James r ebert damon k matteson suny college at oneonta
Download
1 / 22

James R. Ebert Damon K. Matteson SUNY College at Oneonta - PowerPoint PPT Presentation


  • 92 Views
  • Uploaded on
  • Presentation posted in: General

PRELIMINARY SEQUENCE AND EVENT STRATIGRAPHIC CORRELATIONS WITHIN THE HELDERBERG GROUP (SILURIAN-DEVONIAN) BETWEEN NEW YORK AND THE CENTRAL APPALACHIAN BASIN. James R. Ebert Damon K. Matteson SUNY College at Oneonta. New York: Appalachian Standard Succession.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha

Download Presentation

James R. Ebert Damon K. Matteson SUNY College at Oneonta

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


PRELIMINARY SEQUENCE AND EVENT STRATIGRAPHIC CORRELATIONS WITHIN THE HELDERBERG GROUP (SILURIAN-DEVONIAN) BETWEENNEW YORK AND THE CENTRAL APPALACHIAN BASIN

James R. Ebert

Damon K. Matteson

SUNY College at Oneonta


New York: Appalachian Standard Succession

  • Late nineteenth and early twentieth century studies

  • Johnson and Murphy (1969)

  • Helderberg Group

  • Silurian-Devonian

    • Přídolí-Lochkovian

    • Predominantly limestone

    • Some shaly units


Primacy of New Yorkin the Early Literature

  • Early Twentieth Century Stratigraphy and Correlations to New York based on:

    • General lithologic similarities

    • Faunal similarities

  • Names from New York applied from New Jersey to Virginia – the Central Appalachian Basin (CAB)


A New View of Helderberg Stratigraphy

  • Rickard (1962) - migrating coeval facies

  • Laporte (1969) – spectrum of ramp environments


Rickard’s Stratigraphy and the Role of the Appalachian Standard Succession

  • Rickard’s (1962) migrating coeval facies influences correlations

    • in the CAB

    • between NY and the CAB

  • Head (1969, 1972, 1974)

  • Dorobek (1984), Dorobek and Read (1986)


Revised Helderberg Stratigraphy – New YorkEbert and Matteson (2003a,b)


Rationale for Revised Stratigraphy

  • Contacts are unconformable

  • Clarifies placement of the S/D boundary based on conodonts


New Questions in a Classic Setting

  • How does the presence of unconformities in NY affect correlations within the CAB and between NY and the CAB?

  • Are these unconformities widespread? Can they be recognized in the CAB and used as a framework for correlation?

  • What are the relative roles of eustatic and tectonic processes in producing the unconformities?

  • Can basin-wide revision of Helderberg stratigraphy provide new insights on global sea level change around the S/D boundary?


Framework for Stratigraphic Correlations

  • Working model of early correlations

  • Examination of contacts

    • Evidence of erosion

    • Evidence of sediment starvation

  • Biostratigraphic data – FAD Icriodus woschmidti

  • Unique faunal occurrences - Scyphocrinites

  • Recognition of events and marker beds

    • Distinctive facies/lithologies - two

    • Episodes of siliciclastic influx

    • Trangressive maxima - two

    • Bald Hill K-bentonites


Sequence 1: Manlius/Lower Keyser


Sequence 2:Green Vedder/Big Mountain Shale


First Transgressive Maximum and Siliciclastic-bearing Units


Sequence 3: Dayville/U. Manlius/U. Keyser


Sequence 4: Coeymans/New Creek

First Icriodus woschmidti - Silurian/Devonian Boundary

HCU is erosional throughout the basin


Sequence 5:

Kalkberg/Corriganville


An Undiscovered Unconformity in NY?

?


Bald Hill K-bentonites

Basin-wide markers

(Smith, Berkheiser and Way 1986)

Age of S/D Boundary - 418 Ma

(Tucker, et. al. 1998)


Second Transgressive Maximum


Conclusions

  • NY unconformities can be traced into CAB

  • Most unconformities in NY are erosional

  • Most in the CAB are marked by sediment starvation

  • Minelot Falls/Tonoloway-Keyser Unconformity and Howe Cave Unconformity are erosional throughout basin

  • A Přídolí transgressive maximum is now recognized

  • Sequence and event stratigraphic correlations between NY and the CAB are similar to those proposed in the early twentieth century

  • Correlations are preliminary; much more work needs to be done!


ad
  • Login