_version_ 1867171790599487488
author Cavin, Amanda
Underwood, Michael B
Fisher, Andrew T
Johnston-Karas, Aaron
author_facet Cavin, Amanda
Underwood, Michael B
Fisher, Andrew T
Johnston-Karas, Aaron
collection Datos científicos de ciencias marinas y ambientales
contents Sedimentary deposits of Cascadia Basin lap onto the Juan de Fuca Ridge to within 20 km of the spreading axis (Davis and Currie, 1993, doi:10.1139/e93-023). Collectively, these interbeds of hemipelagic mud, mud turbidites, silt turbidites, sand turbidites, and debris-flow deposits act as a relatively low-permeability barrier that inhibits the hydrothermal connection between underlying igneous crust and the overlying reservoir of ocean water. The primary purpose of Leg 168 of the Ocean Drilling Program (ODP) was to explore the causes and consequences of ridge-flank hydrothermal circulation (Shipboard Scientific Party, 1997c, doi:10.2973/odp.proc.ir.168.101.1997). One important aspect of this overall goal was to determine how changes in thickness of the sediment cover affect heat flow, fluid flow, fluid composition, and chemical alteration of the igneous crust. Fluid circulation through the sediment is influenced by a variety of textural parameters and intrinsic physical properties. Physical properties of sediments usually change in a predictable way with increasing depth and mechanical compaction, but different lithologies display different compaction gradients. Shipboard scientists subdivided the sedimentary succession throughout the study area into three principal lithofacies units and subunits. In general, these sequences coarsen and thicken upward from a basal interval of hemipelagic mud through a unit of mud and silt turbidites into a unit of mud, silt turbidites, sand turbidites, and debris-flow deposits. The sediment index properties (bulk density, water content, porosity, and void ratio) were measured aboard the JOIDES Resolution (Shipboard Scientific Party, 1997b, doi:10.2973/odp.proc.ir.168.104.1997; 1997d, doi:10.2973/odp.proc.ir.168.105.1997; 1997a, doi:10.2973/odp.proc.ir.168.106.1997). Shorebased work was devoted to accurate measurements of grain-size parameters. To allow for valid cross-correlation, the samples analyzed for grain-size distributions were taken from core intervals immediately adjacent to those of the physical properties specimens. The main purposes of this report are to show how the grain size and physical properties data are interrelated, and to determine how lithology might affect hydrologic properties of the sedimentary cover.
format Dataset Open Access
id pangaea_https___doi_org_10_1594_PANGAEA_788852
institution PANGAEA
language en
publishDate 2000
publisher PANGAEA
record_format pangaea
spellingShingle (Table T1) Granulometry of sediments from ODP Leg 168 sites
Cavin, Amanda
Underwood, Michael B
Fisher, Andrew T
Johnston-Karas, Aaron
168-1023A; 168-1024B; 168-1025B; 168-1026B; 168-1026C; 168-1027B; 168-1028A; 168-1029A; 168-1030B; 168-1031A; 168-1032A; Calculated; DEPTH, sediment/rock; DRILL; Drilling/drill rig; DSDP/ODP/IODP sample designation; Elevation of event; Event label; Grain size, mean; Grain size, SEDIGRAPH 5000; Grain size, sieving; Joides Resolution; Juan de Fuca Ridge, North Pacific Ocean; Latitude of event; Leg168; Longitude of event; North Pacific Ocean; Ocean Drilling Program; ODP; Percentile 25; Percentile 50; Percentile 75; Sample code/label; Size fraction < 0.004 mm, clay; Size fraction > 0.063 mm, sand; Size fraction 0.063-0.004 mm, silt; Skewness; Sorting
Sedimentary deposits of Cascadia Basin lap onto the Juan de Fuca Ridge to within 20 km of the spreading axis (Davis and Currie, 1993, doi:10.1139/e93-023). Collectively, these interbeds of hemipelagic mud, mud turbidites, silt turbidites, sand turbidites, and debris-flow deposits act as a relatively low-permeability barrier that inhibits the hydrothermal connection between underlying igneous crust and the overlying reservoir of ocean water. The primary purpose of Leg 168 of the Ocean Drilling Program (ODP) was to explore the causes and consequences of ridge-flank hydrothermal circulation (Shipboard Scientific Party, 1997c, doi:10.2973/odp.proc.ir.168.101.1997). One important aspect of this overall goal was to determine how changes in thickness of the sediment cover affect heat flow, fluid flow, fluid composition, and chemical alteration of the igneous crust. Fluid circulation through the sediment is influenced by a variety of textural parameters and intrinsic physical properties. Physical properties of sediments usually change in a predictable way with increasing depth and mechanical compaction, but different lithologies display different compaction gradients. Shipboard scientists subdivided the sedimentary succession throughout the study area into three principal lithofacies units and subunits. In general, these sequences coarsen and thicken upward from a basal interval of hemipelagic mud through a unit of mud and silt turbidites into a unit of mud, silt turbidites, sand turbidites, and debris-flow deposits. The sediment index properties (bulk density, water content, porosity, and void ratio) were measured aboard the JOIDES Resolution (Shipboard Scientific Party, 1997b, doi:10.2973/odp.proc.ir.168.104.1997; 1997d, doi:10.2973/odp.proc.ir.168.105.1997; 1997a, doi:10.2973/odp.proc.ir.168.106.1997). Shorebased work was devoted to accurate measurements of grain-size parameters. To allow for valid cross-correlation, the samples analyzed for grain-size distributions were taken from core intervals immediately adjacent to those of the physical properties specimens. The main purposes of this report are to show how the grain size and physical properties data are interrelated, and to determine how lithology might affect hydrologic properties of the sedimentary cover.
title (Table T1) Granulometry of sediments from ODP Leg 168 sites
topic 168-1023A; 168-1024B; 168-1025B; 168-1026B; 168-1026C; 168-1027B; 168-1028A; 168-1029A; 168-1030B; 168-1031A; 168-1032A; Calculated; DEPTH, sediment/rock; DRILL; Drilling/drill rig; DSDP/ODP/IODP sample designation; Elevation of event; Event label; Grain size, mean; Grain size, SEDIGRAPH 5000; Grain size, sieving; Joides Resolution; Juan de Fuca Ridge, North Pacific Ocean; Latitude of event; Leg168; Longitude of event; North Pacific Ocean; Ocean Drilling Program; ODP; Percentile 25; Percentile 50; Percentile 75; Sample code/label; Size fraction < 0.004 mm, clay; Size fraction > 0.063 mm, sand; Size fraction 0.063-0.004 mm, silt; Skewness; Sorting
url https://doi.org/10.1594/PANGAEA.788852