Mayumy A. CABRERA-RAMÍREZ^1*, Arturo CARRANZA-EDWARDS², John S. ARMSTRONG-ALTRIN² & Leticia ROSALES-HOZ^2
1Facultad de Ingeniería, Departamento de Geología, Universidad Nacional Autónoma de México, Circuito Exterior s/n, 04510, México D.F., México *e-mail:mayumycr@unam.mx; mayari77@yahoo.com.mx
²Instituto de Ciencias del Mar y Limnología, Unidad Académica de Procesos Oceánicos y Costeros, Universidad Nacional Autónoma de México, Circuito Exterior s/n, 04510, México D.F., México
e-mail: dr.arturo.carranza@gmail.com; john_arms@yahoo.com

GEOCHEMISTRY OF PELAGIC SEDIMENTS AND NODULES IN THE ABYSSAL CLARION FRACTURE ZONE, WESTERN MEXICO

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An oceanographic cruise on board the R/V El Puma (from the National Autonomous University of Mexico) was performed around the volcanic rocks of Clarion Island (CIR) in the western region of the Exclusive Economic Zone (EEZ) of Mexico. Surface sediments, nodules and representative rock samples from the CIR were collected. Texture is mainly constituted by silt and clay that suggest the influence of pelagic muds carried from the mainland to the deep sea by sea currents. The sandy fraction (less abundant) of the sediments is characterized by micronodules, pumice and remains of siliceous organisms. The most abundant muddy sediment fraction contains smectite, which played a role in the incorporation and release of metals and REE into the polymetallic nodules. The Mn, Ni, Co and REE concentrations in the studied sediments and nodules were slightly enriched when compared to UCC, NASC and CIR rocks.