What is the fine-grained topic of the following text: Four retrogressive thaw slumps (RTS) located on Herschel Island and the Yukon coast (King Point) in the western Canadian Arctic were investigated to compare the environmental, sedimentological and geochemical setting and characteristics of zones in active and stabilised slumps and at undisturbed sites. Only return the topic.
Comparison of environmental, sedimentological and geochemical characteristics of thaw slumps in the western Canadian Arctic.