The cause of the Siberian Traps is far from certain. I think you are confusing them with the Deccan Traps of India. They, according to some scientists, *may* have been triggered by the K/T, 'dinosaur killer', asteroid impact on the opposite side of the world (Yucatan Peninsula).
“the Siberian Trapps...caused by a meteor impact on the opposite side of the planet...”
There is some question as to whether there is something called the Shiva crater off the west coast of India that has left a caldera 400 by 600 kilometers (or miles), that is the same age as the Yucatan crater and the time of the dinosaur extinction. If this is true, then it may be the primary cause of the Trapps. Then again, I always thought it could have been the Yucatan strike. Kind of like a bullet in the brain causing a hemmorage on the opposite side of the skull.