quote:
had to look up guyot, and now am more confused ...
one source says "A flat-topped submarine mountain" and another says "a seamount of volcanic origin (especially in the Pacific Ocean)"
now it is possible to be both of these or either one and not the other ...
--It is my understanding that they are essentially both. These undersea 'mountains' are built by hot spot volcanism like that seen in Hawaii. Over time as the island moves away from the center of hot spot volcanism (or the corresponding mantle plume moves away from the island
[or even both]), it is eroded and gradually subsides as the oceanic lithosphere on which it stands ages and thickens. The problem with young seafloor timescales such as that implied by CPT is indicative from an analysis of the summit geomorphology of a typical guyot. Summit geomorphology of a typical guyot consists of flat topped Layered lagoonal facies upon a volcanic basment with reef facies 'encrested' around the layered lagoonal facies. And for older guyots there is also a pelagic sediment cover superposing the lagoonal facies.
While you may not necessarily understand the literature, I suggest finding a copy of AGU's geophysical monograph #77. There are 5 papers therein which go into excrutiating detail explaining the geology and geophysics of Western Pacific guyots. And what may be more interesting to you, pretty pictures and detailed schematic interpretations of seismic reflection data.
See: Pringle, Sager, Sliter, Stein;
The Mesozoic Pacific: Geology, Tectonics, and Volcanism, Geophysical Monograph 77. 1993
This message has been edited by TrueCreation, 01-11-2005 01:04 AM