Notes on Paricutin volcano - page 2 
' May 25. 
Ash falling at the casita so decided it was clear to the south. There, 
however, the ash was worst, falling constantly and the falling blocks raised 
much dust from the old ash cover. Soon began to rain, some mud, so began to 
return. The fall of ash consisted of porous material up to 4 inches in diam- 
eter. All, except the larger fragments, appeared to be colder than the sur- 
rounding atmosphere. We all agreed that the ash was chilled. Much more 
ash to the south than to the north. The pine trees were covered above the 
louver branches. The large oaks had mounds of ash beneath them where the num- 
erous twigs intercepted the ash and built up hummocks. These mounds sometimes 
reached a meter and one half above the general level of the ash. 
Found a bluejay with a broken wing, perhaps hit by an elected fragment. 
Found Tako’s house, now covered by ash up to the ridge pole. Luis estimated 
that the ash was about 2 meters deep. 
May 26 
Cloudy with the wind from the northwest. Spent the day collecting specimens. 
In the fumaroles below the casita dug below the ash into loose blocks and found 
beautiful trapezohedral crystals of sal-ammoniac. Collected in the iron fum- 
aroles to the west, A large one, with a golden brown, feathery incrustation had 
a very strong odor of hydrochloric acid. Scrapped off the walls for material for 
analysis. Dug out some others and found that good material had formed below 
the blanket of ash, good crystals of ammonium chloride, also feathery, skeletal 
crystals as delicate as snow crystals; yellow deliquiscent crusts, and minute 
crystals of an orange-red color. 
June 9. 
8 AM - Uruapan. Beautiful clear day. The smoke cloud of Paricutin 
beautifully visible as a tall plume, with the ash cloud extending miles to the 
south. From Uruapan, to the top of the smoke column had an angle of 19°. 
By 9 o’clock clouds began to form below the ash curtain. (Photo) 
11AM - Arrived at the old campamienta. From here the cone was rather 
highly inclined, the high side of the crater to the south. Clouds had fomed 
in many directions, particularly to the south in the direction of the smoke 
drift. Compared to the vapor clouds, the ash cloud had a pinkish brown color. 
(Photo) 
2 PM - Approaching Parangarieutiro, had a good view of the volcano, with 
its large, well defined and normal smoke column. 
3 PM - While awaiting our horse at Parangarieutiro, noticed the smoke 
column diminish to a thin, lazy column of smoke. 
3:30 PM - The smoke column has dwindled to a relatively small wisp, some- 
times hardly discernible and it began to look as if the volcano was about to 
enter a phase of quiescence. There were occasionally ejection of large blocks 
from the crater but without any noise. 
This condition continued to about 8 PM with only small bursts, chiefly 
lathe blocked, slight dust column with occasional weak bursts of smoke, but 
gradually increasing in intensity and frequency. 
9 PM. Bursts increased in intensity, ejecting large blocks but little 
smoke. Bursts 1/2 to 4 seconds apart, some of the large blocks taking 
12 seconds to fall from their ultimate altitude. 
During the period of large blocks these masses showed many irregular and 
curious forms, elongated shapes, such as rod, mace, boomerang, club, hammer, 
T’s and bird shapes. 
From 9 to 2 AM, the crater was in tremendous activity, with rapid and 
huge bursts of brilliant hot lava and tremendous noise so that the surrounding 
hills reverberated and rolled with the sound. During this period we observed 
a number of brilliant displays of "flashing arcs" that rose from the crater 
and sped, almost with the speed of lightning into the clouds above the crater. 
