@article {lynner_crustal_2017,
	title = {Crustal structure across the eastern North American margin from ambient noise tomography},
	journal = {Geophysical Research Letters},
	volume = {44},
	number = {13},
	year = {2017},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1002/2017GL073500},
	pages = {6651{\textendash}6657},
	abstract = {Passive tectonic margins, like the eastern North American margin (ENAM), represent the meeting of oceanic and continental material where no active deformation is occurring. The recent ENAM Community Seismic Experiment provides an opportunity to examine the crustal structure across the ENAM owing to the simultaneous deployment of offshore and onshore seismic instrumentation. Using Rayleigh wave phase and group velocities derived from ambient noise data, we invert for shear velocity across the ENAM. We observe a region of transitional crustal thicknesses that connects the oceanic and continental crusts. Associated with the transitional crust is a localized positive gravitational anomaly. Farther east, the East Coast magnetic anomaly (ECMA) is located at the intersection of the transitional and oceanic crusts. We propose that underplating of dense magmatic material along the bottom of the transitional crust is responsible for the gravitational anomaly and that the ECMA demarks the location of initial oceanic crustal formation.},
	keywords = {ambient noise, crustal structure, eastern North American margin, passive margin},
	issn = {1944-8007},
	doi = {10.1002/2017GL073500},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/2017GL073500},
	author = {Lynner, Colton and Porritt, Robert W.}
}
@article {holmes_crustal_2008,
	title = {Crustal thickness variations along the Southeast Indian Ridge (100{\textdegree}{\textendash}116{\textdegree}E) from 2-D body wave tomography},
	journal = {Geochemistry, Geophysics, Geosystems},
	volume = {9},
	number = {12},
	year = {2008},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2008GC002152},
	abstract = {Axial morphology along the Southeast Indian Ridge (SEIR) systematically changes from an axial high to a deep rift valley at a nearly uniform intermediate spreading rate between 100{\textdegree}{\textendash}116{\textdegree}E, west of the Australian-Antarctic Discordance (AAD). Basalt geochemistry has a consistent Indian{\textendash}mid-ocean ridge basalt (MORB) type isotopic signature, so changes in axial topography are attributed to variations in both mantle temperature and melt supply. Wide-angle seismic refraction lines were shot to four ocean bottom hydrophones within SEIR segments P1, P2, S1, and T, where each segment is characterized by a different morphology. We constructed 2-D crustal velocity models by jointly inverting hand-picked P wave refraction (Pg) and Moho reflection (PmP) traveltime data using a top-down, minimum-structure methodology. The results show a 1.5 km eastward decrease in crustal thickness across the study area, with segment averages ranging from 6.1 km at P1 to 4.6 km at T. Melt generation models require a \~{}30{\textdegree}C decrease in mantle temperature toward the AAD to account for the crustal thickness trend. Significant changes in axial morphology accompany small-scale variations in crustal thickness, consistent with models of crustal accretion where ridge topography is determined by a balance between mantle temperature, melt supply, and cooling from hydrothermal circulation. Layer 3 thins by 3.0 km as layer 2 thickens by 1.4 km between segments P1 and T, reflecting the eastward decrease in melt supply and increase in melt lens depth. The trade-off in seismic layers may be explained by models relating the increase in overburden pressure on a deepening melt lens to the volume of magma erupted into the upper crust rather than cooling at depth to form new lower crustal material.},
	keywords = {crustal structure, mid-ocean ridge, oceanic crust, seismic refraction, seismic tomography, Southeast Indian Ridge},
	issn = {1525-2027},
	doi = {10.1029/2008GC002152},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2008GC002152},
	author = {Holmes, R. Chadwick and Tolstoy, Maya and Cochran, James R. and Floyd, Jacqueline S.}
}
@article {canales_crustal_2007,
	title = {Crustal structure of the Trans-Atlantic Geotraverse (TAG) segment (Mid-Atlantic Ridge, 26{\textdegree}10'N): Implications for the nature of hydrothermal circulation and detachment faulting at slow spreading ridges},
	journal = {Geochemistry, Geophysics, Geosystems},
	volume = {8},
	number = {8},
	year = {2007},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2007GC001629},
	abstract = {New seismic refraction data reveal that hydrothermal circulation at the Trans-Atlantic Geotraverse (TAG) hydrothermal field on the Mid-Atlantic Ridge at 26{\textdegree}10'N is not driven by energy extracted from shallow or mid-crustal magmatic intrusions. Our results show that the TAG hydrothermal field is underlain by rocks with high seismic velocities typical of lower crustal gabbros and partially serpentinized peridotites at depth as shallow as 1 km, and we find no evidence for low seismic velocities associated with mid-crustal magma chambers. Our tomographic images support the hypothesis of Tivey et al. (2003) that the TAG field is located on the hanging wall of a detachment fault, and constrain the complex, dome-shaped subsurface geometry of the fault system. Modeling of our seismic velocity profiles indicates that the porosity of the detachment footwall increases after rotation during exhumation, which may enhance footwall cooling. However, heat extracted from the footwall is insufficient for sustaining long-term, high-temperature, hydrothermal circulation at TAG. These constraints indicate that the primary heat source for the TAG hydrothermal system must be a deep magma reservoir at or below the base of the crust.},
	keywords = {crustal structure, detachment faulting, Mid-Atlantic Ridge, slow spreading ridge, TAG hydrothermal field},
	issn = {1525-2027},
	doi = {10.1029/2007GC001629},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2007GC001629},
	author = {Canales, J. Pablo and Sohn, Robert A. and deMartin, Brian J.}
}
