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Earth Institute Research Projects

Collaborative Research: Integrated Studies of Early Stages of Continental Extension: from Incipient (Okavango) to Young (Malawi) Rifts

Lead PI: Walter R Buck

Unit Affiliation: Marine Geology & Geophysics, Lamont-Doherty Earth Observatory (LDEO)

May 2011 - April 2016
Inactive
Africa ; Sub-Saharan Africa
Project Type: Research

DESCRIPTION: The project will investigate the early stage Okavango Rift and the fully developed Mweru, Luangwa, and Malawi Rifts to address what dynamic processes drive rifting, what mechanisms promote and sustain strain localization, and how rift initiation impacts the crustal and upper mantle structure beneath young rifts and how these structures affect further rift growth. This will be accomplished using a combination of geophysical, geologic, geochemical, and geodynamic techniques.

OUTCOMES: Found that geometry of splays seen in areas of extreme extension places tight bounds on the strength of normal faults. Found that the amount of magma forced into the area below extensionally stressed lithosphere depends strongly on the density contrast between the magma and the surrounding rock and the temperature difference may be small so magma will harden slowly.

SPONSOR:

National Science Foundation (NSF)

FUNDED AMOUNT:

$272,944

EXTERNAL COLLABORATORS:

Oklahoma State, Missouri University of Science & Technology, Woods Hole Oceanographic Institute, University of Texas - El Paso

WEBSITE:

https://www.nsf.gov/awardsearch/showAward?AWD_ID=1009839&HistoricalAwards=false

PUBLICATIONS:

Choi, E. and W. R. Buck. "Constraints on the Strength of Faults from the Geometry of Rider Blocks in Continental and Oceanic Core Complexes," J. Geophys. Res., v.117, 2012. doi:doi:10.1029/2011JB008741.

Whitney, D. L, C. Teyssier, P. Rey and W. R. Buck. "Continental and oceanic core complexes," The Geological Society of America Bulletin, v.125, 2013, p. 273. doi:DOI: 10.1130/B30754.1.

Olive, J. A., M. D. Behn, G. Ito, W. R. Buck, J. Escart├Čn, S. Howell. "Sensitivity of seafloor bathymetry to climate-driven fluctuations in mid-ocean ridge magma supply," Science, v.350, 2015, p. 310. doi:DOI: 10.1126/science.aad0715

Olive, J. A., M. D. Behn, G. Ito, W. R. Buck, J. Escart├Čn, S. Howell. "Response to comment by P. Huybers et al. on ?Sensitivity of seafloor bathymetry to climate-driven fluctuations in mid-ocean ridge magma supply," Science, v.352, 2016, p. 1405. doi:DOI: 10.1126/science.aaf2021

Buck, W. R.. "Geophysics: A third way to rift continents, News and Views," Nature, v.499, 2013, p. 157. doi:doi:10.1038/499157a

Buck, W. R.. "Plate tectonics: Magma for 50,000 years, News and Views," Nature Geoscience, v.6, 2013, p. 811. doi:doi:10.1038/ngeo1951

Choi, E., W. R. Buck, L. Lavier and K.D. Petersen. "Using core complex geometry to constrain fault strength," Geophys. Res. Lett., v.40, 2013, p. 3863. doi:doi:10.1002/grl.50732

KEYWORDS

rift evolutitectonics rift evolution tectonics seismology geology and tectonics geodynamic techniques rifting east african rift system

THEMES

Earth fundamentals