting of theDepends on the structural setting of the
basinbasin
Many types, corresponding to differentMany types, corresponding to differentlocationslocations
Divergent plate margin basinsDivergent plate margin basins
Convergent plate margin basinsConvergent plate margin basins
-
8/9/2019 17156896 Sedimentary Basins Petroleum Geology
8/24
Divergent plate marginDivergent plate margin
basinsbasins Continental Rift Zones (Narrow)Continental Rift Zones (Narrow)
Aulacogene BasinsAulacogene Basins
Continental Rift Zones
Continental Rift Zones
Oceanic Rift BasinsOceanic Rift Basins
Open Ocean PassiveOpen Ocean Passive--Margin BasinsMargin Basins
-
8/9/2019 17156896 Sedimentary Basins Petroleum Geology
9/24
Continental Rift Zones (Narrow)Continental Rift Zones (Narrow)
OriginOrigin large scale mantle convectionlarge scale mantle convection
regional updomingregional updoming ss regional basaltic (flood)regional basaltic (flood)
volcanismvolcanism extensional failure of crustextensional failure of crust
listric normal fault systemlistric normal fault system
subsided/rotated half grabenssubsided/rotated half grabens
widening to form central rift grabenwidening to form central rift graben may:may:
rupturing of crustrupturing of crust
spreading ridge, oceanic basinspreading ridge, oceanic basin
-
8/9/2019 17156896 Sedimentary Basins Petroleum Geology
10/24
Continental Rift Zones (Narrow)Continental Rift Zones (Narrow)
two associated basin typestwo associated basin types central rift graben basincentral rift graben basin
rim basinsrim basins
environments & faciesenvironments & facies
alluvial fan, fluvial, lakealluvial fan, fluvial, lake volcanismvolcanism
initial (flood) basaltic (arch phase)initial (flood) basaltic (arch phase) lavaslavas
intraintra--rift bimodal volcanismrift bimodal volcanism
basaltbasalt--rhyolite lavas & pyroclasticsrhyolite lavas & pyroclastics often peralkalineoften peralkaline
calderas, stratovolcano, shieldscalderas, stratovolcano, shields
mantle magmas melt crustmantle magmas melt crust
-
8/9/2019 17156896 Sedimentary Basins Petroleum Geology
11/24
Continental Rift Zones (Narrow)Continental Rift Zones (Narrow)
Sediment compositionsSediment compositions mixed provenancemixed provenance
exposed crustal rocks at rift marginexposed crustal rocks at rift margin
contemporaneous volcanic sourcescontemporaneous volcanic sources
ExamplesExamples East Africa rift zoneEast Africa rift zone
Rio Grande rift; Rhine grabenRio Grande rift; Rhine graben
May be subsequently deformed byMay be subsequently deformed by
compressional deformationcompressional deformation e.g. Proterozoic Mt. Isa rifte.g. Proterozoic Mt. Isa rift
DevonoDevono--Carb. Mt. Howitt province, VictoriaCarb. Mt. Howitt province, Victoria
-
8/9/2019 17156896 Sedimentary Basins Petroleum Geology
12/24
Aulacogene BasinsAulacogene Basins
Narrow continental rifts which do not evolve into spreading ridgeNarrow continental rifts which do not evolve into spreading ridgeoceanic basins.oceanic basins. e.g North Sea basins, Europe; Gippsland Basin, Bass Basin.e.g North Sea basins, Europe; Gippsland Basin, Bass Basin.
Dominated by initial alluvial fan, fluvial, lake facies; up to 4 km thick.Dominated by initial alluvial fan, fluvial, lake facies; up to 4 km thick.
