Lecture 7 Shallow clastic seas

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Lecture 7 Shallow clastic seas
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epicontinental
pericontinental
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Dominant controls on sedimentation patterns

• Sediment transport (hydraulic regime)
• Sediment supply
• Relative sea-level changes
• Tectonic environment

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Dominant controls on sedimentation patterns

• Sediment transport (hydraulic regime)
• Sediment supply
• Relative sea-level changes
• Tectonic environment

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EXAMPLES
Tectonic environment
U.S. Eastern seaboard
Gulf of Alaska
Taiwan
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Dominant controls on sedimentation patterns

• Sediment transport (hydraulic regime)
• Sediment supply
• Relative sea-level changes
• Tectonic environment

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Dynamic stratigraphic models
Rate of sediment supply exceeds rate of
accommodation-space creation and sediment
dispersal Regression dominates
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Rate of sea-level rise and sediment
transport/dispersal exceeds rate of sediment
supply Transgression dominates
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Dominant controls on sedimentation patterns

• Sediment transport (hydraulic regime)
• Sediment supply
• Relative sea-level changes
• Tectonic environment

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80
3
17
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Tide-dominated shallow seas
Supply-dominated examples are rare Amazon
shelf Bohai gulf
Tidal range gt 3-4 meters
V gt 60 cm/sec
Accommodation-dominated situations are much more
common
Partially enclosed seas, elongate seaways, blind
gulfs
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150
100
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Storm-dominated systems
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Transport, deposition and erosion in the
near-shore environment
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