24-Pet-A1 Principles of Stratigraphy and Sedimentation · May 2016
Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)
EGBC National Exam — Petroleum Engineering, 98-Pet-A1 Principles of Stratigraphy & Sedimentation, 2016-May. 3 hours duration; closed book, no calculator permitted. The paper has two parts: Part 1 (Questions 1–12, Sedimentology and Sedimentary Processes – 10 marks each; answer any eight of the twelve, 80 marks total) and Part 2 (Questions 13–20, Stratigraphy and Sedimentary Basin Analysis – 10 marks each; answer any five of the eight, 50 marks total) – a 130-mark maximum (80 for Part 1 + 50 for Part 2).
Reference texts: Boggs, S. Jr., Principles of Sedimentology and Stratigraphy, 5th ed., Pearson (grain texture, sediment transport, bedforms, carbonate/evaporite systems, sequence stratigraphy, unconformities, stratigraphic principles); Tucker, M.E., Sedimentary Petrology, 3rd ed., Blackwell (carbonate classification, diagenesis, dolomitization); Nichols, G., Sedimentology and Stratigraphy, 2nd ed., Wiley-Blackwell (fluvial systems, sequence stratigraphy, stratigraphic units); Reading, H.G. (ed.), Sedimentary Environments: Processes, Facies and Stratigraphy, 3rd ed., Blackwell (facies models, trace fossils, coastal processes); Selley, R.C. & Sonnenberg, S., Elements of Petroleum Geology, 3rd ed., Academic Press (source rocks, basin classification, reservoir quality); International Commission on Stratigraphy, International Chronostratigraphic Chart (geological time scale).
Question text not reproduced: the examination questions are © Engineers and Geoscientists BC. Open the official past paper (linked at the top of this page) to read the question, then follow the worked solution below.
(a) Definitions. A chronostratigraphic unit is a body of rock strata that was formed during a specific interval of geologic time; it is a material (rock) unit, bounded by time-planes (isochronous surfaces), and is defined and recognized from the rock record itself (e.g., "the Jurassic System" is the body of rock deposited during the Jurassic Period). A geochronologic unit is the corresponding abstract interval of geologic time itself – not rock, but the span of time during which the equivalent chronostratigraphic unit was deposited (e.g., "the Jurassic Period" is the time interval, independent of whether any rock happens to be preserved from it in a given place).
(b) Ranks.
| Chronostratigraphic unit (rock) | Geochronologic unit (time) |
|---|---|
| Eonothem | Eon |
| Erathem | Era |
| System | Period |
| Series | Epoch |
| Stage | Age |
| Chronozone | Chron |
