@article {Tucholke2013,
	title = {{Cemented mounds and hydrothermal sediments on the detachment surface at Kane Megamullion: A new manifestation of hydrothermal venting}},
	journal = {Geochemistry, Geophysics, Geosystems},
	volume = {14},
	year = {2013},
	pages = {3352{\textendash}3378},
	abstract = {Long-lived detachment faults are now known to be important in tectonic evolution of slow-spreading mid-ocean ridges, and there is increasing evidence that fluid flow plays a critical role in development of detachment systems. Here we document a new manifestation of low-temperature hydrothermal venting associated with the detachment fault that formed Kane Megamullion \~{}3.3{\textendash}2.1 m.y. ago in the western rift-valley wall of the Mid-Atlantic Ridge. Hydrothermal effects on the detachment surface include (1) cemented mounds of igneous rock and chalk debris containing hydrothermal Mn oxides and Fe oxyhydroxides, and (2) layered deposits of similar Fe-Mn minerals {\textpm} interbedded chalks. Mounds are roughly conical, \~{}1{\textendash}10 m high, and contain primarily basalts with lesser gabbro, serpentinite, and polymict breccia. The layered Fe-Mn-rich sediments are flat-bedded to contorted and locally are buckled into low-relief linear or polygonal ridges. We propose that the mounds formed where hydrothermal fluids discharged through the detachment hanging wall near the active fault trace. Hydrothermal precipitates cemented hanging-wall debris and welded it to the footwall, and this debris persisted as mounds as the footwall was exhumed and surrounding unconsolidated material sloughed off the sloping detachment surface. Some of the layered Fe-Mn-rich deposits may have precipitated from fluids discharging from the hanging-wall vents, but they also precipitated from low-temperature fluids venting from the exposed footwall through overlying chalks. Observed natural disturbance and abnormally thin hydrogenous Fe-Mn crusts on some contorted, hydrothermal Fe-Mn-rich chalks on \~{}2.7 Ma crust suggest diffuse venting that is geologically recent. Results of this study imply that there are significant fluid pathways through all parts of detachment systems and that low-temperature venting through fractured detachment footwalls may continue for several million years off-axis.},
	keywords = {AUV ABE (Autonomous Benthic Explorer), ROV Jason (Remotely Operated Vehicle)},
	doi = {10.1002/ggge.20186},
	author = {Tucholke, B E and Humphris, S E and Dick, H J B}
}
@article {Hansen2013,
	title = {{Mylonitic deformation at the Kane oceanic core complex: Implications for the rheological behavior of oceanic detachment faults}},
	journal = {Geochemistry, Geophysics, Geosystems},
	volume = {14},
	year = {2013},
	pages = {3085{\textendash}3108},
	abstract = {The depth extent, strength, and composition of oceanic detachment faults remain poorly understood because the grade of deformation-related fabrics varies widely among sampled oceanic core complexes (OCCs). We address this issue by analyzing fault rocks collected from the Kane oceanic core complex at 23{\textdegree}30'N on the Mid-Atlantic Ridge. A portion of the sample suite was collected from a younger fault scarp that cuts the detachment surface and exposes the interior of the most prominent dome. The style of deformation was assessed as a function of proximity to the detachment surface, revealing a \~{}450 m thick zone of high-temperature mylonitization overprinted by a \~{}200 m thick zone of brittle deformation. Geothermometry of deformed gabbros demonstrates that crystal-plastic deformation occurred at temperatures {\textgreater}700{\textdegree}C. Analysis of the morphology of the complex in conjunction with recent thermochronology suggests that deformation initiated at depths of \~{}7 km. Thus we suggest the detachment system extended into or below the brittle-plastic transition (BPT). Microstructural evidence suggests that gabbros and peridotites with high-temperature fabrics were dominantly deforming by dislocation-accommodated processes and diffusion creep. Recrystallized grain size piezometry yields differential stresses consistent with those predicted by dry-plagioclase flow laws. The temperature and stress at the BPT determined from laboratory-derived constitutive models agree well with the lowest temperatures and highest stresses estimated from gabbro mylonites. We suggest that the variation in abundance of mylonites among oceanic core complexes can be explained by variation in the depth of the BPT, which depends to a first order on the thermal structure and water content of newly forming oceanic lithosphere.},
	keywords = {AUV ABE (Autonomous Benthic Explorer), ROV Jason (Remotely Operated Vehicle)},
	doi = {10.1002/ggge.20184},
	author = {Hansen, L N and Cheadle, M J and John, B E and Swapp, S M and Dick, H J B and Tucholke, B E and Tivey, M A}
