Decrease in oceanic crustal thickness since the breakup of Pangaea

Avendonk, H. J. Van; Davis, J. K.; Harding, Jennifer; Lawver, Lawrence A.

doi:10.1038/ngeo2849

Cited by 66 publications

(82 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Seismic reflection and petrologic studies of overthickened crust related to the Atlantic Eastern Magmatic Province (Figure ) and the major element chemistry of post‐breakup lavas adjacent to rifted continental fragments (Brandl et al, ; Kelemen & Holbrook, ) are, however, consistent with lateral temperature variations of around 150 °C at the time of Pangea breakup. This result is in accord also with a recent global compilation suggesting that upper mantle temperatures, crustal production, and cooling rates were enhanced in the Atlantic and Indian ocean basins compared to the Pacific at 170 Ma (Van Avendonk et al, ), a picture which is also inferred on the basis of the unusually smooth Jurassic seafloor in the Atlantic (Whittaker et al, ). On the basis of these varied observational data, we take the maximum lateral upper mantle temperature variation during the Pangean epoch to be 150 ° C.…”

Section: Mantle Thermal Isolation‐to‐remixing and Global Volcanic Sousupporting

confidence: 89%

“…On average, links between mid‐ocean ridge crustal production and sea‐level rise loosely constrain a factor of

\sim

1.9 increase in Creataceous volcanic outgassing (see discussions in Berner, and Lenton et al, ). In addition, as we discuss in greater detail in section , enhanced mid‐ocean ridge (MOR) crustal production following Pangean breakup (Brandl et al, ; Kelemen & Holbrook, ; Van Avendonk et al, ; Whittaker et al, ) was complemented by magmatism and

{CO}_{2}

outgassing along an extensive system of collisional continental arcs (Beerling & Royer, ; Lee & Lackey, ; Lee et al, ), as well as temporally clustered LIP volcanism are distinctive features of the Mesozoic (Figure 4). Volcanism and

{CO}_{2}

outgassing from stratovolcanoes related to mantle melting was further amplified by perhaps a factor of 2–3 by additional crustal contributions of accreted carbonate rocks (Lee et al, ).…”

Section: Pangean and Rodinian Proxy Data: Rapid Transitions In Sourcementioning

confidence: 99%

See 1 more Smart Citation

Ice, Fire, or Fizzle: The Climate Footprint of Earth's Supercontinental Cycles

Jellinek

Lenardic

Pierrehumbert

2020

Geochem Geophys Geosyst

View full text Add to dashboard Cite

Supercontinent assembly and breakup can influence the rate and global extent to which insulated and relatively warm subcontinental mantle is mixed globally, potentially introducing lateral oceanic‐continental mantle temperature variations that regulate volcanic and weathering controls on Earth's long‐term carbon cycle for a few hundred million years. We propose that the relatively warm and unchanging climate of the Nuna supercontinental epoch (1.8–1.3 Ga) is characteristic of thorough mantle thermal mixing. By contrast, the extreme cooling‐warming climate variability of the Neoproterozoic Rodinia episode (1–0.63 Ga) and the more modest but similar climate change during the Mesozoic Pangea cycle (0.3–0.05 Ga) are characteristic features of the effects of subcontinental mantle thermal isolation with differing longevity. A tectonically modulated carbon cycle model coupled to a one‐dimensional energy balance climate model predicts the qualitative form of Mesozoic climate evolution expressed in tropical sea‐surface temperature and ice sheet proxy data. Applied to the Neoproterozoic, this supercontinental control can drive Earth into, as well as out of, a continuous or intermittently panglacial climate, consistent with aspects of proxy data for the Cryogenian‐Ediacaran period. The timing and magnitude of this cooling‐warming climate variability depends, however, on the detailed character of mantle thermal mixing, which is incompletely constrained. We show also that the predominant modes of chemical weathering and a tectonically paced abiotic methane production at mid‐ocean ridges can modulate the intensity of this climate change. For the Nuna epoch, the model predicts a relatively warm and ice‐free climate related to mantle dynamics potentially consistent with the intense anorogenic magmatism of this period.

show abstract

Section: Mantle Thermal Isolation‐to‐remixing and Global Volcanic Sousupporting

confidence: 89%

“…On average, links between mid‐ocean ridge crustal production and sea‐level rise loosely constrain a factor of

\sim

{CO}_{2}

{CO}_{2}

outgassing from stratovolcanoes related to mantle melting was further amplified by perhaps a factor of 2–3 by additional crustal contributions of accreted carbonate rocks (Lee et al, ).…”

