Posters displayed at Dynamic Topography London and Fragile Earth Munich September 2011

1. Title: GLOBAL PALEOGEOGRAPHIC DATASETS TO GROUND-TRUTH DYNAMIC TOPOGRAPHY MODELS
Authors: Lune Gene YEO, Christian HEINE, Dietmar MÜLLER Contact: LUNE.YEO@SYDNEY.EDU.AU
Institution: EarthByte Group, School of Geosciences, The University of Sydney:2006 NSW, Australia
Abstract 90Ma Terrestrial paleoenvironment biota Model G1 paleoshorelines
The topography of the Earth’s surface is subject to constant change due to tectonic, surface processes and Marine paleoenvironment biota Model G1 possible paleoshorelines
mantle-driven vertical motions. While the effects of mantle convection can be approximated via Model B2 paleoshorelines
convection models, there is a lack of temporally and spatially consistent resolution data at global scale to
ground-truth these models. We reverse-engineered data from independent sets of paleogeographic maps
using the GPlates software to construct a set of time-dependent, global and reconstructable Outside scope of study
paleoshorelines for most of the Cretaceous (76-140Ma). Within this framework, we then verify the
paleoshorelines against a community fossil database, and comparisons with published literature. Using
this unified dataset, we compute the amount of change in the lateral shoreline position between individual
time-steps to derive spatio-temporal patterns of relative subsidence and uplift. By taking stable cratonic
blocks as our geographic base reference, we derive the tilting of these blocks and compare changes in
land area for throughout the Cretaceous with published paleoshoreline models. Any given set of
paleoshorelines can be reconstructed using alternative relative and/or absolute plate kinematic models.
We aim to construct a data model and workflow framework which allows for future ground-truthing of
surface dynamic topography models. Ultimately these models may include mantle convection-driven
effects on topography as well as lithospheric extension/compression and eustatic sea level effects.
Notes Figure 1. 90Ma global paleoshorelines rotated to match present day tectonic plate positions
• We obtained our main paleoshoreline dataset (Model G ) by reverse engineering published from Model G1 and Model B2, with well data from an community fossil database3
paleogeographic maps1 which was compared mainly with Model B2
• Our study is currently focused on relatively stable continental interiors (which better record deep earth
signals than deforming regions) including Australia, Africa, Antarctica and the Americas
Between 90Ma and 105Ma
Methodology Example data in map view
Reverse-engineering published
paleogeographic maps1 to obtain Model G1 90Ma
Outside scope of study paleoshorelines
paleoshorelines (Model G) and relative
uplift/subsidence maps Model G1 90Ma
possible paleoshorelines
Paleogeographic Maps
Model G1 105Ma
paleoshorelines
Delayer and
georeference maps, Model G1 105Ma
then extract paleoshorelines
paleoshorelines
Reverse-engineered
Uplift
paleoshorelines
Figure 2. Global distribution of relative uplift and Subsidence
“Cookie-cut” subsidence between 90 and 105Ma . Paleoshorelines are
paleoshorelines and rotated to match present day tectonic plate positions
assign to tectonic plates;
then rotate to present day
140Ma – Model G rotation file 140Ma – Model SUB (Subduction
Reverse-engineered paleoshorelines reference frame) rotation file
in present day coordinates
Present day closed plate
polygons
Difference maps
(relative uplift/subsidence) 140Ma paleoshorelines from
model G1
Between 76 and 90Ma
Figure 1. Present day Model G closed plate polygons1 reconstructed to 140Ma (top figures)
Figure 4. Comparison of land area by continent and 140Ma paleo-shorelines1 assigned to different tectonic plates, reconstructed using
throughout time between our extracted different rotation files: Model G for figures on the left, Model SUB for figures at right. The
paleoshorelines (model G1) and model B2 different colours denote areas covered by different tectonic plates
Australia paleoshorelines
4
30000000 West Gondwana = Africa and South America Model G1 81-58Ma paleoshorelines Geoscience Australia : Frake5:
white-blue – marine;
Area (km sq)
25000000 Model G 1 present day shorelines shaded - land
yellow-brown - land
Australia-
Australia- Australia 20000000
Antarctica- 15000000
Antarctica
India
10000000
5000000
0
150 130 110 90 70
Age
Shale (65Ma)
North America South America
Sandstone (65-80Ma)
40000000 20000000 Carbonates (65-74Ma)
Area (km sq)
Area (km sq)
30000000 15000000 Figure 5. Australian paleoshorelines at 81-58Ma from model G1 (left) with well data (source
20000000 10000000 classified), Geoscience Australia4 at 66-76Ma (middle) and Frake5 at 65.5-89.3Ma (right).
