Tag Archives: ジュラ紀

Hike 34: アローヘッド メサ Arrowhead Mesa

フォートピアース歴史保存跡からスタートして、13km 歩いて帰ってくるという、私たちにとっては少々チャレンジなハイキングでした。 The group hike was quite a challenging 8 mile hike starting from Fort Pearce Heritage site.

そこで、折衷案を出して、出かけました。 So, we made a compromise plan where we would turn back partway through.

結局、10.5kmと366mの高度を歩いて帰ってきました。 We hiked 6.5 miles total with 1000 feet of elevation change.

ここは2.5億年前、三畳紀の面白い地層が露出している場所です。 The area exposes many interesting strata from Triassic period, about 250 million years ago.

大陸移動の畝りを見ながらの小休憩です。 We had a short break with a great view looking out over layers of uplifted rock made by earth movement and erosion.

そこから更に進みます。犬のチェスターは疲れを知りません。We moved on further. Chester the dog doesn’t know the word fatigue.

でも、やはり、みんなと別れて歩いてきた道を引き返す時が来ました。バンちゃんの足底筋膜炎を治療中だからです。But the time came for us to turn back. Because Banchan is under treatment for his plantar fasciitis, we reluctantly said good-bye to everyone.

遠くに離れていくみんなを見送るのは、ちょっと寂しかった。 It was a little sad when we saw our group continue on.

でも、ゆっくりと化石化した木をチェックしたり、虫の観察をしたりしながら歩きました。But we walked slowly on the return, and rather enjoyed examining petrified wood and observing bugs.

虫といえば、こんなに近くで観察するつもりはなかったのに、口の中に飛び込んできたので、飲み込んでしまいました。ハエと同じぐらいの大きさの虫です。大丈夫だよね。死なないよね?Ugh, by the way, I didn’t mean to observe this close, but I swallowed a bug as it flew into my mouth accidentally. I hope it’s okay to eat a fly-sized bug. I won’t die from it, right?

恐竜の足跡 Dinosaur Tracks

Warner Valley Dinosaur Track には、夥しい恐竜の足跡があり、思わず息を呑みます。ジュラ紀の初期、1.95億年前のものです。 Warner Valley Dinosaur Track is quite an impressive place with many dinosaur tracks. They are from 195 million years ago, the beginning of the Jurassic period.

残念ながら、足跡からだけでは恐竜を特定する事はきませんが、おおよその検討はつくようです。Unfortunately paleontologists can’t specify who’s footprint they are with certainty. They can only guess who made them.

人間の歴史の何百倍も時を越えるのは大好きです。 I love to jump back hundreds of times older than human history.

コヨーテビューツの彫刻 - Sculptures at Coyote Buttes

What a magical power of Nature with the aeolian process.

南コヨーテビューツ – Coyote Buttes South

この美しさを守りたい。 I want to protect this beauty.

This is a wonder of nature created over millions of years.

We won the lottery for the South Coyote Buttes entry tickets in the Vermillion Cliffs National Monument.

20 people per day total are allowed to enter, 10 from online applications and 10 in person the day before.

The road to get to the trailhead is through deep sand. Even off-road vehicles could , 8and do, get stuck in there if you don’t know how to drive in sand. So we hired a guide to take us there.

そこからおよそ 2.5 km 、道標もない砂原を歩いて辿り着いたナバホ砂岩のビュート群。ティーピーと呼ばれています。
After about 1.5 miles of hiking, we got to the buttes made of Navajo Sandstone. They are specifically called “Teepees”.

The sandstones in Coyote Buttes are so pretty and so fragile as you can see. So I hesitated even to step on them and had to be very careful where I stepped.

We were able to come this far led by our guide, but I really wondered what people do without a guide. They may walk around not knowing where to go and destroy precious sandstone formations. In fact, this has happened not so long ago.

The erosion of wind and water creates these fragile formations. That is why we want to avoid unnecessary damage.

The Navajo Sandstone is the geological formation formed during the Jurassic period. The area was marshy with a river running through it. So dinosaurs roamed around here as well.

Thank god we had our guide. We even didn’t know of the existence of dinosaur tracks. We blew sand off the surface and revealed many footprints.

It is amazing that we could see the footprints made 200 million years ago because they were protected by layers of rock, until finally revealed again by erosion. My thoughts jumped into the fourth dimension again.

Vermillion Cliffs National Monument is vast. Coyote Buttes is only a small portion of it. There are so many other interesting places in there, that I wonder if we have time to visit them all during the remaining time in my life.

ともあれ、この素晴らしい自然を保護してくれるこの国に、新しい Canon EOS R5 に感謝して帰途につきました。
In any case, we went back home, being grateful that this country protects areas like this well. I was also grateful that my new camera, Canon EOS R5, worked so well for me.

コンクリーション – Concretions

この石、ずっと不思議に思ってました。- I’ve been wondering about this rock.

断面 – cross section

大きさは約 2 x 3 x 2 cm。卵のように中にピンク色の部分があり、しかも、綺麗な楕円形。- The size is about 2 x 3 x 2 cm.  It is like an egg containing an oblong shaped pinkish section.

表面 – surface

三畳紀(約2億年前)のチンル層、でもサンタクララ川に近い場所から持ち帰りました。 – I picked it up near the Santa Clara River in the Chinle formation, Triassic period (about 200 Million years ago).

