Authigenic apatite in a fluvial sandstone sequence: eveidence for rare-earth element mobility during diagenesis and a tool for diagnetic correlation

Malcolm John Hole, S. Chenery, Andrew Clifford Morton, J. E. E. Bouch

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

Apatite grains in heavy-mineral separates of samples from the Statfjord Formation (Triassic-Lower Jurassic, North Sea), exhibit variably corroded detrital cores and euhedral diagenetic overgrowths. In the overlying marine deposits of the Nansen Formation, apatite grains show no evidence of either corrosion or overgrowths. Compositions of detrital apatite in both formations are indistinguishable, indicating that the source areas responsible for Statfjord and Nansen deposition included similar apatite-bearing lithologies. Apatite corrosion in the Statfjord Formation is considered to be a response to leaching by acidic groundwaters during sediment storage on the fluvial floodplain. Any variations in the degree of corrosion that may have been generated by differences in floodplain residence time have been homogenized by sediment reworking.

Laser-ablation microprobe inductively coupled plasma mass spectrometry and wavelength-dispersive electron microprobe analysis indicate that the authigenic apatite contains high abundances (up to 3.5% total) of the rare earth elements (REE), implying a degree of REE mobilization during diagenesis. REE profiles (NASC normalized) for the authigenic apatites are convex-upwards with enrichment of the MREE. The REE are considered to have been derived from dissolution of other REE-bearing heavy minerals (e.g., garnet) during alluvial storage, with possible contributions from dissolved feldspars (which may account for slight positive Eu anomalies) and REEs adsorbed onto clay surfaces. REE mobilization was probably enhanced by fluoride and/or phosphate complexes, although organic complexing related to pedogenic processes is also a possibility. Through the Statfjord Formation, authigenic apatite displays subtle variations in major-element, minor-element, and trace-element chemistry, which may find application as a tool for diagenetic correlation.

Original languageEnglish
Pages (from-to)59-67
Number of pages8
JournalJournal of Sedimentary Research
Volume72
Publication statusPublished - 2002

Keywords

  • NORTHERN NORTH-SEA
  • STATFJORD FORMATION
  • AQUEOUS GEOCHEMISTRY
  • FRACTIONATION
  • ASSEMBLAGES
  • SPECIATION
  • YTTRIUM

Cite this

Authigenic apatite in a fluvial sandstone sequence: eveidence for rare-earth element mobility during diagenesis and a tool for diagnetic correlation. / Hole, Malcolm John; Chenery, S.; Morton, Andrew Clifford; Bouch, J. E. E.

In: Journal of Sedimentary Research, Vol. 72, 2002, p. 59-67.

Research output: Contribution to journalArticle

@article{63b0f34b19eb493fbd19f0920ee4833d,
title = "Authigenic apatite in a fluvial sandstone sequence: eveidence for rare-earth element mobility during diagenesis and a tool for diagnetic correlation",
abstract = "Apatite grains in heavy-mineral separates of samples from the Statfjord Formation (Triassic-Lower Jurassic, North Sea), exhibit variably corroded detrital cores and euhedral diagenetic overgrowths. In the overlying marine deposits of the Nansen Formation, apatite grains show no evidence of either corrosion or overgrowths. Compositions of detrital apatite in both formations are indistinguishable, indicating that the source areas responsible for Statfjord and Nansen deposition included similar apatite-bearing lithologies. Apatite corrosion in the Statfjord Formation is considered to be a response to leaching by acidic groundwaters during sediment storage on the fluvial floodplain. Any variations in the degree of corrosion that may have been generated by differences in floodplain residence time have been homogenized by sediment reworking.Laser-ablation microprobe inductively coupled plasma mass spectrometry and wavelength-dispersive electron microprobe analysis indicate that the authigenic apatite contains high abundances (up to 3.5{\%} total) of the rare earth elements (REE), implying a degree of REE mobilization during diagenesis. REE profiles (NASC normalized) for the authigenic apatites are convex-upwards with enrichment of the MREE. The REE are considered to have been derived from dissolution of other REE-bearing heavy minerals (e.g., garnet) during alluvial storage, with possible contributions from dissolved feldspars (which may account for slight positive Eu anomalies) and REEs adsorbed onto clay surfaces. REE mobilization was probably enhanced by fluoride and/or phosphate complexes, although organic complexing related to pedogenic processes is also a possibility. Through the Statfjord Formation, authigenic apatite displays subtle variations in major-element, minor-element, and trace-element chemistry, which may find application as a tool for diagenetic correlation.",
keywords = "NORTHERN NORTH-SEA, STATFJORD FORMATION, AQUEOUS GEOCHEMISTRY, FRACTIONATION, ASSEMBLAGES, SPECIATION, YTTRIUM",
author = "Hole, {Malcolm John} and S. Chenery and Morton, {Andrew Clifford} and Bouch, {J. E. E.}",
year = "2002",
language = "English",
volume = "72",
pages = "59--67",
journal = "Journal of Sedimentary Research",
issn = "1527-1404",
publisher = "SEPM Society for Sedimentary Geology",

