Exposures of pre-Eocene plutonic rocks located along the inner slope of the Middle America Trench were sampled during deep-sea dives off Manzanillo (lat 18°N–19°N) at depths ranging from 3950 m to 2823 m. Fission-track data show a rapid cooling of these plutonic rocks during the Paleocene. A subaerial unconformity indicates that the plutonic rocks were exposed after Paleocene time. The presence of upper middle bathyal upper Miocene–lower Pliocene marine sediments above the unconformity documents a Neogene subsidence event at a mean rate of 0.35 mm/yr. This subsidence indicates subduction erosion along this segment of the margin.

This content is PDF only. Please click on the PDF icon to access.

First Page Preview

First page PDF preview
You do not currently have access to this article.