Malcolm Frieda L 1979 Observation of manganese deposits in the Cayman Trough, Caribbean Sea by the ALVIN submersible in 1977 dataset https://doi.org/10.1594/PANGAEA.871023 Malcolm Frieda L 1979 Petrography, mineral chemistry and microstructures of gabbros from the Mid-Cayman Rise Spreading Center thesis Master thesis, University of Albany https://scholarsarchive.library.albany.edu/cas_daes_geology_etd/56/ 121 pp The suite of gabbroic rocks collected by the DSRV ALVIN in 1976 and 1977 from the walls of the Mid-Cayman Rise spreading center were studied in detail to provide the best available data on plutonic rocks sampled directly from the ocean floor. The rock types studied include variably deformed and altered gabbros, orthopyroxene gabbros, olivine gabbros and troctolites, and a few amphibolites. Mineral chemical analyses suggest that the various rock types are representative of a fractionation trend from magnesian troctolites through olivine and clinopyroxene gabbros to iron-enriched orthopyroxene gabbros. Within many individual samples, the primary mineral phases are apparently chemically homogeneous despite sometimes considerable alteration, which suggests reequilibration after original crystallization. Variation in mineral-chemistry across the suite is larger than previously reported for ocean-floor gabbros; this may be due to the larger population of this study. The primary or secondary nature of plagioclase and amphibole must be distinguished in discussions of the igneous processes involved in the genesis of these rocks. In this suite, textural evidence is often inconclusive, and although sodic chemistry is assumed to indicate a secondary origin for plagioclase, no chemical indicator was found to apply to amphiboles. Many different deformation textures are observed in the samples, indicating considerable variation in the conditions of deformation within this slowly accreting ridge environment. Ductile features range from mechanical twins and bent crystals (low strain) to complete recrystallization with a well-developed foliation (high strain). Textures suggestive of cataclasis include zones .1-10 mm wide containing very fine, irregular grains; kinked and cracked grains, usually very undulose; and crosscutting fractures. These textures may occur separately, or next to or overprinting each other. Of the variables controlling the formation of deformation features, temperature and water pressure are most easily estimated. Minimum temperature during deformation is suggested by minimum temperature of formation of mineral assemblages unaffected by this deformation. This temperature is greater than 550°C (epidote-amphibolite facies) for the majority of features observed, although sampling may have introduced a bias away from lower temperature features. Observations suggest enhanced recrystallization where the primary mineralogy has been hydrated to a greater extent. Theoretically, confining pressure for the gabbroic rocks in this suite may have varied from about .3-.9kb; fluid pressure should have been within these limits. Based on mineralogical evidence, cataclastic and ductile textures developed at both high and moderate temperatures. This suggests that strain rates and/or pressure vary considerably within regions where rocks are hot as well as where rocks are cooler, and that after high-temperature deformation some rocks cooled quickly enough to prevent significant recrystallization while others cooled more slowly. These interpretations indicate that the Cayman plutonics were raised to their present position by motions which varied from place to place and time to time, and suggests that the structural history of plutonic.rocks formed at slowly accreting plate boundaries is highly variable and complex. Grant John Bruce Moore Carla J carla.j.moore@noaa.gov 0000-0002-2610-8648 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 rrw@luna.ngdc.noaa.gov Virden William T Moore Carla J carla.j.moore@noaa.gov 0000-0002-2610-8648 1992 The NOAA and MMS Marine Minerals Bibliography National Geophysical Data Center, NOAA https://doi.org/10.7289/V53X84KN -81.613 -81.55000000000001 17.632 17.983 -81.58216666666664 17.9125 1977-04-07T00:00:00 1977-04-13T00:00:00 0.0 0.0 not specified NOAA-MMS NOAA and MMS Marine Minerals Geochemical Database https://wiki.pangaea.de/wiki/NOAA-MMS ALV-737 AL73700 17.983 -81.613 -3655.0 1977-04-07T00:00:00 ALV737 ALV737 1977-04-07T00:00:00 1977-04-07 1977-04-07T00:00:00 1977-04-07 Alvin Alvin Grab GRAB ALV-738 AL73800 17.983 -81.55 -3452.0 1977-04-08T00:00:00 ALV738 ALV738 1977-04-08T00:00:00 1977-04-08 1977-04-08T00:00:00 1977-04-08 Alvin Alvin Grab GRAB ALV-739 AL73900 17.632 -81.607 -3676.0 1977-04-10T00:00:00 ALV739 ALV739 1977-04-10T00:00:00 1977-04-10 1977-04-10T00:00:00 1977-04-10 Alvin Alvin Grab GRAB ALV-740 AL74000 17.952 -81.58 -3114.0 1977-04-11T00:00:00 ALV740 ALV740 1977-04-11T00:00:00 1977-04-11 1977-04-11T00:00:00 1977-04-11 Alvin Alvin Grab GRAB ALV-741 AL74100 17.952 -81.583 -3356.0 1977-04-12T00:00:00 ALV741 ALV741 1977-04-12T00:00:00 1977-04-12 1977-04-12T00:00:00 1977-04-12 Alvin Alvin Grab GRAB ALV-742 AL74200 17.973 -81.56 -2775.0 1977-04-13T00:00:00 ALV742 ALV742 1977-04-13T00:00:00 1977-04-13 1977-04-13T00:00:00 1977-04-13 Alvin Alvin Grab GRAB 42 CC-BY-3.0 Creative Commons Attribution 3.0 Unported https://creativecommons.org/licenses/by/3.0/ 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. Event label Event Malcolm Frieda L Event Identification ID Malcolm Frieda L ID DEPTH, sediment/rock Depth sed m depth http://purl.obolibrary.org/obo/PATO_0001595 sediment http://purl.obolibrary.org/obo/ENVO_00002007 rock Length L http://dbpedia.org/resource/Length Malcolm Frieda L Depth sed [m] Position Position position http://purl.obolibrary.org/obo/PATO_0000140 Visual description Malcolm Frieda L Position Deposit type Deposit type Malcolm Frieda L Deposit type Quantity of deposit Quantity Malcolm Frieda L Quantity Substrate type Substrate substrate Malcolm Frieda L Substrate Sediment type Sediment sediment http://purl.obolibrary.org/obo/ENVO_00002007 Malcolm Frieda L Sediment Description Description description Malcolm Frieda L Description supplement citable author21391 author53898 author53899 author53900 author53901 author53916 author568 author60047 basis61 campaign3379628 campaign3379629 campaign3379630 campaign3379631 campaign3379632 campaign3379633 campaign44397 campaign44398 campaign44399 campaign44400 campaign44401 campaign44402 event2830443 event2830444 event2830445 event2830446 event2830447 event2830448 geocode1 geocode1599 geocode1600 geocode1601 geocode500000 geocode8128 license101 method11098 method268 param144749 param144750 param48490 param53214 param7055 param7056 param88037 pi60047 project4198 ref67195 ref67263 ref88958 term1073131 term1073316 term38263 term40710 term41044 term41056 term43863 topotype1