Afghanistan…The Khyber Pass
The Khyber Pass, eastern Afghanistan-western Pakistan
If you asked a geologist about the Safed Koh Mountain range and the Khyber Pass, he’d describe it something like this: millions of years ago a vast, shallow sea covered what would someday be central Asia. The rivers that cascaded off the north-central Asian highlands dumped billions of tons of sand and rock into this shallow sea, creating a massive, unstable load that caused the Earth’s crust to sag. This huge load of sediment caused the inward collapse of the sea floor, and, as the mountain-building forces contracted, thrusting out of this shallow sea was a mountain range like the world had never seen. As dynamic forces shaped the landscape, great rifts and faults broke and separated the bedded rock, creating deep, pulverized fissures of soft unstable rock.
This mountain range blocked the moist air of the East Asian subcontinent, and the western side of the range became dryer and dryer—a desert. The towering rock front caught the moist air on its upper reaches, and sent torrents of water and ice down to tear at the bare rocks As these torrential rains, snows, and sandblasting winds tore at the very fabric of these peaks, they were eroded until they became, today, less than half their original height. As the destructive forces of nature pounded the mountains, any weakness was quickly exploited, and the soft pulverized rock of the mountain rifts and faults eroded rapidly, creating deep canyons and lowering the mountain ranges. Finally, after hundreds of thousands of years, the Khyber Pass glistened, a gap in the mountains, as if a sword from God had struck, slicing a passageway for humans to leave their African homeland and populate the emergent land mass that lay eastward beyond the Pass.
