Floodplain of Kamchatka River: Age and specific of formation of Sediments

Abstract

The sediments of the floodplain of Kamchatka River in its middle course have been studied. Two types of floodplain accumulation environment are distinguished: stable (overgrowth of oxbow lakes distant from the main channel) and dynamic (banks of the central part of the valley, subject to regular flooding). Radiocarbon dating of buried organics was carried out. The oldest peat formed around 3200 14C years (3460 cal BP), during a period of low water flow, which may have been caused by climatic changes. Formation of the floodplain-oxbow alluvium began not later than 3.8 thousand years ago. Changes in hydrological regime and major reorganization of the river channel led to the formation of a new surface, possibly due to seismic processes. The age of that seismic event may be several hundred years older than the beginning of subaerial sedimentation on the high floodplain in the middle course of Kamchatka river.

Keywords

• channel processes
• geochronology
• radiocarbon dating
• holocene
• central kamchatka