From Surf Wiki (app.surf) — the open knowledge base

Darriwilian

Second and last age of the Middle Ordovician epoch

Field	Value
name	Darriwilian
color	Darriwilian
time_start	469.4
time_start_uncertainty	0.9
time_end	458.2
time_end_uncertainty	0.7
timeline	Ordovician
name_formality	Formal
celestial_body	earth
usage	Global (ICS)
timescales_used	ICS Time Scale
chrono_unit	Age
strat_unit	Stage
timespan_formality	Formal
lower_boundary_def	FAD of the Graptolite Undulograptus austrodentatus
lower_gssp_location	Huangnitang Section, Huangnitang Village, Changshan, Zhejiang, China
lower_gssp_coords
lower_gssp_accept_date	1997
upper_boundary_def	FAD of the Graptolite Nemagraptus gracilis
upper_gssp_location	Fågelsång section, Sularp Brook, Skåne, Sweden
upper_gssp_coords
upper_gssp_accept_date	2002

The Darriwilian is the upper stage of the Middle Ordovician. It is preceded by the Dapingian and succeeded by the Upper Ordovician Sandbian Stage. The lower boundary of the Darriwilian is defined as the first appearance of the graptolite species Undulograptus austrodentatus around million years ago. It lasted for about 10.8 million years until the beginning of the Sandbian around million years ago. This stage of the Ordovician was marked by the beginning of the Andean-Saharan glaciation.

Naming

The name Darriwilian is derived from Darriwil, a parish in County of Grant, Victoria (Australia). The name was proposed in 1899 by Thomas Sergeant Hall.

GSSP

The GSSP of the Darriwilian is the Huangnitang Section () near the village Huangnitang, 3.5 km southwest of Changshan County Town (Zhejiang, China). It is an outcrop of the Ningkuo Formation, consisting of mainly black shale. The lower boundary of the Darriwilian is defined as the first appearance datum of the graptolite species Undulograptus austrodentatus in that section.

A secondary fossil marker is the graptolite Arienigraptus zhejiangensis.

Biostratigraphy

The base of the Darriwilian is also the base of the Undulograptus austrodentatus graptolite zone. This zone lies just above the North Atlantic Microzarkodina parva conodont zone. The base also lies in the upper part of the North American Histiodella altifrons conodont zone.

The Undulograptus austrodentatus graptolite zone is known from outcrops around the world, making the base of the Darriwilian easily correlatable.

Regional stages

The Darriwilian overlaps with the upper Arenig and the Llanvirn. The base of the Darriwilian can be correlated with a level in the Fennian stage of the Arenig.

References

(September 1997). "Definition of a global boundary stratotype for the Darriwilian Stage of the Ordovician System". Episodes.
(June 2000). "A proposed global boundary stratotype for the base of the Upper Series of the Ordovician System: The Fågelsång section, Scania, southern Sweden". Episodes.
"GSSP Table – Paleozoic Era". Geologic Timescale Foundation.
(28 May 2016). "Glacial onset predated Late Ordovician climate cooling". Paleoceanography and Paleoclimatology.
"Darriwilian".
(10 May 2023). "A short history of the Ordovician System: from overlapping unit stratotypes to global stratotype sections and points". [[The Geological Society of London]].
"GSSP for Darriwilian Stage". Geologic Timescale Foundation.
Mitchell, C. E.. (1997). "Definition of a global boundary stratotype for the Darriwilian Stage of the Ordovician System". Episodes.
(2012). "The Geologic Time Scale 2012". Elsevier Science Ltd.

Info: Wikipedia Source

This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page.

darriwilian middle-ordovician ordovician-geochronology

Want to explore this topic further?

Ask Mako anything about Darriwilian — get instant answers, deeper analysis, and related topics.

Research with Mako

Free with your Surf account

Content sourced from Wikipedia, available under CC BY-SA 4.0.

This content may have been generated or modified by AI. CloudSurf Software LLC is not responsible for the accuracy, completeness, or reliability of AI-generated content. Always verify important information from primary sources.

Report