IMPACT DID NOT TRIGGER DECCAN VOLCANISM - EVIDENCE FROM ANJAR-K T BOUNDARY INTERTRAPPEAN SEDIMENTS/

Many hypotheses including asteroid and cometary impacts, Deccan volcan ism, impact induced volcanism and coincidental impact and volcanism ha ve been put forth to explain the observed enhancement of iridium and m ass extinction at the K/T boundary (KTB). The identification of KTB la yer within the Deccan intertrappean sediments at Anjar, about half way between Flow III and Flow IV provides new constraints on some of thes e hypotheses. The chemical characteristics of this layer show high con centrations of Ir, Os and other siderophiles accompanied by enrichment of chalcophiles and depletion of lithophiles. The Os/Ir approximately 1.1, close to the meteoritic value and other chemical and stratigraphi c criteria indicate that it may be the ejecta fallout layer, resulting from a bolide impact at the KTB. Presence of three basalt flows below this layer implies that the volcanism was already active when this la yer was deposited and impact of the K/T bolide did not trigger Deccan volcanism.