© Nicolas ThibaultPhoto of the Danish Island Mors and it's sediment layers.
Researchers have long been stumped for an explanation of how tens of millions of years-old giant crystals known as glendonites came to be on the Danish islands of Fur and Mors. A recent study from the University of Copenhagen offers a possible explanation to the conundrum:
major volcanic eruptions resulted in episodes of much cooler prehistoric climates than once thought.Some of the world's largest specimens of rare calcium carbonate crystals known as glendonites are found in Denmark. The crystals were formed between 56 and 54 million of years ago, during a period known to have had some of the highest temperatures in Earth's geologic history. Their presence has long stirred wonder among researchers the world over.
"Why we find glendonites from a hot period, when temperatures averaged above 35 degrees, has long been a mystery. It shouldn't be possible," explains Nicolas Thibault, an associate professor at the University of Copenhagen's Department of Geosciences and Natural Resource Management.
This is because glendonites are composed of ikaite, a mineral that is only stable, and can therefore only crystallize, at temperatures of less than four degrees Celsius.
© Bo SchultzPhoto of researcher Henrik Lyngård digging up a glendonite.
Volcanoes responsible for cold intervalsIn their
new study, Nicolas Thibault, along with department colleagues Madeleine Vickers, Christian Bjerrum and Christoph Korte, performed chemical analyses of the Danish glendonites.
Their work reveals that the early Eocene Epoch, between 56 and 48 million years ago, was not at all as uniformly warm as once thought.
"Our study proves that there must have been periods of cold during the Eocene Epoch. Otherwise, these crystals couldn't exist — they would have simply melted. We also propose a suggestion for how this cooling might have happened, and in doing so, potentially solve the mystery of how glendonites in Denmark and the rest of the world came to be," says Nicolas Thibault. He adds:
"There were probably a large number of volcanic eruptions in Greenland, Iceland and Ireland during this period. These released sulphuric acid droplets into the stratosphere, which could have remained there for years, shading the planet from the sun and reflecting sunlight away. This helps to explain how regionally cold areas were possible, which is what affected the climate in early Eocene Denmark."
© Bo SchultzPhoto of a glendonite.
Layers of volcanic ash in rockThe presence of volcanic activity is revealed by, among other things, sedimentary layers visible on Fur, where layers of volcanic ash are clearly visible as bands in the coastal bluffs.
"Our study helps solve a mystery about glendonites, as well as demonstrating that cooler episodes are possible during otherwise warmer climates. The same can be said for today, as we wise up to the possibility of abrupt climate change," concludes Nicolas Thibault.
The study was conducted in collaboration with researchers from England, Switzerland and Norway, and has been published in the scientific journal
Nature Communications.
Reader Comments
The 35 degree temperature might be true of the hellscape at the earlier K/T boundary.
The PETM was created by Houston Oil’s control of geology. The Integrated Ocean Drilling Program (IODP) is Houston’s minion. The PETM’s evidence is based upon making the K/T boundary IODP cores younger by 10 million years.
By correlating the drilling cores, the ocean sediments would also show the impact points for Interstellar Asteroids (at the K/T).
The PETM is not found on land (as this article shows), so the IODP’s control of the ocean drilling technology meant that Houston had a monopoly on verifying their own fiction.
The K/T boundary was already associated with an impact and the IODP cores showed far more detail about where and when those impacts had occurred. The oil companies straight up lied (with government help) about the K/T boundary cores and created the Paleocene Eocene Thermal Maximum to hide the evidence of multiple interstellar impacts at the K/T.
The heavy isotope enrichment of multiple elements in the black shale (source rock for oil) indicates that the lighter isotopes were blown off of the face of the Earth.
Interstellar asteroid impacts create the geological conditions for oil. That is why the oil companies never allowed any public discussion of interstellar asteroids and geology. That is also why you are learning about this for the first time.
Interstellar Asteroids are the secret cause … not electric arcs.