I am a happy person. I like to laugh, eat good food with good people, read, and travel. But there have only been a handful of moments in my existence where I have felt truly full of life. June 13th, 2016 held one of those moments. Every passing day on this paradise, I learn or try something new, which is exciting in and of itself, but June 13th was different than the other days. That was the day that I decided geology and I would be together forever.
The day started similar to most. We had a lesson at 10 am and headed off to another new place – the Akrotiri Peninsula on the southwestern tip of Thera in Santorini. Here, we would be standing on the oldest evidence of volcanic activity on Santorini. This island may only be 11 miles long, but there are so many new places to be explored. For the explorer (and possible future geologist) in me, this is really exciting because it means that every day will have new people, new stories to tell, and of course, new rocks.
The Akrotiri Peninsula has successfully made itself my favorite place to be on this island. All it took was a quick glance at the still-seeming blue waters and the brilliantly jagged cliffs and I was hooked. From the foot of the lighthouse, I could see distant islands and swaying boats. I could hear the excitement in my classmates voices as they were sharing the same appreciation for the beauty of this place. ‘This is paradise’, I thought, ‘How am I expected to leave a place like this in only 6 days?’ Figure A, below, is an attempt to try to capture the beauty of the peninsula that I was taken aback by.
After my mind finally adjusted to the fact that where I was standing was real, I was able to move forward up the trail to the lighthouse to look at the rocks that constructed the place that I was so awestruck by. All I knew was that this part of the island was formed from domes. Domes are volcanoes constructed of very thick lava – I like to think of toothpaste being squeezed out of the tube. Toothpaste is thick and will round out when it is squeezed out. Similarly, the lava coming from a dome volcano is very thick and will essentially round itself as it creeps over the landscape.
Often, dome volcanoes will form on top of a pre-existing volcano or landmass. However, the dome that I was seeing had a tough upbringing. This volcano spent thousands of years under hundreds of meters of water, slowly creeping its way to the surface.
When the class had made it to the top of the outcrop, I immediately noticed a red bed of rock, just a few meters below the lighthouse. This rock so clearly stood out to me because everything around it was a creamish white color. How did this red section of rock wedged under a lighter layer? Figure B, below, shows the section of red in comparison to the light layer.
The red rock that I had observed was a marine conglomerate deposit. A conglomerate is a type of rock composed of other rounded rocks held together by a matrix (kind of like a natural glue for rocks). When I first learned that marine conglomerate laid above the dome, I was surprised and slightly confused. I had always just assumed that magma would either engulf whatever surrounded it because of the high temperature or destroy material through explosions.
In this particular situation, the temperature of the sea floor had to be low enough and there had to be enough pressure on the dome from the water above it in order to suppress the explosion of the volcano, making the lava have more of an effusive flow than a violent eruption. The effusive flow of lava allowed for the marine conglomerate to be preserved rather than destroyed.
So let’s fast forward a few thousand years. The dome has made its way out of the water and the marine conglomerate is preserved. But the volcano hasn’t put in its two weeks yet. Another eruption of volcanic material occurs on top of the marine conglomerate. The interaction of the marine conglomerate and the new, 900 degree lava oxidized the marine conglomerate to give it the beautiful red hue it holds today (to learn more about the process of oxidation, please visit my first blog post: https://nauingreece.wordpress.com/2016/06/06/karavolades-stairs-a-600-step-geologic-wonderland/).
The color of the red conglomerate was so vivid and raw. I believe that it is impossible to capture the true essence of the beauty without seeing it up close. That being said, I had to get a closer look at this magnificent creation of water versus fire. As I was examining the rock with my professor, Lisa Skinner, we noticed that the marine conglomerate was not red all the way through, meaning that the volcanic material only oxidized about half of the bed.
When I saw that clear gradient between the lower tan conglomerate and the upper red conglomerate, my heart dropped and my eyes flashed into the past. I was imagining this eruption taking place. I could see the calm marine sediment, delicately preserved on top of a volcanic dome. I saw the lava come from a short distance away with an intent to disrupt the peaceful conglomerate. I was entirely swept away in this single moment. My mind and imagination were completely emerged in the story that these rocks were telling me.
Professor Skinner caught me in my trance. She told me more about this amazing bed of rock that we were studying while I patiently listened feeling like a kindergartener being given crayons for the first time. Then, she stopped and she said to me with a smile on her face, “You’re going to be a geologist Jenna”. I laughed, but I was beaming on the inside. I believe that on that cloudy Monday afternoon, I had a true moment of life.
June 13th was the day that I learned about the beginnings of this beautiful island. This was the day where I walked on 650-550 thousand year old rock. I sat, I observed, and I listened to its story. I was taken back in time when I mentally pictured the thick lava flow towering over the marine sediments. I was taken forward in time when I realized that this was what I wanted my life to be. My visit to the Akrotiri Domes may have been a marker for the end of my trip, but it marks the beginning of a journey…my journey with geology.