Magmatism, hydrothermalism, and carbon cycling in the sedimented Guaymas Basin

Online Access: Get full text
Author(s): Soule, Samuel A.; Teske, Andreas; Lizarralde, Daniel; Ravelo, Ana Christina; Aiello, Ivano Walter; Mortera-Gutierrez, Carlos A.; Berndt, Christian; Torres, Marta E.; Canet, Carlos
Author Affiliation(s): Primary:
Woods Hole Oceanographic Institution, United States
University of North Carolina at Chapel Hill, United States
University of California, Santa Cruz, United States
Moss Landing Marine Laboratories, United States
National Autonomous University of Mexico, Mexico
Leibniz Institute of Marine Sciences, Germany
Oregon State University, United States
Universidad Nacional Autonoma de Mexico, Mexico
Volume Title: AGU 2017 fall meeting
Source: American Geophysical Union Fall Meeting, Vol.2017; American Geophysical Union 2017 fall meeting, New Orleans, LA, Dec. 11-15, 2017. Publisher: American Geophysical Union, Washington, DC, United States
Note: In English
Summary: The central Gulf of California is characterized by thickly-sedimented, young oceanic spreading centers that lack the seafloor volcanic deposition common to mature, deep-water mid-ocean ridges. Instead, ascending magmas are emplaced within the sediment as sills, which drive hydrothermal circulation and decarbonation of the sediments. Guaymas Basin, a prime example of these processes, is comprised of two short overlappy spreading segments. Decades of study in the southern spreading center have revealed numerous high-temperature hydrothermal vents driven by shallow fluid circulation over magmatic sills, and deeper fluid circulation along rift graben bounding faults. Drilling studies in the southern basin led to a model of shallow sill intrusion within a 1-2 km wide magmatic zone at the rift axis and subsequent deepening of the sill horizon due to subsidence and burial by sediment. Seismic observations in the northern Guaymas Basin, however, have suggested that sill intrusion may occur over a much wider area, up to 40 km from the rift axis. In addition, seafloor mapping has shown numerous sites of fluid flow (n=100) across the northern Guaymas basin that correlate spatially with the subsurface distribution of sills. More recently, a cruise to the area located a high-temperature black smoker vent at the edge of the northern rift basin, which was previously thought to be devoid of active hydrothermal systems. Further, close inspection of one of the identified seafloor fluid flow sites located 40 km from the rift axis found active fluid flow at 70°C as well as typical hydrothermal sulfide-oxidizing vent fauna (Riftia tube worms, Beggiatoaceae bacterial mat), validating the hypothesis of magmatically-driven fluid flow at extreme distances from the presumed center of magmatic accretion. Together, these findings have motivated an IODP drilling leg to this region provisionally scheduled for 2019. This presentation will summarize the new findings at the northern Guaymas Basin, including an ROV cruise scheduled for October 2017, and explore their implications for magmatism in sedimented environments, which includes both young oceanic spreading centers such as the active Guaymas Basin and the development of large igneous provinces responsible for global-scale climate shifts in Earth history.
Year of Publication: 2017
Research Program: IODP2 International Ocean Discovery Program
Key Words: 07 Marine Geology and Oceanography; Carbon; Carbon cycle; East Pacific; Geochemical cycle; Guaymas Basin; Gulf of California; International Ocean Discovery Program; Magmatism; North Pacific; Northeast Pacific; Pacific Ocean; Planning; Thermal regime
Record ID: 2019016382
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data supplied by, and/or abstract, Copyright, American Geophysical Union, Washington, DC, United States

Similar Items