Tukgahgo Mountain

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Tukgahgo Mountain
Tukgahgo1.jpg
Mount Tukgahgo in early fall.
Highest point
Elevation 4,675 ft (1,425 m) [1]
Coordinates 59°18′01″N 135°37′46″W / 59.30028°N 135.62944°W / 59.30028; -135.62944
Geography
Location Haines Borough, Alaska, U.S.
Parent range Takshanuk Mountains
Topo map USGS Skagway (B-2)
Climbing
First ascent Unknown
Easiest route Scramble

Tukgahgo Mountain (TUG-a-ho) is located in the Takshanuk Mountains with a peak elevation of 4,675 feet (1,425 m) in the U.S. state of Alaska. It is situated 6.6 miles (10.6 km) north of Haines, 3.5 miles (5.6 km) to the southwest of Chilkoot, and 16 miles (26 km) to the southwest of Skagway.[2] It is one of eight peaks in Haines Borough.[3] Geological investigations of the veins in the mountain have revealed silver, gold, platinum, and palladium mineralization, derived from mid-Cretaceous events.

Geography[edit]

Takshanuk Mountains Range

Tukgahgo, an indigenous name given by the Tlingits, was recorded by geologist Eugene C. Robertson and published by the United States Geological Survey (USGS) in 1952.[2][4] In order to climb the Tukgahgo Mountain and reach the summit, detailed information needs to be ascertained from the topographic maps published by USGS and the Skagway B-2 USGS quadrangle map.[3] A part of the Coast Mountains, Tukgahgo is situated 3.5 miles (5.6 km) from Chilkoot, while Skagway is 16 miles (26 km) to the southwest. Vanderbilt Point is located 3 miles (4.8 km) west of Tukgahgo's summit. The head of Shakuseyi Creek is on the east slope of the mountain.[5]

Geology[edit]

New geological findings close to Tukgahgo and the eastern ridge have been reported. In 1991, when the sampling was carried out by geologists, a rock formation 2,500 ft (760 m) to the southwest of Tukgahgo Mountain on the northwest trending Chilly peak (elevation 4,520 ft (1,380 m)[1] was initially given the informal title "Chilly."[6] The geologic formations of the area consist of metabasalts and amphibolites, which are enclosed as roof pendants within the hornblende diorite, granodiorite and monzonite. The intrusive rocks are inferred to be part of the Mount Kashagnak pluton.[7] A few quartz veins were also identified, though they were scattered; they are integral to the Tukgahgo Mountain fault.[6] This fault is small and close to the summit. The fault is within the Skagway B-2 Quadrangle and has a southeast (140 degree) strike or trend, with a movement of 1,480 feet (450 m); the movement is recorded as down on the northeast side compared to the southwest side. Along the fault metabasalts to the southwest are in fault contact with the diorite intrusive.[7]

Samples collected from the veins were analyzed for metals like molybdenum, platinum and palladium. One vein with visible molybdenite assayed at 1,240 ppm across the vein. Quartz veins also revealed pyrite, chalcopyrite, malachite, and molybdenite. The gold content was reported to be 0.824 ppm, while silver and copper contents were of the order of 2.70 ppm and 2,140 ppm, respectively. The mineralization is interpreted as of mid-Cretaceous age. The metallic elements identified as present in the vein structures include silver, gold, copper, with minor quantities of palladium and platinum but no mining operations have been reported.[6]

References[edit]

  1. ^ a b Skagway (B-2), Alaska, 15 minute Quadrangle, USGS 1954
  2. ^ a b "Feature Detail Report for: Tukgahgo Mountain". U.S. Geological Survey. Retrieved 11 February 2013. 
  3. ^ a b "Tukgahgo Mountain Summit- Alaska Mountain Peak Information". Mountainzone.com. Retrieved 11 February 2013. 
  4. ^ William Bright (2004). Native American Placenames of the United States. University of Oklahoma Press. pp. 517–. ISBN 978-0-8061-3598-4. Retrieved 7 February 2013. 
  5. ^ Geological Survey Professional Paper. U.S. Government Printing Office. 1967. pp. 859, 989, 1017–. Retrieved 14 February 2013. 
  6. ^ a b c "Unnamed Occurrences (ARDF - SK025; near Tukgahgo Mountain), Skagway District, Juneau District, Haines Borough, Alaska, USA". mindat.org. Retrieved 12 February 2013. 
  7. ^ a b "Geology and Geochemistry of the Skagway B-2 Quadrangle, Southeastern Alaska" (pdf). Division of Geological and Geophysical Surveys State of Alaska. pp. 17–18. Retrieved 12 February 2013. 

External links[edit]

Coordinates: 59°18′01″N 135°37′46″W / 59.30028°N 135.62944°W / 59.30028; -135.62944