Hi Himashu,
This is my response to your PM:
Scientists have found high levels of iridium in certain geological formations around the world, SUGGESTING the cataclysmic impact of a meteor millions of years ago.
Your doubts about this sentence are valid. This sentence means that scientists suggested the cataclysmic impact. However, it the discovery of high levels of iridium in certain geological formations that has suggested the fact. Hence, even though this sentence is grammatically correct, it fails to communicate the logical meaning.
This is the reason why the mentioned OG sentence is also incorrect:
The Olympic Games helped to keep peace among the pugnacious states of the Greek world, proclaiming a sacred truce during the festival’s month.
The Olympic Games certainly cannot perform the function of “proclaiming” and hence does not make sense with the subject of the preceding modified clause.
The other form of the sentence that you have cited can be used to convey the logical meaning.
This would be my version of these sentences with Noun = Noun Modifier
Scientists have found high levels of iridium in certain geological formations around the world, a discovery that suggests the cataclysmic impact of a meteor millions of years ago.
OR
Scientists have found high levels of iridium in certain geological formations around the world, a discovery suggesting the cataclysmic impact of a meteor millions of years ago.
Hope this helps.

Thanks.
Shraddha