Lecture 6 Thrust Systems PDF
Document Details
Uploaded by ExtraordinaryCubism
University of Benghazi
2024
C. Jackson
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Summary
This lecture provides an overview of thrust tectonic settings and associated structural elements. Topics of interest include thrust fault settings, continental collision settings, subduction and gravitational systems. The lecture also covers different styles of faults and folds, including diagrams and examples to illustrate the concepts.
Full Transcript
28/01/2025 University of Benghazi Faculty of Science Department of Earth Sciences Advanced Structural Geology GEOL 6501 – MSc 6. Thrust Tectonic Settings Dr. Awad Bilal Fall 2024 C...
28/01/2025 University of Benghazi Faculty of Science Department of Earth Sciences Advanced Structural Geology GEOL 6501 – MSc 6. Thrust Tectonic Settings Dr. Awad Bilal Fall 2024 C. Jackson Extensional or Contractional Contractional fault – Forms due to shortening of the layers – Rock units become duplicated – Includes reverse and thrust fault Extensional fault – Forms due to lengthening of a layer – Involves loss of stratigraphic section – Includes normal fault 1 28/01/2025 Extensional & contractional Faults 2 28/01/2025 Thrust fault tectonic settings Subduction: accretionary prisms Continental collision settings Iinversion orogens Gravitational / deepwater fold-thrust belts Thrust setting: Thrust fault systems Thrust fault-related folding 3 28/01/2025 Contractional Structure Nomenclature fault-related fold (hangingwall anticline) fault-related fold (footwall syncline) fault tip shortening thrust (flat) slide courtesy of Lidia Lonergan C. Jackson Fault-Related Fold Types Fold type can evolve through time with increasing displacement… Detachment fold 4 28/01/2025 5 28/01/2025 6 28/01/2025 7 28/01/2025 8 28/01/2025 9 28/01/2025 Thick-skinned FTB – subsurface interpretation 10 28/01/2025 Tracing horizons and identifying detachments will help you find faults… 11 28/01/2025 Tracing horizons and identifying detachments will help you find faults… Thrust, Flat, Ramp and Folds Tracing horizons and identifying detachments will help you find faults… 12 28/01/2025 Thrust, Flat, Ramp and Folds Shortening results in formation of forward- propagating (‘in- sequence’) thrusts that get younger towards the foreland; older thrusts passively transported in hangingwall of younger thrusts 13 28/01/2025 14 28/01/2025 15 28/01/2025 Growth Strata synkinematic prekinematic Shaw (2005) C. Jackson Growth Strata C. Jackson 16 28/01/2025 Growth Strata Shaw (2005) Which thrust was most recently active? Can you work out which one moved first? C. Jackson Fault‐related fold styles and progressions in fold‐thrust belts: Insights from sandbox modeling JGR Solid Earth, Yan et al. 2016, DOI: (10.1002/2015JB012397) 17 28/01/2025 Detachment folding 18 28/01/2025 Detachment folding Detachment folding 19 28/01/2025 20 28/01/2025 Fault propagation folding, Hammersley Range, Western Australia 21 28/01/2025 22 28/01/2025 23 28/01/2025 24 28/01/2025 25 28/01/2025 Seismic Imaging and Uncertainty Niger Delta, offshore Nigeria Exercises 26
