(Appendix) Coarse-sand fraction abundance and composition at DSDP Site 86-579 and Hole 86-580
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| Formato: | Dataset Open Access |
| Lenguaje: | en |
| Publicado: |
PANGAEA
1985
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| _version_ | 1867171810447982592 |
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| author | Krissek, Lawrence A Morley, Joseph J Lofland, Darlene K |
| author_facet | Krissek, Lawrence A Morley, Joseph J Lofland, Darlene K |
| collection | Datos científicos de ciencias marinas y ambientales |
| contents | The abundance and composition of the coarse-sand fraction (250 µm-2 mm) of samples from Deep Sea Drilling Project Sites 579 and 580 were investigated to determine the chronology of ice rafting at these locations. The ice-rafting signal at these sites is reduced relative to the generalized ice-rafting chronology of the North Pacific (Kent et al., 1971) because of increased distance to the ice-rafting source areas. These data, however, do record the general increase in ice-rafting importance as sediment age decreases, especially between 0 and 1.0 m.y. ago. In addition, peaks in ice-rafting importance since 1.0 m.y. ago at Sites 579 and 580 are generally synchronous with periods of major ice-rafting influence throughout the North Pacific. The first occurrence of ice-rafted debris at the Matuyama/Gauss magnetic boundary supports a proposed age of approximately 2.47 m.y. for the onset of major Northern Hemisphere glaciation. The coarse-sand fraction at Sites 579 and 580 contains a significant component of non-ice-rafted material, particularly biogenic particles and volcanic pumice. Under these conditions, the standard assumption that the weight percent of the coarse-sand fraction reflects variations in ice-rafting importance may not be valid. For samples taken at some distance from the source of ice-rafted debris, both the abundance and the composition of the coarse-sand fraction must be considered to obtain a valid measure of the influence of sediment transport via ice rafting. |
| format | Dataset Open Access |
| id | pangaea_https___doi_org_10_1594_PANGAEA_802673 |
| institution | PANGAEA |
| language | en |
| publishDate | 1985 |
| publisher | PANGAEA |
| record_format | pangaea |
| spellingShingle | (Appendix) Coarse-sand fraction abundance and composition at DSDP Site 86-579 and Hole 86-580 Krissek, Lawrence A Morley, Joseph J Lofland, Darlene K 86-579; 86-579A; 86-580; AGE; Biogenic particles; Counting 250-2000 µm fraction; Deep Sea Drilling Project; DEPTH, sediment/rock; DRILL; Drilling/drill rig; DSDP; DSDP/ODP/IODP sample designation; Event label; Glomar Challenger; Ice rafted debris; Leg86; North Pacific Ocean; Sample code/label; Size fraction 2.000-0.250 mm; Volcanic components; Wet sieving The abundance and composition of the coarse-sand fraction (250 µm-2 mm) of samples from Deep Sea Drilling Project Sites 579 and 580 were investigated to determine the chronology of ice rafting at these locations. The ice-rafting signal at these sites is reduced relative to the generalized ice-rafting chronology of the North Pacific (Kent et al., 1971) because of increased distance to the ice-rafting source areas. These data, however, do record the general increase in ice-rafting importance as sediment age decreases, especially between 0 and 1.0 m.y. ago. In addition, peaks in ice-rafting importance since 1.0 m.y. ago at Sites 579 and 580 are generally synchronous with periods of major ice-rafting influence throughout the North Pacific. The first occurrence of ice-rafted debris at the Matuyama/Gauss magnetic boundary supports a proposed age of approximately 2.47 m.y. for the onset of major Northern Hemisphere glaciation. The coarse-sand fraction at Sites 579 and 580 contains a significant component of non-ice-rafted material, particularly biogenic particles and volcanic pumice. Under these conditions, the standard assumption that the weight percent of the coarse-sand fraction reflects variations in ice-rafting importance may not be valid. For samples taken at some distance from the source of ice-rafted debris, both the abundance and the composition of the coarse-sand fraction must be considered to obtain a valid measure of the influence of sediment transport via ice rafting. |
| title | (Appendix) Coarse-sand fraction abundance and composition at DSDP Site 86-579 and Hole 86-580 |
| topic | 86-579; 86-579A; 86-580; AGE; Biogenic particles; Counting 250-2000 µm fraction; Deep Sea Drilling Project; DEPTH, sediment/rock; DRILL; Drilling/drill rig; DSDP; DSDP/ODP/IODP sample designation; Event label; Glomar Challenger; Ice rafted debris; Leg86; North Pacific Ocean; Sample code/label; Size fraction 2.000-0.250 mm; Volcanic components; Wet sieving |
| url | https://doi.org/10.1594/PANGAEA.802673 |