Strata2.1

1

• Strata2.1
• Forward Modeling to learn about the controls of
  Tectonics, sedimentation and eustasy on
  stratigraphic geometry
• Strata2.1 is Open Source software was written by
  Flemings, Grotzinger, Morris and Nelson, 1996

2
Baltimore Canyon Trough

• Movie produced by students Spinelli an Hotsinski
• http//hydro.geosc.psu.edu/Sed_html/movie1.html

Sea-level drops produces major regional
unconformity
3
Mixed Carbonate-clastic systemsMiddle to Late
Ordovician, Central Pennsylvania

• The following movie was created by Roberta
  Hotsinski and Andrew Hoover http//hydro.geosc.ps
  u.edu/Sed_html/movie2.html

4
Low heat-flux rift basin

• http//hydro.geosc.psu.edu/Sed_html/movie4.html

Sediment traps heat faster than it can escape
(thermal blanket effect)
5
High sediment-flux rift basin

• http//hydro.geosc.psu.edu/Sed_html/movie5.html

A thick thermal blanket traps heat in deeper
parts of the basin
6
Near-forebulge stratigraphy

• Prediction

7
Near-forebulge stratigraphy

• Prediction

8
Near-forebulge stratigraphy

• Prediction

Erosion
9
Near-forebulge stratigraphy

• Prediction

10
Near-forebulge stratigraphy

• Strata 2.1

11
Near-forebulge stratigraphy

• Strata 2.1

Erosion
12
Input parameters in Strata

• Sediment types
• Compaction and composition
• Tectonic styles
• Sea-level changes
• Heat flow

Output data in Strata (versus time)
Depth-sections Time-sections Wheeler
plots Seismic responses
13
Input parameters in Strata

• Sediment types
• Compaction and composition
• Tectonic styles
• Sea-level changes
• Heat flow

Output data in Strata (versus time)
Depth-sections Time-sections Wheeler
plots Seismic responses
14
Sediment Types
Clastic sediments
Continental diffusion rate
pelagic
Marine diffusion rate
Sediment flux
Sedimentation rates
15
q-volume sediment flux (m2/s) k- diffusion
constant h-elevation x-horizontal distance
Continental diffusion rate
Values can vary across the model and input in
tabular form (x q1 x2 q2 x3 q3 etc.)
Sedimentation rates
16
Sediment Types
Carbonate sediments

• Sedimentation rate types simple exponential
  decay (epeiric)

• Sedimentation rate types constant and simple
  exponential decay below a certain depth
  (oceanic)

Sedimentation rates
17
Input parameters in Strata

• Sediment types
• Compaction and composition
• Tectonic styles
• Sea-level changes
• Heat flow

Output data in Strata (versus time)
Depth-sections Time-sections Wheeler
plots Seismic responses
18
Compaction and Composition
Porosity versus depth- exponential compaction
relation Sand-shale ratios based on water-depth
or diffusion constants
19
Input parameters in Strata

• Sediment types
• Compaction behavior
• Tectonic styles
• Sea-level changes
• Heat flow

Output data in Strata (versus time)
Depth-sections Time-sections Wheeler
plots Seismic responses
20
Tectonic styles of subsidence

• Subsidence increases linearly left to right
  (foreland)
• Subsidence is constant (flat geometry/cratonic)
• Subsidence increases linearly right to left
  (passive)
• Simple elastic flexure or local isostasy (Te0)

21
Input parameters in Strata

• Sediment types
• Compaction behavior
• Tectonic styles
• Sea-level changes
• Heat flow

Output data in Strata (versus time)
Depth-sections Time-sections Wheeler
plots Seismic responses
22
Sea-level changes

• As a file (all parameters can be entered as such)
• As a sinusoid

23
Input parameters in Strata

• Sediment types
• Compaction behavior
• Tectonic styles
• Sea-level changes
• Heat flow

Output data in Strata (versus time)
Depth-sections Time-sections Wheeler
plots Seismic responses
24
Heat Flow

• mW/m2 (e.g., 60 for continents)
• Thermal conductivity is calculated as a funciton
  of the sand, shale and fluid content which may be
  derived from the sedimentation diffusion
  constants and water depths
• Thermal maturation indices can then be calculated
• Heat flow is one-dimensional (hot-to-cold
  --down-up)

25
Input parameters in Strata

• Sediment types
• Compaction behavior
• Tectonic styles
• Sea-level changes
• Heat flow

Output data in Strata (versus time)
Depth-sections Time-sections Wheeler
plots Seismic responses
26
Input parameters in Strata

• Sediment types
• Compaction behavior
• Tectonic styles
• Sea-level changes
• Heat flow

Output data in Strata (versus time)
Depth-sections Time-sections Wheeler
plots Seismic responses
27
Wheeler Plot
Erosion
sea-level drop
time
distance
28
Input parameters in Strata

• Sediment types
• Compaction behavior
• Tectonic styles
• Sea-level changes
• Heat flow

Output data in Strata (versus time)
Depth-sections Time-sections Wheeler
plots Seismic responses
29
Seismic Responses

• Seismic velocity is calculated using the ration
  of sand, shale and water
• Density for sand, shale and fluid is user-input
• Seismic sections are displayed