Kasei Valles is a giant System of Channels and Canyons located in the Martian Region known as Mare Acidalium - in the Lunae Palus Quadrangle of Mars - and it is centered at about 24,6° North Latitude and 65,0° West Longitude. The System is approx. 1780 Km (such as about 1105,379 miles) long and was named for the word "Mars", in Japanese Language.
Kasei Valles is one of the largest Outflow Channel Sysems of the whole Red Planet and this huge Surface Feature can reach, in some places, a maximum width of about 300 miles (such as approx. 482,802 Km). In contrast, and just out of curiosity, the Earth's Grand Canyon is only about 18 miles (such as approx. 28,968 Km) wide at its largest point.
Kasei Valles is also one of the longest and continuous (---> without interruptions) Outflow Channels of Mars; it begins in the Region of Echus Chasma, near the Great Valles Marineris Canyon System, then it runs Northward, and appears to empty into Chryse Planitia, not far away from the place where the NASA - Viking 1 landed.
Please note, as far as this picture is concerned, the light and dark gray color of the Sand and Dust which are deposited on the central portion the bed of this section of Kasei. In our humble opinion, as IPF, this could be the simple consequence of a rare (---> unusually happening) mixture of different kinds of Orangish Dust and light-Brown Sands, with, most likely, some truly large quantities of Dark Volcanic Ashes, which are now laying inside and on top of them (Volcanic Ashes that, in eons, solidified and were not blown away, probably because of the lack - or maybe rare, weak and minimal - amount of currents (---> Winds) that, from time to time, may form and blow inside this specific location of Kasei). However, the reason of such an unusual color may also be found in a chromatic distortion of the Original Colors of this Area that was caused by our colorization processes and techniques.