John Firth | Texas A&M University (original) (raw)
Papers by John Firth
Comptes Rendus De L Academie Des Sciences Serie Ii Fascicule A-sciences De La Terre Et Des Planetes, 1997
Quatre sites ont été forés dans le talus volcanoclastique sous-marin de l'île volcanique de Gran ... more Quatre sites ont été forés dans le talus volcanoclastique sous-marin de l'île volcanique de Gran Canaria au cours du Leg ODP 157. La sédimentation du talus enregistre l'évolution volcanique de l'île. Les grandes phases éruptives s'expriment clairement par d'importants apports clastiques contemporains au niveau du talus. En revanche, les périodes d'inactivité volcanique se traduisent par des taux de sédimentation très faibles. II est possible ainsi d'établir un découpage volcanostratigraphique à partir des sédiments marins.Four sites have been drilled in the submarine volcaniclastic apron of the volcanic island of Gran Canaria during the ODP Leg 157. The volcaniclastic submarine apron reflects the volcanological evolution of the island. The main volcanic phases are recorded in the sedimentation by an important contemporaneous clastic influx on the apron. However, periods of volcanic quiescence are characterized by very weak sedimentation rates. Consequently, it is possible to establish a volcanostratigraphy from the sedimentary record of the apron.
This Scientific Prospectus is based on pre-cruise JOIDES panel discussions. The operational plans... more This Scientific Prospectus is based on pre-cruise JOIDES panel discussions. The operational plans within reflect JOIDES Planning Committee and thematic panel priorities. During the course of the cruise, actual site operations may indicate to the Co-Chief Scientists and the Operations Superintendent that it would be scientifically or operationally advantageous to amend the plan detailed in this prospectus. It should be understood that any proposed changes to the plan presented here are contingent upon approval of the Director of the Ocean Drilling Program in consultation with the Planning Committee and the Pollution Prevention and Safety Panel.
Proceedings of the Ocean Drilling Program, 1989
ABSTRACT During Ocean Drilling Program (ODP) Leg 105, three sites (Sites 645 through 647) were dr... more ABSTRACT During Ocean Drilling Program (ODP) Leg 105, three sites (Sites 645 through 647) were drilled in Baffin Bay and the Labrador Sea to examine the tectonic evolution and the climatic and oceanic histories of this region. Biostrati-graphic and magnetostratigraphic ...
... Description/Abstract, From April to June 1989, Leg 126 of the Ocean Drilling Program successf... more ... Description/Abstract, From April to June 1989, Leg 126 of the Ocean Drilling Program successfully drilled the Izu-Bonin intraoceanic arc: Sites 787 ... Explosive arc volcanism increased dramatically 250 Ka, leaving 165-428 m of fine to coarse pumiceous sediments in layers that are ...
Any opinions, findings, and conclusions or recommendations expressed in this publication are thos... more Any opinions, findings, and conclusions or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of the National Science Foundation, the participating agencies, Joint Oceanographic Institutions, Inc., Texas A&M University, or Texas A&M Research Foundation.
OCEANS 91 Proceedings, 1991
Three scientific legs of the Ocean Drilling Program (ODP) are described to illustrate the program... more Three scientific legs of the Ocean Drilling Program (ODP) are described to illustrate the program's broad contribution to the assessment of the oceanic environment and of its non-living resources. The technical capabilities of the drillship, JOlDES Resolution, in reeentering drill holes and in deploying/ recovering large objects to/from the ocean floor are discussed. The development of a mining-style diamond coring
We report on the taxonomic, biostratigraphical and paleoceanographic significance of early Paleoc... more We report on the taxonomic, biostratigraphical and paleoceanographic significance of early Paleocene, Oligocene, and middle Miocene to middle Pliocene ostracod faunas from IODP Sites U1367, U1368 and U1370. Sites U1367 (4289 m water depth) and U1368 (3740 water depth) are located near the center of the South Pacific Gyre (SPG) along ~26° S latitude, whereas Site U1370 (5074 m water depth) is located in the southwestern region of the SPG at 41° S latitude. The SPG is the largest of the ocean gyres, its center farther from continents and productive ocean regions than the center of any other gyre, and is considered Earth’s largest oceanic desert. According to the magnetic sea floor lineations the crustal age has been estimated to be between 33.3 and 33.7 Ma at Site U1367, between 13.4 and 13.6 Ma at U1368, and between 73.6 and 79.5 Ma at U1370. Carbonate ooze are the dominant lithology at Sites U1367 and U1368, whereas at Site U1370 carbonate ooze was present only within a short (<2...
