16461
It is geologically distinct from the nearby Appalachian Mountains and surrounding uplands , and is composed of volcanic basalt ( also known as " trap rock " ) and sedimentary rock in faulted and tilted layers many hundreds of feet thick .
 Appalachian Mountains
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: media, plant, vehicle, astronomical object, time, disease, animal, location, person, organization, mythical figure, food, biology, geographical phenomenon, instrument, event 
Text: {0} 
Answer:
 Appalachian Mountains