Abstract Earth's long-term sea-level history is characterized by widespread continental flooding ... more Abstract Earth's long-term sea-level history is characterized by widespread continental flooding in the Cretaceous period (∼ 145 to 65 million years ago), followed by gradual regression of inland seas. However, published estimates of the Late Cretaceous sea-level high differ by half an order of magnitude, from∼ 40 to∼ 250 meters above the present level. The low estimate is based on the stratigraphy of the New Jersey margin.
Abstract The present-day Australian monsoon delivers substantial moisture to the northern regions... more Abstract The present-day Australian monsoon delivers substantial moisture to the northern regions of a predominantly arid continent. However, the pre-Quaternary history of the Australian monsoon is poorly constrained due to sparse and often poorly dated paleoclimate proxy evidence. Sedimentological and paleontological data suggest that warm, humid, and seasonal environments prevailed in central and north Australia during the Miocene, though it is unclear whether these were products of the Australian monsoon.
ABSTRACT An important component in the interpretation and assessment of a hydrocarbon exploration... more ABSTRACT An important component in the interpretation and assessment of a hydrocarbon exploration target is an accurate and self-consistent plate kinematic reconstruction of the region of interest. Identifying changes in tectonic regime assists in the analysis of associated structures, stratigraphy, subsidence/uplift and thermal anomalies.
Abstract The early to middle Miocene was significantly warmer than present, particularly at high ... more Abstract The early to middle Miocene was significantly warmer than present, particularly at high latitudes. Relatively few climatic details are known about this time period compared with earlier (eg, Cretaceous/Eocene) and later (eg, Quaternary) intervals.
The Eocene India-Eurasia collision is a first order tectonic event whose nature and chronology re... more The Eocene India-Eurasia collision is a first order tectonic event whose nature and chronology remains controversial. We test two end-member collision scenarios using coupled global plate motion-subduction models. The first, conventional model, invokes a continental collision soon after∼ 60 Ma between a maximum extent Greater India and an Andean-style Eurasian margin.
We present four companion digital models of the age, age uncertainty, spreading rates, and spread... more We present four companion digital models of the age, age uncertainty, spreading rates, and spreading asymmetries of the world's ocean basins as geographic and Mercator grids with 2 arc min resolution. The grids include data from all the major ocean basins as well as detailed reconstructions of back-arc basins. The age, spreading rate, and asymmetry at each grid node are determined by linear interpolation between adjacent seafloor isochrons in the direction of spreading.
The junction between the Tethys and Panthalassa oceans is one of the most ill-constrained portion... more The junction between the Tethys and Panthalassa oceans is one of the most ill-constrained portions of Cretaceous palaeogeographic maps due to a lack of preserved in-situ oceanic crust from this region. Yet the development of this junction along the northern margin of the Australian plate impacts on our understanding of the Cretaceous evolution of the entire northern and eastern margin of Australia. The present day tectonics of the region (Fig.
Abstract The cause of the Laramide phase of mountain building remains uncertain 1. Conceptual mod... more Abstract The cause of the Laramide phase of mountain building remains uncertain 1. Conceptual models implicate the subduction of either ocean ridges 2 or conjugates of the buoyant Hess 3 or Shatsky 4 oceanic plateaux. Independent verification of these models has remained elusive, because the putative ridges or plateaux are no longer at the Earth's surface. Inverse convection models 5 have identified two prominent seismic anomalies on the recovered Farallon plate.
The Middle Miocene Climatic Optimum (MMCO), which occurred between 17 and 15 Ma, was the last of ... more The Middle Miocene Climatic Optimum (MMCO), which occurred between 17 and 15 Ma, was the last of a series of warming events to have punctuated the Cenozoic and is the warmest the planet has been since 35 Ma (∼ 6° C warmer than present at middle latitudes). Paradoxically, CO2 concentrations during the MMCO are reported at present-day values or less and an explanation for warming has yet to be established.
Abstract Whittaker et al.(Reports, 5 October 2007, p. 83) presented reconstructions for Australia... more Abstract Whittaker et al.(Reports, 5 October 2007, p. 83) presented reconstructions for Australia and Antarctica showing a change in relative plate motion∼ 53 million years ago, coincident with an inferred major global plate reorganization. This comment addresses problematic areas in their assumptions and the geological consequences of their reconstructions.