Eos, Transactions American Geophysical Union, 1997
Crocodilian teeth, fish teeth, scales, and bones, and teeth and bones of uncertain affinities occ... more Crocodilian teeth, fish teeth, scales, and bones, and teeth and bones of uncertain affinities occur within a mudstone deposit sandwiched between basalt flows at the base of ODP Hole 865A on Allison Guyot in the middle of the Pacific Ocean. Age control from large benthic foraminifers, Sr-isotope stratigraphy, and radiometric ages of the basalt place the age of this assemblage
ODP Preliminary Report, 1993
Eos, Transactions American Geophysical Union, 1993
Scientific Drilling, 2011
No abstract available.…
Marine Micropaleontology, 1998
A diverse assemblage of acritarchs, prasinophytes and dinoflagellate cysts occurs in an organic r... more A diverse assemblage of acritarchs, prasinophytes and dinoflagellate cysts occurs in an organic rich black mud in Core Fl-533, taken from the Alpha Ridge, Arctic Ocean. Similarities between this assemblage and others described from the Canadian Arctic allow this black mud to be dated as early Maastrichtian, based primarily on the presence of Cerodinium leptodermum, and the absence of exclusively Campanian and upper Maastrichtian taxa. The high abundance of Comasphaeridium and marine derived amorphous organic matter may indicate a shelf to upper slope environment, possibly deposited during a marine transgression. An abundance of prasinophyte algal cysts, a moderately high peridinioid=gonyaulacoid dinoflagellate cyst ratio, and high species diversity indicate high paleoproductivity, most likely associated with upwelling conditions. When interpreted within the context of two nearby biosiliceous-rich Maastrichtian cores also taken from Alpha Ridge, and from paleogeographic reconstructions, these results indicate that an upwelling region probably existed along the eastern Arctic Ocean during at least part of the Maastrichtian, and formed different sedimentary facies in shelf to slope environments, similar to facies patterns recognized in lower latitude paleo-upwelling regions.
Comptes Rendus De L Academie Des Sciences Serie Ii Fascicule A-sciences De La Terre Et Des Planetes, 1997
Quatre sites ont été forés dans le talus volcanoclastique sous-marin de l'île volcanique de Gran ... more Quatre sites ont été forés dans le talus volcanoclastique sous-marin de l'île volcanique de Gran Canaria au cours du Leg ODP 157. La sédimentation du talus enregistre l'évolution volcanique de l'île. Les grandes phases éruptives s'expriment clairement par d'importants apports clastiques contemporains au niveau du talus. En revanche, les périodes d'inactivité volcanique se traduisent par des taux de sédimentation très faibles. II est possible ainsi d'établir un découpage volcanostratigraphique à partir des sédiments marins.Four sites have been drilled in the submarine volcaniclastic apron of the volcanic island of Gran Canaria during the ODP Leg 157. The volcaniclastic submarine apron reflects the volcanological evolution of the island. The main volcanic phases are recorded in the sedimentation by an important contemporaneous clastic influx on the apron. However, periods of volcanic quiescence are characterized by very weak sedimentation rates. Consequently, it is possible to establish a volcanostratigraphy from the sedimentary record of the apron.
This Scientific Prospectus is based on pre-cruise JOIDES panel discussions. The operational plans... more This Scientific Prospectus is based on pre-cruise JOIDES panel discussions. The operational plans within reflect JOIDES Planning Committee and thematic panel priorities. During the course of the cruise, actual site operations may indicate to the Co-Chief Scientists and the Operations Superintendent that it would be scientifically or operationally advantageous to amend the plan detailed in this prospectus. It should be understood that any proposed changes to the plan presented here are contingent upon approval of the Director of the Ocean Drilling Program in consultation with the Planning Committee and the Pollution Prevention and Safety Panel.
Proceedings of the Ocean Drilling Program, 1989
ABSTRACT During Ocean Drilling Program (ODP) Leg 105, three sites (Sites 645 through 647) were dr... more ABSTRACT During Ocean Drilling Program (ODP) Leg 105, three sites (Sites 645 through 647) were drilled in Baffin Bay and the Labrador Sea to examine the tectonic evolution and the climatic and oceanic histories of this region. Biostrati-graphic and magnetostratigraphic ...