Paleoshorelines are rotated to match present day tectonic plate positions
10000000 5000000
0 0
Variations in Paleoshorelines
150 130 110 90 70 110 100 90 80 70 • Paleoshoreline models examined cover a time range of a 2nd order sea level change (>5Ma6)
• Geographic variation in timing of transgressions and regressions, the accuracy of biostratigraphic
Age Age
correlations, post depositional erosion and the fact that marine rocks often grade through marginal
marine to non-marine rocks are also considerations
• Different interpretations of paleoshorelines and tectonic plate movements also exist (e.g. Different
Africa West Gondwana timings for Africa-South America divergence between Model G1 and B2 (Figure 4) and Different timings
40,000,000 47000000 for Africa-South America divergence between Model G and Frake’s model (Figure 5)
Area (km sq)
Area (km sq)
46500000
30,000,000 References
46000000
20,000,000
45500000 1. Golonka, J., Krobicki, M., Pająk, J., Van Giang, N. & Zuchiewicz, W. Global Plate Tectonics and
10,000,000 Paleogeography of Southeast Asia. (Faculty of Geology, Geophysics and Environmental Protection,
45000000
AGH University of Science and Technology, Arkadia, 2006).
0 44500000 2. Smith, A. G., Smith, D.G., Funnell, B.M. Atlas of Mesozoic and Cenozoic Coastlines. (Cambridge
110 100 90 80 70 160 140 120 100 University Press, 1994).
Age Age 3. Paleobiology Database (ed Paleobiology Database group) (2011).
4. Yeung, M. J. B., M. (ed Geoscience Australia) (Geoscience Australia, Canberra, 2009).
Africa diverges from South Africa diverges from South 5. Frakes, L. et al. Australian Cretaceous shorelines, stage by stage. Palaeogeography, palaeoclimatology,
America after 105Ma (Model B) America after 126Ma (Model G) palaeoecology 59, 31-48 (1987).
6. Haq, B. U. & Schutter, S. R. A chronology of Paleozoic sea-level changes. Science 322, 64 (2008).

2. Abstract No.:189852 Title: ESTIMATING VERTICAL MOTIONS THROUGH TIME USING PALEOGEOGRAPHIES
Authors: Lune Gene YEO, Christian HEINE, Dietmar MÜLLER Contact: LUNE.YEO@SYDNEY.EDU.AU
Institution: EarthByte Group, School of Geosciences, The University of Sydney:2006 NSW, Australia
Abstract 140Ma – Model G rotation file 140Ma – Model SUB (Subduction
The topography of the Earth's surface is subject to constant change due to tectonic, surface processes and reference frame) rotation file
mantle-driven vertical motions. However, determining the individual contributions of different
mechanisms for vertical motion change through geological history from the sedimentary record is
Present day closed plate
extremely difficult due to a missing absolute reference base level. We reverse-engineered data from
polygons
independent sets of paleogeographic maps using the GPlates software to construct a set of time-dependent,
global paleoshorelines from the for most of the Cretaceous (76-140Ma). Within this framework, we then
verify the paleoshorelines against a community fossil database, and comparisons with published literature.
