Polylines defining the channel thalweg and / or channel edge of buried or open features. Chronological information is presented as calendar age BP. Confidence is defined as follows: 1. High: Sampled feature with good age and palaeoenvironmental control. 2. Sampled feature with poor or none age and palaeoenvironmental control. 3. Constructed by remote sensing data only. 4. Low: Reasonable without any direct evidence.