On the third day, we will see the formation around the boundary between Ordovician and Silurian. I am very interested in this area because of Graptolites and other fossils in the black shale. So everyone took pictures of them. We then visited two outcrops of Ordovician "stromatolites". However, the interpretation of this "stromatolite" was discussed at the site. The same "stromatolite" was also observed in Kanchanaburi, western Thailand, in September last year. Please have a look at the following page: http://seagull.stars.ne.jp/2023_SciUS/Kanchanaburi/index.html
朝コーランの詠唱で起こされて,朝食までまだ早いので,ホテルすぐ横のビーチを散歩しました.満月の大潮で潮が引いて,広大な干潟が出現していました.ビーチは砂なのに,干潟は泥が主体というのも面白いです.
I was awakened by the recitation of the Koran in the morning, and since it was still early for breakfast, I went for a walk on the beach right next to the hotel. It was a full moon and the tide was low, creating vast mud flats. It is interesting that the beach is sandy, but the lagoon are mainly mud. |
今日午前の最初の巡検地.オルドビス紀の頁岩がシルル紀に漸移する場所です.筆石の模型がありますね.
This is the first site we visited this morning, where Ordovician shales are transitioning to Silurian. There is a model of a graptolites at the entrance. |
古い石切り場で,手前がオルドビス紀,水の溜まった対岸がシルル紀と,現地説明板ではされています.ここで筆石を探します.実はメンバーはずっと入口の方で探していたのですが,私が絶対奥にあるはずだと,この場所まで来て見事な筆石を見つけました.さすがにFossil
Hunter50年の実績は伊達ではないです!
The old quarry, with the Ordovician in the foreground and the Silurian on the other side of the pool of water, is described on a board at the site. This is where we look for graptolites. Actually, the members of the group had been looking for it at the entrance, but I thought for sure it must be at the back, so we came to this place and found a beautiful and abundant graptolites. The 50 years of experience of Fossil Hunter is no joke! |
結構見事な筆石が,そこかしことはいかないまでも,探すとそれなりに見つかりました.大分以前にノルウエイのオスロ湾の古生代層から,筆石が採集できて,日本に送ったことがあり,そのときの様子と比較してください. http://yossi-okamoto.net/.../Futen/2008_Norway/Oslo_5.html I have found quite a few nice graptolite, not all over the place, but enough to look for. Compare this with a graptolite I collected from a Paleozoic layer in Oslo Bay, Norway, and sent to Japan a long time ago. |
これはびっしりと筆石が並んでいて,この日の一番のサンプルで,皆さんに写真を撮ってもらいました.オスロのものより密集度がはるかに高いですね.さすがに世界GeoParkだけはあります.
This was the best sample of the day, and I asked everyone to take pictures. As expected of a world GeoPark. |
これが現地で議論になった,丸い化石です.筆石の頭の部分ではないかと誰かが言っていたのですが,私は懐疑的です.
This is the round fossil that was discussed at the site. Someone said it might be the head of a graptolite, but I am skeptical. |
そ
れより地質構造的に面白いのは,手前がオルドビス紀とシルル紀の境界にあたりますが,はるか奥の石灰岩の山は完全にオルドビス紀です.そうすると,右の水
たまりに向かって傾く,層理面の解釈がおかしなことになりませんか?高校から大学教養程度の,地質学の議論の対象として面白いと思います.
The interesting geological feature is that the limestone mountain at the far end is completely Ordovician, while the one in the foreground is at the boundary between Ordovician and Silurian. Then, the stratigraphic plane tilting toward the pool on the right is oddly interpreted, isn't it? This is an interesting subject for discussion in high school and college geology. |
さて午前中2か所目の露頭は,バナナの実の向こうにある看板の場所です.
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同じくオルドビス紀のストロマトライトだと説明板にはあるのですが.説明するのが,今回の巡検リーターで元筑波大学教授の久田先生です.2017年のコラート高原の恐竜巡検でもお世話になりました. http://seagull.stars.ne.jp/2017Thai_Khon_Kaen/Part1.html The sign says that it is a stromatolite of Ordovician age as well. The outcrop is explained by Dr. Hisada, a former Tsukuba University professor and the leader of this excursion, who also helped us with the 2017 Korat Plateau Dinosaur field trip. |
これが問題の「ストロマトライト」です.かっこで囲んだのは,議論があるからです.同行のチュラ大のVさんは,乾裂ではないかと意見を述べていました.前述のカンチャナブリの露頭での議論でも同様の,堆積構造や生痕化石との意見があり,議論の元となっているようです.
