Mid-Ocean Ridges: Geodynamics Written in the Seafloor

Olive, Jean‐Arthur

doi:10.1016/b978-0-323-85733-8.00018-4

Cited by 4 publications

(3 citation statements)

References 126 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Abyssal hills can be quantified by statistical parameters such as the RMS height, characteristic width and length, and orientation (Goff & Jordan, 1988). Studies have documented how these parameters are sensitive to MOR spreading properties, including spreading rate, crustal thickness, and mantle temperature (Bird & Pockalny, 1994; Goff, 1991, 2020; Goff et al., 1995, 1997; Malinverno, 1991; Olive, 2023; Sauter et al., 2011). There is a prospect, therefore, of utilizing abyssal hill morphology as a proxy to investigate temporal and spatial variations in MOR processes across the ocean basins.…”

Section: Introductionmentioning

confidence: 99%

Regional Variations in the Spreading‐Rate Dependence of Abyssal Hill Roughness as Indicators of Mantle Heterogeneity

Goff

2023

Geophysical Research Letters

View full text Add to dashboard Cite

Abyssal hills are potential proxy records of mid‐ocean ridge faulting and volcanism, as well as the spreading rates and mantle properties that influence these processes. Satellite gravity‐based global prediction of abyssal hill root‐mean‐square (RMS) heights could provide such a proxy, but are broadly influenced off‐axis by pelagic sediment cover, which can lower their values by preferentially filling lows. Here I formulate a sediment‐corrected RMS height prediction by estimating an empirical relationship between mean RMS and sediment thickness as a function of spreading rate. I utilize these values to investigate regional variations in the spreading‐rate dependence of mean RMS across eight regions world‐wide, focusing on half spreading rates <40 mm/yr where spreading rate dependence is strongest. I find that regional variations in this relationship are significant, likely indicating heterogeneity in mantle properties between the different regions.

show abstract

Section: Introductionmentioning

confidence: 99%

Regional Variations in the Spreading‐Rate Dependence of Abyssal Hill Roughness as Indicators of Mantle Heterogeneity

Goff

2023

Geophysical Research Letters

View full text Add to dashboard Cite

show abstract

“…Paleomagnetic data record 46°± 6°rotation below temperatures of 580°C ( 27), but the total magnitude of rotation in the lithosphere, on the basis of initial fault dips at other oceanic core complexes, is estimated to be at least 60°to 70° ( 28,29). If asthenospheric upwelling was vertical (30,31), we would expect a further rotation of 20°to 30°. Although internal deformation during exhumation in both the asthenosphere and lithosphere will have affected the orientation of the section, we are confident that the original plunge of the drill hole was low (<30°) and essentially across the upwelling zone.…”

Section: Mantle Composition and Structure: Melt Migration Controlsmentioning

confidence: 99%

A long section of serpentinized depleted mantle peridotite

Lissenberg,

McCaig,

Lang

et al. 2024

Science

View full text Add to dashboard Cite

The upper mantle is critical for our understanding of terrestrial magmatism, crust formation, and element cycling between Earth’s solid interior, hydrosphere, atmosphere, and biosphere. Mantle composition and evolution have been primarily inferred by surface sampling and indirect methods. We recovered a long (1268-meter) section of serpentinized abyssal mantle peridotite interleaved with thin gabbroic intrusions. We find depleted compositions with notable variations in mantle mineralogy controlled by melt flow. Dunite zones have predominantly intermediate dips, in contrast to the originally steep mantle fabrics, indicative of oblique melt transport. Extensive hydrothermal fluid-rock interaction is recorded across the full depth of the core and is overprinted by oxidation in the upper 200 meters. Alteration patterns are consistent with vent fluid composition in the nearby Lost City hydrothermal field.

show abstract

“…Fan et al (2021) suggest that the observed lithosphere thickness results from a thermal balance between deep periodic sill intrusions and hydrothermal circulation in the upper lithosphere driven by their heat. More details on spreading-related processes including hydrothermal activity can be found in the excellent reviews by Olive (2023) and Früh-Green et al (2022).…”

Section: Introductionmentioning

confidence: 99%

How Hydrothermal Cooling and Magmatic Sill Intrusions Control Flip‐Flop Faulting at Ultraslow‐Spreading Mid‐Ocean Ridges

Glink,

Hasenclever

2024

Geochem Geophys Geosyst

View full text Add to dashboard Cite

Abstract“Flip‐flop” detachment mode represents an endmember type of lithosphere‐scale faulting observed at almost amagmatic sections of ultraslow‐spreading mid‐ocean ridges. Recent numerical experiments using an imposed steady temperature structure show that an axial temperature maximum is essential to trigger flip‐flop faults by focusing flexural strain in the footwall of the active fault. However, ridge segments without significant melt budget are more likely to be in a transient thermal state controlled, at least partly, by the faulting dynamics themselves. Therefore, we investigate which processes control the thermal structure of the lithosphere and how feedbacks with the deformation mechanisms can explain observed faulting patterns. We present results of 2‐D thermo‐mechanical numerical modeling including serpentinization reactions and dynamic grain size evolution. The model features a novel form of parametrized hydrothermal cooling along fault zones as well as the thermal and rheological effects of periodic sill intrusions. We find that the interplay of hydrothermal fault zone cooling and periodic sill intrusions in the footwall facilitates the flip‐flop detachment mode. Hydrothermal cooling of the fault zone pushes the temperature maximum into the footwall, while intrusions near the temperature maximum further weaken the rock and promote the formation of new faults with opposite polarity. Our model allows us to put constraints on the magnitude of two processes, and we obtain most reasonable melt budgets and hydrothermal heat fluxes if both are considered. Furthermore, we frequently observe two other faulting modes in our experiments complementing flip‐flop faulting to yield a potentially more robust alternative interpretation for existing observations.

show abstract

Mid-Ocean Ridges: Geodynamics Written in the Seafloor

Cited by 4 publications

References 126 publications

Regional Variations in the Spreading‐Rate Dependence of Abyssal Hill Roughness as Indicators of Mantle Heterogeneity

Regional Variations in the Spreading‐Rate Dependence of Abyssal Hill Roughness as Indicators of Mantle Heterogeneity

A long section of serpentinized depleted mantle peridotite

How Hydrothermal Cooling and Magmatic Sill Intrusions Control Flip‐Flop Faulting at Ultraslow‐Spreading Mid‐Ocean Ridges

Contact Info

Product

Resources

About