Extricating dynamic topography from subsidence patterns: Examples from Eastern North America's passive margin

Morris, M.; Fernandes, Victoria M.

doi:10.1016/j.epsl.2019.115840

Cited by 10 publications

(8 citation statements)

References 61 publications

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“…Steckler & Watts, 1978;Cloetingh et al, 1990). Recent stratigraphic analyses estimate that 0.3-1.0 km of waterloaded drawdown has occurred over the last 20 Myr, centered on the Baltimore Canyon Trough (Morris et al, 2020). Since the rifting event responsible for forming the passive margin ended in Early Jurassic times and there is no evidence of extensional tectonics in any of the Neogene stratigraphy, a phase of dynamic drawdown appears to be the most likely driving mechanism (Kominz et al, 2016;Morris et al, 2020).…”

Section: Observational Constraintsmentioning

confidence: 99%

Observations and models of dynamic topography: Current status and future directions.

Davies¹,

Ghelichkhan²,

Hoggard³

et al. 2022

Preprint

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The slow creeping motion of Earth’s mantle drives transient changes in surface topography across a variety of spatial and temporal scales. Recent decades have seen substantial progress in understanding this so-called `dynamic topography’, with a growing number of studies highlighting its fundamental role in shaping the surface of our planet. In this review, we outline the current frontiers of geodynamical research into dynamic topography. It begins with a summary of ongoing observational, theoretical and computational efforts that aim to quantify the present-day expression of dynamic topography, including its geographical distribution and sensitivity to different components of the mantle's flow regime. Next, observational constraints that shed light on how dynamic topography has changed over time are summarised, and compared with predictions from a range of geodynamical modelling studies, to highlight our current understanding of its evolution through the geological past. Although many model predictions can be reconciled with the available observational constraints, these comparisons demonstrate that there remain inconsistencies, particularly at shorter spatial and temporal scales. These discrepancies allow us to isolate the shortcomings of existing modelling approaches and identify pathways towards improving future reconstructions of dynamic topography through space and time. Such reconstructions are vital if we are to robustly connect the evolution of Earth's surface environments to the processes that are occurring deep within its interior.

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Section: Observational Constraintsmentioning

confidence: 99%

Observations and models of dynamic topography: Current status and future directions.

Davies¹,

Ghelichkhan²,

Hoggard³

et al. 2022

Preprint

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show abstract

“…A general challenge with using these important inventories to constrain histories of, say, sub-plate support is their sparsity. In contrast, stratigraphy along passive margins and the relationship between age and depth of the oceans provide well resolved estimates of modern and ancient sub-plate support (see e.g., Czarnota et al, 2013;Hoggard et al, 2016;Lodhia et al, 2018;Morris et al, 2020).…”

Section: Previous Workmentioning

confidence: 99%

“…Amplitudes of global sea-level change are estimated to vary by as much as as 200 m, whilst mantle-driven processes can produce changes in vertical motions of similar or greater amplitudes, and comparable timescales (Miller , 2005;Lovell , 2010). For example, backstripping of stratigraphy along passive margins combined with upper mantle shear wave tomographic models indicate that sub-plate support can generate up to ∼ 1 km of uplift or subsidence at ∼ 10 − 10, 000 km wavelengths, on timescales of 1 − 100 Ma (e.g., Czarnota et al, 2013;Flament et al, 2013;Lodhia et al, 2018;Morris et al, 2020).…”

Section: Sea-levelmentioning

confidence: 99%

Cretaceous to Recent net continental uplift from paleobiological data: Insights into sub-plate support

Fernandes

2020

GSA Bulletin

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There are many geoscience problems for which constraining histories of uplift or subsidence of Earth’s surface is of direct or indirect importance, for example reconstructing tectonics, mantle convection, geomorphology, sedimentary and chemical flux, biodiversity, glacio-eustasy, and climate change. The least equivocal constraints on timing and amplitude of vertical motions on geological timescales come from the distribution of rock formed in shallow marine environments. However, obtaining enough observations at sufficiently large spatial and temporal scales (∼100−10,000 km, ca. 1−100 Ma) to constrain histories of regional topographic evolution remains challenging. To address this issue, we adapted modern inventories of paleobiological and paleoenvironmental data to generate a new compilation of >24,000 spot measurements of uplift on all continents and numerous oceanic islands. Uncertainties associated with paleobathymetry, post-deposition compaction, and glacio-eustasy are assessed. The compilation provides self-consistent and, in places, high-resolution (<100-km-length scale, <1 Ma) measurements of Cretaceous to Recent (post-deposition) net uplift across significant tracts of most continents. To illustrate how the database can be used, records from western North America and eastern South America are combined with geophysical observations (e.g., free-air gravity, shear, and Pn-wave tomography) and simple isostatic calculations to determine the origins of topography. We explore how lithospheric thinning and mantle thermal anomalies may generate uplift of the observed wavelengths and amplitudes. The results emphasize the importance of large inventories of paleobiological data for understanding histories of tectonic and mantle convective processes and consequently landscapes, climate, and the environment.

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“…Mantle convective processes may uplift or depress continental margins by hundreds of meters (Flament et al, 2013;Moucha et al, 2008;Müller et al, 2018). Such vertical motions have been reported in Australia (Müller et al, 2016), eastern North America (Morris et al, 2020;Schmelz et al, 2021), West Africa (Al-Hajri et al, 2009) and the North Atlantic (Schiffer & Nielsen, 2016). A spectacular example for the surface effect of mantle dynamics over continental margins was presented by Champion et al (2008) and Hartley et al (2011).…”

Section: Uplift Mechanismsmentioning

confidence: 88%

Quantifying Permanent Uplift Due To Lithosphere‐Hotspot Interaction

Lang

Brink

2022

Tectonics

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Vertical motions that accompany the passage of the lithosphere over a mantle hotspot can shed light on the nature of the hotspot and its effect on the lithosphere. However, quantifying the temporal vertical and spatial extent, is challenging due to the paucity of evidence in the geological record. Here, we utilize dense seismic and well data covering the intersection of the Great Meteor Hotspot (GMH) track with the U.S. Atlantic continental margin to constrain the surface expression of the hotspot passage under the lithosphere. The continuous sedimentary record of the eastern North American margin during its passage over the hotspot allows determination of the timing, magnitude, width and rate of denudation. We find that a ∼300 km wide region was denuded by up to 850 m between ∼97 and 86 Ma, ∼10 m.y. after the passage of the GMH. Stratigraphic relationships suggest a decaying rock uplift rate with time and no subsequent sagging. The broad, long‐lasting, and delayed uplift was modeled as a surface manifestation of either sub‐lithospheric mantle depletion, permanently eroded base of the continental lithosphere, or intrusions of depleted magma. We consider sub‐lithospheric depletion to be the most likely cause, based on seismic imaging results.

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Extricating dynamic topography from subsidence patterns: Examples from Eastern North America's passive margin

Cited by 10 publications

References 61 publications

Observations and models of dynamic topography: Current status and future directions.

Observations and models of dynamic topography: Current status and future directions.

Cretaceous to Recent net continental uplift from paleobiological data: Insights into sub-plate support

Quantifying Permanent Uplift Due To Lithosphere‐Hotspot Interaction

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