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                          Medinan North American Stage
 
                          From 443.7 +/- 1.5 To 438 Ma
 
  Start Defined By:  Graptolites, lowest occurrences of Parakidograptus 
     acuminatus and Akidograptus ascensus.
 
  Start Based On:  Gradstein, Ogg, Smith, _A Geologic Time Scale 2004_
 
 -- Overlaps With --
  ICS Stage:      Aeronian (439 - 436)
  Regional Stage: Idwian   (439 - 437.5)
 
 -- 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:        Llandovery     (443.7 - 428.2)
  Australian Stage: Keiloran       (443.7 - 433)
  Regional Stage:   Alexandrian    (443.7 - 436)
 
 -- Preceeded By --
  Period:               Ordovician      (488.3 - 443.7)
  Epoch:                Late Ordovician (460.9 - 443.7)
  ICS Stage:            Hirnantian      (445.6 - 443.7)
  Australian Stage:     Bolindian       (450 - 443.7)
  General Stage:        Ashgill         (449 - 443.7)
  North American Stage: Cincinnatian    (451 - 443.7)
 
 -- Followed By --
  Chinese Stage:        Shinulanian (438 - 433)
  North American Stage: Niagaran    (438 - 421.3)
 
 -- Contains the Following Stages --
  ICS Stage:     Rhuddanian (443.7 - 439)
  Chinese Stage: Longmaxian (443.7 - 438)
 

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.