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Development of northwest Pacific guyots: General results from Ocean Drilling Program legs 143 and 144
Author(s) -
Flood Peter
Publication year - 1999
Publication title -
island arc
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.554
H-Index - 58
eISSN - 1440-1738
pISSN - 1038-4871
DOI - 10.1046/j.1440-1738.1999.00222.x
Subject(s) - geology , subsidence , oceanography , sea level , waves and shallow water , drilling , paleontology , mechanical engineering , structural basin , engineering
Results of the Ocean Drilling Program legs 143 and 144, which investigated the nature and origin of seven guyots in the northwest Pacific Ocean, document a history of prolonged volcanism (128–84 Ma), followed by subsidence, accumulation of shallow‐water carbonates, emersion following a sea‐level fall, then continued subsidence, and drowning. Generally, the life span of a guyot is of the order of 5–20 million years. The stratigraphic sequence in each guyot consists of 3–10 m‐thick, shoaling‐upward cycles, which display a 100‐Ka periodicity perhaps related to sea‐level fluctuations. The drilling results indicate that the demise of the shallow‐water carbonate platforms is related to either a temporal (110–100 Ma) event or paleolatitude location (0–10°S) involving nutrient‐rich water not conducive to production of calcium carbonate by shallow‐water organisms. Following emergence and erosion, re‐submergence occurred during a rise of sea‐level. However, the rate of sediment accumulation was unable to keep pace with the rate of sea‐level rise and the guyots drowned. Subsidence continued as the lithospheric plate cooled. The majority of guyots are now at ~ 1500 m below sea‐level. Plate movements over the past 100 million years have carried the guyots from ~ 14°S to their current location in the northwest Pacific. Guyots are flat‐topped submerged volcanic islands capped by thick sequences of shallow‐water carbonates. The flat‐top morphology is constructional, not related to wave planation as originally thought and reported in most textbooks.