PANGAEA_874632 Annotated record of the detailed examination of Mn deposits at the mouth of the Gulf of California during an IPOD Site Survey prior to DSDP Leg 65 Lewis, B T R; Snydsman, W E; McClain, J S; Holmes, M L; Lister, C R B Annotated record of the detailed examination of Mn deposits at the mouth of the Gulf of California during an IPOD Site Survey prior to DSDP Leg 65 1983 PANGAEA Dataset https://doi.pangaea.de/10.1594/PANGAEA.874632 Earth Science Event label Identification DEPTH, sediment/rock Position Deposit type Quantity of deposit Size Substrate type Sediment type Description Uniform resource locator/link to image geoscientificInformation Dredge HYPO01MV-053D HYPO01MV-073D HYPOGENE TT099 TT099-DH09 TT099-DH12 Visual description Melville Thomas G. Thompson (1964) 1972-04-08 1975-06-01 Complete 22.332 24.775 -109.203 -108.15 0.0 m (DEPTH, sediment/rock) 0.0 m (DEPTH, sediment/rock) NOAA-MMS NOAA and MMS Marine Minerals Geochemical Database unrestricted CC-BY-3.0: Creative Commons Attribution 3.0 Unported English PANGAEA Data Publisher for Earth & Environmental Science https://www.pangaea.de/ Data Center Contact Michael Diepenbroek info@pangaea.de

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Bremen Bremen 28359 Germany online 31 data points text/tab-separated-values Lewis, B T R; Snydsman, W E; McClain, J S; Holmes, M L; Lister, C R B (1983): Site Survey Results at the Mouth of the Gulf of California, Leg 65, Deep Sea Drilling Project. In: Lewis, B.T.R.; Robinson, P.; et al., Initial Reports of the Deep Sea Drilling Project, 65, Initial Reports of the Deep Sea Drilling Project, 65, U.S. Government Printing Office, https://doi.org/10.2973/dsdp.proc.65.106.1983 Grant, John Bruce (1967): A comparison of the chemistry and mineralogy with the distribution and physical aspects of marine manganese concretions of the Southern Oceans. Contributions of the Sedimentology Research Laboratory, Florida State University, 19, 99 pp, https://ntrl.ntis.gov/NTRL/dashboard/searchResults/titleDetail/PB177287.xhtml Grant, John Bruce; Moore, Carla J; Alameddin, George; Chen, Kuiying; Barton, Mark (1992): The NOAA and MMS Marine Minerals Geochemical Database. National Geophysical Data Center, NOAA, https://doi.org/10.7289/V52Z13FT Warnken, Robin R; Virden, William T; Moore, Carla J (1992): The NOAA and MMS Marine Minerals Bibliography. National Geophysical Data Center, NOAA, https://doi.org/10.7289/V53X84KN

During an IPOD site survey at the mouth of the Gulf of California, an axial valley about 50 km long and 600 meters deep was found on the East Pacific Rise (EPR) south of the Tamayo Fracture Zone. Magnetic anomalies along the axis of the rise change character from the axial valley to normal sections of the EPR, and off-axis anomalies tend to meander slightly with age, probably indicating that the axial injection zone wanders slightly with time. Along the Baja California margin the magnetic lineations cut across the bathymetric expression of the margin, suggesting that the original rifting of Baja from the mainland occurred along a roughly linear zone. A decrease of heat flow and an increase in sediment thickness and water depth with age from 0 to 3.5 m.y. are consistent with concepts of plate tectonics. Seismic refraction data across and adjacent to the axis of spreading suggest the presence of low-velocity material under the axis, possibly the result of a magma chamber, and a crust which thickens rapidly away from the axis. ** For all details see the full metadata description at "https://doi.pangaea.de/10.1594/PANGAEA.874632"! ** From 1983 until 1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions. At the time it was the most extended data compilation on ferromanganese deposits world wide. Initially published in a proprietary format incompatible with present day standards it was jointly decided by AWI and NOAA to transcribe this legacy data into PANGAEA. This transfer is augmented by a careful checking of the original sources when available and the encoding of ancillary information (sample description, method of analysis...) not present in the NOAA-MMS database.

https://doi.org/10.2973/dsdp.proc.65.106.1983 Site Survey Results at the Mouth of the Gulf of California, Leg 65, Deep Sea Drilling Project https://doi.org/10.7289/V52Z13FT The NOAA and MMS Marine Minerals Geochemical Database https://doi.org/10.7289/V53X84KN The NOAA and MMS Marine Minerals Bibliography https://ntrl.ntis.gov/NTRL/dashboard/searchResults/titleDetail/PB177287.xhtml A comparison of the chemistry and mineralogy with the distribution and physical aspects of marine manganese concretions of the Southern Oceans https://wiki.pangaea.de/wiki/NOAA-MMS NOAA-MMS DIF 9.4 2026-04-30