Galbraith Lake Earthcache EarthCache
Galbraith Lake Earthcache
-
Difficulty:
-
-
Terrain:
-
Size: 
(other)
Please note Use of geocaching.com services is subject to the terms and conditions
in our disclaimer.
Turnoff is at milepost 275 on the Dalton Highway, then continue past airstrip buildings towards campground for 2.5 miles on unimproved road. Outhouse, trash containers, no drinking water. As with all caches on the Dalton Highway, come prepared with extra food, water, clothing, gas, and a spare tire or two.
Coordinates will bring you to several interpretive signs. Look across the valley, across the lake, and you may notice a light gray, crumbling mountain. This peak is part of the Brooks Range, formed of what geologists call “Lisburne limestone.” The layers of this ancient, sedimentary rock show strong deformations that reflect the history of their movements.
All the rock layers of this mountain were once a single, 1000-foot-thick layer of limestone that began as ocean floor deposits over 100 miles to the south. After the rock was formed, it was split into several layers by the forces of the restless earth. As time passed, the layers were shoved northward, shuffled like a deck of cards, and in some places, completely overturned. The result was the complete rearrangement of the original layers, so that in some areas older rocks now rest on top of the younger ones – and in others, all the layers have been rolled together like a jelly roll.
When you log this cache, email the owner the answers to these questions:
1. What is the name of the layer of newer rock that is overturned and under the Lisburne limestone? Hint: it is not light gray.
2. Averaged together over the years it took to build the Brooks Range, what is the rate of growth for the mountains? Hint: the rate is about the same speed as _____ ___________ ______.
3. And to discourage armchair finds, on the sign nearby entitled The Buzz and Flutter of Arctic Summers, there is an interesting fact about the northern female mosquitos. Finish the sentences, “ Unlike most of their southern relatives, some northern female mosquitos _______________________________ eggs. If ______________________, ______________________ eggs.”
Posting a photo is not required, but it is always welcome.
Resources used to develop this earthcache are all found on location, on the interpretive signs there.
Additional Hints
(No hints available.)