I think it is in Tales of Suspense #39 that the cover dated March 1963. May 1968 Iron Man #1 received its own title.
The type of stream valley likely to form in a mountainous area is a V- shaped valley. This is a narrow valley that has a profile giving the impression of the letter V. This kind of valley is characterized by steeply sloping sides. It results from a stream eroding downward, a process referred to as downcutting. V - shaped valleys form in mountains or highland areas where streams are in their youthful stage and are flowing rapidly down steep slopes.
The beginnings of a brain first become apparent around four weeks after conception when the neural plate folds to form the neural tube