かたや、こちら。左側の石にはニキビのようなボツボツが見えますよね。この石はペンシルベニア紀からペルム紀(約3億年前)の地層が混じり合う山道(Mojave Desert Joshua Tree rd) からのものです。On the other hand, the sample rock on the left side of the picture below, has spots on the surface.  It came from Mojave Desert Joshua Tree Rd where several formations are mixed, from Pennsylvanian to Triassic period (about 300 million years ago).

クローズアップすると、やはりボコボコと突起しているのがわかります。直径 2 mm ぐらいです。Here is a close-up image.  You can see that they protruding.  The size is about 2 mm.

この岩も同じ道で見かけました。- I found this rock on the same road as well.

近づいてみると、丸くはないけどボコボコ突起してます。念のため、動物の糞ではありません。- You can see that they are protrusions from the rock, not animal droppings.

最後にこちら、ジュラ紀(約1.7億年)のスノーキャニオン州立公園内のナバホ砂岩層。 – Lastly, this is a wall of the Navajo Sandstone Formation, Jurassic period (about 170 million years ago) at Snow Canyon State Park.

どうやらこれはコンクリーションらしいんです。- It seems that they are concretions based on my research.

生成のされ方は、まだ研究途中のようですが、鉄分が主成分らしいです。風化されたことによって表面に出ていますが、岩の中にできるんですね。面白い。- We still don’t know exactly how they were formed yet, but they are mainly iron.  They form inside the rock but erosion of the surrounding rock exposes them on the surface of the rock.  Isn’t it interesting?

石の国 - Rock Country

クリストファー コロンバスのアメリカ大陸の発見の話ではありません。(念のための注記:い・し・の・く・に と言ってコロンバスがアメリカ大陸を発見した1492年を暗記しました。)- This is not about the discovery of Americas by Christopher Columbus.  (Note: The Japanese Title is “Ishi no Kuni”.  The meaning is literally “Ishi” = “Rock” and “Kuni” = “Country”.  However, the pronounciation of “I” and “Shi” also means “one” and “four”.  Similarly, the pronunciation of “Ku” and “Ni” also means “nine” and “two”.  So all together, it becomes the number 1492, the year of the discovery of the Americas by Christopher Columbus.)

ここ、セイントジョージはコロラド高原の西南端。ナバホ砂岩に覆われていて、とても美しい町。この砂岩の美しさの原因は砂岩に浸み込んだ鉄分にある。その鉄分が酸化して白い砂が赤、ピンク、紫などに変色した結果だと言われている。ただ、ジュラ紀、1.8 億年も前から長い年月をかけての圧縮作用であっても、砂でできているが故、ライムストーンなどと比べルト、そんなに硬くないらしい。 – The city of Saint George, UT, is located at the very southwest corner of the Colorado plateau.  The area is covered by the Navajo sandstone formation.  Because it includes iron, the colors of the layers include reds, pinks, purples, etc. depending on the amount of iron oxide in that layer.  During the Jurassic period, about 180 million years ago, it was compressed under great pressure, but it is not so hard compared to limestone because it is “sandstone” after all.

新年早々、硬い話になりました。 – Sorry for being such a hard topic from the beginning of the new year.

でも、ジャ〜ン!ついに発見したんですよ。理想の石。- But I wanted to write about this because we finally found the ideal rock.  See below picture!

石屋さんが紹介してくれた石切場は、 私たちの家から約1時間半ほどの場所、Kanab という美しい町にありました。- The rock engraving shop suggested we go to this quarry in Kanab, about 1.5 hours away from our house.  

そこで1時間以上探索。諦めかけていた時に突然現れた。- It caught our eyes after searching more than an hour when we were about to give up.

そもそもなぜ石探しをしていたかというと、日本でいう表札のためです。下の写真の中央にある石は場所的にも形としても表札に理想的なんですが、この石はやわらかい。カービングには適していないんですね。- You may ask me “why a rock?”  It’s a good question.  We were looking for a rock to engrave our house address number on it.  See picture below.  The rock in the middle is the perfect size and location for its purpose.  Unfortunately, it has one problem. It is too soft.

ほら、こんな感じで十五年前に設置されてから、雨風によって表面の損傷がよく分かります。- If you look at it closely, you can see how much it’s been damaged by rain and wind. 

この石の色好きなんですが、石屋さんによると5-10年もしたら、見えなくなると言われてしまいました。この地、セイントジョージ産の石は柔らかいんです。そこで、もう少し硬い石探しが始まったというわけです。- I like this rock, but if we used it, the house number would not be visible in 5-10 years according to the rock engraving shop.  The red rock from Saint George is unfortunately too soft.  This is the reason why we went out to look for a rock.

Kanab の赤石はもっと硬いらしい。来週、石屋さんが引き取りに行って、その後、家の番号をカービング。そして、ここに設置されます。- The red sandstone in Kanab is known to be harder.  Once the rock we picked out is moved to the shop, they will engrave our house number and install it at the front of our lot.

そうしたら、私たちの長かった石の国への引っ越しが、完了だ〜〜〜!  Then, we can finally declare that our move to the Rock Country is complete.  It took 10 long months!