ash fell visibly as far eastward as the Great Plains of the Central United States, more than 930 miles away. Several lahars poured down the volcano into river valleys, ripping trees from their roots and destroying roads and bridges…” On May 18, when Mount St.
Helens erupted with a catastrophic Lateral blast explosion estimated to be the equivalent to about 24 megatons (million tons) of TNT (note: Hiroshima’s unranium bomb was equal to about 15 kilotons of TNT; Nagasaki’s plutonium was about 21 kt TNT; Tsar Bomba – was powerful nuclear bomb detonated equaled 50,000 kt TNT or 50 megatons – 50 million tons of TNT), the top 1,300 feet of the mountain blew off sending tens of thousands of trees into the nearby Spirit Lake.
These deposits include fine pumice ash laminae and beds from one millimeter thick to greater than one meter thick, each representing just a few seconds to several minutes of accumulation.
A deposit accumulated in less than one day, on June 12, 1980, is 25 feet thick and contains many thin laminae and beds.
Of the thousands of trees due to weight, times of deposit (months to years), and location of the lake bottom; the trees settled at different depth levels into the soil or CHANGING how many scientists now view ‘petrified forests’ in the Stratigraphic Records.