Mineral-rich waters from the Apennine Mountains of Italy flowed through ancient Rome's Anio Novus aqueduct, leaving behind a detailed rock record of previous conditions. Two studies have documented the occurrence of anti-gravity growth ripples in the layers of limestone within the Anio Novus.
The studies apply advanced engineering principles and high-resolution microscopes to establish a new theory about how the travertine formed.
The Anio River and an underground lake near Subiaco, Italy provided the water for the Anio Novus aqueduct.
The researchers collected upstream-downstream oriented travertine samples that show light and dark layers and wavy shapes.
The layers in the Anio Novus travertine are thought to be the result of changes in flow rate initiated by the Romans. travertine with similar forms in ancient aqueduct systems can be found anywhere in the world.
The crystalline architecture of travertine and other similar mineral deposits are influenced by how microbes thrive in mineral rich waters. He and his group have spent a lot of time showing the geological history of mineral formations and even the human body.
The waters of Subiaco are similar to the waters of Yellowstone National Park, where waterborne microbes form mats and biofilms that play a critical role in the shape and structure of the famous stepped travertine features. There are fossils and plant debris in the dark layers of Anio Novus travertine. The Anio Novus, the longest and most significant of the ancient Roman aqueducts, has a knowledge base and experience required to begin unraveling its history.
The geometry of the rippled layers of the Anio Novus travertines was carefully measured by the two professors.
The only way to form ripples is through fluid shear and gravity-dependence. There is a theory that water or wind can move loose debris into wavelike shapes that slowly advance and are influenced by gravity to form the familiar asymmetric ripple shapes we see along riverbanks, dunes and in the ancient sedimentary rocks deposited in these environments.
The Anio Novus travertine crystals were formed by the interplay of the forces of gravity and the shape and composition of microbial colonies, according to the team.
The researchers said that the processes that control travertine crystal growth ripples are very similar to those that control the ripples of the sea. Crystal growth ripples are not dependent on gravity, and the geometries of ripples along the vertical walls of the aqueduct are similar to those along the floors.
The team measured the ripples to see if they reflected the flow of water through the aqueduct.
Since few researchers had ever seen these structures as ripples, no one had used the power of the shape of a ripple to create this kind of reconstruction.
When the aqueducts were first turned on, the water flowed through at a rate of about one meter per second, much faster than previously thought.
The researchers said that the ceilings of the aqueduct channels are made of rippled travertine. According to this observation, previous studies were incorrect in saying that the layers formed due to seasonal flow change or that Romans used engineering means to control the flow rate.
The aqueducts were much more robust than thought. The rate of flow was constant and the flow was greater than anticipated.
The ancient microbes and their biomolecules are being pulled from the travertine to learn more about the Romans' drinking habits.
Archeologists and historians are interested in what happened to the Roman Empire. Information gleaned from the demise of the aqueducts can be useful in this endeavor.
More information: Duncan Keenan-Jones et al, Travertine crystal growth ripples record the hydraulic history of ancient Rome's Anio Novus aqueduct, Scientific Reports (2022). DOI: 10.1038/s41598-022-05158-2The depositional and diagenetic history of travertine was documented in the GSA Special Papers. Pubs.geoscienceworld.org/gsa/b... istory-of-travertine.
Journal information: Scientific Reports
All Rights Reserved © 2024
