Correlation between wet bulk density and carbonate content from IODP Hole 321-U1338A, 321-U1338B and 321-U1338C

Fuente: PANGAEA
Guardado en:
Detalles Bibliográficos
Autores principales: Reghellin, Daniele, Dickens, Gerald Roy, Backman, Jan
Formato: Dataset Open Access
Lenguaje:en
Publicado: PANGAEA 2015
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1867168567154180096
author Reghellin, Daniele
Dickens, Gerald Roy
Backman, Jan
author_facet Reghellin, Daniele
Dickens, Gerald Roy
Backman, Jan
collection Datos científicos de ciencias marinas y ambientales
contents Sediment cores collected from the Eastern Equatorial Pacific Ocean display a clear positive second-order relationship between wet bulk density (WBD) and carbonate content. This has long interested the paleoceanography community because detailed Gamma Ray Attenuation Porosity Evaluator (GRAPE) measurements, which approximate WBD, might be used to determine records of carbonate content at very high temporal resolution. Although general causes for the relationship are known, they have not been presented and discussed systematically on the basis of first principles. In this study, we measure the mass and carbonate content of 50 sediment samples with known WBD from Site U1338, before and after rinsing with de-ionized water; we also determine the mass related proportion of coarse (> 63 µm) material. Samples exhibit clear relationships between WBD, carbonate content, mass loss upon rinsing, and grain size. We develop a series of mathematical expressions to describe these relationships, and solve them numerically. As noted by previous workers, the second-order relationship between WBD and carbonate content results from the mixing of biogenic carbonate and biogenic silica, which have different grain densities and different porosities. However, at high carbonate content, a wide range in WBD occurs because samples with greater amounts of coarse carbonate have higher porosity. Moreover compaction impacts carbonate particles more than biogenic silica particles. As such, a single two-component equation cannot be used to determine carbonate content accurately across depth intervals where both the porosity and type of carbonate vary. Instead, the WBD-carbonate relationship is described by an infinite series of curves, each which represents mixing of multiple sediment components with different densities and porosities. Dissolved ions also precipitate from pore space during sample drying, which adds mass to the sediment. Without rinsing samples, simple empirical relationships between WBD and carbonate content are further skewed by salt dilution.
format Dataset Open Access
id pangaea_https___doi_org_10_1594_PANGAEA_855226
institution PANGAEA
language en
publishDate 2015
publisher PANGAEA
record_format pangaea
spellingShingle Correlation between wet bulk density and carbonate content from IODP Hole 321-U1338A, 321-U1338B and 321-U1338C
Reghellin, Daniele
Dickens, Gerald Roy
Backman, Jan
Integrated Ocean Drilling Program / International Ocean Discovery Program; IODP
Sediment cores collected from the Eastern Equatorial Pacific Ocean display a clear positive second-order relationship between wet bulk density (WBD) and carbonate content. This has long interested the paleoceanography community because detailed Gamma Ray Attenuation Porosity Evaluator (GRAPE) measurements, which approximate WBD, might be used to determine records of carbonate content at very high temporal resolution. Although general causes for the relationship are known, they have not been presented and discussed systematically on the basis of first principles. In this study, we measure the mass and carbonate content of 50 sediment samples with known WBD from Site U1338, before and after rinsing with de-ionized water; we also determine the mass related proportion of coarse (> 63 µm) material. Samples exhibit clear relationships between WBD, carbonate content, mass loss upon rinsing, and grain size. We develop a series of mathematical expressions to describe these relationships, and solve them numerically. As noted by previous workers, the second-order relationship between WBD and carbonate content results from the mixing of biogenic carbonate and biogenic silica, which have different grain densities and different porosities. However, at high carbonate content, a wide range in WBD occurs because samples with greater amounts of coarse carbonate have higher porosity. Moreover compaction impacts carbonate particles more than biogenic silica particles. As such, a single two-component equation cannot be used to determine carbonate content accurately across depth intervals where both the porosity and type of carbonate vary. Instead, the WBD-carbonate relationship is described by an infinite series of curves, each which represents mixing of multiple sediment components with different densities and porosities. Dissolved ions also precipitate from pore space during sample drying, which adds mass to the sediment. Without rinsing samples, simple empirical relationships between WBD and carbonate content are further skewed by salt dilution.
title Correlation between wet bulk density and carbonate content from IODP Hole 321-U1338A, 321-U1338B and 321-U1338C
topic Integrated Ocean Drilling Program / International Ocean Discovery Program; IODP
url https://doi.org/10.1594/PANGAEA.855226