What are two pieces of evidence used to support the theory that dinosaurs became extinct as a result of volcanic eruptions about 65 million years ago?

The causes of extinction of the dinosaurs were-

A huge meteorite of diameter 10-15 km, hit the earth about 65 million years back and caused the global extinction of plant and animal species upto 75-80 %.Volcanic eruptions such as Deccan traps are also an evidence of the dinosaur's extinction.The Cretaceous-Tertiary (K-T) boundary also supports the evidence of that global mass extinction, as Iridium (an element) is present that suggests a mass extinction event.