Palaeoenvironmental control on multi-scale vertical and lateral heterogeneities within a Triassic - Jurassic carbonate ramp system (Musandam Peninsula)
File(s)
Author(s)
Honig, Martin Robert
Type
Thesis
Abstract
Sedimentologic heterogeneities in carbonate systems are caused by various
processes during and after deposition and can have a profound influence on
reservoir properties relevant for hydrocarbon recovery or carbon storage. This
study is focussed on examining and quantifying sedimentologic heterogeneities
on an equatorial, Triassic-Jurassic, Middle Eastern, epeiric carbonate ramp
(Musandam Peninsula, UAE and Oman) at the regional scale (~ 45 km), the
‘inter-well’ scale (~ 1.9 km) and the metre- to tens of metres scale (~120 m).
The stratigraphic ages of the examined strata were refined using a combination
of the existing biostratigraphic framework and chemostratigraphic analysis
(stable carbon and radiogenic strontium isotopes). Results suggest that the
regional architecture and carbonate factory evolution across the Triassic-
Jurassic boundary was mainly governed by relative sea level changes and not
affected by ocean acidification in the equatorial region. Lithofacies types were
deposited and are preserved as facies mosaics on the shallow-marine
carbonate ramp, despite an overall ‘layer-cake’ type bedding pattern.
Geostatistical analysis reveals that facies have a probability of 60 % of being
laterally discontinuous over distances between 220 and 1100 m on the shallowmarine
carbonate ramp. The comparison with other preserved facies mosaics
as well as with modern analogous systems suggests that the large amount of
lateral facies variability, also observed within individual beds at the metre-scale,
is a result of the combination between locally heterogeneous carbonate
production as well as of coeval mixing and re-sedimentation processes. The
combination of laterally heterogeneous facies types and vertical exposure
stages is likely the result of constant autocyclic mixing and re-shuffling of grains
within the shallow-marine EOD and allocyclic changes in relative sea level. This
study highlights the capability of neritic carbonate successions to archive
palaeoceanographic changes in deep time as well as to preserve small-scale
facies mosaics.
processes during and after deposition and can have a profound influence on
reservoir properties relevant for hydrocarbon recovery or carbon storage. This
study is focussed on examining and quantifying sedimentologic heterogeneities
on an equatorial, Triassic-Jurassic, Middle Eastern, epeiric carbonate ramp
(Musandam Peninsula, UAE and Oman) at the regional scale (~ 45 km), the
‘inter-well’ scale (~ 1.9 km) and the metre- to tens of metres scale (~120 m).
The stratigraphic ages of the examined strata were refined using a combination
of the existing biostratigraphic framework and chemostratigraphic analysis
(stable carbon and radiogenic strontium isotopes). Results suggest that the
regional architecture and carbonate factory evolution across the Triassic-
Jurassic boundary was mainly governed by relative sea level changes and not
affected by ocean acidification in the equatorial region. Lithofacies types were
deposited and are preserved as facies mosaics on the shallow-marine
carbonate ramp, despite an overall ‘layer-cake’ type bedding pattern.
Geostatistical analysis reveals that facies have a probability of 60 % of being
laterally discontinuous over distances between 220 and 1100 m on the shallowmarine
carbonate ramp. The comparison with other preserved facies mosaics
as well as with modern analogous systems suggests that the large amount of
lateral facies variability, also observed within individual beds at the metre-scale,
is a result of the combination between locally heterogeneous carbonate
production as well as of coeval mixing and re-sedimentation processes. The
combination of laterally heterogeneous facies types and vertical exposure
stages is likely the result of constant autocyclic mixing and re-shuffling of grains
within the shallow-marine EOD and allocyclic changes in relative sea level. This
study highlights the capability of neritic carbonate successions to archive
palaeoceanographic changes in deep time as well as to preserve small-scale
facies mosaics.
Version
Open Access
Date Issued
2016-07
Date Awarded
2016-11
Copyright Statement
Attribution NoDerivatives 4.0 International Licence (CC BY-ND)
Advisor
John, Cedric
Sponsor
Qatar Petroleum
Shell
Qatar Science & Technology Park
Publisher Department
Earth Science & Engineering
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)