{"id":{"repo_id":"rice","oai_identifier":"oai:repository.rice.edu:1911/19058"},"canonical_url":"https://search.dev.ndltd.org/etd/rice/oai:repository.rice.edu:1911/19058","repository":{"repo_id":"rice","name":"Rice University","base_url":"https://repository.rice.edu/server/oai/request"},"display":{"title":"RADIOLARIAN BIOSTRATIGRAPHIC AND PALEOCEANOGRAPHIC STUDIES OF MONTEREY-LIKE ROCKS OF THE HUMBOLDT BASIN, NORTHERN CALIFORNIA","abstract":"The middle and upper Miocene sediments of the Humboldt Basin, northern California, have been investigated for the presence of radiolarian fauna. The vast majority of the radiolaria found are cold water indicators, however there are four distinct periods of invasion of warm water fauna. Two minor ones occurring at 11.5ma and approximately 8.0ma and two major events at 5.0ma and approximately 5.5ma. Occurrences of radiolaria indicative of low oxygen conditions, cold deep forms, and radiolarians associated with the California Current indicate that Paleoceanic circulation in the Humboldt Basin region at 6.5ma was similar to "normal" (anti-El Nino-like) circulation of Recent time. Depositional environments and paleoceanographic circulation are modeled from information obtained from 192 Miocene to Pliocene samples of five stratigraphic sections across the subaerially exposed southern margin of the paleo-basin. Radiolarian fauna indicate that initial deposition was in a basin open to deep marine waters. Through time and in a west to east direction, the radiolarian populations exhibit increasingly shelfal characteristics as shallow water sediments prograded to the west. Total organic carbon data from key chronozones support the models of oceanic circulation developed for the key time planes. The fluctuations in the California Current System are the dominant controls on faunal distribution and organic carbon preservation. An example of doming of deep water masses (Weinheimer et al., 1986) indicating analogous El Nino-like circulation is detected and differentiated from other similar appearing events of a different nature (normal, anti-El Nino circulation).","abstract_html":"The middle and upper Miocene sediments of the Humboldt Basin, northern California, have been investigated for the presence of radiolarian fauna. The vast majority of the radiolaria found are cold water indicators, however there are four distinct periods of invasion of warm water fauna. Two minor ones occurring at 11.5ma and approximately 8.0ma and two major events at 5.0ma and approximately 5.5ma. Occurrences of radiolaria indicative of low oxygen conditions, cold deep forms, and radiolarians associated with the California Current indicate that Paleoceanic circulation in the Humboldt Basin region at 6.5ma was similar to "normal" (anti-El Nino-like) circulation of Recent time. Depositional environments and paleoceanographic circulation are modeled from information obtained from 192 Miocene to Pliocene samples of five stratigraphic sections across the subaerially exposed southern margin of the paleo-basin. Radiolarian fauna indicate that initial deposition was in a basin open to deep marine waters. Through time and in a west to east direction, the radiolarian populations exhibit increasingly shelfal characteristics as shallow water sediments prograded to the west. Total organic carbon data from key chronozones support the models of oceanic circulation developed for the key time planes. The fluctuations in the California Current System are the dominant controls on faunal distribution and organic carbon preservation. An example of doming of deep water masses (Weinheimer et al., 1986) indicating analogous El Nino-like circulation is detected and differentiated from other similar appearing events of a different nature (normal, anti-El Nino circulation).","abstract_has_math":false,"creators":["NELSON, CARL OWEN"],"institution":"Rice University","degree_name":"Doctor of Philosophy","degree_level":"Doctoral","degree_discipline":"Natural Sciences","degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":1987,"date_issued":"1987","date_published":"1987","updated_at":"2026-07-24T04:10:24Z","subjects":["Paleoecology"],"languages":["eng"],"rights":["Copyright is held by the author, unless otherwise indicated. Permission to reuse, publish, or reproduce the work beyond the bounds of fair use or other exemptions to copyright law must be obtained from the copyright holder."],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://hdl.handle.net/1911/19058","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["NELSON, CARL OWEN"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2007-08-21T01:41:17Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2007-08-21T01:41:17Z"]},{"key":"dc:date.issued","label":"Date","values":["1987"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Natural Sciences"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Doctoral"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Doctor of Philosophy"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Rice University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Paleoecology"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright is held by the author, unless otherwise indicated. Permission to reuse, publish, or reproduce the work beyond the bounds of fair use or other exemptions to copyright law must be obtained from the copyright holder."]