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http://hdl.handle.net/1834/734
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| Title: | Mobility and immobility of mid-ocean ridges and their implications to mantle dynamics |
| Authors: | Masalu, D.C.P. |
| ASFA Terms: | Geology
Mid-ocean ridges |
| Issue Date: | 2002 |
| Citation: | Tanzanian Journal of Science , 28 (1), p. 77-85 |
| Abstract: | In the past two decades, the mobility of mid-ocean ridges relative to the
mantle (absolute migration) has been correlated with major observable
features, such as spreading asymmetry and asymmetry in the abundance
of seamounts. The mobility of mid-ocean ridges is also thought to be an
important factor that influences the diversity of ridge-crest basalts. However,
this mobility has not yet been defined and mapped. The absolute migration
of global mid-ocean ridges since 85 Ma has been computed and mapped.
Global mid-ocean ridges have migrated extensively at varying velocities
during that period. Presently, the fast-migrating ridges are the Pacific-
Antarctic, Central Indian Ridge, Southeast Indian Ridge, Juan de Fuca,
Pacific-Nazca, Antarctic-Nazca, and the Australia-Antarctic ridges, migrating
at velocities of between 3.3 and 5.5 cm/yr. The slow-migrating ridges are
the Mid-Atlantic and the Southwest Indian ridges, migrating at velocities
between 0.3 and 2.0 cm/yr. Comparison of these results with mantle
tomography results show that the slow-migrating ridges have deeper depth
of origin than the fast-migrating ones, suggesting a correlation between
the absolute migration velocity and the depth of origin of ridges.
Furthermore, the Southwest Indian ridge appears to be tapping the same
portion of mantle as did the Central Indian ridge. These results have
important thermo-chemical implications, such as variations in the extent
of melting and mineralogical composition of the mantle beneath different
ridges, which may influence mantle dynamics. |
| URI: | http://hdl.handle.net/1834/734 |
| Related document: | http://www.ajol.info/viewarticle.php?id=3445&j... |
| Appears in Collections: | Articles (IMS)
Miscellaneous
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