Section: Pangean and Rodinian Proxy Data: Rapid Transitions In Sourcementioning

confidence: 99%

Ice, Fire, or Fizzle: The Climate Footprint of Earth's Supercontinental Cycles

Jellinek

Lenardic

Pierrehumbert

2020

Geochem Geophys Geosyst

View full text Add to dashboard Cite

show abstract

“…Diffraction surfaces are shown as white curves. Black bars indicate reflection points for the DRs on all OBS records basin crust dating from 65 to 85 Ma reported by Van Avendonk et al (2017). Thus, our data provide no evidence for substantial magmatic underplating due to plume activity beneath the northeastern Hawaiian Arch (e.g., Leahy et al 2010).…”

Section: Crustal and Uppermost Mantle Structurementioning

confidence: 71%

Active-source seismic survey on the northeastern Hawaiian Arch: insights into crustal structure and mantle reflectors

Ohira

Kodaira

Moore

et al. 2018

Earth Planets Space

View full text Add to dashboard Cite

Seismic refraction and multi-channel seismic reflection surveys were conducted on the northeastern Hawaiian Arch to examine the effect of hotspot volcanism on the seismic structure of the crust and uppermost mantle. The crustal thickness deduced from the refraction data was typical for oceanic crust, which suggests that magmatic underplating does not occur, at least in our survey area, although the crustal seismic velocity may be influenced by flexure of the lithosphere on the arch. We identified high P-wave velocities (~ 8.65 km/s) in the uppermost mantle parallel to the paleo-seafloor spreading direction, which indicates that the shallower mantle structure immediately below the Moho preserves the original structure formed at a mid-ocean ridge. Moreover, we observed wide-angle reflection waves at large offsets in ocean-bottom seismometer records. The travel time analysis results showed that these waves were reflected from mantle reflectors at depths of 30-85 km below the seafloor, which are considered to represent heterogeneities consisting of frozen melts created during the cooling of the plate.

show abstract

“…This has dynamic significance because newly formed oceanic lithosphere is compositionally buoyant with respect to the underlying mantle due to the low density of the crust and lower density of the harzburgite portion of the lithosphere that overlies the undepleted peridotite. This age estimate varies as a function of crustal thickness (thicker crust will require longer cooling), metamorphic phase changes (blueschist and eclogite densify the crust requiring a shorter cooling period), serpentinization of the slab mantle (leading again to longer estimates for cooling), or secular variations in the temperature of the upper mantle, with warmer conditions in the past leading to the formation of thicker and more buoyant crust (van Avendonk et al, 2017;Vlaar et al, 1993). Prior to that, the thermal buoyancy of the warm oceanic lithosphere can aid the exhumation of the OC.…”

Section: Conditions That Lead To Warmer-than-average Subduction Zone mentioning

confidence: 99%

Mafic High‐Pressure Rocks Are Preferentially Exhumed From Warm Subduction Settings

Keken

Wada

Abers

et al. 2018

Geochem Geophys Geosyst

View full text Add to dashboard Cite

The oceanic crust that enters a subduction zone is generally recycled to great depth. In rare and punctuated episodes, however, blueschists and eclogites derived from subducted oceanic crust are exhumed. Compilations of the maximum pressure‐temperature conditions in exhumed rocks indicate significantly warmer conditions than those predicted by thermal models. This could be due to preferential exhumation of rocks from hotter conditions that promote greater fluid productivity, mobility, and buoyancy. Alternatively, the models might underestimate the forearc temperatures by neglecting certain heat sources. We compare two sets of global subduction zone thermal models to the rock record. We find that the addition of reasonable amounts of shear heating leads to less than 50 °C heating of the oceanic crust compared to models that exclude this heat source. Models for young oceanic lithosphere tend to agree well with the rock record. We test the hypothesis that certain heat sources may be missing in the models by constructing a global set of models that have high arbitrary heat sources in the forearc. Models that satisfy the rock record in this manner, however, fail to satisfy independent geophysical and geochemical observations. These combined tests show that the average exhumed mafic rock record is systematically warmer than the average thermal structure of mature modern subduction zones. We infer that typical blueschists and eclogites were exhumed preferentially under relatively warm conditions that occurred due to the subduction of young oceanic lithosphere or during the warmer initial stages of subduction.

show abstract

Decrease in oceanic crustal thickness since the breakup of Pangaea

Cited by 66 publications

References 38 publications

Ice, Fire, or Fizzle: The Climate Footprint of Earth's Supercontinental Cycles

Ice, Fire, or Fizzle: The Climate Footprint of Earth's Supercontinental Cycles

Active-source seismic survey on the northeastern Hawaiian Arch: insights into crustal structure and mantle reflectors

Mafic High‐Pressure Rocks Are Preferentially Exhumed From Warm Subduction Settings

Contact Info

Product

Resources

About