Controlling Factors_2014_ Basin Analysis

What are the controlling factors of the sedimentary rocks recording ?

AP Dr. David MENIERUniversiti Teknologi PETRONAS

QAB 3033: Basin Analysis12th of June 2014

Factors controlling the stratigraphy recording

Homewood et al., 2000

The concept of Accommodation, Jervey, 1988

The accommodation space is controlling largely by external processes such as changes In sea level, climate, tectonic movements, volcanic activity, compaction and longer termSubsidence rates which together define a depositional base level

1. Sediment supply (volume, composition, grain size)

Controlling factors

Siliclastic sediments

Others: evaporites, carbonates, diatomites, cherts,ironstones, phosphoritesand carbonaceous sediments

CLIMATE / TECTONIC / BEDROCK GEOLOGY / BASINAL WATER CHEMISTRY

Terrigenous extrabasinal particles

Biochemical intrabasinal

2. Terrigenous systemsDeep-water system are supplied from an adjacent shelf or deltaShelves are supplied from coasts and coastal plains, may be deltaic

Deltas are supplied from alluvial systems

The rate of sediment is controlled more by the volume of sediment availablein a given time interval than by transport capacities

Coarse-grained or gravel-rich alluvial, delatic, deep-sea systems

Medium-grained or sand-rich systems

Fine-grained mud-rich systems

- Small and steep- High competence required, sediment transport and deposition are short-time- Frequent and related to catastrophic events (floods, slumping caused by seismic shocks, etc.)

- To be intermediate in size and moderate gradients- The range of grain sizes means: physical processes of transport and deposition operate a wide large of energy level- Frequent and related to catastrophic events (floods, slumping caused by seismic shocks, etc.)

- Can be small in size, but the majority are large, with low gradients (delta plains, submarine fans,...)- Where sediment supply are high, the rapid deposition of muds and silts caused frequent slumpingon delta slopes and submarine fans in depsite of the low gradient

- Single point source- Multiple sources

The pattern of sediment supply delivery to the basin is also important.

3. Biochemical and chemical systems

- Temperature- Water chemistry- Penetration of the light into the water- Hermatypic corals and larger foraminifera are light dependent- Molluscs, bryozoans, crinoids and brachiopods depend on phytoplancton

- Planktonic foraminifera and coccoliths- Radiolaria, diatoms, siliciflagellates and some sponges- Nutrient-rich waters in zones of oceanic producing- Dissolution of the particles throught the water column (CCD; ACD)

Production of biochemical sediment (lakes and Sea) is controlled by the nature and productivity of the biota

In deep basins only surface waters penetrated by light produce significant sediment

Evaporites are precipitated directly from sea or lake waters and have become concentrated to form brines

4. Climate

- Temperature, Precipitation and locally, winds regimes- Mean annual temperature and precipitation- Fluctuations (seasons, magnitude and frequency of extreme events)- Long term, medium term, short term

- The sun's radiation- The rotation of the earth (deflecting effect as the coriolis force)- In the northern hemisphere: anticlockwise rotation- In the southern hemisphere: clockwise rotation- The distribution of continents and oceans

- Periglacial*; Humid temperate*; Dry continental*, Tropical arid, Tropical semi-arid*;Tropical wet-dry*; Humid tropical; Glacial-* season

- Temperature: evaporites, glacail tills, some oolites, palaesols, vegetation and many faunas- Climate also governs sediment yield (Devonian time, carboneferous time)

Two main aspects of climate

The meteorological patterns of the Earth are primarily a consequence of the interactionof

Eight morphoclimatic regions are defined

Climate is a prime control on many sedimentary facies and they can be excellent palaeoclimatic indicators

Climate zonation

Global Heat Balance: Introduction to Heat Fluxes

Climate

• Three cell circulation model

Motion of oceanic currents

5. Tectonic movements and subsidence

- Isostatic movements: vertical adjustments in the lithosphere arisingfrom its loading or unloading by Water, sediment or ice- or by thermal or dynamic changes in the mantle- sediment loading may enhance crustal subsidence by a factor of 3

- Himalayas produce the largest volumes of sediment- Many moutain belts : american cordillera, the Pyrenees, the Alps and Zagros moutains of Iranhave a foreland basin, formed as a result crustal loading by the nearby mountain belt- Subduction zones: accretionary wedge, forearc, volcanic arc and backarc basin- Strike-slip basin, and extensonational rifts- Fault blocks- Broad passive continental margins- Large stable cratons of NAmerica, Russian, Australian shield

Tectonic movements affect sedimentation in a number of different ways and on many different scales

Global scale and source of sediment

Mod. from Scotese and PALEOMAP (2005)

Southeast Asia Cenozoic Paleogeographic Evolution60 ma

Faulting

Rifting

V

V

V V

V

V

V

V

Paleocene


faulting

Riftingv

v

v

vv

v

Early Eocene


Rifting

Rifting

V

VV

V

V V

V

Late Eocene


RiftingV

V

VV

V

V

V

V

Oligocene


Quiescence

Rifting

V

V

V

V

V

V

V

V

V

Early Miocene


Compression

and uplift

V

V

V V

VV

V

V

VV

V

V

Late Miocene


Compression

V

V

V

VV

V

V

V

VV

V

V

V V

Present day

Gas and Oil fields

1000 km0-10

-5

0

5

10

15

20

95 100 105 110 115 120 125 130 135

PhitsanulokYinggehaiHue

Pearl River Mouth

Luconia

Sarawak

Baram

Sabah

Qui Nohn

East Vietnam

West Natuna

Malay

Pattani

Western KraGrabens

Chumphon

North Sumatra

Central Sumatra

South Sumatra Sunda/ Asri

Billiton

Pembuang

NW Java NE Java

Barit

oKutei

TarakanMuara

Sandakan

Palawan

Penyu

Sper

mon

de

Lombok

East Natuna

Con Son

Cuu Long

Balabac

SW

NWNE

KetungauMelawi

AUSTRALIA

SE ASIA

Eastern

Indonesia

Philippine

Arc

Mesozoic Basins

Beibuwan

6. Sea-level changes

- Eustatic sea-level change- Relative sea-level change

- Shorter-term variations include those due to : waves, tides, (diurnal, semi-diurnal), Tsunamis, volcanic phenomena- Longer-term variations: the interplay of changes in global sea level and basin floor subsidence anf uplift- Glacioisostasy or glacioisostatic oscillations

- Changes in the total volume of mid-ocean ridges- Continental collision- Influx of terrigenous sediment- Mid-plate (hotspot)- Owing the thermal cooling and densification of the oceanic lithosphere

Sea-level changes are of two types

Sea-level changes occur on a variety of scales

Changes in the volume of the ocean basins may have many causes

WHAT IS SEA LEVEL ?

(Homewood et al., 1999)

(Bertram et al., 1996)

7. Milankovitch processes and orbital forcing

The Milankovitch theory has become accepted as an importantcontrol on climatic variations outside the ice ages and on the natureof sedimentary sequences not only on pelagic and lacustrine sediments,but also on terrigenous clastic sediments

Controlling Factors_2014_ Basin Analysis

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