We compute the amount of change in the lateral shoreline position between individual time-steps to derive
spatio-temporal patterns of relative subsidence and uplift. By taking stable cratonic blocks as our
geographic base reference, we derive the tilting of these blocks and compare changes in land area for
throughout the Cretaceous with published paleoshoreline models. Based on the amount of change, we 140Ma paleoshorelines from
identify potential basins in Australia to be queried in greater detail using additional data in further studies. model G
Any given set of paleoshorelines can be reconstructed using alternative relative and/or absolute plate
kinematic models. We aim to construct a data model and workflow framework which allows for future
ground-truthing of surface dynamic topography models. Ultimately these models may include mantle Figure 1. Present day Model G closed plate polygons1 reconstructed to 140Ma (top figures)
convection-driven effects on topography as well as lithospheric extension/compression and eustatic sea and 140Ma paleo-shorelines1 assigned to different tectonic plates, reconstructed using
level effects. different rotation files: Model G for figures on the left, Model SUB for figures at right. The
different colours denote areas covered by different tectonic plates
Notes
• We obtained our main paleoshoreline dataset (Model G ) by reverse engineering published Between 76Ma and 90Ma
paleogeographic maps1 which was compared mainly with Model B2
• Our study is currently focused on relatively stable continental interiors (which better record deep earth
signals than deforming regions) including Australia, Africa, Antarctica and the Americas Outside scope
of study
Methodology Example data in map view
Reverse-engineering published
paleogeographic maps1 to obtain
paleoshorelines (Model G) and relative
uplift/subsidence maps
Sandstone (65-83Ma)
Paleogeographic Maps Carbonates (65-74Ma)
Shale (65Ma)
Delayer and
georeference maps, Between 90Ma and 105Ma
then extract
paleoshorelines
Reverse-engineered Outside scope
paleoshorelines of study
“Cookie-cut”
paleoshorelines and
assign to tectonic plates;
then rotate to present day
Sandstone (97Ma)
Reverse-engineered paleoshorelines Shale (97Ma)
in present day coordinates Extrusive igneous (97Ma)
Mudstone (95Ma)
Between 105Ma and 126Ma
Outside scope
Difference maps of study
(relative uplift/subsidence)
Between 76 and 90Ma Is attached as
one landmass
(126Ma only)
Figure 4. Comparison of land area by continent Is attached as
throughout time between our extracted Sandstone (112-125Ma)
one landmass
paleoshorelines (model G1) and model B2
Australia paleoshorelines
30000000 West Gondwana = Africa and South America
Area (km sq)
25000000 Between 126Ma and 140Ma
Australia-
Australia- Australia 20000000
Antarctica- 15000000
Antarctica
India
10000000 Outside scope
5000000 of study
0
150 130 110 90 70
Age Is attached
as one
landmass
Is attached as Sandstone (132-135Ma)
North America South America one landmass
40000000 20000000
Area (km sq)
Area (km sq)
30000000 15000000
Model G later paleoshorelines Model G earlier paleoshorelines
20000000 10000000 Model G later possible paleoshorelines Model G earlier paleoshorelines
10000000 5000000 Uplift Subsidence
0 0 Figure 2. Global distribution of relative uplift and subsidence throughout the Cretaceous.
150 130 110 90 70 110 100 90 80 70 Paleoshorelines are rotated to match present day tectonic plate positions
Age Age
Potential for more detailed examination (from Figure 2)
• Basin histories may be queried in further detail at basin level using more data
Africa West Gondwana (e.g.: well, seismic) for comparison with uplift/subsidence distributions
47000000 above. Some potential study areas in Australia (see inset figures of Australia
40,000,000
in Figure 2 and map of basins in Northwest Australia on right) include:
Area (km sq)
Area (km sq)
46500000
30,000,000 o Browse basin – is the uplift between 105 and 90Ma due to higher sediment
46000000 deposition rates or tectonic inversion?
20,000,000
45500000 o Bonaparte basin – does the subsidence between 140 and 126Ma and the
10,000,000 45000000 subsequent uplift from 105Ma correspond to tectonic or sedimentary
44500000 influence?
0
o Are any of these vertical changes in topography due to deep earth influences?
110 100 90 80 70 160 140 120 100
Age Age References
1 Golonka, J., Krobicki, M., Pająk, J., Van Giang, N. & Zuchiewicz, W. Global Plate Tectonics and
Africa diverges from South Africa diverges from South Paleogeography of Southeast Asia. (Faculty of Geology, Geophysics and Environmental
America after 105Ma (Model B) America after 126Ma (Model G) Protection, AGH University of Science and Technology, Arkadia, 2006).
2 Smith, A. G., Smith, D.G., Funnell, B.M. Atlas of Mesozoic and Cenozoic Coastlines. (Cambridge
University Press, 1994).