Editing Silurian (section)

=== Perturbations ===
The climate and [[carbon cycle]] appear to be rather unsettled during the Silurian, which had a higher frequency of isotopic excursions (indicative of climate fluctuations) than any other period.<ref name=Munnecke2010/> The [[Ireviken event]], [[Mulde event]], and [[Lau event]] each represent isotopic excursions following a minor mass extinction<ref>{{Cite journal| last1 = Samtleben | first1 = C.| last2 = Munnecke | first2 = A.| last3 = Bickert | first3 = T.| title = Development of facies and C/O-isotopes in transects through the Ludlow of Gotland: Evidence for global and local influences on a shallow-marine environment| journal = Facies| volume = 43| pages = 1–38| year = 2000| issue = 1| doi = 10.1007/BF02536983| bibcode = 2000Faci...43....1S| s2cid = 130640332}}</ref> and associated with rapid sea-level change. Each one leaves a similar signature in the geological record, both geochemically and biologically; pelagic (free-swimming) organisms were particularly hard hit, as were [[brachiopods]], [[corals]], and [[trilobites]], and extinctions rarely occur in a rapid series of fast bursts.<ref name=Munnecke2010/><ref name="TrotterEtAl2016PPP">{{cite journal |last1=Trotter |first1=Julie A. |last2=Williams |first2=Ian S. |last3=Barnes |first3=Christopher R. |last4=Männik |first4=Peep |last5=Simpson |first5=Andrew |title=New conodont δ18O records of Silurian climate change: Implications for environmental and biological events |journal=Palaeogeography, Palaeoclimatology, Palaeoecology |date=February 2016 |volume=443 |pages=34–48 |doi=10.1016/j.palaeo.2015.11.011|bibcode=2016PPP...443...34T }}</ref> The climate fluctuations are best explained by a sequence of glaciations, but the lack of [[tillite]]s in the middle to late Silurian make this explanation problematic.<ref name="Calner2008">{{cite book |last1=Calner |first1=Mikael |title=Mass Extinction |chapter=Silurian global events – at the tipping point of climate change |date=2008 |pages=21–57 |doi=10.1007/978-3-540-75916-4_4|isbn=978-3-540-75915-7 }}</ref>