Stratigraphic development of an Upper Jurassic deepmarine syn-rift succession, Inner Moray Firth Basin, Scotland

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

The stratigraphic development of an Upper Jurassic syn-rift succession exposed at outcrop in the Inner Moray Firth Basin has been investigated using high-resolution biostratigraphy and sedimentology.A continuous 970 m thick section, exposed in the hangingwall of the Helmsdale Fault was logged in detail. The succession spans 8 Ma and contains eight lithofacies types, which indicate
deposition in a deep marine setting. Boulder beds contain large, angular clasts, with bed thicknesses typically >2 m and poor sorting suggesting deposition by debris flows. An inverse clast stratigraphy is observed; the oldest boulder beds contain sandstone clasts of Upper Old Red Sandstone (ORS) with younger debris flows containing clasts of Middle ORS calcareous siltstone. A marked change
from siliciclastic to carbonate dominated sedimentation occurred during the Early Tithonian, interpreted primarily as a result of change in lithologies in the footwall catchment from sandstone to calcareous siltstone, which reduced supply of siliciclastic sediment. Secondary factors are identified as increased aridity in the Early Tithonian, which reduced sand supply from the hinterland and a third-order Early Tithonian eustatic sea-level rise, which trapped coarser clastic sediment within the hinterland. Biostratigraphy allows calculation of variations in sedimentation rates with recognition of: (1) an early rift phase characterised by sandy turbidite deposition, when sedimentation rates averaged 0.08 m/ky, (2) a rift climax phase from the Early Kimmeridgian where sedimentation rates
increased steadily to a maximum of 0.64 m/ky in the Early Tithonian, with strata dominated by boulder scale clast-supported debris flows and (3) a late stage of rifting from the mid Tithonian, where sedimentation rates decreased to 0.07 m/ky. Overall sedimentation rates are comparable to those of other deep marine rift basins. Unroofing a resistant lithology on the footwall of a rift has important implications for siliciclastic sediment supply in rift basins
Original languageEnglish
Pages (from-to)1-25
Number of pages25
JournalBasin Research
Volume24
DOIs
Publication statusPublished - 2012

Fingerprint

Tithonian
clast
Jurassic
sedimentation rate
boulder
debris flow
Old Red Sandstone
basin
footwall
siltstone
biostratigraphy
lithology
sandstone
sedimentation
unroofing
Kimmeridgian
clastic sediment
climax
aridity
turbidite

Cite this

@article{a2f7a190732743619ffdec90dccb2bd5,
title = "Stratigraphic development of an Upper Jurassic deepmarine syn-rift succession, Inner Moray Firth Basin, Scotland",
abstract = "The stratigraphic development of an Upper Jurassic syn-rift succession exposed at outcrop in the Inner Moray Firth Basin has been investigated using high-resolution biostratigraphy and sedimentology.A continuous 970 m thick section, exposed in the hangingwall of the Helmsdale Fault was logged in detail. The succession spans 8 Ma and contains eight lithofacies types, which indicate deposition in a deep marine setting. Boulder beds contain large, angular clasts, with bed thicknesses typically >2 m and poor sorting suggesting deposition by debris flows. An inverse clast stratigraphy is observed; the oldest boulder beds contain sandstone clasts of Upper Old Red Sandstone (ORS) with younger debris flows containing clasts of Middle ORS calcareous siltstone. A marked change from siliciclastic to carbonate dominated sedimentation occurred during the Early Tithonian, interpreted primarily as a result of change in lithologies in the footwall catchment from sandstone to calcareous siltstone, which reduced supply of siliciclastic sediment. Secondary factors are identified as increased aridity in the Early Tithonian, which reduced sand supply from the hinterland and a third-order Early Tithonian eustatic sea-level rise, which trapped coarser clastic sediment within the hinterland. Biostratigraphy allows calculation of variations in sedimentation rates with recognition of: (1) an early rift phase characterised by sandy turbidite deposition, when sedimentation rates averaged 0.08 m/ky, (2) a rift climax phase from the Early Kimmeridgian where sedimentation rates increased steadily to a maximum of 0.64 m/ky in the Early Tithonian, with strata dominated by boulder scale clast-supported debris flows and (3) a late stage of rifting from the mid Tithonian, where sedimentation rates decreased to 0.07 m/ky. Overall sedimentation rates are comparable to those of other deep marine rift basins. Unroofing a resistant lithology on the footwall of a rift has important implications for siliciclastic sediment supply in rift basins",
author = "McArthur, {Adam Daniel} and Hartley, {Adrian John} and Jolley, {David William}",
year = "2012",
doi = "10.1111/j.1365-2117.2012.00557.x",
language = "English",
volume = "24",
pages = "1--25",
journal = "Basin Research",
issn = "0950-091X",
publisher = "Wiley-Blackwell",