May extend throughMay extend through crustal subsidence & extensioncrustal subsidence & extension marine transgression; no oceanic crustmarine transgression; no oceanic crust
coastal plain rivers, coal swamp shoreline, shelf & slope environmentcoastal plain rivers, coal swamp shoreline, shelf & slope environment(e.g. Gippsland, Bass basins(e.g. Gippsland, Bass basins
ProvenanceProvenance continental, mixedcontinental, mixed
plutonic, metasedimentary, metavolcanic, contemporaneous volcanicplutonic, metasedimentary, metavolcanic, contemporaneous volcanic ss marine carbonatesmarine carbonates
-
8/9/2019 17156896 Sedimentary Basins Petroleum Geology
13/24
Continental Rift ZonesContinental Rift Zones
OriginOrigin regionally extensive mantle convectionregionally extensive mantle convection
= ? driven by subduction oceanic spreading ridge under continent= ? driven by subduction oceanic spreading ridge under continent
e.g. ?Western U.S.A.e.g. ?Western U.S.A.
Extensional failure of crustExtensional failure of crust
complex
lystric fault systemcomplex
lystric fault system down to 15 km, Western U.S.A.down to 15 km, Western U.S.A.
uprise of mantle + metamorphic core complexesuprise of mantle + metamorphic core complexes -- regional uplift, up to 2regional uplift, up to 2--3 km3 km
widespread volcanism in complex multiple graben rift basinswidespread volcanism in complex multiple graben rift basins
Environments and faciesEnvironments and facies alluvial fan, fluvial, lacustrinealluvial fan, fluvial, lacustrine
VolcanismVolcanism
flood basalts, bimodal basaltflood basalts, bimodal basalt--rhyoliterhyolite--andesite: lavas & pyroclasticsandesite: lavas & pyroclastics tholeiitic, alkaline, calctholeiitic, alkaline, calc--alkaline: lavas & pyroclastics.alkaline: lavas & pyroclastics.
ProvenanceProvenance mixed crustal sourcesmixed crustal sources
contemporaneous volcanic sourcescontemporaneous volcanic sources
-
8/9/2019 17156896 Sedimentary Basins Petroleum Geology
14/24
Oceanic Rift BasinsOceanic Rift Basins
Initially narrow (e.g. Red Sea)Initially narrow (e.g. Red Sea)
may evolve into open oceanic basinsmay evolve into open oceanic basins
OriginOrigin narrow continental rifts evolvenarrow continental rifts evolve
breakbreak--upup
oceanic spreading ridgeoceanic spreading ridge oceanic crust in axial basinsoceanic crust in axial basins
continental crust at basin margincontinental crust at basin margin
Environments & faciesEnvironments & facies alluvial fans, fan deltas, shoreline narrow shelf, slope, abyssal plainalluvial fans, fan deltas, shoreline narrow shelf, slope, abyssal plain
VolcanismVolcanism MORB tholeiitic oceanic crustMORB tholeiitic oceanic crust
Lavas, hyaloclastiteLavas, hyaloclastite
ProvenanceProvenance mixed continentalmixed continental
contemporaneous volcanicscontemporaneous volcanics
shelf carbonate, evaporitesshelf carbonate, evaporites
oceanic carbonate, evaporitesoceanic carbonate, evaporites
oceanic pelagic, hemioceanic pelagic, hemi--pelagicpelagic
-
8/9/2019 17156896 Sedimentary Basins Petroleum Geology
15/24
Open Ocean PassiveOpen Ocean Passive--MarginMargin
BasinsBasins Evolve from oceanic rift basinsEvolve from oceanic rift basins Become passive margin basins when MORsBecome passive margin basins when MORs -- large, wide oceanlarge, wide ocean
basins.basins.
Half graben system evolves into coastal plainHalf graben system evolves into coastal plain--continental shelf &continental shelf &slopeslope oceanic abyssal plain systemoceanic abyssal plain system
VolcanismVolcanism none expected after breaknone expected after break--upup
perhaps intraplate hot spot volcanismperhaps intraplate hot spot volcanism
Sedimentation & provenanceSedimentation & provenance as for oceanic rift basinas for oceanic rift basin
+ well developed shelf+ well developed shelf--slope seds (slope seds (ss carbonate seds.)carbonate seds.)