}

TY - JOUR

T1 - Authigenic apatite in a fluvial sandstone sequence: eveidence for rare-earth element mobility during diagenesis and a tool for diagnetic correlation

AU - Hole, Malcolm John

AU - Chenery, S.

AU - Morton, Andrew Clifford

AU - Bouch, J. E. E.

PY - 2002

Y1 - 2002

N2 - Apatite grains in heavy-mineral separates of samples from the Statfjord Formation (Triassic-Lower Jurassic, North Sea), exhibit variably corroded detrital cores and euhedral diagenetic overgrowths. In the overlying marine deposits of the Nansen Formation, apatite grains show no evidence of either corrosion or overgrowths. Compositions of detrital apatite in both formations are indistinguishable, indicating that the source areas responsible for Statfjord and Nansen deposition included similar apatite-bearing lithologies. Apatite corrosion in the Statfjord Formation is considered to be a response to leaching by acidic groundwaters during sediment storage on the fluvial floodplain. Any variations in the degree of corrosion that may have been generated by differences in floodplain residence time have been homogenized by sediment reworking.Laser-ablation microprobe inductively coupled plasma mass spectrometry and wavelength-dispersive electron microprobe analysis indicate that the authigenic apatite contains high abundances (up to 3.5% total) of the rare earth elements (REE), implying a degree of REE mobilization during diagenesis. REE profiles (NASC normalized) for the authigenic apatites are convex-upwards with enrichment of the MREE. The REE are considered to have been derived from dissolution of other REE-bearing heavy minerals (e.g., garnet) during alluvial storage, with possible contributions from dissolved feldspars (which may account for slight positive Eu anomalies) and REEs adsorbed onto clay surfaces. REE mobilization was probably enhanced by fluoride and/or phosphate complexes, although organic complexing related to pedogenic processes is also a possibility. Through the Statfjord Formation, authigenic apatite displays subtle variations in major-element, minor-element, and trace-element chemistry, which may find application as a tool for diagenetic correlation.

AB - Apatite grains in heavy-mineral separates of samples from the Statfjord Formation (Triassic-Lower Jurassic, North Sea), exhibit variably corroded detrital cores and euhedral diagenetic overgrowths. In the overlying marine deposits of the Nansen Formation, apatite grains show no evidence of either corrosion or overgrowths. Compositions of detrital apatite in both formations are indistinguishable, indicating that the source areas responsible for Statfjord and Nansen deposition included similar apatite-bearing lithologies. Apatite corrosion in the Statfjord Formation is considered to be a response to leaching by acidic groundwaters during sediment storage on the fluvial floodplain. Any variations in the degree of corrosion that may have been generated by differences in floodplain residence time have been homogenized by sediment reworking.Laser-ablation microprobe inductively coupled plasma mass spectrometry and wavelength-dispersive electron microprobe analysis indicate that the authigenic apatite contains high abundances (up to 3.5% total) of the rare earth elements (REE), implying a degree of REE mobilization during diagenesis. REE profiles (NASC normalized) for the authigenic apatites are convex-upwards with enrichment of the MREE. The REE are considered to have been derived from dissolution of other REE-bearing heavy minerals (e.g., garnet) during alluvial storage, with possible contributions from dissolved feldspars (which may account for slight positive Eu anomalies) and REEs adsorbed onto clay surfaces. REE mobilization was probably enhanced by fluoride and/or phosphate complexes, although organic complexing related to pedogenic processes is also a possibility. Through the Statfjord Formation, authigenic apatite displays subtle variations in major-element, minor-element, and trace-element chemistry, which may find application as a tool for diagenetic correlation.

KW - NORTHERN NORTH-SEA

KW - STATFJORD FORMATION

KW - AQUEOUS GEOCHEMISTRY

KW - FRACTIONATION

KW - ASSEMBLAGES

KW - SPECIATION

KW - YTTRIUM

M3 - Article

VL - 72

SP - 59

EP - 67

JO - Journal of Sedimentary Research

JF - Journal of Sedimentary Research

SN - 1527-1404

ER -