We present results of the first middle Miocene climate modelling study using the latest NCAR Comm... more We present results of the first middle Miocene climate modelling study using the latest NCAR Community Atmosphere Model (CAM v. 3.1) and Community Land Model (CLM v. 3.0) coupled to a slab ocean. We examine the sensitivity of the middle Miocene climate to varying concentrations of atmospheric carbon dioxide (180, 355 and 700 ppm). Model simulations are forced with realistic Miocene boundary conditions for continental geometry, topography and vegetation.
Utilizing general circulation models (GCMs) for paleoclimate study requires the construction of a... more Utilizing general circulation models (GCMs) for paleoclimate study requires the construction of appropriate model boundary conditions. We present a middle Miocene paleotopographic and paleobathymetric reconstruction geographically constrained at 15 Ma for use in GCMs. Paleotopography and paleogeography are reconstructed using a published global plate rotation model and published geological data.
The kinematics and time-dependence of back-arc extension or compression is one of the most poorly... more The kinematics and time-dependence of back-arc extension or compression is one of the most poorly understood aspects of plate tectonics, and has nearly exclusively been studied from snapshots of present-day observations. Here we combine absolute and relative plate motions with reconstructions of now subducted ocean floor to analyse subduction kinematics and upper plate strain from geological observations since 80 Ma along the 3200 km long Sunda-Java trench, one of the largest subduction systems on Earth.
Abstract A variety of paleogeographic atlases have been constructed, with applications from paleo... more Abstract A variety of paleogeographic atlases have been constructed, with applications from paleoclimate, ocean circulation and faunal radiation models to resource exploration; yet their uncertainties remain difficult to assess, as they are generally presented as lowresolution static maps. We present a methodology for ground-truthing paleogeographic 5 maps, by linking the GPlates plate reconstruction tool to the global Paleobiology Database and a Phanerozoic plate motion model.
Abstract A marked bend in the Hawaiian-Emperor seamount chain supposedly resulted from a recent m... more Abstract A marked bend in the Hawaiian-Emperor seamount chain supposedly resulted from a recent major reorganization of the plate-mantle system there 50 million years ago. Although alternative mantle-driven and plate-shifting hypotheses have been proposed, no contemporaneous circum-Pacific plate events have been identified. We report reconstructions for Australia and Antarctica that reveal a major plate reorganization between 50 and 53 million years ago.
We present a new algorithm for modeling a self-consistent set of global plate polygons. Each plat... more We present a new algorithm for modeling a self-consistent set of global plate polygons. Each plate polygon is composed of a finite list of plate margins, all with different Euler poles. We introduce a" continuously closed plate"(CCP), such that, as each margin moves independently, the plate polygon remains closed geometrically as a function of time. This method solves emerging needs in computational geodynamics to combine kinematic with dynamic models.
Ocean circulation is investigated using the Community Climate System Model 3 (CCSM3) forced with ... more Ocean circulation is investigated using the Community Climate System Model 3 (CCSM3) forced with early to middle Miocene (∼ 20–14 Ma) topography, bathymetry, vegetation and modern CO2. Significant bottom water formation is modeled in the Weddell Sea along with intermediate North Component Water formation in the North Atlantic. This is attributed primarily to stronger-and weaker-than-modern convective preconditioning in the Weddell and Labrador Seas, respectively.
The Philippine Sea plate, located between the Pacific, Eurasian and Australian plates, is the wor... more The Philippine Sea plate, located between the Pacific, Eurasian and Australian plates, is the world's largest marginal basin plate. The motion of the Philippine Sea plate through time is poorly understood as it is almost entirely surrounded by subduction zones and hence, previous studies have relied on palaeomagnetic analysis to constrain its rotation.
Abstract Two main hypotheses compete to explain the mid-Cretaceous global sea-level highstand: a ... more Abstract Two main hypotheses compete to explain the mid-Cretaceous global sea-level highstand: a massive pulse of oceanic crustal production that occurred during the Cretaceous Normal Superchron (CNS) and the “supercontinent breakup effect,” which resulted in the creation of the mid-Atlantic and Indian ocean ridges at the expense of subducting old ocean floor in the Tethys and the Pacific.
We present a revised model for the formation of southwest Pacific backarc basins from 120 Ma to t... more We present a revised model for the formation of southwest Pacific backarc basins from 120 Ma to the present day. Our aim is to improve our understanding of the tectonic regime operating in the region and its consequences for global plate motions. Such an understanding helps explain present-day structures observed on the continental and oceanic lithosphere and the underlying mantle.
