source, but before long, as the thin ash 
deposit became mixed with the soil, the 
favorable effects of the ashfall would 
have been felt. 
Ilopango tephra may have actually 
reached as far as the Maya lowlands, 
where the Classic period of Maya civili- 
zation flowered from a.d. 300 to 900. 
Recent cores from northern Guatema- 
lan lakes, taken by Edward Deevey and 
others of the University of Florida, 
show a drastic increase in silica in the 
Early Classic period. Silica is the domi- 
nant material of the Ilopango ash. If 
chemical tests confirm Ilopango was 
the source of the lake-core silica, we 
would still have to know the depth of 
the ash deposit in order to tell whether 
the lowlands suffered any initial detri- 
mental effects. As the tephra weathered 
and was incorporated into lowland 
soils, however, it certainly would have 
been beneficial. 
We may speculate that Ilopango ac- 
tually played a role in the emergence of 
Classic Maya civilization in the low- 
lands. In addition to possibly receiving 
a thin deposit of ash, the lowlands 
would have been affected by the arrival 
of thousands of immigrants. A more in- 
tensive agricultural system would have 
been needed to feed the enlarged popu- 
lation, and a more complex political 
and social system would have been re- 
quired to organize and control it. W'hile 
I am convinced that Classic Maya civi- 
lization would have emerged in any 
case, the process may well have been 
accelerated. We can even point to at 
least one lowland site, Tikal, that prof- 
ited directly from the disaster in the 
southeastern Maya area. Strategically 
located midway between the headwa- 
ters of two river systems to the east and 
west, Tikal appears to have seized con- 
trol of the eastern end of the major Me- 
soamerican trade route, which ex- 
tended as far as the basin of Mexico, site 
of present-day Mexico City. With the 
old route in shambles after the eruption 
of Ilopango, trade was rerouted to the 
north, contributing to the burst of pros- 
perity so noticeable in Early Classic Ti- 
kal. 
Had it not been for Ilopango, Classic 
Maya civilization might have flowered 
first in El Salvador and adjacent south- 
ern Guatemala, instead of in the low- 
lands to the north. Because of the thick 
blanket of ash covering the country- 
side, however, people abandoned cen- 
tral and western El Salvador, along 
with adjoining areas of Guatemala and 
Honduras, for at least a few decades, 
and in the worst hit areas, for about two 
centuries. Composed predominantly of 
silica, the ash from Ilopango was an 
“acid” tephra. It provided few of the 
nutrients needed for plant growth and 
weathered relatively slowly. We will 
not know the details of vegetative suc- 
cession in El Salvador until we have 
taken lake cores and analyzed the pol- 
len, diatoms, and other sedimentary 
materials they contain. In general 
^ 
Andrew Tomfco 
35 
