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Three-dimensional basin analysis of theHeidelberg Basin, Upper Rhine Graben
David C. Tanner, Nicole Martini, Hermann Buness, Gerald Gabriel, Charlotte M. Krawczyk
0 km 30
Leibniz Institute for Applied Geophysics
Contents
LocationNew and old reflection seismics of the Heidelberg BasinStratigraphy3D Geometrical Model (GoCAD)Decompaction and Subsidence Analysis (3Dmove)Conclusions
Location / Database
0 1 km
Quarternary thickness in the URG after Bartz 1974
Location of reflection seismics in theHeidelberg Basin
Borehole A
Uni Nord
StratigraphyBorehole A
Base Quaternary
Base Pliocene
Base Upper Miocene
Base Hydrobien beds (Lower Miocene)
Internal Pliocene
Reflection Seismics
LIAG P-wave profile 3, Heidelberg, Depth section (Buness et al., 2008)
N S
1000
500
0
1500
Dep
th(m
)
Base Quarternary
Internal PlioceneBase Pliocene
Base Upper Miocene
Base Hydrobrien beds
3
MethodCorrelation
digitized withtif2segy
Seismic Borehole
InterpretedSeismics (Time)
Coordinates
Depths of beds
Conversion
withPromax2D Interpreted
Seismics (Depth)
LIAG Industry
correlation withgeog. coordinates
2D Model
3D Model
Interpretion
picked by hand
digital
Depth surfaces - Depocentre
Base Quaternary3471000 3473000 3475000 3477000
5470000
5471000
5472000
5473000
5474000
5475000
5476000
5477000
5478000
5479000
5480000
Internal Pliocene3471000 3473000 3475000 3477000
5470000
5471000
5472000
5473000
5474000
5475000
5476000
5477000
5478000
5479000
5480000
Base Pliocene3471000 3473000 3475000 3477000
5470000
5471000
5472000
5473000
5474000
5475000
5476000
5477000
5478000
5479000
5480000
Base Upper Miocene3471000 3473000 3475000 3477000
5470000
5471000
5472000
5473000
5474000
5475000
5476000
5477000
5478000
5479000
5480000
Base Hydrobien beds3471000 3473000 3475000 3477000
5470000
5471000
5472000
5473000
5474000
5475000
5476000
5477000
5478000
5479000
5480000
-2100-2000-1900-1800-1700-1600-1500-1400-1300-1200-1100-1000-900-800-700-600-500-400-300-200-100
Depth (m]
Method of Correlating Seismics• Problem: No connection between LIAG (red) and industry (blue) seismic lines
• Solution: Strike projection
0 1
Schriêsheim
Uni Nord
Stereographic projection
averagestrike direction
32
8101 8306
Method of Gridding Surfaces• Original data
• Seismic interpretation @ every 10th CMP
• ca. 900 points per surface
• Data were gridded using Discrete Point Interpolation (GOCAD) and the Point Krigingalgorithm (Surfer)
• Output grid with X Y spacing of 100 m.
N
Difference between DSI and Kriging(e.g. Base Quaternary)
3D Model
GoCAD model,5x vertical exaggeration
1 kmBase Quarternary
Base Pliocene
Base UpperMiocene
Base HydrobienBeds (Miocene)
Calculation of Porosity
Core sample
Water-saturated Sample
Saturated Mass
Dry Mass
Submerged Mass
Calculation of Porosity
Rock Volume
Dry Mass
Volume of absorbed water
Porosity
Saturation in water (24h)
Drying (48-72h) at 130°C
Dry Sample
Porosity change with depth
Athy, 1930
Silt Fine Sand Medium Sand
Uni Nord borehole
Decompaction and Backstripping I
Decompaction and Backstripping II
Subsidence
A. Western edge of model, towards graben centre
B. Depocentre of the Heidelberg Basin
Dep
th(m
)Time (Ma) Time (Ma)
0.05 mm/a
0.1 mm
/a
0.1 mm/a
0.2 mm
/a
Conclusions
1. We interpreted reflection seismics to produce a 3D model of the Heidelberg Basin, with 5 stratigraphic horizons.
2. The model shows the depth of the (mini) basin, and movement of the depocentre.
3. We suggest that the basin is pull-apart basin, centered on a „breached“ relay zone.
4. The porosity of the Quaternary sediments decreases exponentiallywith depth. We used this information to incrementally decompact the Heidelberg Basin, to examine the true changes in basin morphology.
5. Subsidence of the Heidelberg Basin was fast (twice as fast as the average in the URG); average rates are 0.1 mm a-1 and rise to 0.2 mm a-1 during the Quaternary.
References
Tanner, D.C., Martini, N., Buness, H., Gabriel, G. & Krawczyk, C.M. (2010). Three-dimensionalbasin analysis of the Heidelberg Basin, Upper Rhine Graben. GeoDarmstadt 10-13th October2010. Schriftenreihe der Deutschen Gesellschaft für Geowissenschaften 68, 548-549.Tanner, D.C., Martini, N., Buness, H., Gabriel, G. & Krawczyk, C.M. (2010). The Heidelberg BasinDrilling Project - basin analysis. European Geosciences Union General Assembly, Vienna 2nd-7th May 2010.Athy, L.F. (1930) Density, Porosity and Compaction of Sedimentary Rocks. AAPG Bulletin Volume14: 1–24.Buness, H., Gabriel, G. & Ellwanger, D. (2008) The Heidelberg Basin drilling project: Geophysicalpre-site surveys. Quaternary Science Journal (Eiszeit und Gegenwart) 2008, 57/3–4: 338-366.Ellwanger, D., Gabriel, G., Hoselmann, C., Lämmermann-Barthel, J., Weidenfeller, M. (2005) TheHeidelberg Drilling Project (Upper Rhine Graben, Germany). Quarternaire 2005, 16/3: 191–199.Martini, N. (2009) 3D-Modellierung im Umfeld des Heidelberger Beckens. Diplomkartierung, Universität Hannover, 23 S., unveröffentlichtMartini, N. (2010) Retrodeformation des Heidelberger Beckens. Diplomarbeit, Universität Hannover, 88 S., unveröffentlicht