Rock weathering in the McMurdo Dry Valleys is stranger than the “normal” erosion we observe every day. Here at Conrow Glacier erosion is thought to result from a combination of processes. For instance, it is thought that snow sublimates and leaves behind salt that can break down rocks. It is easily seen when parts of the bottom of boulders erode away. Freeze-thaw weathering is important in the Dry Valleys and occurs when water seeps into rock fractures and alternately freezes and melts. When the water freezes it expands, making the fractures larger. Another common process is thermal stress weathering; when rocks get warm they expand and when they are cold they shrink. Eventually the continual expanding and contracting of a rock will cause it to crack.
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| Crazy dolerite that has been almost completely eroded in its middle. All that is left is a pillar in the center and its base. |
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| Heart-shaped rock. It is a granite located in the second to last moraine at Conrow Glacier. |
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| Large boulder that has been fractured along pre-existing joints. See orange notebook for scale. |
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