Limestones

Limestones

I remember a shocking news story sometime ago about the
National Museum in Jakarta concerning stolen paintings. The whole
story was surprising indeed. But museums normally carry a lot of
wonders and curiosities, and some big surprises as well.

I visited the National Museum last year for the first time. I
was surprised to see some fossil corals in black limestone
covering the museum's floor. The corals were Michelinia,
Raphrentites and Cyathaxonia of Early Carboniferous age (some 330
million years ago). Corals are whitish gray in color, and are
embedded in the black limestone known as marbre noir in Western
Europe. This type of limestone has long been quarried in Tournia,
west Belgium, and used widely in Europe, together with petit
granite, also from the same place. In Brussels, the capital of
Belgium and center of the EU, you will see these limestones in
abundance because they are used for road pavement. I happened to
know this because I once lived in Belgium.

Presumably, when the National Museum was constructed, some
building materials were shipped from the Netherlands to Jakarta
(then Batavia). We can tell this because the characteristic
features of rocks are often so prominent as to indicate their
origin.

In the Museum of Geology in Bandung where I work, walls and
pillars are covered by panels of gray limestone which, I was
told, came from Padalarang, west of Bandung. The limestone is
known as Radjamandala limestone among geologists, and is Late
Oligocene to Miocene in age (about 25 million years ago).

Quarrying operations in Padalarang are rather extensive.
Limestones are used for making lime, of course, and for
ornamental stones such as "marble". In a factory near the quarry,
large blocks of limestone are cut into slabs and then polished.
These yellowish, grayish, and sometimes pinkish limestone slabs
have been widely used in Indonesia. For instance, you can see
them covering the walls and floors of the entrance hall at the
President Hotel, where I am currently staying. These limestones
have been even exported to a number of foreign countries. They
are full of fossil corals, hydrozoas, foraminifera and calcareous
algae.

Perhaps in the future, teachers should bring their students to
one of the hotels besides the National Museum and ask them to
take a close look at the surface of the limestone walls there.
Students may be curious and will be surprised to find the remains
of some creatures that once lived on the floor of the ancient
Javanese Sea.

MAKOTO KATO

Jakarta