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://hdl.handle.net/1911/19058"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The middle and upper Miocene sediments of the Humboldt Basin, northern California, have been investigated for the presence of radiolarian fauna. The vast majority of the radiolaria found are cold water indicators, however there are four distinct periods of invasion of warm water fauna. Two minor ones occurring at 11.5ma and approximately 8.0ma and two major events at 5.0ma and approximately 5.5ma. Occurrences of radiolaria indicative of low oxygen conditions, cold deep forms, and radiolarians associated with the California Current indicate that Paleoceanic circulation in the Humboldt Basin region at 6.5ma was similar to "normal" (anti-El Nino-like) circulation of Recent time. Depositional environments and paleoceanographic circulation are modeled from information obtained from 192 Miocene to Pliocene samples of five stratigraphic sections across the subaerially exposed southern margin of the paleo-basin. Radiolarian fauna indicate that initial deposition was in a basin open to deep marine waters. Through time and in a west to east direction, the radiolarian populations exhibit increasingly shelfal characteristics as shallow water sediments prograded to the west. Total organic carbon data from key chronozones support the models of oceanic circulation developed for the key time planes. The fluctuations in the California Current System are the dominant controls on faunal distribution and organic carbon preservation. An example of doming of deep water masses (Weinheimer et al., 1986) indicating analogous El Nino-like circulation is detected and differentiated from other similar appearing events of a different nature (normal, anti-El Nino circulation)."]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["RADIOLARIAN BIOSTRATIGRAPHIC AND PALEOCEANOGRAPHIC STUDIES OF MONTEREY-LIKE ROCKS OF THE HUMBOLDT BASIN, NORTHERN CALIFORNIA"]}]}],"canonical_facts":{"dc:creator":["NELSON, CARL OWEN"],"dc:date.accessioned":["2007-08-21T01:41:17Z"],"dc:date.available":["2007-08-21T01:41:17Z"],"dc:date.issued":["1987"],"dc:description.abstract":["The middle and upper Miocene sediments of the Humboldt Basin, northern California, have been investigated for the presence of radiolarian fauna. The vast majority of the radiolaria found are cold water indicators, however there are four distinct periods of invasion of warm water fauna. Two minor ones occurring at 11.5ma and approximately 8.0ma and two major events at 5.0ma and approximately 5.5ma. Occurrences of radiolaria indicative of low oxygen conditions, cold deep forms, and radiolarians associated with the California Current indicate that Paleoceanic circulation in the Humboldt Basin region at 6.5ma was similar to "normal" (anti-El Nino-like) circulation of Recent time. Depositional environments and paleoceanographic circulation are modeled from information obtained from 192 Miocene to Pliocene samples of five stratigraphic sections across the subaerially exposed southern margin of the paleo-basin. Radiolarian fauna indicate that initial deposition was in a basin open to deep marine waters. Through time and in a west to east direction, the radiolarian populations exhibit increasingly shelfal characteristics as shallow water sediments prograded to the west. Total organic carbon data from key chronozones support the models of oceanic circulation developed for the key time planes. The fluctuations in the California Current System are the dominant controls on faunal distribution and organic carbon preservation. An example of doming of deep water masses (Weinheimer et al., 1986) indicating analogous El Nino-like circulation is detected and differentiated from other similar appearing events of a different nature (normal, anti-El Nino circulation)."],"dc:format.mimetype":["application/pdf"],"dc:identifier.uri":["https://hdl.handle.net/1911/19058"],"dc:language.iso":["eng"],"dc:rights":["Copyright is held by the author, unless otherwise indicated. Permission to reuse, publish, or reproduce the work beyond the bounds of fair use or other exemptions to copyright law must be obtained from the copyright holder."],"dc:subject":["Paleoecology"],"dc:title":["RADIOLARIAN BIOSTRATIGRAPHIC AND PALEOCEANOGRAPHIC STUDIES OF MONTEREY-LIKE ROCKS OF THE HUMBOLDT BASIN, NORTHERN CALIFORNIA"],"dc:type":["Thesis"],"thesis:degree_discipline":["Natural Sciences"],"thesis:degree_level":["Doctoral"],"thesis:degree_name":["Doctor of Philosophy"],"thesis:institution_name":["Rice University"]},"updated_at":"2026-07-24T04:10:24Z"}