uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Distribution of diagenetic alterations in  within depositional facies and sequence stratigraphic framework of  fluvial sandstones: Evidence from the Petrohan Terrigenous Group, Lower Triassic, NW Bulgaria
Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
Show others and affiliations
2009 (English)In: Marine and Petroleum Geology, ISSN 0264-8172, E-ISSN 1873-4073, Vol. 26, no 7, 1212-1227 p.Article in journal (Refereed) Published
Abstract [en]

Sequence stratigraphy of fluvial deposits is a controversial topic because changes in relative sea level will eventually have indirect impact on the spatial and temporal distribution of depositional facies. Changes in the relative sea level may influence the accommodation space in fluvial plains, and hence have impact on types of fluvial system, frequency of avulsion, and style of vertical and lateral accretion. This study aims to investigate whether depositional facies and changes in the fluvial system of the Lower Triassic Petrohan Terrigenous Group sandstones (NW Bulgaria) in response to changes in the relative sea level have an impact on the spatial and temporal distribution of diagenetic alterations. Eogenetic alterations, which were encountered in the fluvial sandstones, include: (i) mechanically Infiltrated clays, particularly in channel and crevasse splay sandstones towards the top of the owstand systems tract (LST) and the base of the highstand systems tract (HST). (ii) Pseudomatrix, which resulted from mechanical compaction of mud intraclasts, occurs mainly in channel sandstones at the base of the LST and towards the top of the HST and thus led to porosity and permeability deterioration. (iii) Calcite (delta O-18(VPDB)= -8.1 parts per thousand to -7.5 parts per thousand and delta C-13(VPDB) = -7.87 parts per thousand to -6.3 parts per thousand) and dolomite (delta O-18(VPDB) = -8.3 parts per thousand to -5.2 parts per thousand and delta 13C(VPDB) = -8.3 parts per thousand to -7.1 parts per thousand), which are associated with palaeosol horizons developed on top of crevasse splay and channel sandstones of transgressive systems tract (TST) and LST: Such extensive eogenetic calcite cements may act as potential layers for the formation of reservoir compartments for underlying sandstones. Mesogenetic alterations include: (i) calcite (delta O-18(VPDB) = -18.4 parts per thousand to -12.8 parts per thousand and delta C-13(VPDB) = -8.6 parts per thousand to -6.8 parts per thousand) and dolomite (delta O-18(VPDB) = -14.7 parts per thousand to - 12.4 parts per thousand and delta C-13(VPDB) = -8.0 parts per thousand to -7.0 parts per thousand), which were formed in all depositional facies and systems tract´sandstones, (ii) illite, which is the dominant diagenetic clay mineral in all depositional facies and systems tracts, was associated with albitization of detrital K-feldspars, and (iii) quartz overgrowths, which are most abundant in TST rather than LST and HST sandstones, because of the presence of suitable infiltrated clays and pseudomatrix in the latter sandstones. Such cementation by calcite, dolomite, and quartz overgrowths and formation of illite led to porosity and permeability deterioration during mesodiagenesis. The results of this study revealed the importance of integration of diagenesis with depositional facies and sequence stratigraphy of fluvial sandstones in improving our ability to predict the spatial and temporal distribution of eogenetic alterations and their subsequent impact on mesogenetic alterations, and thus on reservoir quality modifications.

Place, publisher, year, edition, pages
2009. Vol. 26, no 7, 1212-1227 p.
Keyword [en]
Diagenesis, Fluvial sandstones, Sequence stratigraphy, Lower Triassic (NW Bulgaria)
National Category
Earth and Related Environmental Sciences
Identifiers
URN: urn:nbn:se:uu:diva-93827DOI: 10.1016/j.marpetgeo.2008.08.003ISI: 000267143700014OAI: oai:DiVA.org:uu-93827DiVA: diva2:167428
Available from: 2005-11-22 Created: 2005-11-22 Last updated: 2017-12-14Bibliographically approved
In thesis
1. Diagenesis and Sequence Stratigraphy: Predictive Models for Reservoir Quality Evolution of Fluvial and Glaciogenic and Non-glaciogenic, Paralic Deposits
Open this publication in new window or tab >>Diagenesis and Sequence Stratigraphy: Predictive Models for Reservoir Quality Evolution of Fluvial and Glaciogenic and Non-glaciogenic, Paralic Deposits
2005 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Development of a predictive model for the distribution of diagenetic alterations and related evolution of reservoir quality of sandstones was achieved by integrating the knowledge of diagenesis to sequence stratigraphy. This approach allows a better elucidation of the distribution of eogenetic alterations within sequence stratigraphy, because changes in the relative sea level induce changes to: (i) pore water chemistry, (ii) residence time of sediments under certain near-surface geochemical conditions, (iii) variations in the detrital composition, and (iv) amounts and type of organic matter.

This thesis revealed that eogenetic alterations, which are linked to sequence stratigraphy and have an impact on reservoir quality evolution, include formation of: (i) pseudomatrix and mechanically infiltrated clays in fluvial sandstones of the lowstand and highstand systems tracts (LST and HST, respectively), (ii) kaolinite in tide-dominated deltaic and foreshore-shoreface sandstones of HST, Gilbert-type deltaic sandstones of LST and fluvial deltaic sandstones of LST, (iii) kaolinite and mechanically infiltrated clays in sandstones lying below sequence boundary, (iv) K-feldspar overgrowths in fluvial deltaic LST, (v) glaucony towards the top of fluvial deltaic LST immediately below and at transgressive surface (TS) and in foreshore and shoreface transgressive systems tracts (TST) below parasequence boundaries (PB) and maximum flooding surface (MFS), (vi) framboidal pyrite and extensive cementation by calcite and dolomite in foreshore and shoreface and tide-dominated deltaic TST, and shoreface and tidal flat HST bioclastic-rich arenites particularly in the vicinity of PB, TS and MFS, (vii) pervasive cementation by iron oxide in shoreface-offshore and shoreface sandstones of TST immediately below the MFS, (viii) zeolites and palygroskite in shoreface sandstones of TST and HST, particularly above PB, and (ix) cementation by siderite in Gilbert-type deltaic sandstones of LST, tide-dominated deltaic and foreshore-shoreface sandstones of HST and in tide-dominated deltaic sandstones of TST, particularly at MFS. Moreover, this thesis revealed that the distribution of eogenetic alterations strongly control, and thus provide information for constraining the distribution patterns of mesogenetic alterations, such as illitization of mechanically infiltrated clays and dickitization of kaolinite, and hence of related reservoir quality evolution of sandstones during progressive burial.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2005. 65 p.
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 127
Keyword
Earth sciences, Siliciclastic diagenesis, Sequence stratigraphy, Glacial and non-glacial, Fluvial, Paralic and shallow marine, Geovetenskap
National Category
Earth and Related Environmental Sciences
Identifiers
urn:nbn:se:uu:diva-6179 (URN)91-554-6415-7 (ISBN)
Public defence
2005-12-12, Hambergsalen, Geocentrum, Villavägen 16, Uppsala, 10:15
Opponent
Supervisors
Available from: 2005-11-22 Created: 2005-11-22 Last updated: 2013-05-15Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text
By organisation
Department of Earth Sciences
In the same journal
Marine and Petroleum Geology
Earth and Related Environmental Sciences

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 600 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf