The structure of the incoherent sediments in the Ita Mai Tai Guyot (Pacific Ocean) based on geoacoustic profiling data

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• Tugolesov, D. D.
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• Pletnev, S. P.

Abstract

The results of geoacoustic studies carried out by the acoustic MAK-1M system in the southeastern Ita Mai Tai Guyot (Magellan Seamounts, Pacific Ocean) are discussed. The obtained geoacoustic sections characterize the incoherent part of the sedimentary sequence with high resolution. The geoacoustic stratification is well correlative with the deep-sea drilling data: the acoustic units are reliably correlated with the lithostratigraphic units defined in the cores of DSDP holes 200 and 202. Three geoacoustic units are distinguished in the sedimentary section (from the top downward): unit I corresponding in age to the terminal Miocene (Messinian)-Quaternary; unit II correlated with the Late Miocene (Tortonian); unit III accumulated in the Early Eocene-Early Miocene. The acoustic basement is composed of reefogenic limestones that were formed at different stages of the guyot's development through the Aptian-Turonian to Late Paleocene-Eocene. The sonar images allow the distribution of the incoherent carbonate sediments to be contoured along the periphery of the summit's plateau.