Logged in as: Anonymous User sign in
Research_banner
Csl_research
 
Printer Friendly Format

 

Geobiology, Geochemistry and Diagenesis of Carbonates

Diagenesis continuously alters carbonate rocks and consequently their petrophysical properties. Our research projects have thus a double focus; one to understand the diagenetic processes, and two, to relate the diagenetic alterations to the resulting rock properties. 
Modern sediments on Great Bahama Bank and elsewhere provide baseline information about the geochemical signature of “unaltered” carbonate platform sediments. Cores from the shallow subsurface along the western margin of Great Bahama Bank and in Florida document the effects of early diagenesis on porosity, velocity, and permeability in platform carbonates and grainstone shoal complexes in particular. The geochemical studies of the dolomites and limestones from deeper cores on Great Bahama Bank and the Marion Plateau are ideal to examine the influence of burial diagenesis on the petrophysical properties and to assess the fluid flow in isolated carbonate platforms. Deeply buried rocks that were later uplifted such as the Mississippian Madison Formation underwent several episodes of diagenesis from shallow to deep burial. Our current geochemical projects in this formation try to unravel these different episodes and to document the importance of each event on the reservoir quality of the formation. In addition, we test the applicability of geochemical tracers, in particular δ13C for the stratigraphic correlation of the widely spaced section in Wyoming and Idaho and to other sections around the world.

Current Projects



MICROBIAL MEDIATION ON EARLY CEMENTATION PROCESSES

Diaz_et_al

Project Media
     
Diaz_et_a...2020.pdf
Media Type:Media Type
File Size:749KB

 

Investigators: Mara R. Diaz, Ralf J. Weger, and Gregor P. Eberli

Project Objectives:

  • To elucidate whether initial stabilization and cementation of carbonate grains are mediated by microbial interactions of indigenous microbial communities.
  • To study whether EPS exudates play an imminent role in the early stages of sediment stabilization and cementation by cohering sediment particles and providing a template for nucleation to occur.
  • To identify textural forms and mineral microstructure composition of early marine cementation areas using petrographic thin-sections, SEMEDS and X-Ray diffraction analyses.

 



     

EXPLORING SIGNATURES OF DIAGENESIS USING ROLLING WINDOW REGRESSION

Oehlert___Swart

Project Media
     
Oehlert__...2020.pdf
Media Type:Media Type
File Size:494KB

 

Investigators: Amanda M. Oehlert and Peter K. Swart

Project Objectives:

  • Analyze trace metals and REE concentrations in Clino, San Salvador, and Enewetak cores.
  • Examine zones of diagenetic alteration and diagenetic surfaces using Rolling Window Regression Analysis.
  • Expand characterization of geochemical signatures unique to specific diagenetic processes in marine carbonates.
  • Evaluate impacts of oceanography, sea level, and climate on diagenetic zones.


     

CENOZOIC EXPRESSION OF ROLLING WINDOW REGRESSION IN MARINE CARBONATES AROUND THE GLOBE

Oehlert_et_al_2

Project Media
     
Oehlert_e...20_2.pdf
Media Type:Abstract
File Size:216KB

 

Investigators: Amanda M. Oehlert, Megan E. Smith, Colleen Brown, and Peter K. Swart

Project Objectives:

  • Evaluate RWR trends in geochemical parameters (stable isotopes, trace elements) from:
    • Shallow marine environments
      • Clino, Unda, Enewetak, San Salvador.
    • Periplatform settings
      • Great and Little Bahama Banks, Maldives.
    • Pelagic Environments
      • Walvis Ridge, Nicaraguan Rise, Queensland Plateau, Madingley Rise.
  • Assess the utility of RWR in chemostratigraphic correlations, biogeochemical cycling, and reconstruction of diagenetic events in a range of Cenozoic depositional environments.

 



     

COMPARISON OF ISOTOPIC PATTERNS IN THE PACIFIC AND ATLANTIC: C AND O

Swart_et_al

Project Media
     
Swart_et_...2020.pdf
Media Type:Media Type
File Size:1MB

 

Investigators: Peter K. Swart, Megan Smith, Amanda M. Oehlert, and Colleen Brown

Project Objectives:

  • Determine the role of global sea-level changes in controlling patterns in C and O isotopic composition of bulk carbonates and C isotopic composition of organic material.

 



     

COMPARISON OF ISOTOPIC PATTERNS IN THE PACIFIC AND ATLANTIC: S, Δ47, AND B

Moore___Swart

Project Media
     
Moore___S...2020.pdf
Media Type:Media Type
File Size:259KB

 

Investigators: Evan Moore and Peter K. Swart

Project Objectives:

  • Compare changes in S (δ34S), B (δ11B), and clumped isotopes (Δ47 and Δ48) in diagenetically altered material from the Atlantic (Bahamas) and the Pacific (Enewetak).


     

TWIN CLUMPED PROXIES AND BEYOND: A NEW CLUMPED ISOTOPE PROXY, Δ48

Swart___Lu

Project Media
     
Swart___L...2020.pdf
Media Type:Media Type
File Size:159KB

 

Investigators: Peter K. Swart and Chaojin Lu

Project Objectives:

  • To determine the rates of change in the Δ48 value in carbonate minerals relative to changes in the Δ48 value during heating and cooling for the purposes of geospeedometry. This allows the determination of the burial history of carbonate containing rocks. 
  • Improve the calibration between temperature and Δ48 values.


     

BURIAL HISTORY OF RESERVOIR STRATA USING TWIN CLUMPED ISOTOPES: Δ48 AND Δ47

Swart_et_al_2

Project Media
     
Swart_et_...20_2.pdf
Media Type:Media Type
File Size:153KB

 

Investigators: Peter K. Swart, Chaojin Lu, Ralf J. Weger, and Gregor P. Eberli

Project Objectives:

  • Apply clumped isotope methods to diagenetic and ‘original’ carbonate material from a range of different sedimentary basins in order to ascertain burial history.



     
 

 

 

||©Comparative Sedimentology Laboratory 2004||