PASSIVE MODE

1
PASSIVE MODE
SALT DOES NOT ACTIVELY DEFORM SEDIMENT. MOST
FEATURES ARE ATTRIBUTED TO SALT WITHDRAWAL.
ACTIVE MODE
SALT ACTIVELY PUSHES SEDIMENT COVER OUT OF THE
WAY AS I TRIES TO RISE TO THE SAE FLOOR.
2
VERTICAL MOTION

• FORCE
• DEFFERENTIAL LOADING OR DENSITY DIFFRENCES

RESULTANT SALT DOMES SALT DIAPIRS SHALE DOMES
3
FAULT RECOGNITION

• ABRUPT TERMINATION OF REFLECTION
• OFFSET OF A REFLECTION
• DIFRACTION
• CHANGE IN RELECTION PATTERN
• CHANGE IN DIP
• CHANGE IN FREQUENCY
• DISTORTION OF DATA BELOW FAULT
• - VELOCITY ANOMALY
• - SHADOW ZONE
• REFLECTION FROM FAULT PLANE

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4
NORMAL FAULTS

• HORST AND GRABEN
• TITLED BLOCKS
• HIGH ANGLE SAMPLE FAULTS
• UNCONFORMITY ON PRE-FAULT SEDIMENTS
• STRUCTURES ANGULAR IN CROSS SECTION
• FAULTS DIP TOWARD UPLIFT
• DRAPE COMMON
• DRAG ON DOWNSIDE OF FAULTS
• FAULTS RELAY, ZIG-ZAG IN MAP VEIW
• DIFRACTIONS ON DOWNSIDE OF FAULTS
• OFTEN HIDDEN BY OVERLYING STRUCTURE

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UPTHRUST FAULTS

• FAULT FORMS ZONE OF INTENSE DEFORMATION
• BLOCKY AWAY FROM FAULT
• FAULT IS HIGH ANGLE - MAY SPLIT OUT
• ONE PERIOD OF MOTION
• STRUCTURES PARALLEL FAULTS
• STRUCTURES ANGULAR IN CROSS SECTION
• GRAVITY AND MAGNATIC EXPRESSION PROBABLE

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EN ECHELON FOLDS AND FAULTS

• STRUCTURES AT ANGLE TO THRUOGH-GOING FAULTS
• STRUCTURES ASYMMETRICAL
• ANTICLINES PREDOMINATE
• FAULT-STRUCTURE RELATION CHANGES LINE TO LINE
• FAULTS VERY HIGH ANGLE
• FAULTS SPLY UPWARD INTO SHALLOWER BEDS
• THROUGH-GOING FAULT GENERALLY NOT SEEN
• EXTENSIONAL FAULTS MAY DEVELOP ON CRESTS
• GRAVITY AND MAGNETICS MAY SHOW

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FLOWER STRUCTURES

• PARALLEL THROUGH-GOING FAULT
• DIE OUT DOWNWARD
• COMPOSED OF COMPLEX PATTEN OF ABERRANT WEDGES
• FAULTS NEARLY VERTICAL BUT SPLAY OUT UPWARD
• STRUCTURE -FAULT RELATION CHANGES LINE TO LINE
• STRUCTURING DIES UOT ABRUPTLLY
• ANTICLINES PREDOMINATE
• DIFRACTIONS COMMON
• GRAVITY AND MAGNATICS MAY SHOW

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8
FOLD AND THRUST BELT ROLES

• COMPRESSIONAL AND DETACHED
• DOMINANT VERGENCE DIRECTION
• OUTWARD DEVELOPMENT OF THRUST SHEEETS
• THRUSTS OUT UPSECTION IN DIRECTION OF TRANSPORT
• THRUST BRING OLDER ROCKS OVER YOUNGER ROCKS
• EXISTENCE OF PREFERRED DETACHMENTS IN SECTION
• EXISTENCE OF A REGOINAL TECTONIC LEVEL

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COMPATIBILITY WITH GRAVITY DATA
A GEOLOGICAL MODEL THAT IS COMPATIBLE WITH THE
OBSERVED GRAVITY DATA IS POSSIBLY CORRECT. A
GEOLOGICAL MODEL WHOSE GRAVITY EXPONSE DISAGREES
WITH THE OBSERVED GRAVITY DATA IS DEFINITELY
WRONG.
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SALT STRUCTURES
INTRODUCTION TYPES OF STRUCTURES AND TRAPS 1.
CLASSIFICATION 2. VARIATIONS DUE TO GROWTH
HISTORY 3. DETACHED NORMAL FAULTS SEISMIC
INTERPRETATION 1. REFLECTION QUALITY 2.
INTERNAL SEISMIC CHARACTER OF SALT 3. WHAT TO
USE WITHOUT SALT REFLECTION 4. DOME WITH SHADOW
DOME 5. INTERPRETATION PROBLEMS
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SALT FEATURE
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SUMMARY OF HYDROCARBONE TRAPS RELATED TO SALT
PILLOW

• A TRAP IS A DOUBLY-PLUNGING ANTICLINE
• STRTIGRAPHIC COMPLICATIONS ONLAP, LOSS OF
  SECTION ON TO CREST VARATION BETWEEN FAULT
  BLOCKS
• STRUCTURAL COMPLICATIONS COMPLEX TRAP
  SEGMENTATION BY FAULTS FAULT SEAL

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SALT STRUCTURES
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