Stratigraphy Facies definition contacts and successions Walthers Law

Stratigraphy • Facies - definition - contacts and successions - Walther’s Law • Correlation - basis - examples • Name That Formation Text: Manual p. 29 -35

Facies: Definition • Aspects of a rock that characterize it. • Mappable, aerially restricted part of a lithostratigraphic body that differs from it coeval equivalents. • A distinctive rock type that is characteristic of a particular environment. • A body of rock distinguished on the basis of its fossil content.

Facies: Definition Environment: physical, chemical, biological conditions vs Facies: sediment properties - Lithofacies - Biofacies

Facies: Definition (AGI, 1999)

Facies: Definition Meandering Stream Facies (Boggs, p. 280)

Facies: Contacts (Boggs, p. 464)

Facies: Contacts intercalated gradual gradational abrupt Vertical Contacts Lateral Contacts intertonguing pinchout (Boggs, p. 453)

Transgressive Shelf Fining Upward Regressive Shelf Coarsening Upward Delta Coarsening Upward Fining Upward Meandering Stream Fining Upward Facies: Successions (Boggs, p. 260)

Facies: Walther’s Law: environmental relationship between lateral facies and vertically-stacked strata

Facies: Walther’s Law Transgression: landward movement of shoreline Regression: seaward movement of shoreline

Facies: Walther’s Law Facies Regression (Progradation) Time lines (E. Mc. Bride) Diachronous Lithostratigraphic Units

Facies: Walther’s Law http: //www. gpc. edu/~pgore/geology/historical_lab/stratigraphy. php

Facies: Walther’s Law

Facies: Walther’s Law http: //www. gpc. edu/~pgore/geology/historical_lab/stratigraphy. php

Stratigraphy • Facies - definition - contacts and successions - Walther’s Law • Correlation - basis - examples • Name That Formation Text: Manual p. 29 -35

Correlation • demonstrate that rocks at distant places are equivalent - lithology / stratigraphic position - fossil content - age*

9 miles Correlation Castille Formation, NM Types of Data: • Outcrop descriptions • Cores • Well Cuttings • Well Logs • Geophysical data (Anderson et al. , 1972)

Correlation

Correlation ≠ Matching

Correlation Basis of Correlation: 1. trace lateral continuity 2. lithology*

Correlation http: //www. gpc. edu/~pgore/geology/historical_lab/stratigraphy. php

Correlation Ir Ir (Boggs, p. 476) Ir Ir

Correlation

Correlation Marker Bed – Ash Fall http: //www. es. ucsc. edu/~pkoch/lectures/lecture 1. html

Correlation Basis of Correlation: 1. trace lateral continuity 2. lithology* 3. rock properties 4. stratigraphic successions

Correlation Stratigraphic Successions (Boggs, p. 479)

Correlation http: //www. gpc. edu/~pgore/geology/historical_lab/stratigraphy. php

Correlation Basis of Correlation: 1. trace lateral continuity 2. lithology* 3. rock properties 4. stratigraphic successions 5. fossil content

Correlation • • • index fossils principles of stratigraphy marker horizons geophysical properties geochemical properties http: //www. uwsp. edu/geo/faculty/ozsvath/images/stratigraphy. jpg

Correlation Basis of Correlation: 1. trace lateral continuity 2. lithology* 3. rock properties 4. stratigraphic successions 5. fossil content 6. chemical, magnetic, or geophysical properties

Correlation (Boggs, p. 483)

Correlation Fence Diagrams (416 M)

Correlation Fence Diagrams (Prothero and Schwab, p. 486)

Stratigraphy • Facies - definitions - contacts and successions - Walther’s Law • Correlation - basis - examples • Name That Formation Text: Manual p. 29 -35

Correlation: Examples

Correlation: Examples ? ?

Correlation: Examples ?

Correlation: Examples ?

Correlation: Examples

Stratigraphy • Facies - definitions - contacts and successions - Walther’s Law • Correlation - basis - examples • Name That Formation Text: Manual p. 29 -35

Name That Formation Lithostratigraphy Super Group Formation Member / Tongue / Lentil Tongue / Bed / Flow Formation: mappable rock body with distinct boundaries

K, L, M = members (Boggs, p. 662)

Name That Formation Define as: _____ Group _____ Formation _______ Member of _____ Formation _______ Lentil of ______ Formation _______ Tongue of ______ Member Bed of ______ Formation / Member * Formations can NOT interfinger. manual, p. 44