Abstract Earth's long-term sea-level history is characterized by widespread continental flooding ... more Abstract Earth's long-term sea-level history is characterized by widespread continental flooding in the Cretaceous period (∼ 145 to 65 million years ago), followed by gradual regression of inland seas. However, published estimates of the Late Cretaceous sea-level high differ by half an order of magnitude, from∼ 40 to∼ 250 meters above the present level. The low estimate is based on the stratigraphy of the New Jersey margin.
Abstract The present-day Australian monsoon delivers substantial moisture to the northern regions... more Abstract The present-day Australian monsoon delivers substantial moisture to the northern regions of a predominantly arid continent. However, the pre-Quaternary history of the Australian monsoon is poorly constrained due to sparse and often poorly dated paleoclimate proxy evidence. Sedimentological and paleontological data suggest that warm, humid, and seasonal environments prevailed in central and north Australia during the Miocene, though it is unclear whether these were products of the Australian monsoon.
ABSTRACT An important component in the interpretation and assessment of a hydrocarbon exploration... more ABSTRACT An important component in the interpretation and assessment of a hydrocarbon exploration target is an accurate and self-consistent plate kinematic reconstruction of the region of interest. Identifying changes in tectonic regime assists in the analysis of associated structures, stratigraphy, subsidence/uplift and thermal anomalies.
Abstract The early to middle Miocene was significantly warmer than present, particularly at high ... more Abstract The early to middle Miocene was significantly warmer than present, particularly at high latitudes. Relatively few climatic details are known about this time period compared with earlier (eg, Cretaceous/Eocene) and later (eg, Quaternary) intervals.
The Eocene India-Eurasia collision is a first order tectonic event whose nature and chronology re... more The Eocene India-Eurasia collision is a first order tectonic event whose nature and chronology remains controversial. We test two end-member collision scenarios using coupled global plate motion-subduction models. The first, conventional model, invokes a continental collision soon after∼ 60 Ma between a maximum extent Greater India and an Andean-style Eurasian margin.
We present four companion digital models of the age, age uncertainty, spreading rates, and spread... more We present four companion digital models of the age, age uncertainty, spreading rates, and spreading asymmetries of the world's ocean basins as geographic and Mercator grids with 2 arc min resolution. The grids include data from all the major ocean basins as well as detailed reconstructions of back-arc basins. The age, spreading rate, and asymmetry at each grid node are determined by linear interpolation between adjacent seafloor isochrons in the direction of spreading.
The junction between the Tethys and Panthalassa oceans is one of the most ill-constrained portion... more The junction between the Tethys and Panthalassa oceans is one of the most ill-constrained portions of Cretaceous palaeogeographic maps due to a lack of preserved in-situ oceanic crust from this region. Yet the development of this junction along the northern margin of the Australian plate impacts on our understanding of the Cretaceous evolution of the entire northern and eastern margin of Australia. The present day tectonics of the region (Fig.
Abstract The cause of the Laramide phase of mountain building remains uncertain 1. Conceptual mod... more Abstract The cause of the Laramide phase of mountain building remains uncertain 1. Conceptual models implicate the subduction of either ocean ridges 2 or conjugates of the buoyant Hess 3 or Shatsky 4 oceanic plateaux. Independent verification of these models has remained elusive, because the putative ridges or plateaux are no longer at the Earth's surface. Inverse convection models 5 have identified two prominent seismic anomalies on the recovered Farallon plate.
The Middle Miocene Climatic Optimum (MMCO), which occurred between 17 and 15 Ma, was the last of ... more The Middle Miocene Climatic Optimum (MMCO), which occurred between 17 and 15 Ma, was the last of a series of warming events to have punctuated the Cenozoic and is the warmest the planet has been since 35 Ma (∼ 6° C warmer than present at middle latitudes). Paradoxically, CO2 concentrations during the MMCO are reported at present-day values or less and an explanation for warming has yet to be established.
Abstract Whittaker et al.(Reports, 5 October 2007, p. 83) presented reconstructions for Australia... more Abstract Whittaker et al.(Reports, 5 October 2007, p. 83) presented reconstructions for Australia and Antarctica showing a change in relative plate motion∼ 53 million years ago, coincident with an inferred major global plate reorganization. This comment addresses problematic areas in their assumptions and the geological consequences of their reconstructions.
