Furongian

From Wikipedia, the free encyclopedia
  (Redirected from Late Cambrian)
Jump to: navigation, search
Key events in the Cambrian
view • discuss • edit
-550 —
-540 —
-530 —
-520 —
-510 —
-500 —
-490 —
F
u
r
o
n
g
i
a
n
 
 
 
 
* * * * * * * * * * * *
* * * * * * * * * * * * * * * * * * * * * * * * *
Baykonur
glaciation
Baykonur
glaciation
* * * * * * * * * * * *
* * * * * * * * * * * * * * * * * * * * * * * * *
Orsten Fauna
Archaeocyatha extinction
SSF diversification, first brachiopods & archaeocyatha
Treptichnus pedum trace
Large negative peak δ 13Ccarb excursion
First Cloudina & Namacalathus mineral tubular fossils
Stratigraphic scale of the ICS subdivisions and Precambrian/Cambrian boundary.

The Furongian is the fourth and final series of the Cambrian. It lasted from ~497 to 485.4 ± 1.9 million years ago. It succeeds the still unnamed 3rd series of the Cambrian and precedes the Lower Ordovician Tremadocian stage. It is subdivided into three stages: the Paibian, Jiangshanian and the unnamed 10th stage of the Cambrian.[1]

Naming[edit]

The Furongian was also known as the "Series 4" of the Cambrian and replaced the older term "Upper Cambrian" and equivalent to the local term "Hunanian". The name "Furongian" was ratified by the International Commission on Stratigraphy in 2003. Furong (芙蓉) means "lotus" in Chinese and refers to Hunan which is known as the "lotus state".[2]

Definition[edit]

The lower boundary is defined in the same way as the GSSP of the Paibian stage. Both begin with the first appearance of the trilobite Glyptagnostus reticulatus around ~497 million years ago.[3] The upper boundary is the lower boundary and GSSP of the Tremadocian stage which is the first appearance of the conodont Iapetognathus fluctivagus around 485.4 ± 1.9 million years ago.[4]

Subdivisions[edit]

The following table shows the subdivisions of the Furongian series/epoch:[1]

Epoch Stage Age (mya)
Lower Ordovician
Floian 477.7 ± 1.4
Tremadocian 485.4 ± 1.9
Furongian
Stage 10 ~489.5
Jiangshanian ~494
Paibian ~497
Series 3
Guzhangian ~500.5
Drumian ~504.5
Stage 5 ~509

Biostratigraphy[edit]

The base of two of three stages of the Furongian are defined as the first appearance of a trilobite. The base of the Paibian is the first appearance of Glyptagnostus reticulatus and the base of the Jiangshanian is the first appearance of Agnostotes orientalis.[2][5] The still unnamed Cambrian Stage 10 might be defined as the first appearance of Lotagnostus americanus or the conodont Eoconodontus notchpeakensis.[6]

The Furongian can be divided into a number of trilobite zones:

Series Stage Trilobite zone Trilobite GSSP
Furongian Stage 10 Saukia zone (upper part), Eurekia apopsis zone, Tangshanaspis Zone, Parakoldinioidiazone, Symphysurina zone[6] Lotagnostus americanus (undecided)
Jiangshanian Ellipsocephaloides zone, Saukia zone (lower part)[6] Agnostotes orientalis
Paibian  ? (?) Glyptagnostus reticulatus
Cedaria

References[edit]

  1. ^ a b "GSSP Table - Paleozoic Era". Geologic Timescale Foundation. Retrieved 17 November 2012. 
  2. ^ a b Peng, Shanchi; Babcock, Loren; Robison, Richard; Lin, Huanling; Rees, Margaret; Saltzman, Matthew (30 November 2004). "Global Standard Stratotype-section and Point (GSSP) of the Furongian Series and Paibian Stage (Cambrian)". Lethaia 37 (4): 365–379. doi:10.1080/00241160410002081. 
  3. ^ "GSSP for the Paibian". Retrieved 12 November 2012. 
  4. ^ "GSSP for the Cambrian - Ordovician Boundary". Retrieved 17 November 2012. 
  5. ^ "GSSP for Jiangshanian". Retrieved 12 November 2012. 
  6. ^ a b c Landing, E.; Westrop, S.R.; Adrain, J.M. (19 September 2011). "The Lawsonian Stage - the Eoconodontus notchpeakensis FAD and HERB carbon isotope excursion define a globally correlatable terminal Cambrian stage". Bulletin of Geosciences: 621–640. doi:10.3140/bull.geosci.1251. 
Preceded by Proterozoic Eon Phanerozoic Eon
Paleozoic Era Mesozoic Era Cenozoic Era
Cambrian Ordovician Silurian Devonian Carboniferous Permian Triassic Jurassic Cretaceous Paleogene Neogene 4ry