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                               Homerian ICS Stage
                                 (Lockportian)
 
                     From 426.2 +/- 2.4 To 422.9 +/- 2.5 Ma
 
  Start Defined By:  Graptolite, lowest occurrence of Cyrtograptus lundgreni.
  End Defined By:  Imprecise.  Just below base of local acritarch Leptobrachion 
     longhopense range zone.  May be near base of Neodiversograptus nilssoni 
     graptolite zone.
 
  Start Based On:  Gradstein, Ogg, Smith, _A Geologic Time Scale 2004_
  End Based On:  Gradstein, Ogg, Smith, _A Geologic Time Scale 2004_
 
  Global Stratotype Section and Point:  Whitwell Coppice, Homer, Shropshire, 
     southwest England, UK
 
 -- Overlaps With --
  Chinese Stage: Xiushanian (429 - 425.5)
  Chinese Stage: Guandian   (425.5 - 422)
 
 -- A Substage of --
  Eon:                  Phanerozoic    (542 - -5.5012e-005)
  Era:                  Paleozoic      (542 - 251)
  Period:               Silurian       (443.7 - 416)
  Epoch:                Early Silurian (443.7 - 422.9)
  Sub-Epoch:            Wenlock        (428.2 - 422.9)
  Australian Stage:     Melbournian    (428.2 - 416)
  North American Stage: Niagaran       (438 - 421.3)
 
 -- Preceeded By --
  ICS Stage: Sheinwoodian (428.2 - 426.2)
 
 -- Followed By --
  Epoch:     Late Silurian (422.9 - 416)
  Sub-Epoch: Ludlow        (422.9 - 418.7)
  ICS Stage: Gorstian      (422.9 - 421.3)
 
 -- Contains the Following Stages --
  Regional Stage: Whitwellian (426.2 - 425.4)
  Regional Stage: Gleedonian  (425.4 - 422.9)
 

This page was automatically generated from the GeoWhen database (version 1.1.0).  Please read the introduction regarding the accuracy and reliability of this information.  Comments, corrections, and additions can be sent to geowhen@robertrohde.com.  References to published academic literature are preferred.

Introduction

Geologic Timeline
(No Stages)

Geologic Timeline
(With Stages)

A-Z Stage List

Regional Information

Download Files


2003-2005 GeoWhen Database
Prepared By Robert A. Rohde


This page was last updated on Tuesday, January 18, 2005.