The geological record of oceanic crustal accretion and tectonism at slow-spreading ridges
Jaroslow, Gary E.
MetadataShow full item record
KeywordSea-floor spreading; Structural geology; Plate tectonics; Geodynamics; Geology; Maurice Ewing (Ship) Cruise EW9208; Knorr (Ship : 1970-) Cruise KN138
The objective of this Thesis was to interpret the structural development of slowspreading ridge segments by: 1) delineating the nature, magnitude, and relative importance of primary tectonic and volcanic processes that control crustal morphology, 2) investigating the spatial and temporal variability of these processes, and 3) examining how rheological variations in the lithosphere control its structural configuration. To that end, this Thesis provides detailed documentation of faults and volcanoes (seamounts) at the Mid-Atlantic Ridge from 25°25'N to 27°10'N and extending from zero-age crust at the ridge axis to -29 Ma crust on the ridge flank. This information was used to analyze the evolution of ocean crust from initial formation in the rift valley to degradation by aging processes on the ridge flank. Accumulation of sediments affects the seafloor morphological expression of ocean crustal structure, and sediment thicknesses were also mapped to facilitate study of the morphological record of crustal accretion and tectonism. In addition, deformation conditions in the lithosphere were analyzed by study of microstructure and geothermometry of abyssal peridotite mylonites recovered from fault zones at slow-spreading ridges.
Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution December 1996
Suggested CitationThesis: Jaroslow, Gary E., "The geological record of oceanic crustal accretion and tectonism at slow-spreading ridges", 1996-12, DOI:10.1575/1912/5693, https://hdl.handle.net/1912/5693
Showing items related by title, author, creator and subject.
Escartin Guiral, Javier E. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1996-08)Two-thirds of the Earth's surface is oceanic crust formed by magmatic and tectonic processes along mid-ocean ridges. Slow-spreading ridges, such as the Mid-Atlantic Ridge, are discontinuous and composed of ridge segments. ...
Detailed studies of the structure, tectonics, near bottom magnetic anomalies and microearthquake seismicity of the Mid-Atlantic Ridge near 37°N Macdonald, Ken C. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1975-09)The Mid-Atlantic Ridge is one of the most well known and yet poorly understood spreading centers in the world. A detailed investigation of the Mid-Atlantic Ridge crest near 37°N (FAMOUS) was conducted using a deeply towed ...
Jordahl, Kelsey A. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1999-02)Changes in morphology of the Marquesas Fracture Zone are correlated with small changes in Pacific-Farallon relative motion. The simple flexural signal of a locked fracture zone may be obscured by tectonic effects, and ...