Abstract

By focusing on impact-triggered phenomena having occurred synchronously with or shortly prior to formation boundaries, two glass sand pits (Upper Maastrichtian) located near Uhry, North Germany have been studied in regard to the K/T boundary throughout the last 40 years during progressive exploitation of glass sand. However, a clastic sequence of sand, mass flow and pelite deposited in a deep channel of about 10 - 12 m in depth, eroded into the glass sand, surprisingly shows an Upper Eocene/Lower Oligocene age, well defined by a Dinocyst assemblage (Chiripteridium c. galea, Enneado cysta arcuata, Areoligera tauloma = D 12na - D 14na) from a 0.5 meter thick pelite that marks the Rupelian transgression within an estuarian system running northwest/southeastward. The section exposes a high energy mass flow and formerly solid frozen angular glass sand blocks of up to a meter-size embedded in fluvial sand of the channel base. Furthermore, erratic clastics of up to 0.4 meter in diameter appear at the pelite base. The “unusual” Dinocyst assemblage is of autochthonous origin and comprises the fresh water alga Pediastrum Kawraiskyias indicator for cold climate, hitherto only known from Quaternary. Missing pollen indicate a vegetation-less hinterland. Thus, there cannot be any doubt that around the E/O b. at least one “rare event” has happened as verified by short tremendous flooding and significant temperature fall (“cosmic winter”). According to the attitude of the global impact scientific community, these phenomena belong to the spectrum of “indirect effects” of major impacts. Radiometric ages of relevant major impact events underline that both impact craters of Popigai, Russia (100 Kilometer in diameter, 35.7 Ma) and Chesabreake, USA (85 Kilometer in diameter, 35.5 Ma) happened shortly before the E/O b.(33.75 Ma). In addition, a tektite strewn field along the eastern coast of the USA and micro-tektites (Gulf of Mexico, Caribbean Sea, Barbados) yield an age of ~34.4 Ma, close to the E/O b. Consequently, there does exist an extremely high probability that Uhry site hosts impact-triggered products at the E/O b. It should be stressed that the Upper Eocene Epoch comprises an amazingly high number of impact events during the time-span 34.2 - 37.0 Ma.

Highlights

  • This paper follows the spirit of both following quotations:“Since merely effects are accepted on the screen of science, it seems to be constrained to trace something quite scarce and remote if we search for “indirect effects”

  • A clastic sequence of sand, mass flow and pelite deposited in a deep channel of about 10 - 12 m in depth, eroded into the glass sand, surprisingly shows an Upper Eocene/Lower Oligocene age, well defined by a Dinocyst assemblage (Chiripteridium c. galea, Enneado cysta arcuata, Areoligera tauloma = D 12na - D 14na) from a 0.5 meter thick pelite that marks the Rupelian transgression within an estuarian system running northwest/southeastward

  • Since the uppermost Maastrichtian and the Paleocene are missing in the section, it can be concluded that the K/T transitional sequence had been eroded since the beginning of salt diapirism [27]

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Summary

Introduction

This paper follows the spirit of both following quotations:. “Since merely effects are accepted on the screen of science, it seems to be constrained to trace something quite scarce and remote if we search for “indirect effects”. Sch.) “The recognition of the sedimentologic consequences of “Convulsive Events” (“Rare Events”) poses a special challenge to sedimentary geologists. Meeting this challenge will almost certainly demonstrate that “Convulsive Geologic Events” have greater relevance to the sedimentary record than has been previously recognized. For checking some of the parameters listed above, two glass sand pits located atUhry Village near Braunschweig, North Germany have been studied throughout the last 25 years during the continuous sand/gravel exploitation for glass industries (Figure 1(a), [27]) Both pits (Schlingmeier, Ewers) expose Maastrichtian glass sand and Upper Eocene/Lower Oligocene clastics, comprising several unconformities, all overlain with Pleistocene moraine and fluvio-glacial deposits (Figure 2(a) and Figure 2(b), Latitude 5797500, Longitude 4422600/4422160)

Geologic and Paleogeographic Setting
Biostratigraphy and Major Impacts
Lower Eocene Sand and Pelite
Discussion and Interpretation
Findings
Conclusions
Closing Statement
Full Text
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