
irviken karyakram

silurian kaal key dauran teen apekshaakrit chhoti vilupt honey vaali ghatnaaon (irviken, mulde aur laau ghatanaaen) mein seey irviken ghatana pahali thee. yeh landwary/wenlock seema (madhya silurian,) parr huaa. yeh ghatana sabse achchi tarah seey irewicken, gottland mein darj kii gaee haye, jahan 50 pratishat seey adhik trilobite prajaatiyan vilupt hoe gaeen; iss antaral mein vaishvik connodont prajaatiyon kaa 80 pratishat bhee vilupt hoe gayaa.
ghatana kii shareer rachana.
yeh ghatana lagbhag 200,000 varshon taka chully, joe wenlock yug key aadhar parr faili hui thee. yeh vaishvik sheetlan kii avadhi seey judaa huaa haye.
isamen aathh vilupt honey vaale "datum point" shamil hain-pahale chaar niyamit roop seey harr 30,797 varshon mein antar kiye jaate hain, aur milankovic tirchha chakr seey judey hotey hain. paanchvaan aur chhathaa sambhavatah poorv-kramik chakron mein adhikatam koo darshaata haye, jisaki avadhi lagbhag 16.5 aur 19 kaa haye. antim dou detta bahut aage hain, isaliye milankovic parivartanon key saath jodana kathin haye.
hataahat.
ghatana key liye jimmedaar tantra gahare mahasagaron mein utpann huaa, aur uthale shelf samudron mein apana raasta banaaya. tadnusar, uthale paani kii chattaanen mushkil seey prabhaavit huin, jabaki pelogic aur hemipalogic jeev jaise kii graptolytes, conodonts aur trilobite sabse adhik prabhaavit hue.
bhoo-rasayan.
pahale vilupt honey key baad, δ13c aur δ18o abhilekhon mein bhraman dekhe jaate hain; δ13c + 1.4 seey + 4.5 taka badhata haye, jabaki δ18o − 5.6 seey −5.0 taka badhata haye.