}
@article {Dick2010,
	title = {{Mantle melting, melt transport, and delivery beneath a slow-spreading ridge: the paleo-MAR from 23 degrees15'N to 23 degrees 45'N}},
	journal = {Journal of Petrology},
	volume = {51},
	number = {1-2},
	year = {2010},
	pages = {425{\textendash}467},
	abstract = {Kane Megamullion, an oceanic core complex near the Mid-Atlantic Ridge (MAR) abutting the Kane Transform, exposes nearly the full plutonic foundation of the MARK paleo-ridge segment. This provides the first opportunity for a detailed look at the patterns of mantle melting, melt transport and delivery at a slow-spreading ridge. The Kane lower crust and mantle section is heterogeneous, as a result of focused mantle melt flow to different points beneath the ridge segment in time and space, over an \~{}300{\textendash}400 kyr time scale. The association of residual mantle peridotite, dunite and troctolite with a large \~{}1 km+ thick gabbro section at the Adam Dome Magmatic Center in the southern third of the complex probably represents the crust{\textendash}mantle transition. This provides direct evidence for local melt accumulation in the shallow mantle near the base of the crust as a result of dilation accompanying corner flow beneath the ridge. Dunite and troctolite with high-Mg Cpx represent melt{\textendash}rock reaction with the mantle, and suggest that this should be taken into account in modeling the evolution of mid-ocean ridge basalt (MORB). Despite early precipitation of high-Mg Cpx, wehrlites similar to those in many ophiolites were not found. Peridotite modes from the main core complex and transform wall define a depletion trend coincident with that for the SW Indian Ridge projecting toward East Pacific Rise mantle exposed at Hess Deep. The average Kane transform peridotite is a lherzolite with 5{\textperiodcentered}2{\%} Cpx, whereas that from the main core complex is a harzburgite with only 3{\textperiodcentered}5{\%} Cpx. As the area corresponds to a regional bathymetric low, and the crust is apparently thin, it is likely that most residual mantle along the MAR is significantly more depleted. Thus, harzburgitic and lherzolitic ophiolite subtypes cannot be simply interpreted as slow- and fast-spreading ridges respectively. The mantle peridotites are consistent with a transform edge effect caused by juxtaposition of old cold lithosphere against upwelling mantle at the ridge{\textendash}transform intersection. This effect is far more local, confined to within 10 km of the transform slip zone, and far smaller than previously thought, corresponding to \~{}8{\%} as opposed to 12{\textperiodcentered}5{\%} melting of a pyrolitic mantle away from the transform. Excluding the transform, the overall degree of melting over 3 Myr indicated by the peridotites is uniform, ranging from \~{}11{\textperiodcentered}3 to 13{\textperiodcentered}8{\%}. Large variations in composition for a single dredge or ROV dive, however, reflect local melt transport through the shallow mantle. This produced variable extents of melt{\textendash}rock reaction, dunite formation, and melt impregnation. At least three styles of late mantle metasomatism are present. Small amounts of plagioclase with elevated sodium and titanium and alumina-depletion in pyroxene relative to residual spinel peridotites represent impregnation by a MORB-like melt. Highly variable alumina depletion in pyroxene rims in spinel peridotite probably represents cryptic metasomatism by small volumes of late transient silica-rich melts meandering through the shallow mantle. Direct evidence for such melts is seen in orthopyroxenite veins. Finally, a late hydrous fluid may be required to explain anomalous pyroxene sodium enrichment in spinel peridotites. The discontinuous thin lower crust exposed at Kane Megamullion contrasts with the {\textgreater}700 km2 1{\textperiodcentered}5 km+ thick Atlantis Bank gabbro massif at the SW Indian Ridge (SWIR), clearly showing more robust magmatism at the latter. However, the SWIR spreading rate is 54{\%} of the MAR rate, the offset of the Atlantis II Fracture Zone is 46{\%} greater and Na8 of the spatially associated basalts 16{\%} greater{\textemdash}all of which predict precisely the opposite. At the same time, the average compositions of Kane and Atlantis II transform peridotites are nearly identical. This is best explained by a more fertile parent mantle beneath the SWIR and demonstrates that crustal thickness predicted by simply inverting MORB compositions can be significantly in error.},
	keywords = {ROV Jason (Remotely Operated Vehicle)},
	issn = {0022-3530},
	doi = {10.1093/petrology/egp088},
	url = {http://dx.doi.org/10.1093/petrology/egp088},
	author = {Dick, H J B and Lissenberg, C J and Warren, J M}
}
