Charcoal is remnants of plantations that turn into charcoal because directly hit by hot and fast pyroclastic flow. They didn't burn and turn into ashed because the flow is so fast oxygen didn't contact them. Charcoal can be used to measure age of rocks hence tracing a history of a volcanic eruption.
Charcoal in Punikan
Charcoal in Batukliang
Charcoal in Luk Beach
A charcoal layer is commonly situated in the end of inter-rocks layers, with pyroclastic flow above it consisted of tufa and limestone. Charcoal can be found in several locations such as Punikan, Batukliang, Gangga, Sembalun and Luk Beach. Radiocarbon dating from charcoal sample indicates a consistency with the eruption in 13th century (Lavigne and friends, 2013).
Remains of pyroclastic clouds during Mt Samalas' eruption or Pyroclastic Density Current (PDC) of 35-meter high can be seen in Luk Beach. In the western part of the beach, on a not too high PDC, there is coral sediment at about 2 meter above mean sea level. This coral sediment is interpreted as sediment from tsunami following Mt Tambora eruption in the year 1815.