The reason I put it in parentheses is because there is some controversy. V san of Chula University who accompanied us expressed his opinion that it might be a dry fissure. The same opinion was expressed in the aforementioned discussion at the outcrop in Kanchanaburi, that it is a sedimentary structure or trace fossil, and it seems to be a source of controversy. |
ここで私がちょっと化石を探してみました.見事な直角貝が少し岩を登ったところにありました.久田先生によく見つけたとほめていただきました.しかしこれで味をしめて,同様に別の岩に上ったときに,蟻の攻撃にあい,身体中の何カ所かを噛まれました.痛い痛い!
Here I did a little fossil hunting. I found a magnificent right-angled shell a little further up the rock. Dr. Hisada praised me for finding it. However, I got a taste of it, and when I went up to another rock, I was attacked by ants and bitten in several places on my body. Ouch, ouch! |
こちらが「ストロマトライト」の第2露頭ですが.こちらは地元の人がピーと呼ぶ精霊が祀られた場所です.東屋で保存されています.
This is the place where the spirit, called "Pea" by the locals, is enshrined. It is preserved in a pavilion. |
こちらの方が風化の程度が弱く,構造はみやすかった.ここにも化石の破片はみつかりました.
Fossil fragments were also found here. |
さて2か所回ってやや疲れたので,ガソリンスタンドでトイレ休憩.こちらのスタバに相当するAmazonでカプチーノ.これ普通で頼むと甘すぎるのでLess Sweet 25%で頼むのがコツ.
Cappuccino at Amazon, the equivalent of Starbucks here. If you order a regular cappuccino, it is too sweet, so the trick is to order a Less Sweet 25%. |
少し遅い昼食をレストランで取って,さて午後のメインはこの崖の中腹にある,鍾乳洞まで旧坂を上ります.こちらも当然国立公園で,入場料が必要です.
After a late lunch at a restaurant, the afternoon's main activity is to climb up the old hill to the limestone caves in the middle of the cliff. This is also a national park and an entrance fee is required. |
か
なりの急坂は整備された階段で,それを登り切ってやっと鍾乳洞の入口に到着.これは30年前に仏僧が,瞑想の場所を探していて,偶然見つけたそうです.現
在は観光洞としてオープンしていましが,からなず地元のガイドと一緒でないと入れないシステムです.昨日のカヌーといい,この日のガイドといい,地元の人
をうまく雇用するシステムが作られていて,これもGeoParkの目的の一つだそうです.
The steep hill is a well-maintained stairway, and after climbing it, we finally arrived at the entrance of the cave. It is said that 30 years ago, a Buddhist monk was looking for a place to meditate and found this cave by chance. The cave is now open as a tourist cave, but you have to be accompanied by a local guide to enter. The canoeing yesterday and the guiding on this day were both done by a system that employs local people, which is one of the purposes of Geo-Parks, according to the tour guide. |
これ内部は本当に天井が高く,また鍾乳石が見つかって日が浅いので,まったく汚れていない真っ白な色が特徴です.なかなか日本の鍾乳洞では経験できないスケールと美しさに圧倒されました.さすが世界GeoParkだけはあります.クリックで動画.
The
ceiling inside the cave is really high, and the stalactites have not
been discovered for a long time, so they have a pure white color and are
not stained at all. I was overwhelmed by the scale and beauty of the cave, which I could not experience in any other limestone caves in Japan. It is indeed a world-class Geo-Park. Click to Video. |
この生成過程はなかなかよい,鍾乳石形成の物理モデルを考える好例かと. This formation process is a good example of a physical model of stalactite formation. |
途中に大きなシンクホールが.ここだけ日が当たって藻が繁殖して緑色になっている.ここでガイドの人が化石があると教えてくれたようです.
There is a large sink-hole on the way. Only here the sun shines and algae grows, turning the area green. The guide told us that there were fossils in this sink-hole. |
でみんなで左側の壁を必死で探しました.これはアンモナイトに似ていますが,内部構造がないので巻貝かもしれない.
This one looks like an ammonite, but it might be a mollusk because it has no internal septa structure. |
こちらはご存じ直角貝Nautiloid.たくさん見つかりました.
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階段を下って国立公園入口に戻るとここにも,やはりPrayer Roomの看板.ここはムスリムの人々の住む世界なのです.
Back down the stairs to the entrance of the national park, there is also a sign for a Prayer Room. This is the world where Muslims live. |
さてホテルに帰る道すがら,まるで桂林のような(行ったことはないけど)奇岩怪石が林立する地帯と抜けました.さすがに広大な石灰岩の大地が削られたことがわかります.
It was indeed a vast area of limestone that had been cut down. |