Symposium on Remote Sensing for Resources Development and Environmental Management / Enschede / August 1986 
Notes on the geomorphology of the Borobudur plain (Central Java, 
Indonesia) in an archaeological and historical context 
Jan J.Nossin & Caesar Voute 
ITC, Enschede, Netherlands 
ABSTRACT 
In the second half of the Quaternary, a lake originated at the place of the present Borobudur plain, as a 
result of blocking of the Progo channel by Merapi fluviovolcanics piling up after slipfaulting against the 
Menoreh Hills. The lake has existed long enough to leave deposits which are locally 10 metres thick. 
Faulting in a northeasterly trend, along the present course of the lower K. Tangsi, has initiated uplift of 
the southeastern block. The existence of the fault is derived from the behaviour of the drainage pattern , 
notably a ninety-degree turn in the K.Tangsi, which then follows a clear lineament implied to be the 
faultline. This lineament exercises strong influence on the drainage pattern of the area. 
The uplift of the southeastern block has initiated the draining of the lake and led to steep incision of 
the Progo and Sileng rivers. This incision is marked by at least two, but most probably three main terrace 
phases. 
Considerable time therefore has elapsed since the onset of the final draining of the lake. It is therefore 
concluded that the lake had disappeared long before the Borobudur temple was constructed. The slipfaulting 
in the Merapi deposits which may have initiated the whole train of events, must be much older of age than 
the 1006 AD catastrophic eruption of the Merapi. 
l.THE BOROBUDUR PLAIN 
The Borobudur temple stands on a faultblock of 
volcanic rocks including the Gunung Gandul-Gunung 
Sipadang hills (Benschop Koolhoven, 1929). This 
outlier of intrusive ’younger andesites’ (Rahardjo 
c.s., 1977) overlooks a plain toward the S, SE and 
E, at an average height of 240 - 250 metres a.s.l. 
This plain, into which the K.Sileng sinks its 
incised meanders, is made up of alluvial deposits. 
It is bordered to the S by the andesites of the 
Menoreh Hills reaching over 900 metres a.s.l. To 
the E, it is bordered by the young fluviovolcanics 
of the G. Merapi. 
The plain continues north-and northwestward, where 
it is not made of alluvial deposits, but of young 
deposits derived from the G.Sumbing. The plain here 
lies somewhat higher, around 265 - 270 metres 
a.s.l. 
Nine shallow water borings near the Borobudur 
temple, in the plain, have shown a thickness of 
over 10 metres of sandy/clayey lake deposits 
(Purbohadiwidjojo and Sukardi , 1966; Voûte, 1969). 
2. OBJECTIVE, METHODOLOGY 
The objective of this paper is, to analyze the 
geomorphic setting and trace the evolution of the 
(lake)plain, in order to verify certain ar- 
chaeologically significant hypotheses on the 
presence of an ancient lake and on the impact of 
major volcanic events. 
Air photo interpretation was carried out on three 
sets of photos: 
- colour-IR photos of 1972, at an approximate scale 
of 1:10.000; 
- colour-IR photos of 1982, at an approximate 
scale of 1:30.000; 
- black/white panchromatic photos of 1982 ,at 
approximately 1:50.000. 
Additional data were obtained during field observa 
tions in 1985, and also from the geological map of 
the Yogyakarta Quadrangle (Rahardjo c.s., 1977), 
and from published papers. 
The interpretations of the air photos are presented 
in the form of sketchmaps. 
3. THE ARCHAEOLOGICAL AND HISTORICAL CONTEXT 
Borobudur has engaged the attention of scholars for 
over a century, resulting in more than 500 learned 
studies in several languages. Moreover, preserva 
tion and restoration work has been carried out on 
the monument in successive phases, again extending 
over a period of more than 100 years, culminating 
in the world-wide known Unesco-supported campaign 
of the years 1968-1983 (Soekmono, 1972; Voûte, 
1983). Especially during this last phase much 
additional research covering a wide range of sub 
jects was carried out. 
But still a number of mysteries exist, surrounding 
this ancient temple, as reflected even in the title 
of one of the books on Borobudur (Bernet Kempers, 
1976). 
One of these concerns the often debated existence 
of a former lake around the temple, involving two 
utterly different and conflicting assumptions, and 
another the probable reason for the apparently 
sudden eclipse, in the 10th-llth century, of the 
old Mataram Kingdom of Central Java.