Sediment fill in the Middle America Trench inferred from gravity anomalies
A sequence of free-air gravity anomaly profiles across the Middle America Trench are used to model the sediment fill ofunconsolidated pelagic and hemipelagic sediment facies, and partially altered bedrock material. The shift of the free-air forearclow from the bathymetric minimum in the trench is us...
| Autores: | , , |
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| Formato: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2003 |
| País: | México |
| Recursos: | Universidad Nacional Autónoma de México |
| Repositorio: | Redalyc-UNAM |
| OAI Identifier: | oai:redalyc.org:56842403 |
| Acesso em linha: | https://www.redalyc.org/articulo.oa?id=56842403 |
| Access Level: | acceso abierto |
| Palavra-chave: | Ciencias de la Tierra Mexico Subduction gravity anomalies trench sediment fill Middle America Trench |
| Resumo: | A sequence of free-air gravity anomaly profiles across the Middle America Trench are used to model the sediment fill ofunconsolidated pelagic and hemipelagic sediment facies, and partially altered bedrock material. The shift of the free-air forearclow from the bathymetric minimum in the trench is used to estimate the amount of low-density sediment. The gravity effect of thefill is relatively small, suggesting that the dominant processes in the Middle America trench are sediment subduction and scrapingof unconsolidated pelagic sediments from the top of the subducting oceanic plate. The sediment volume in the trench tends toincrease southward from Jalisco to Oaxaca. In the Guatemala basin this tendency is less clear. There is some correlation betweenthe amount of fresh sediment fill and the convergence rate at the trench, except for the profiles with an extensive terrigenoussediment contribution or the areas of subduction of prominent bathymetric features. |
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