Clay mineral indicators of geological and geochemical subaerial modification of near-surface Tertiary sediments on the northeastern Grand Banks of Newfoundland
Based on mineralogical studies of clay-sized material, two sedimentary environments have been interpreted for the Tertiary sediments on northeastern Grand Banks of Newfoundland: (i) an acidic leaching environment (pH < 7.0) is observed as a weathered, probably desiccated crust directly underlying...
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Canadian Science Publishing
1987
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crcansciencepubl:10.1139/e87-206 2024-09-15T18:20:05+00:00 Clay mineral indicators of geological and geochemical subaerial modification of near-surface Tertiary sediments on the northeastern Grand Banks of Newfoundland Segall, M. P. Buckley, D. E. Lewis, C. F. M. 1987 http://dx.doi.org/10.1139/e87-206 http://www.nrcresearchpress.com/doi/pdf/10.1139/e87-206 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Earth Sciences volume 24, issue 11, page 2172-2187 ISSN 0008-4077 1480-3313 journal-article 1987 crcansciencepubl https://doi.org/10.1139/e87-206 2024-08-15T04:09:31Z Based on mineralogical studies of clay-sized material, two sedimentary environments have been interpreted for the Tertiary sediments on northeastern Grand Banks of Newfoundland: (i) an acidic leaching environment (pH < 7.0) is observed as a weathered, probably desiccated crust directly underlying the Tertiary–Quaternary unconformity; and (ii) an alkaline marine environment directly underlies the weathered zone. The weathered zone has been sampled at depths of 2–3 m (locally) below the seabed surface in the study area. Mineralogically the < 2 μm size fraction is characterized by relatively high kaolinite concentrations (7 – 18%) and a clinochlore component. The more deeply buried sediments have been deposited under marginal to normal marine conditions (a regressive phase, pH 7–8). Clay-sized components in this zone are characterized by high concentrations of expandable minerals (average 45%) and chamosite.Sediments from both of these environments differ from the thin, clay-poor Late Pleistocene – Holocene sands and gravels at the present seabed surface. Late Pleistocene – Holocene sediments have clay-sized mineralogical suites, partially reworked from weathered zone components (up to 15% kaolinite, locally) but are mostly derived from a northern latitude provenance (high illite (average 28%), quartz (average 14%), and feldspar (average 19%)). Expandable mineral phases range from 0 to 24%.The differing clay-sized mineralogical signatures indicate (i) alteration of the Tertiary marine sediments (expandable minerals) by acidic leaching to form a kaolinite-enriched weathered zone; (ii) the reworking of weathered zone materials during deglacial marine transgressions; (iii) the incorporation of sediments from the weathered zone into the Holocene sedimentary regime during Recent times, possibly by ice scouring; (iv) input from northern latitude provenances by reworking of earlier deposited glacial material; and (v) minor clay input to the Late Pleistocene – Holocene sands and gravels from ice rafting over the past ... Article in Journal/Newspaper Newfoundland Canadian Science Publishing Canadian Journal of Earth Sciences 24 11 2172 2187 |
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Canadian Science Publishing |
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crcansciencepubl |
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English |
description |
Based on mineralogical studies of clay-sized material, two sedimentary environments have been interpreted for the Tertiary sediments on northeastern Grand Banks of Newfoundland: (i) an acidic leaching environment (pH < 7.0) is observed as a weathered, probably desiccated crust directly underlying the Tertiary–Quaternary unconformity; and (ii) an alkaline marine environment directly underlies the weathered zone. The weathered zone has been sampled at depths of 2–3 m (locally) below the seabed surface in the study area. Mineralogically the < 2 μm size fraction is characterized by relatively high kaolinite concentrations (7 – 18%) and a clinochlore component. The more deeply buried sediments have been deposited under marginal to normal marine conditions (a regressive phase, pH 7–8). Clay-sized components in this zone are characterized by high concentrations of expandable minerals (average 45%) and chamosite.Sediments from both of these environments differ from the thin, clay-poor Late Pleistocene – Holocene sands and gravels at the present seabed surface. Late Pleistocene – Holocene sediments have clay-sized mineralogical suites, partially reworked from weathered zone components (up to 15% kaolinite, locally) but are mostly derived from a northern latitude provenance (high illite (average 28%), quartz (average 14%), and feldspar (average 19%)). Expandable mineral phases range from 0 to 24%.The differing clay-sized mineralogical signatures indicate (i) alteration of the Tertiary marine sediments (expandable minerals) by acidic leaching to form a kaolinite-enriched weathered zone; (ii) the reworking of weathered zone materials during deglacial marine transgressions; (iii) the incorporation of sediments from the weathered zone into the Holocene sedimentary regime during Recent times, possibly by ice scouring; (iv) input from northern latitude provenances by reworking of earlier deposited glacial material; and (v) minor clay input to the Late Pleistocene – Holocene sands and gravels from ice rafting over the past ... |
format |
Article in Journal/Newspaper |
author |
Segall, M. P. Buckley, D. E. Lewis, C. F. M. |
spellingShingle |
Segall, M. P. Buckley, D. E. Lewis, C. F. M. Clay mineral indicators of geological and geochemical subaerial modification of near-surface Tertiary sediments on the northeastern Grand Banks of Newfoundland |
author_facet |
Segall, M. P. Buckley, D. E. Lewis, C. F. M. |
author_sort |
Segall, M. P. |
title |
Clay mineral indicators of geological and geochemical subaerial modification of near-surface Tertiary sediments on the northeastern Grand Banks of Newfoundland |
title_short |
Clay mineral indicators of geological and geochemical subaerial modification of near-surface Tertiary sediments on the northeastern Grand Banks of Newfoundland |
title_full |
Clay mineral indicators of geological and geochemical subaerial modification of near-surface Tertiary sediments on the northeastern Grand Banks of Newfoundland |
title_fullStr |
Clay mineral indicators of geological and geochemical subaerial modification of near-surface Tertiary sediments on the northeastern Grand Banks of Newfoundland |
title_full_unstemmed |
Clay mineral indicators of geological and geochemical subaerial modification of near-surface Tertiary sediments on the northeastern Grand Banks of Newfoundland |
title_sort |
clay mineral indicators of geological and geochemical subaerial modification of near-surface tertiary sediments on the northeastern grand banks of newfoundland |
publisher |
Canadian Science Publishing |
publishDate |
1987 |
url |
http://dx.doi.org/10.1139/e87-206 http://www.nrcresearchpress.com/doi/pdf/10.1139/e87-206 |
genre |
Newfoundland |
genre_facet |
Newfoundland |
op_source |
Canadian Journal of Earth Sciences volume 24, issue 11, page 2172-2187 ISSN 0008-4077 1480-3313 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/e87-206 |
container_title |
Canadian Journal of Earth Sciences |
container_volume |
24 |
container_issue |
11 |
container_start_page |
2172 |
op_container_end_page |
2187 |
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1810458449275781120 |