We present results of the first middle Miocene climate modelling study using the latest NCAR Comm... more We present results of the first middle Miocene climate modelling study using the latest NCAR Community Atmosphere Model (CAM v. 3.1) and Community Land Model (CLM v. 3.0) coupled to a slab ocean. We examine the sensitivity of the middle Miocene climate to varying concentrations of atmospheric carbon dioxide (180, 355 and 700 ppm). Model simulations are forced with realistic Miocene boundary conditions for continental geometry, topography and vegetation.
Utilizing general circulation models (GCMs) for paleoclimate study requires the construction of a... more Utilizing general circulation models (GCMs) for paleoclimate study requires the construction of appropriate model boundary conditions. We present a middle Miocene paleotopographic and paleobathymetric reconstruction geographically constrained at 15 Ma for use in GCMs. Paleotopography and paleogeography are reconstructed using a published global plate rotation model and published geological data.
The kinematics and time-dependence of back-arc extension or compression is one of the most poorly... more The kinematics and time-dependence of back-arc extension or compression is one of the most poorly understood aspects of plate tectonics, and has nearly exclusively been studied from snapshots of present-day observations. Here we combine absolute and relative plate motions with reconstructions of now subducted ocean floor to analyse subduction kinematics and upper plate strain from geological observations since 80 Ma along the 3200 km long Sunda-Java trench, one of the largest subduction systems on Earth.
Abstract A variety of paleogeographic atlases have been constructed, with applications from paleo... more Abstract A variety of paleogeographic atlases have been constructed, with applications from paleoclimate, ocean circulation and faunal radiation models to resource exploration; yet their uncertainties remain difficult to assess, as they are generally presented as lowresolution static maps. We present a methodology for ground-truthing paleogeographic 5 maps, by linking the GPlates plate reconstruction tool to the global Paleobiology Database and a Phanerozoic plate motion model.
Abstract A marked bend in the Hawaiian-Emperor seamount chain supposedly resulted from a recent m... more Abstract A marked bend in the Hawaiian-Emperor seamount chain supposedly resulted from a recent major reorganization of the plate-mantle system there 50 million years ago. Although alternative mantle-driven and plate-shifting hypotheses have been proposed, no contemporaneous circum-Pacific plate events have been identified. We report reconstructions for Australia and Antarctica that reveal a major plate reorganization between 50 and 53 million years ago.
We present a new algorithm for modeling a self-consistent set of global plate polygons. Each plat... more We present a new algorithm for modeling a self-consistent set of global plate polygons. Each plate polygon is composed of a finite list of plate margins, all with different Euler poles. We introduce a" continuously closed plate"(CCP), such that, as each margin moves independently, the plate polygon remains closed geometrically as a function of time. This method solves emerging needs in computational geodynamics to combine kinematic with dynamic models.
Ocean circulation is investigated using the Community Climate System Model 3 (CCSM3) forced with ... more Ocean circulation is investigated using the Community Climate System Model 3 (CCSM3) forced with early to middle Miocene (∼ 20–14 Ma) topography, bathymetry, vegetation and modern CO2. Significant bottom water formation is modeled in the Weddell Sea along with intermediate North Component Water formation in the North Atlantic. This is attributed primarily to stronger-and weaker-than-modern convective preconditioning in the Weddell and Labrador Seas, respectively.
The Philippine Sea plate, located between the Pacific, Eurasian and Australian plates, is the wor... more The Philippine Sea plate, located between the Pacific, Eurasian and Australian plates, is the world's largest marginal basin plate. The motion of the Philippine Sea plate through time is poorly understood as it is almost entirely surrounded by subduction zones and hence, previous studies have relied on palaeomagnetic analysis to constrain its rotation.
Abstract Two main hypotheses compete to explain the mid-Cretaceous global sea-level highstand: a ... more Abstract Two main hypotheses compete to explain the mid-Cretaceous global sea-level highstand: a massive pulse of oceanic crustal production that occurred during the Cretaceous Normal Superchron (CNS) and the “supercontinent breakup effect,” which resulted in the creation of the mid-Atlantic and Indian ocean ridges at the expense of subducting old ocean floor in the Tethys and the Pacific.
We present a revised model for the formation of southwest Pacific backarc basins from 120 Ma to t... more We present a revised model for the formation of southwest Pacific backarc basins from 120 Ma to the present day. Our aim is to improve our understanding of the tectonic regime operating in the region and its consequences for global plate motions. Such an understanding helps explain present-day structures observed on the continental and oceanic lithosphere and the underlying mantle.
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Papers by Maria Seton