}

TY - JOUR

T1 - Stratigraphic development of an Upper Jurassic deepmarine syn-rift succession, Inner Moray Firth Basin, Scotland

AU - McArthur, Adam Daniel

AU - Hartley, Adrian John

AU - Jolley, David William

PY - 2012

Y1 - 2012

N2 - The stratigraphic development of an Upper Jurassic syn-rift succession exposed at outcrop in the Inner Moray Firth Basin has been investigated using high-resolution biostratigraphy and sedimentology.A continuous 970 m thick section, exposed in the hangingwall of the Helmsdale Fault was logged in detail. The succession spans 8 Ma and contains eight lithofacies types, which indicate deposition in a deep marine setting. Boulder beds contain large, angular clasts, with bed thicknesses typically >2 m and poor sorting suggesting deposition by debris flows. An inverse clast stratigraphy is observed; the oldest boulder beds contain sandstone clasts of Upper Old Red Sandstone (ORS) with younger debris flows containing clasts of Middle ORS calcareous siltstone. A marked change from siliciclastic to carbonate dominated sedimentation occurred during the Early Tithonian, interpreted primarily as a result of change in lithologies in the footwall catchment from sandstone to calcareous siltstone, which reduced supply of siliciclastic sediment. Secondary factors are identified as increased aridity in the Early Tithonian, which reduced sand supply from the hinterland and a third-order Early Tithonian eustatic sea-level rise, which trapped coarser clastic sediment within the hinterland. Biostratigraphy allows calculation of variations in sedimentation rates with recognition of: (1) an early rift phase characterised by sandy turbidite deposition, when sedimentation rates averaged 0.08 m/ky, (2) a rift climax phase from the Early Kimmeridgian where sedimentation rates increased steadily to a maximum of 0.64 m/ky in the Early Tithonian, with strata dominated by boulder scale clast-supported debris flows and (3) a late stage of rifting from the mid Tithonian, where sedimentation rates decreased to 0.07 m/ky. Overall sedimentation rates are comparable to those of other deep marine rift basins. Unroofing a resistant lithology on the footwall of a rift has important implications for siliciclastic sediment supply in rift basins

AB - The stratigraphic development of an Upper Jurassic syn-rift succession exposed at outcrop in the Inner Moray Firth Basin has been investigated using high-resolution biostratigraphy and sedimentology.A continuous 970 m thick section, exposed in the hangingwall of the Helmsdale Fault was logged in detail. The succession spans 8 Ma and contains eight lithofacies types, which indicate deposition in a deep marine setting. Boulder beds contain large, angular clasts, with bed thicknesses typically >2 m and poor sorting suggesting deposition by debris flows. An inverse clast stratigraphy is observed; the oldest boulder beds contain sandstone clasts of Upper Old Red Sandstone (ORS) with younger debris flows containing clasts of Middle ORS calcareous siltstone. A marked change from siliciclastic to carbonate dominated sedimentation occurred during the Early Tithonian, interpreted primarily as a result of change in lithologies in the footwall catchment from sandstone to calcareous siltstone, which reduced supply of siliciclastic sediment. Secondary factors are identified as increased aridity in the Early Tithonian, which reduced sand supply from the hinterland and a third-order Early Tithonian eustatic sea-level rise, which trapped coarser clastic sediment within the hinterland. Biostratigraphy allows calculation of variations in sedimentation rates with recognition of: (1) an early rift phase characterised by sandy turbidite deposition, when sedimentation rates averaged 0.08 m/ky, (2) a rift climax phase from the Early Kimmeridgian where sedimentation rates increased steadily to a maximum of 0.64 m/ky in the Early Tithonian, with strata dominated by boulder scale clast-supported debris flows and (3) a late stage of rifting from the mid Tithonian, where sedimentation rates decreased to 0.07 m/ky. Overall sedimentation rates are comparable to those of other deep marine rift basins. Unroofing a resistant lithology on the footwall of a rift has important implications for siliciclastic sediment supply in rift basins

U2 - 10.1111/j.1365-2117.2012.00557.x

DO - 10.1111/j.1365-2117.2012.00557.x

M3 - Article

VL - 24

SP - 1

EP - 25

JO - Basin Research

JF - Basin Research

SN - 0950-091X

ER -