Grain size of Miocene volcanic ash layers from sites 998, 999, and 1000; implications for source areas and dispersal

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doi: 10.2973/odp.proc.sr.165.002.2000
Author(s): Carey, Steven N.; Sigurdsson, Haraldur
Author Affiliation(s): Primary:
University of Rhode Island, Graduate School of Oceanography, Narragansett, RI, United States
Other:
University of Rhode Island, United States
Ocean Drilling Program, United States
University of Puerto Rico, Puerto Rico
University of North Carolina at Chapel Hill, United States
Paleontological Research Institution, United States
Université de Lyon I, France
Rice University, United States
Université Pierre et Marie Curie, France
INGEOMINAS, Colombia
GEOMAR, Federal Republic of Germany
Teikoku Oil Company, Japan
Danmarks Tekniske Universitet, Denmark
Institut Mediterranéen de Technologie, France
University of Missouri, United States
Boston University, United States
Swiss Federal Institute of Technology, Switzerland
Lamont-Doherty Earth Observatory, United States
University of Southampton, United Kingdom
Durham University, United Kingdom
Rosenstiel School of Marine and Atmospheric Science, United States
Bremen University, Federal Republic of Germany
Volume Title: Proceedings of the Ocean Drilling Program, scientific results, Caribbean Ocean history and the Cretaceous/Tertiary boundary event; covering Leg 165 of the cruises of the drilling vessel JOIDES Resolution, Miami, Florida, to San Juan Puerto Rico, sites 998-1002, 19 December 1995-17 February 1996
Volume Author(s): Leckie, R. Mark; Sigurdsson, Haraldur; Acton, Gary D.; Abrams, Lewis J.; Bralower, Timothy J.; Carey, Steven N.; Chaisson, William P.; Cotillon, Pierre; Cunningham, Andrew D.; D'Hondt, Steven L.; Droxler, André W.; Galbrun, Bruno; Gonzalez, Juan; Haug, Gerald H.; Kameo, Koji; King, John W.; Lind, Ida L.; Louvel, Véronique; Lyons, Timothy W.; Murray, Richard W.; Mutti, Maria; Myers, Greg; Pearce, Richard B.; Pearson, D. Graham; Peterson, Larry C.; Röhl, Ursula; Garman, Phyllis
Source: Proceedings of the Ocean Drilling Program, scientific results, Caribbean Ocean history and the Cretaceous/Tertiary boundary event; covering Leg 165 of the cruises of the drilling vessel JOIDES Resolution, Miami, Florida, to San Juan Puerto Rico, sites 998-1002, 19 December 1995-17 February 1996, R. Mark Leckie, Haraldur Sigurdsson, Gary D. Acton, Lewis J. Abrams, Timothy J. Bralower, Steven N. Carey, William P. Chaisson, Pierre Cotillon, Andrew D. Cunningham, Steven L. D'Hondt, André W. Droxler, Bruno Galbrun, Juan Gonzalez, Gerald H. Haug, Koji Kameo, John W. King, Ida L. Lind, Véronique Louvel, Timothy W. Lyons, Richard W. Murray, Maria Mutti, Greg Myers, Richard B. Pearce, D. Graham Pearson, Larry C. Peterson, Ursula Röhl and Phyllis Garman. Proceedings of the Ocean Drilling Program, Scientific Results, Vol.165, p.101-113. Publisher: Texas A & M University, Ocean Drilling Program, College Station, TX, United States. ISSN: 0884-5891
Note: In English. 39 refs.CD-ROM format, ISSN 1096-2514; WWW format, ISSN 1096-7451; all chapters are also available on the included CD-ROM and on the Web in PDF format; illus., incl. 3 tables, sketch maps
Summary: Crystal size measurements have been carried out on tephra fall layers of Miocene to Holocene age from Sites 998, 999, and 1000 in the western Caribbean Sea. Maximum crystal size is used as a proxy for the grain-size characteristics of the layers and an index of atmospheric dispersal from source eruptions. Crystal sizes range from 50 to 650 µm with the majority falling between 200 and 300 µm. All three sites exhibit a coarsening in the grain size of tephra layers with increasing age to the early Miocene that broadly correlates with an increase in the frequency of layers. Analysis of the present lower and upper level atmospheric circulation in the western Caribbean suggests that the layers were derived from source eruptions to the west of the sites somewhere in the Central American region. Minimum distances to these sources are on the order of 700 km. Crystal sizes in tephra layers at these distances are consistent with their derivation from energetic pyroclastic flow-forming eruptions that ejected tephra to stratospheric levels by large-scale ignimbrite- and Plinian-style plumes. Coarsening of the layers during the Miocene peak of explosive volcanism cannot be attributed to any major change in paleowind intensity and is taken to represent the occurrence of more energetic eruptions that were able to disperse tephra over larger areas.
Year of Publication: 2000
Research Program: ODP Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Ash falls; Atlantic Ocean; Atmospheric transport; Caribbean Sea; Cenozoic; Depositional environment; Eruptions; Grain size; Leg 165; Lithostratigraphy; Marine sediments; Miocene; Neogene; North Atlantic; ODP Site 1000; ODP Site 998; ODP Site 999; Ocean Drilling Program; Provenance; Quaternary; Sedimentation; Sedimentation rates; Sediments; Size distribution; Tertiary; Volcanic ash; Volcaniclastics; Volcanism
Coordinates: N163313 N163313 W0795200 W0795200
N124437 N124437 W0784422 W0784422
N192923 N192923 W0825610 W0825610
Record ID: 2000062883
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