Logging Clastics

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Logging Clastics

• Depth Scale
• Contacts
• Grain Size
• Rock Type
• Bioturbation
• Color
• Fossils and Sedimentary Structures
• Comments

Text Manual, p. 21-27 Compton, Ch. 11 p.
376-378
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Logging Clastics
Goals

• To accurately and graphically represent
• Thicknesses of rock types.
• Detailed, sequential descriptions.
• Exact stratigraphic position of rock types,
• sedimentary structures, and fossils.

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Logging Clastics
http//sealevel2.jpl.nasa.gov/
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Logging Clastics
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Logging Clastics
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Logging Clastics

• Depth Scale
• Contacts
• Grain Size
• Rock Type
• Bioturbation
• Color
• Fossils and Sedimentary Structures
• Comments

Text Compton, Ch. 11 p. 376-378
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Depth Scale

• Calculate total depth and appropriate scale /
  units

Deepest (bottom) ? Shallowest (top)
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Contacts

• Mark major contacts
• Determine nature of contacts (sharp,
  gradational, erosional)

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Contacts
S Sharp G Gradational SI Sharp irregular B
Gradational-interbedded SC Sharp
conformable VS Visibly scoured SD Sharp
disconformable BU Burrowed ST Stylolite
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Grain Size

• Determine grain size between major contacts.
• Plot weathering profile of gravelsandmud.

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Grain Size
Weathering Profile
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Logging Clastics

• Depth Scale
• Contacts
• Grain Size
• Rock Type
• Bioturbation
• Color
• Fossils and Sedimentary Structures
• Comments

Text Manual, p. 21-27 Compton, Ch. 11 p.
376-378
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Rock Type

• Determine rock type(s) and fill in patterns

(see Compton, p. 376-377)
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Rock Type
(Manual, p. 92)
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Bioturbation

• Determine extent of bioturbation

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Color

• Indicate color with letter symbols.

L - Light G - Gray C - Cream M - Medium B -
Brown W - White D - Dark R - Red Bk - Black m -
Mottled O - Orange Cl - Clear Y - Yellow Gn
- Green Bl Blue
Example LBG light brownish gray
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Logging Clastics

• Depth Scale
• Contacts
• Grain Size
• Rock Type
• Bioturbation
• Color
• Fossils and Sedimentary Structures
• Comments

Text Manual, p. 21-27 Compton, Ch. 11 p.
376-378
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Fossils and Sedimentary Structures

• Indicate fossils and sedimentary structures

(Manual p. 21a)
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Fossils and Sedimentary Structures
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Fossils and Sedimentary Structures
Carbonate Structures
(Manual, p. 94)
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Comments

• Include comments of features not depicted
  graphically
• - soil horizons
• - organics
• - accessory minerals
• - cements
• - porosity

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Examples
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Examples
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Examples
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Examples