Tatsuishi Seashore Geopark Nagasaki on the Shimabara Peninsular was a volcanic island in a shallow sea. The shallow sea was covered with sand and mud near the present Tatsuishi coast. The stratum from that period is called the Kuchinotsu formation and the uneven surface is known as a surface of uncomformity.
The activity of the Unzen volcano began near Obama on the western part of present Shimabara Peninsula. The first eruption was so intense that the whole magma degassed and the explosions sent volcanic material to the Tatsuishi Seashore Geopark Nagasaki. The volcanic activity continued but Obama was a considerable distance so not so much volcanic material reached the Tatsuishi Seashore.
As the mountain grew, the stratum then eroded in the Tatsuishi coast and another ‘surface of uncomformity’ on top of the first one began. Then a part of the Unzen volcano which continued to grow reached the Tatsuishi coast and again can be seen in the stratum. It was about 700 000 years ago that the stratum was initially completed. It was 500,000 years ago that the Unzen volcano started activity. Then, about 300 000 years ago the stratum of the Unzen volcano which built up reached the Tatsuishi shore again. The beginnings of the Unzen volcano from over 400 000 years ago is recorded on the stratum as well.
All this information doesn't mean much to you and me but to a geologist it is like 1's and 2's, basic data that shows the way the Earth was formed all those years ago and the best thing is that it is really accessible, just metres off the main highway, available 365 days a year and free for anyone who would like to take a look. So, even if you are not a great geological fan but would like to see nature in its purest form then this is the place for you.
Please check out Tatsuishi Seashore Geopark Nagasaki here on a map:
Please click on the photos below to enlarge:
Here is to another million years
Nice place to step back in time
That's a lot of time and years
Lots of layers
Where it all began for the Shimabara Peninsular
Please click on the videos below to see the Tatsuishi Seashore Geopark Nagasaki in more detail: