Research team with Goethe University participation successfully proposes former quarry in Lower Saxony as Global Stratotype Section and Point.
The international team of geoscientists led by Prof. Silke Voigt from the Goethe University Frankfurt, Prof. Ireneusz Walaszczyk from the University of Warsaw and Dr. André Bornemann from LBEG have thoroughly investigated 40 meters (130 feet) of the geological strata sequence in the former limestone quarry at Hasselberg. The researchers determined that this is only sequence in the transition between Turonian and Coniacian without gaps and it therefore represents a perfect rock sequence to serve geoscientists from all over the world as a reference for their research — a “Global Stratotype Section and Point (GSSP)” or, in the jargon of geosciences, a “golden nail.”
Certain group of bivalve mollusks of the family Inoceramidae, first appeared in the Coniacian, and are found in large numbers in Salder. In Bed 46 of the quarry, the German-Polish scientific team found the oldest appearance of the Inoceramid species Cremnoceramus deformis erectus, which marks the time boundary. Careful studies also revealed other microfossils and a characteristic change in the ratio of the carbon isotopes 12C and 13C, a so-called negative anomaly in the carbon cycle.
A Global Time Stamp for Earth’s History
“This means that variable geological sequences, such as marine shelf sediments in Mexico or the deep sea in the tropical Atlantic, can now be compared and classified in time,” explains Prof. Silke Voigt. “This is important in order to be able to make an exact chronological classification even in the case of incomplete successions and ultimately to see, for example, what the climate was like at a certain time in the past in different places in the world.”
Professor Ireneusz Walaszczyk says: “The sequence in Salzgitter-Salder prevails over other candidates, for example from the USA, India, Madagascar, New Zealand and Poland, because we have a perfect rock boundary sequence here over 40 meters, with a well-defined record of events which took place in this interval of geological time.”
“The Zechstein Sea left behind massive salt layers in the North German Basin more than 250 million years ago,” explains André Bornemann. “The rock layers deposited later exerted pressure on these salt layers, some of which bulged up into large salt domes, deforming younger layers in the process. Salder is located near such a salt dome, so that here the fossil-rich rock layers of the Cretaceous period are steeply upright, resulting in a wonderful profile that is very accessible for scientific investigations. That’s why we at LBEG have designated this place as a geotope, and this is one of the most important geopoints of the Harz-Braunschweiger Land-Ostfalen UNESCO Global Geopark.”
Background:
In the limestone quarry at Hasselberg near Salder in the north-east of the Salzgitter mountain range, limestone and marl used to be quarried for the cement industry and later for ore processing. Today, it is the location of a well-known biotope and geotope which is the property of the Stiftung Naturlandschaft (Natural Landscape Foundation) and established by the BUND regional association of Lower Saxony. While the care of the quarry site has been entrusted to the Salzgitter district group of BUND, the Harz-Braunschweiger Land-Ostfalen UNESCO Global Geopark looks after the geoscientific part of the quarry. The quarry is not freely accessible for nature conservation reasons, but guided walks are occasionally offered.
90 million years ago, in the second half of the Cretaceous, it was tropically warm on Earth: the ice-free poles ensured high sea levels, and Central Europe consisted of a cluster of islands. In the sea, ammonites developed a tremendous variety of forms, while dinosaurs reigned on land. The first flowering plants began to compete with horsetails and ferns. About 89.39 million years ago, the climate began to cool slightly, sea levels began sink, and a new period in Earth history, the Coniacian, replaced the Turonian.
References:
“The Global Boundary Stratotype Section and Point (GSSP) for the base of the Hauterivian Stage (Lower Cretaceous), La Charce, southeast France” by Jörg Mutterlose, Peter F. Rawson, Stéphane Reboulet, with contributions by François Baudin, Luc Bulot, Laurent Emmanuel, Silvia Gardin, Mathieu Martinez and Maurice Renard, 1 June 2021, Episodes.
DOI: 10.18814/epiiugs/2020/020072
“Reassessment of the Salzgitter-Salder section as a potential stratotype for the Turonian–Coniacian boundary: stable carbon isotopes and cyclostratigraphy constrained by calcareous nannofossils and palynology” by Silke Voigt, Tobias Püttmann, Jörg Mutterlose, André Bornemann, Ian Jarvis, Martin Pearce and Irek Walaszczyk, 4 September 2020, Newsletters on Stratigraphy.
DOI: 10.1127/nos/2020/0615
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5 Comments
This is fascinating to me because even though I am certainly no scientist, I still understand exactly what is going on here. I’ve always loved every aspect of natural history. Thank you!
The geologic time scale presented regarding evolution of lifeform including environments citing to Golden Nail,Germany is revelent.Congrztulation and thanks to the authors.Lifeform seems to seen from 2 billion years before have menifested on half billion years before.Present physical form enhaced in 250-240 million years before.So dinosaurs must attend movement <90 million years before.Likely time period for flowering plants started from 90_ million years before anď these competed with horsetails and ferns was due to Nature's law.Facts occured near the region of DecanTrap and EasternGhats has been noted in India.
The geologic time scale presented regarding evolution of lifeform including environments citing to Golden Nail,Germany is revelent.Congrztulation and thanks to the authors.Lifeform seems to seen from 2 billion years before have menifested on half billion years before.Present physical form enhaced in 250-240 million years before.So dinosaurs must attend movement <90 million years before.Likely time period for flowering plants started from 90_ million years before anď these competed with horsetails and ferns was due to Nature's law.Facts occured near the region of DecanTrap and EasternGhats has been noted in India.
Thus,every step of geological evolution process was strictly framed and regulated by Physical law of planet as basic foundation to govern.This was continued untill<90 million years before in the geologic history of evolution.
The present research paper along with other recent contributions from the America on evolution of lifefom in planet earth parallel to geologic tectonic plate evolution dealt in parts leads to a central idea,that is lacking any flaw in universality or deviation from physical laws.This is confirming from the sole time period or point either associated with any event perfectly.So uniformness is seen in every study can able to relate some unique process and more studies are needed to establish the fact or phenomena.But things are changed only after <90 million years before when first Dinosaurs enhanced dynamism and started to regin in land.
It would be of great interest to see the actual data that defines the sequence boundary interpretation. Many wells drilled in the Gulf of Mexico onshore and offshore have penetrated the boundary..