| 1. |
- Schmitz, Birger, et al.
(författare)
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An extraterrestrial trigger for the mid-Ordovician ice age : Dust from the breakup of the L-chondrite parent body
- 2019
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Ingår i: Science Advances. - : American Association for the Advancement of Science (AAAS). - 2375-2548. ; 5:9
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Tidskriftsartikel (refereegranskat)abstract
- The breakup of the L-chondrite parent body in the asteroid belt 466 million years (Ma) ago still delivers almost a third of all meteorites falling on Earth. Our new extraterrestrial chromite and 3He data for Ordovician sediments show that the breakup took place just at the onset of a major, eustatic sea level fall previously attributed to an Ordovician ice age. Shortly after the breakup, the flux to Earth of the most fine-grained, extraterrestrial material increased by three to four orders of magnitude. In the present stratosphere, extraterrestrial dust represents 1% of all the dust and has no climatic significance. Extraordinary amounts of dust in the entire inner solar system during >2 Ma following the L-chondrite breakup cooled Earth and triggered Ordovician icehouse conditions, sea level fall, and major faunal turnovers related to the Great Ordovician Biodiversification Event.
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| 2. |
- Bergström, Stig M., et al.
(författare)
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Darriwili (Keskordoviitsiumi) δ13Corg kemostratigraafia koos graptoliitide biostratigraafiaga klassikalisel röstånga alal skåne maakonna loodeosas lõunarootsis
- 2020
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Ingår i: Estonian Journal of Earth Sciences. - : Estonian Academy Publishers. - 1736-4728. ; 69:3, s. 121-133
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Tidskriftsartikel (refereegranskat)abstract
- The largely covered Middle Ordovician succession in the classic geological Röstånga area in northwestern Scania has not been studied for some 80 years. A new drill core through a succession ranging from the lower–middle Darriwilian to the lower Sandbian has provided a unique opportunity to investigate the graptolite biostratigraphy and the δ13Corg chemostratigraphy, and clarify their stratigraphic relations, through this ~90 m thick interval, which is developed within a black shale facies. The lithology, biostratigraphy and chemostratigraphy are closely similar to those of the coeval strata in the Fågelsång area, southcentral Scania, including the presence of the Fågelsång Phosphorite, which was previously unrecorded in the Röstånga area. The new data are particularly important in providing evidence of the relations between graptolite biostratigraphy and δ13Corg chemostratigraphy. The Fågelsång3 and Röstånga2 drill core successions are currently the only Darriwilian sequences in the world where these relations have been well established.
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| 3. |
- Bergström, Stig M., et al.
(författare)
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Darriwilian (Middle Ordovician) chemostratigraphy linked to graptolite, conodont and trilobite biostratigraphy in the Fågelsång-3 drill core, Scania, Sweden
- 2018
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Ingår i: GFF. - : Informa UK Limited. - 2000-0863 .- 1103-5897. ; 140:3, s. 229-240
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Tidskriftsartikel (refereegranskat)abstract
- A recent core drilling in the geologically classical Fågelsång area resulted in a 58.70-m-long drill core through the lowermost Sandbian Sularp Shale, the Darriwilian Almelund Shale and Komstad Limestone, and part of the late Tremadocian to earliest Darriwilian Tøyen Shale. The shales contain zone index graptolites that are used for an update of the standard Darriwilian graptolite zone succession in Baltoscandia in which six zones are now recognized. The Komstad Limestone interval and lowermost part of the Almelund Shale have beensubdivided into four conodont zones. The δ13Corg chemostratigraphy, which has been established through the entire drill core based on 120 closely spaced samples, shows a somewhat subdued development of the middle Darriwilian Isotope Carbon Excursion (MDICE), which is dated in terms of graptolite biostratigraphy. The Fågelsång isotope curve is correlated with a closely similar δ13Ccarb curve from a coeval, apparently stratigraphically essentially continuous, succession at Kårgärde in south-central Sweden, which previously has been subdivided into 13 conodont zones and subzones. For the first time, these conodont zonal units can be calibrated with Fågelsång graptolite zones using δ13Corg chemostratigraphy. The several new results of this study are expected to be useful for assessing biostratigraphic relations between units in shale and carbonate facies in Baltoscandia and elsewhere in the world.
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| 4. |
- Bergström, Stig M., et al.
(författare)
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Maurits Lindström - A renaissance geoscientist
- 2007
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Ingår i: GFF. - : the Geological Society of Sweden. - 1103-5897. ; 129:2, s. 65-69
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- This issue of the GFF is dedicated to Professor Maurits Lindström on the occasion of his 75th birthday by students, colleagues, and friends in recognition of his profound impact on the Science of Geology as researcher and teacher during more than half a century.
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| 5. |
- Bergström, Stig M., et al.
(författare)
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The age of the Middle Ordovician Winneshiek Shale : reply to a critical review by Lindskog & Young (2019) of a paper by Bergström et al. (2018a)
- 2020
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Ingår i: Lethaia. - : Scandinavian University Press / Universitetsforlaget AS. - 0024-1164 .- 1502-3931. ; 53:1, s. 1-4
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Tidskriftsartikel (refereegranskat)abstract
- A recent review by Lindskog & Young (2019) of a paper published in Lethaia by Bergström et al. (2018a) contains many errors, misleading statements and unsupported opinions. Their review claims that we did not consider biostratigraphy in our efforts to chemostratigraphically date the Winneshiek Shale. That this is incorrect is shown by the fact that Liu et al. (2017), which contains a two-page review of all fossil evidence that has a bearing on the age of the Winneshiek Shale and was written by Bergström, was cited in Bergström et al. (2018a) and used extensively in our chemostratigraphical age assessment of the unit. Interestingly, recent research provides support for our conclusion regarding the age of the Winneshiek Shale, indicating that at least its upper part is coeval with the Nicholsonograptus fasciculatus Graptolite Zone and the Eoplacognathus pseudoplanus Conodont Zone. In constructing their arguments, Lindskog & Young (2019) provide no alternative interpretations or corrections of scientific value.
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| 9. |
- Ahlberg, Per, et al.
(författare)
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Jan Bergström 1938-2012
- 2013
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Ingår i: Kungliga Fysiografiska Sällskapet i Lund Årsbok 2011-2012. - 1402-1277. ; 2011-2012, s. 113-115
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Bokkapitel (refereegranskat)
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| 10. |
- Ahlberg, Per, et al.
(författare)
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Maurits Lindström 1932-2009
- 2011
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Ingår i: Kungliga Fysiografiska Sällskapet i Lund Årsbok 2009-2010. - 1402-1277. ; 2009-2010, s. 138-140
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Bokkapitel (refereegranskat)
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