TectonicsTectonics postpost--breakbreak--up thermal & later isostatic subsidence of continental marginup thermal & later isostatic subsidence of continental margin
transgressiontransgression
-
8/9/2019 17156896 Sedimentary Basins Petroleum Geology
16/24
Convergent Plate MarginConvergent Plate Margin
BasinsBasins
-
8/9/2019 17156896 Sedimentary Basins Petroleum Geology
17/24
Continental Margin ArcContinental Margin Arc--SubductionSubduction
Associated Basins
Associated Basins
OriginOrigin oceanic plate being subducted under continentaloceanic plate being subducted under continental
marginmargin
trench, accretionary prism, continental margintrench, accretionary prism, continental marginvolcanic arcvolcanic arc
E.g. Andes, Cascades arcE.g. Andes, Cascades arc
VolcanismVolcanism calccalc--alkaline arc volcanismalkaline arc volcanism
andesites, dacites, rhyolites, rhyodacites, minor basaltsandesites, dacites, rhyolites, rhyodacites, minor basalts
hydrous fluids from subducting lab melt mantle above, & bothhydrous fluids from subducting lab melt mantle above, & boththen melt the base of the crustthen melt the base of the crust
lavas + pyroclasticslavas + pyroclastics
-
8/9/2019 17156896 Sedimentary Basins Petroleum Geology
18/24
Continental Margin ArcContinental Margin Arc--SubductionSubduction
Associated Basins
Associated Basins Basin types: environments & faciesBasin types: environments & facies
Trench basinTrench basin deep marinedeep marine
turbidites, pelagic seds.turbidites, pelagic seds.
Forearc basinForearc basin perched on "scraped off", imbricate thrust faulted, accretionary prismperched on "scraped off", imbricate thrust faulted, accretionary prism
alluvial fan, fluvial, shoreline shelf, deep turbidite fansalluvial fan, fluvial, shoreline shelf, deep turbidite fans
Back arcBack arc--foreland basinforeland basin lies behind arclies behind arc
at foot of craton directed fold & thrust belt if presentat foot of craton directed fold & thrust belt if present
alluvial fan, fluvial, lakesalluvial fan, fluvial, lakes
IntraIntra--arcarc arc volcanoes often lie in major grabenarc volcanoes often lie in major graben
alluvial fan, fluvial, lakealluvial fan, fluvial, lake
-
8/9/2019 17156896 Sedimentary Basins Petroleum Geology
19/24
Continental Margin ArcContinental Margin Arc--SubductionSubduction
Associated Basins
Associated Basins
Sediment compositionsSediment compositions
TrenchTrench
metasedimentary debris eroded off accretionary prismmetasedimentary debris eroded off accretionary prism
v. minor volcanic debrisv. minor volcanic debris pelagic sed.pelagic sed.
Forearc basinForearc basin
voluminous volcanic debrisvoluminous volcanic debris
BackBack--arc basinarc basin arc & thrust belt derivedarc & thrust belt derived
mixed volc., metamixed volc., meta--sed., metamorphic, plutonicsed., metamorphic, plutonic
IntraIntra--arc basinsarc basins: lavas, volcanic seds, pyroclastics: lavas, volcanic seds, pyroclastics
-
8/9/2019 17156896 Sedimentary Basins Petroleum Geology
20/24
Island ArcIsland Arc--Subduction AssociatedSubduction Associated
BasinsBasins E.g. Marianas, TongaE.g. Marianas, Tonga--Kermadec arcsKermadec arcs
OriginOrigin oceanic plate is subducted under another oceanic plateoceanic plate is subducted under another oceanic plate
trench, accretionary prism, volcanic island arctrench, accretionary prism, volcanic island arc
volcanic arc on oceanic lithospherevolcanic arc on oceanic lithosphere
back arc basin(s) originate by rifting of arc block, development ofback arc basin(s) originate by rifting of arc block, development ofsmall spreading ridgesmall spreading ridge
widening basin; oceanic crustwidening basin; oceanic crust
arc block migrates trenchward as subducting plate "rolls back".arc block migrates trenchward as subducting plate "rolls back".
