Minutes 1998 Curators of Marine Geological Samples Meeting
SEDIMENT CLASSIFICATIONWolf Berger was unable to organize the subcommittee to investigate sediment classification schemes, as designated at the 1996 Curators' meeting. (Berger withdrew from the SIO Curatorship upon accepting the Interim Directorship of SIO.) At Bill Riedel's (SIO Curatorial Advisor) suggestion, Paula Worstell prepared a sediment classification scheme to "place on the table" at the present meeting. Paula Worstell noted that preliminary core descriptions are the primary basis for future sample requests. Incomplete sediment descriptions lead to imprecise sample selection. Core describers need to "use the same words to mean the same things." Ideally data containing absolute percentages of grain sizes and sediment components should be accessible. That would negate the need for a classification system as each user could apply whatever classification he/she desired and each requestor could simply search on suitable components. But, in lieu of the detailed percentage data, a field containing the sediment name, as defined by a classification scheme, could relay considerable information about the core. Paula's system is a modification of the ODP classification scheme tailored to fit the general format of the Curators' database. It is completely descriptive, based on what can be observed (directly and microscopically), without need for prior sedimentological interpretation. Every common lithologic component (mineral or fossil grain) is placed into a class, the relative percentages of which determine the sediment name. Discussion centered around some details of the system. Not all agreed with the elimination of the "mixed sediment" class. Not all agreed that detailed component data/and or sediment description were necessary to the Curators' database. Paula argued that most requestors use two factors in selecting samples: geographic area AND area of research interest. Therefore the Curators' database should provide both "underway" and lithologic data. Some felt that placing detailed sediment descriptions and component information in the Curators' database was not necessary and added greatly to the effort of submitting cruise data.
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