(Table 1) Lead isotope ratios of zircons from sample 122 of ODP Hole 153-922A
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| Format: | Dataset Open Access |
| Langue: | en |
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PANGAEA
1998
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| _version_ | 1867169038914813952 |
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| author | Pilot, Joachim Werner, Carl-Dietrich Haubrich, Frank Baumann, Nils |
| author_facet | Pilot, Joachim Werner, Carl-Dietrich Haubrich, Frank Baumann, Nils |
| collection | Datos científicos de ciencias marinas y ambientales |
| contents | According to the theory of plate tectonics, rocks found in the vicinity of mid-ocean ridges - where oceanic plates are created - should be relatively young (at most several Myr old). Here we report the discovery of zircons with ages of about 330 and 1,600 Myr that were drilled from exposed gabbros beneath the Mid-Atlantic Ridge near the Kane fracture zone (Cannat and ODP Shipboard Scientific Party, 1995; Werner, 1997, doi:10.2973/odp.proc.sr.153.031.1997; Werner and Pilot, 1997, doi:10.2973/odp.proc.sr.153.018.1997; Pilot et al., 1996). Age determinations were made using the 207Pb/206Pb evaporation method (Kober, 1987, doi:10.1007/BF00375526) and confirmed with conventional U–Pb dating and ion microprobe (SHRIMP) analysis. We suggest two plausible explanations for the origin of these unusually old zircons. During the opening of the Atlantic, sheared crustal material or delaminated continental lithosphere sank into small roll-like circulation cells (Nocolas, 1995; Rabinowicz et al., 1984, doi:10.1016/0012-821X(84)90042-6) that developed in the shallow mantle at each side of the ridge axis and the material was then transported through these cells to the ridge axis. Alternatively, material from the continental crust has been trapped within the Kane fracture zone since the opening of the Atlantic Ocean basin through a series of transform migrations and ridge jumps (Bonatti and Crane, 1982, doi:10.1038/300343a0; Kepezhinskas and Dmitiev, 1992), with portions of this material subsequently migrating down the ridge axis. |
| format | Dataset Open Access |
| id | pangaea_https___doi_org_10_1594_PANGAEA_770366 |
| institution | PANGAEA |
| language | en |
| publishDate | 1998 |
| publisher | PANGAEA |
| record_format | pangaea |
| spellingShingle | (Table 1) Lead isotope ratios of zircons from sample 122 of ODP Hole 153-922A Pilot, Joachim Werner, Carl-Dietrich Haubrich, Frank Baumann, Nils 153-922A; DEPTH, sediment/rock; DRILL; Drilling/drill rig; Joides Resolution; Lead-204/Lead-206 ratio; Lead-204/Lead-206 ratio, error; Lead-206/Uranium-238 ratio; Lead-206/Uranium-238 ratio, error; Lead-207/Lead-206 ratio; Lead-207/Lead-206 ratio, standard error; Lead-207/Uranium-235 ratio; Lead-207/Uranium-235 ratio, error; Lead-208/Lead-206 ratio; Lead-208/Lead-206 ratio, error; Leg153; Mass spectrometry (MS); North Atlantic Ocean; Ocean Drilling Program; ODP; Sample code/label According to the theory of plate tectonics, rocks found in the vicinity of mid-ocean ridges - where oceanic plates are created - should be relatively young (at most several Myr old). Here we report the discovery of zircons with ages of about 330 and 1,600 Myr that were drilled from exposed gabbros beneath the Mid-Atlantic Ridge near the Kane fracture zone (Cannat and ODP Shipboard Scientific Party, 1995; Werner, 1997, doi:10.2973/odp.proc.sr.153.031.1997; Werner and Pilot, 1997, doi:10.2973/odp.proc.sr.153.018.1997; Pilot et al., 1996). Age determinations were made using the 207Pb/206Pb evaporation method (Kober, 1987, doi:10.1007/BF00375526) and confirmed with conventional U–Pb dating and ion microprobe (SHRIMP) analysis. We suggest two plausible explanations for the origin of these unusually old zircons. During the opening of the Atlantic, sheared crustal material or delaminated continental lithosphere sank into small roll-like circulation cells (Nocolas, 1995; Rabinowicz et al., 1984, doi:10.1016/0012-821X(84)90042-6) that developed in the shallow mantle at each side of the ridge axis and the material was then transported through these cells to the ridge axis. Alternatively, material from the continental crust has been trapped within the Kane fracture zone since the opening of the Atlantic Ocean basin through a series of transform migrations and ridge jumps (Bonatti and Crane, 1982, doi:10.1038/300343a0; Kepezhinskas and Dmitiev, 1992), with portions of this material subsequently migrating down the ridge axis. |
| title | (Table 1) Lead isotope ratios of zircons from sample 122 of ODP Hole 153-922A |
| topic | 153-922A; DEPTH, sediment/rock; DRILL; Drilling/drill rig; Joides Resolution; Lead-204/Lead-206 ratio; Lead-204/Lead-206 ratio, error; Lead-206/Uranium-238 ratio; Lead-206/Uranium-238 ratio, error; Lead-207/Lead-206 ratio; Lead-207/Lead-206 ratio, standard error; Lead-207/Uranium-235 ratio; Lead-207/Uranium-235 ratio, error; Lead-208/Lead-206 ratio; Lead-208/Lead-206 ratio, error; Leg153; Mass spectrometry (MS); North Atlantic Ocean; Ocean Drilling Program; ODP; Sample code/label |
| url | https://doi.org/10.1594/PANGAEA.770366 |