VolcanismVolcanism island arc tholeiitic volcanicsisland arc tholeiitic volcanics
basalts, basaltic andesitesbasalts, basaltic andesites
back arc basin tholeiitic crustback arc basin tholeiitic crust
-
8/9/2019 17156896 Sedimentary Basins Petroleum Geology
21/24
Island ArcIsland Arc--Subduction AssociatedSubduction Associated
BasinsBasins Basin types, environments, facies, provenanceBasin types, environments, facies, provenance
Trench basinTrench basin turbidites, pelagic sedimentsturbidites, pelagic sediments
metasedimentary sed. from accretionary prismmetasedimentary sed. from accretionary prism
arc derived volcanic sedimentarc derived volcanic sediment
ForeFore--arc basinarc basin on accretionary prismon accretionary prism
volcanic seds., carbonatesvolcanic seds., carbonates
turbiditesturbidites
Back arc basinBack arc basin arc derived volcaniclastic turbidite apronarc derived volcaniclastic turbidite apron
pelagic sediments, especially where basin is largepelagic sediments, especially where basin is large
no continental derived sedimentno continental derived sediment
only rare silicic volcanismonly rare silicic volcanism
-
8/9/2019 17156896 Sedimentary Basins Petroleum Geology
22/24
Continental Collision Belts & BasinsContinental Collision Belts & Basins
E.g. Himalayan mountain chain, European AlpsE.g. Himalayan mountain chain, European Alps
OriginOrigin long term subduction of oceanic plate under continental margin, will bringlong term subduction of oceanic plate under continental margin, will bring
"passenger" continent into collision with arc host continent."passenger" continent into collision with arc host continent.
oceanic basin closes during collisionoceanic basin closes during collision
subducting continent under thrust oversubducting continent under thrust over--riding continentriding continent uplift, mountain range, double continental crust thicknessuplift, mountain range, double continental crust thickness
VolcanismVolcanism subduction related volcanism stop at collision, when subduction stopsubduction related volcanism stop at collision, when subduction stop
granitoid plutonism may occur due to extremely thickened crustgranitoid plutonism may occur due to extremely thickened crust magmas won't rise because of compressional stress fieldmagmas won't rise because of compressional stress field
Basin types, environments, facies provenanceB
asin types, environments, facies provenance foreland basin at foot of fold & thrust beltforeland basin at foot of fold & thrust belt subject to isostatic subsidencesubject to isostatic subsidence
huge sediment flux off mountain belthuge sediment flux off mountain belt
alluvial fan, braided river, meandering river, lake environments & faciesalluvial fan, braided river, meandering river, lake environments & facies
metasedimentary, met. (include high grade plutonic, reflecting deep crustalmetasedimentary, met. (include high grade plutonic, reflecting deep crustalerosion)erosion)
-
8/9/2019 17156896 Sedimentary Basins Petroleum Geology
23/24
Continental StrikeContinental Strike--Slip BasinsSlip Basins
E.g. California borderland basins associated with SanE.g. California borderland basins associated with SanAndreas strikeAndreas strike--slip fault systemslip fault system
OriginOrigin strikestrike--slip along nonslip along non--linear faultslinear faults
opening "holes" or basins at fault jogs or bendsopening "holes" or basins at fault jogs or bends
VolcanismVolcanism usually none, unless "accidental" intraplateusually none, unless "accidental" intraplate
Basin types, environments, facies, provenanceBasin types, environments, facies, provenance
"pull"pull--apart" or strikeapart" or strike--slip basinsslip basins alluvial fans, rivers, lakesalluvial fans, rivers, lakes
alluvial, lacustrine, coal, ?evaporite seds.alluvial, lacustrine, coal, ?evaporite seds.
provenance: whatever is being eroded from exposed crustprovenance: whatever is being eroded from exposed crust
-
8/9/2019 17156896 Sedimentary Basins Petroleum Geology
24/24
Stable Continental Interior BasinsStable Continental Interior Basins
E.g. Lake Eyre BasinE.g. Lake Eyre Basin
Intracratonic (= within stable continentalIntracratonic (= within stable continental
crustal mass)crustal mass) Long term stabilityLong term stability
Flat topographyFlat topography
River, desert, lake environments & faciesRiver, desert, lake environments & facies Mature basement derived sed.Mature basement derived sed. ss
evaporitesevaporites