... Description/Abstract, From April to June 1989, Leg 126 of the Ocean Drilling Program successf... more ... Description/Abstract, From April to June 1989, Leg 126 of the Ocean Drilling Program successfully drilled the Izu-Bonin intraoceanic arc: Sites 787 ... Explosive arc volcanism increased dramatically 250 Ka, leaving 165-428 m of fine to coarse pumiceous sediments in layers that are ...
Any opinions, findings, and conclusions or recommendations expressed in this publication are thos... more Any opinions, findings, and conclusions or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of the National Science Foundation, the participating agencies, Joint Oceanographic Institutions, Inc., Texas A&M University, or Texas A&M Research Foundation.
OCEANS 91 Proceedings, 1991
Three scientific legs of the Ocean Drilling Program (ODP) are described to illustrate the program... more Three scientific legs of the Ocean Drilling Program (ODP) are described to illustrate the program&amp;amp;amp;amp;#x27;s broad contribution to the assessment of the oceanic environment and of its non-living resources. The technical capabilities of the drillship, JOlDES Resolution, in reeentering drill holes and in deploying/ recovering large objects to/from the ocean floor are discussed. The development of a mining-style diamond coring
We report on the taxonomic, biostratigraphical and paleoceanographic significance of early Paleoc... more We report on the taxonomic, biostratigraphical and paleoceanographic significance of early Paleocene, Oligocene, and middle Miocene to middle Pliocene ostracod faunas from IODP Sites U1367, U1368 and U1370. Sites U1367 (4289 m water depth) and U1368 (3740 water depth) are located near the center of the South Pacific Gyre (SPG) along ~26° S latitude, whereas Site U1370 (5074 m water depth) is located in the southwestern region of the SPG at 41° S latitude. The SPG is the largest of the ocean gyres, its center farther from continents and productive ocean regions than the center of any other gyre, and is considered Earth’s largest oceanic desert. According to the magnetic sea floor lineations the crustal age has been estimated to be between 33.3 and 33.7 Ma at Site U1367, between 13.4 and 13.6 Ma at U1368, and between 73.6 and 79.5 Ma at U1370. Carbonate ooze are the dominant lithology at Sites U1367 and U1368, whereas at Site U1370 carbonate ooze was present only within a short (<2...
Eos, Transactions American Geophysical Union, 1997
Crocodilian teeth, fish teeth, scales, and bones, and teeth and bones of uncertain affinities occ... more Crocodilian teeth, fish teeth, scales, and bones, and teeth and bones of uncertain affinities occur within a mudstone deposit sandwiched between basalt flows at the base of ODP Hole 865A on Allison Guyot in the middle of the Pacific Ocean. Age control from large benthic foraminifers, Sr-isotope stratigraphy, and radiometric ages of the basalt place the age of this assemblage
ODP Preliminary Report, 1993
Eos, Transactions American Geophysical Union, 1993
Scientific Drilling, 2011
No abstract available.…
Marine Micropaleontology, 1998
A diverse assemblage of acritarchs, prasinophytes and dinoflagellate cysts occurs in an organic r... more A diverse assemblage of acritarchs, prasinophytes and dinoflagellate cysts occurs in an organic rich black mud in Core Fl-533, taken from the Alpha Ridge, Arctic Ocean. Similarities between this assemblage and others described from the Canadian Arctic allow this black mud to be dated as early Maastrichtian, based primarily on the presence of Cerodinium leptodermum, and the absence of exclusively Campanian and upper Maastrichtian taxa. The high abundance of Comasphaeridium and marine derived amorphous organic matter may indicate a shelf to upper slope environment, possibly deposited during a marine transgression. An abundance of prasinophyte algal cysts, a moderately high peridinioid=gonyaulacoid dinoflagellate cyst ratio, and high species diversity indicate high paleoproductivity, most likely associated with upwelling conditions. When interpreted within the context of two nearby biosiliceous-rich Maastrichtian cores also taken from Alpha Ridge, and from paleogeographic reconstructions, these results indicate that an upwelling region probably existed along the eastern Arctic Ocean during at least part of the Maastrichtian, and formed different sedimentary facies in shelf to slope environments, similar to facies patterns recognized in lower latitude paleo-upwelling regions.