Joint reports

Geology and Geochemistry of Mud-Volcano Ejecta, Azerbaijan

  • The executive companies: GIA / EXXON
  • The year of publication: March 1999
  • Code: -
  • Volumes: total 1
    volumes with appendixes in same amount: 1


This report summarizes the results of a joijnt study between the Geology Institute of Azerbaijan and Exxon Ventures (CIS) Inc. The joint study investigated the geology of geochemistry of lithified ejecta brought to the surface by mud-volcanoes in the Gobustan area of Azerbaijan.

The main objectives of this study were to build a better understanding of the source rock depositional environmnets through the analysis of ejecta. These lithified rock fragments were analyzed in terms of their lithology, biostratigraphy, and organic geochemistry. Age-dated samples were placed in a regional and stratigraphic context.

Lithoclasts brought to the surface by erupting mud-volcanoes offer a unique opportunity to characterize the sedimentary section which is generally too deep to be sampled by conventional drilling. The mud-volcanoes in the Gobustan area of Azerbaijan are rooted within the Oligocene-Miocene section of the Maikop Formation. In the context of pertoleum exploration, the lithified rock fragments brought to the surface offer the following:

  • Reconstruction, through biostratigraphic and lithologic analyses, of the sedimentary section beyond present-day drill depths;
  • Assessment of the source rock potential of organic-rich rocks;
  • Assessment of the thermal maturity level of the sedimentary section, and
  • Opportunity for regional and vertical mapping of rock properties

    The conclusions of the present study are:

    • The mud-ejecta samples are immature to early mature with respect to hydrocarbon generation;
    • With a geothermal grdaient of 200C/km, the early mature ejecta-samples are likely derived from about 4 km depth. (This applies for samples GIA-18 (Koun/M.Paleogene) and GIA-76 (Maikop), from the Osmanbozdag and Boyuk Kamizadag mud-volcanoes, respectively).
    • Organic sulfur contents are low. Free sulfur present in the depositional environment from early sulfate reduction has mostly bound with iron to form pyrite. The results are generation of sweet crudes and gases.
    • The Maikop samples are, for the most part, dominated by algal organic matter as evidenced by visual kerogen and biomarker analyses. As with the Maikop outcrops, the lithology and organic matter content of the Maikop can vary significantly from laminated shales to sandstones and marine algal to herbaceous and terrigenous organic matter.
    • Based on the geochemistry results, it apperas that the Maikop section envolved from an overall transgressive system during early to Middle Maikop (shorelines moved further away from our sampling points), followed by a highstanding system Late Maikop and Upper Miocene (shorelines, amd associated terrigenous input, closer to our sampling sites).


    Geology and Geochemistry of Mud-Ejecta Samples

    Study Objectives
    Mud Volcanoes
    Significance of Mud-Ejecta


    Geological and Geochemical Analyses

    Results and Discussion

    Ejecta Database
    Ejecta Lithology
    Evaluation of Data Integraty
    Evaluation of HC staining
    Organic Richness and Quality
    Organic Matter Quality and Maturity
    Sulfur Analytical Data
    Timing of HC Generation


    Appendix A: Modeled Stratigraphic Sections at Mud-Volcano Localities


    Appendix B: Photographs of Mud-Ejecta (photos of analyzed rocks with age and their type dating)


    Appendix C: Thin Section Photographs and Descriptions


    Appendix D: Pyrograms from Rock Eval Pyrolysis


    Appendix E: Photographs of Kerogen Concentrates


    Appendix F: Solvent Extraction Data


    Appendix G: Pyrograms from Pyrolysis-GC


    Appendix H: Gas Chromatograms of the Saturate Fraction of the Extractable Organic Matter


    Appendix I: GC / MS (Biomarker) data of the Saturate Fraction of the Extractable Organic Matter


    Appendix J: Kinetics Data