Glass Ice Plains
The Glass Ice Plains are a famous geographic feature of Caudal E4, near the Blackthorn Territory. Less a true set of plains than a huge, shallow lake that remains frozen through most of the year, the Glass Ice Plains are famous for their crystal-clear waters and tendency to form jagged 'shards' where the different ice plates undergo subduction.
The Glass Ice Plains lie just on the other side of the commissure from the wet Caudal A cube layer. Water from the western side pooled in the commissure and froze in layers over geological time - forming a sedimentary ice crust that has been since excavated to clear a travel route - but not before forming a vast lake on the dorsal (location:5f55f631-5080-4215-8ed1-8c4001e1751b) side. Because the Dorsal Tesseract is defined by its relative dearth of geological activity, the lake is shallow and of relatively even depth throughout. Though waves tend to freeze into its surface during the initial seasonal freeze, dust carried on the strong winds throughout the long winter polishes these away, rendering the surface smooth and glassy as the season progresses.
The waters of the Glass Ice Plains were once quite healthful for drinking, as the winds also had a tendency of depositing trace minerals from erosion in the same way that glacers in other Caudal cubes carved away minerals through their gradual progress. The use of modern fertilizers and pesticides in the nearby Blackthorn Territories have somewhat lestened the purity of the water, but it is still relatively safe for spur-of-the-moment consumption if boiled; drinking the water over the long-term requires distillation or other treatment to remove these pollutants.