Let's Got To The Museum / Specimens Unveil Geological History

Let's got to the museum / Specimens unveil geological history

By Kazuyoshi Nakaya / Yomiuri Shimbun Staff WriterNAGATORO, Saitama — In 1916, poet and novelist Kenji Miyazawa (1896-1933) visited the Chichibu area in Saitama Prefecture and composed a tanka poem about the beauty of striped metamorphic rocks lying on the riverbed of the Arakawa river: "The colors of rocks on the Arakawa river look like Hakata obi sashes with really stylish patterns."

Back then, the poet, who later wrote masterpieces like "Ginga Tetsudo no Yoru" (Milky Way Railroad), was a second-year student at the Morioka Imperial College of Agriculture and Forestry (now the Faculty of Agriculture of Iwate University) and was interested in minerals. He ventured all the way to the mountainous area of Saitama Prefecture because it was a geological sanctuary where various types of rocks could be found.



Taku Yaginuma / Special to The Yomiuri Shimbun

Scallop, starfish and Japanese Babylon shellfish fossils found in the Chichibu area


Taku Yaginuma / Special to The Yomiuri Shimbun

Metamorphic rocks along the nearby Arakawa river have characteristic brown striped patterns


Taku Yaginuma / Special to The Yomiuri Shimbun

A stone monument marking the "birthplace of Japanese geology" built in 1993


The Yomiuri Shimbun


The Saitama Museum of Natural History in Nagatoro, Saitama Prefecture, is located near a rocky area called Iwadatami, a scenic spot where crystalline schists composed of stacked, pie-like mineral layers lie along the Arakawa river.

The museum is considered the successor to a facility displaying Chichibu mineral and plant specimens founded in 1922 and possesses around 160,000 objects, including rocks and fossils found in the area.

Upon entering, visitors first come across a 12-meter-long replica of the giant ancient shark Carcharodon megalodon suspended overhead. Walking further into the museum, you can view the skeletons of Paleoparadoxia, an ancient sea animal similar to a dugong, and of a small baleen whale called Chichibu kujira (Diorocetus chichiuensis).

Why were marine animal fossils discovered in the Chichibu area, which is far from the sea?

The area had been the seabed of the old Chichibu Bay for about 2 million years until about 15 million years ago, during which a six-kilometer-deep layer of earth accumulated. Due to subsequent crustal movements, the area become dry land and various rocks and fossils are often found in the vicinity.

A large stone monument marking "the birthplace of Japanese geology" prominently stands in front of the museum.

According to the monument, Edmund Naumann, the first professor of geology at the Tokyo Imperial University (now the University of Tokyo), conducted research in Nagatoro. His students would later visit the area, too.

"There aren’t many museums that can tell the history of geology through objects collected in the neighborhood," said Hiromichi Kitagawa, 34, a curator of the museum. Even today, local residents occasionally contact the museum about fossil discoveries.


Saitama Museum of Natural History

The museum opened in 1981 as the Saitama Prefectural Natural History Museum before being renamed in 2006. It inherited materials from a facility founded by Chichibu Railway Co. dedicated to displaying Chichibu mineral and plant specimens. The museum’s Paleoparadoxia, Chichibu whale and other animal skeletons have been designated as national natural monuments.

Address: 1417-1, Nagatoro, Nagatoromachi, Saitama Prefecture

Open: 9 a.m. to 4:30 p.m. (until 5 p.m. in July and August). Generally closed on Mondays.

Admission: ¥200 for adults and ¥100 for high school or university students

Inquiries: (0494) 66-0404Speech