Gweld cod am Triasig

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[[Cyfnod (daeareg)|Cyfnod]] [[daeareg]]ol (a system stratigraffaidd) yw'r '''Triasig''' sy'n para 50.9 miliwn o flynyddoedd: o ddiwedd a Cyfnod Permaidd {{Period end|Permian}} miliwn o flynyddoedd [[CP]], hyd at cychwyn y [[Jwrasig]], {{Period start|Jurassic}} miliwn o flynyddoedd [[CP|Cyn y Presennol]] (CP).

Dyma gyfnod cyntaf y [[gorgyfnod]] [[Mesosöig]] a amcangyfrifir ei fod 251-66 miliwn o flynyddoedd [[CP]]. Mae cychwyn a diwedd y Triasig yn digwydd ac yn dynodi digwyddiadau mawr sy'n ymwneud â [[difodiant]] (''extinction'').<ref name="SahneyBenton2008RecoveryFromProfoundExtinction">{{ cite journal | url=http://journals.royalsociety.org/content/qq5un1810k7605h5/fulltext.pdf |author1=Sahney, S.  |author2=Benton, M.J.  |lastauthoramp=yes | year=2008 | title=Recovery from the most profound mass extinction of all time | journal=Proceedings of the Royal Society: Biological | doi=10.1098/rspb.2007.1370 | volume = 275 |format=PDF | pmid=18198148 | issue=1636 | pmc=2596898 | pages=759–65}}</ref>

Bathwyd y term 'Triasig' yn 1834 gan [[Friedrich Awst von Alberti|Friedrich von Alberti]], ar ôl y 3 haen o greigiau a geir ledled [[yr Almaen]] a gorllewin [[Ewrop]]: gwely o graig coch y ''red bed'', calchfaen forol a chyfres o garreg laid a [[tywodfaen|thywodfaen]] - sef y "Trias".<ref>Friedrich von Alberti, ''Beitrag zu einer Monographie des bunten Sandsteins, Muschelkalks und Keupers, und die Verbindung dieser Gebilde zu einer Formation'' [Contribution to a monograph on the colored sandstone, shell limestone and mudstone, and the joining of these structures into one formation] (Stuttgart and Tübingen, (Germany):  J. G. Cotta, 1834).  Alberti coined the term "Trias" on  [https://books.google.com/books?id=1ClSAAAAcAAJ&pg=PA324#v=onepage&q&f=false page 324] :<br>"… bunter Sandstein, Muschelkalk und Keuper das Resultat einer Periode, ihre Versteinerungen, um mich der Worte E. de Beaumont’s zu bedeinen, die Thermometer einer geologischen Epoche seyen, … also die bis jezt beobachtete Trennung dieser Gebilde in 3 Formationen nicht angemessen, und es mehr dem Begriffe Formation entsprechend sey, sie zu einer Formation, welche ich vorläufig ''Trias'' nennen will, zu verbinden."<br>( … colored sandstone, shell limestone, and mudstone are the result of a period ; their fossils are, to avail myself of the words of E. de Beaumont, the thermometer of a geologic epoch ; … thus the separation of these structures into 3 formations, which has been maintained until now, isn't appropriate, and it is more consistent with the concept of "formation" to join them into one formation, which for now I will name "trias".)</ref>

==Gweler hefyd==
*Yr [[uwchgyfandir]]oedd: [[Gondwana]], [[Lawrasia]] a [[Pangaea]]
*Y [[Cyfnod (daeareg)|cyfnodau]]: [[Permaidd]], [[Jwrasig]] a'r [[Cretasaidd]]

==Cyfeiriadau==
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[[Categori:Cyfnodau daearegol]]