Can a guy answer this question?  High heels do produce a large amount of pressure In Wikipedia, the stiletto heel answer includes:  They also transmit a large amount of force in a small area, and are therefore often strengthened by a metal tube, into which is inserted a metal or hard plastic tip. The great pressure transmitted through such a heel (greater than that exerted by an elephant standing on one foot[4]) can cause damage to carpets and floors. The heel will also sink into lawns, making high heels impractical for outdoor wear.  In Wikipedia High-heeled footwear appears this answer:  The stiletto of certain kinds of high-heels can damage some types of floors. Such damage can be prevented by heel protectors, also called covers, guards, or taps, which fit over the "stiletto" tips to keep them from direct, marring contact with delicate surfaces, such as linoleum (rotogravure) or urethane-varnished wooden floors. Heel protectors are widely used in ballroom dancing, as such dances are often held on wooden flooring. The bottom of most heels usually has a plastic or metal heel tip that wears away with use and can be easily replaced.  

Hope this helps.  If you need a specific answer in terms of pressure/square inch, ask at a Reference Desk at your College or public library.  In my other life, I am a reference librarian at a university.  On vacation now and thought I would at least confirm your answer and give a lead to something more definite.

EDL