Pfupisa nyaya yacho:  Pasi ringave riri kutambura nokuchinja kuri muwirirano yaro yebiochemical yakafanana neiyo inofungidzirwa kuva yakaparadza hafu youpenyu hwose makore ane mamirioni 200 apfuura. Ikoku kuri mukuwirirana nefundo yeBritain iyo yakawana mugariro une ngwavaira unonzi'marine photic zone euxinia' wakaitika mune rimwe ramakungwa apamberi penhau. Izvi zvinoitika kana mvura yomumvura yegungwa inenge yacheneswa nezuva isisina okisijeni uye yaiswa chepfu nehydrogen sulphide. Upenyu hweTriassic hwakasvika kumugumo wokupera simba mumamiriro okunze anopisa zvikuru, achidziisa makungwa kusvikira kumugariro wokudziya, maererano nefundo itsva. Mufananidzo uri kuratidzwa nemhizha wezvingave zvakaitika mumakungwa makore mamiriyoni 200 akapfuura. Vanyori vokudzidza vanotya kuti nyika nhasi inogona kutambura migumisiro yakafanana. Hydrogen sulphide inogadzirwa nemakemikari anorarama pasina okisijeni uye ine muchetura wakanyanya kune zvimwe zvinhu zvipenyu zvakawanda. Vanyori vokudzidza vanotya kuti nyika nhasi yaigona kutambura migumisiro yakafanana inoparirwa nouwandu hwecarbon dioxide iri kugadzirwa kupfurikidza nokupiswa kwamafuta. Chikwata chakatungamirirwa neYunivhesiti yeSouthampton chakadzidza mamorekuru emiti akaumbwa achibva mumatombo anogara mumatombo akaunganidzwa pakutanga pasi pegungwa rePanthalassic riri kuchamhembe kwakadziva kumabvazuva, rakanga rakakomberedza nyika yePangea. Matombo acho zvino ari pachena paQueen Charlotte Islands, kure nemhenderekedzo yeBritish Columbia, Canada. Chikwata chakatungamirirwa neYunivhesiti yeSouthampton chakadzidza mamorekuru emhuka akaumbwa kubva mumatombo anogarwa ayo pakutanga akaunganidzwa pasi pegungwa rePanthalassic riri kuchamhembe kwakadziva kumabvazuva. Matombo acho zvino ari pachena paQueen Charlotte Islands, kure nemhenderekedzo yeBritish Columbia, Canada. Nyanzvi dzakawana zviratidzo zvebhakitiriya iyo yakanga yarasikirwa zvikuru nokushayikwa kweoxygen uye chehydrogen sulphide chepfu iyo ingadai yakaparirwa nokuputsika kukuru kwemakomo anoputika mumaplate eTectonic ePasi. 'Sezvo mahwendefa epasi akachinjwa kuti aputse Pangaea, kutsemuka kukuru kwemakomo anoputika kungadai kwakabudisa carbon dioxide mumhepo yakapoteredza pasi, kuchitungamirira kukwira kwetembiricha kubva...
Mwero weCO2 unoburitswa nokupisa mafuta akawanikwa mumatongo wakawedzera. Iye zvino zvava kuenzana nezvakabuda mumakomo anoputika munguva yeTriassic. Ikoku kwakaparira mugariro une ngwavaira unonzi'marine photic zone euxinia' Izvi zvinoitika kana mvura yomumakungwa isisina okisijeni.