Fredrik Terfelt

Lund University | LU · Department of Physics, Division of Nuclear Physics, Astrogeobiology Laboratory

Extraterrestrial chrome spinel and chromite extracted from the sedimentary rock record are relicts from coarse micrometeorites and rarely meteorites. They are studied to reconstruct the paleoflux of meteorites to the Earth and the collisional history of the asteroid belt. Minor element concentrations of Ti and V, and oxygen isotopic compositions of...

This volume pays tribute to the great career and extensive and varied scientific accomplishments of Walter Alvarez, on the occasion of his 80th birthday in 2020, with a series of papers related to the many topics he covered in the past 60 years: Tectonics of microplates, structural geology, paleomagnetics, Apennine sedimentary sequences, geoarchaeo...

Although the ~200 impact craters known on Earth represent only a small fraction of the craters originally formed, the available data suggest an excess of craters by one order of magnitude, in number, in the interval ca. 470-440 Ma during the Ordovician. Most of these "excess" craters may be related to the breakup of the L-chondrite parent body (LCP...

Significance The standard view of meteorite delivery to Earth is that of the cascading model where large asteroid break-ups generate new fragment populations that feed the inner solar system with material for extended time periods. Our investigated time windows, stretching from the Cambrian to the present, do not support this model. In fact, of 70...

Based on sediment‐dispersed extraterrestrial spinel grains in the Bottaccione limestone section in Italy, we reconstructed the micrometeorite flux to Earth during the early Paleocene. From a total of 843 kg of limestone, 86 extraterrestrial spinel grains (12 grains > 63 μm, and 74 in the 32–63 μm fraction) have been recovered. Our results indicate...

The δ¹³C chemostratigraphy of five of the seven Ordovician global stages has been published previously but no such data have been available from the Floian GSSP and most of the Sandbian GSSP in Sweden. This lack of information has now been remedied by isotope data obtained from series of closely spaced shale samples collected from the Floian strato...

We have reconstructed the distribution of extraterrestrial chrome spinels in a marine limestone section across the Frasnian–Famennian stratotype section at Coumiac in southern France, providing the first insights on the types of micrometeorites and meteorites that fell on Earth at this time. The data can test whether the small cluster of roughly co...

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 ³ He 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 Ordov...

We have reconstructed the distribution of extraterrestrial chrome spinels in a marine limestone section across the Frasnian–Famennian stratotype section at Coumiac in southern France, providing the first insights on the types of micrometeorites and meteorites that fell on Earth at this time. The data can test whether the small cluster of roughly co...

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...

Central Italy has been a cradle of geology for centuries. For more than 100 years, studies at the Umbria and Marche Apennines have led to new ideas and a better understanding of the past, such as the Cretaceous-Paleogene (K-Pg) boundary event, or the events across the Eocene-Oligocene transition from a greenhouse to an icehouse world. The Umbria-Ma...

Late Sandbian to early Katian δ¹³Ccarb chemostratigraphy has in Norway been described in only two previous reports that dealt with two geographically rather widely separated areas, namely the Oslo-Asker district and the Nes-Hamar district. No data have been available from the Ordovician outcrop areas between these districts that could help clarify...

The precise age of the Winneshiek Shale, a recently discovered Konservat‐Lagerstätte located in a very unusual depositional setting inside the Decorah impact structure, has remained uncertain in the absence of biostratigraphically highly diagnostic fossils. This chemostratigraphical study, based on δ13Corg data from 36 drill core samples through th...

We show that Earth's sedimentary strata can provide a record of the collisional evolution of the asteroid belt. From 1652 kg of pelagic Maiolica limestone of Berriasian-Hauterivian age from Italy, we recovered 108 extraterrestrial spinel grains (32-250 μm) representing relict minerals from coarse micrometeorites. Elemental and three oxygen isotope...

During the late Eocene there was an enigmatic enhancement in the flux of extraterrestrial material to Earth. Evidence comes from sedimentary ³He records indicating an increased flux of interplanetary dust during ca. 2 Myr, as well as two very large impact structures, Popigai (100 km diameter) and Chesapeake Bay (40-85 km), that formed within 10-20...

Most meteorites that fall today are H and L type ordinary chondrites, yet the main belt asteroids best positioned to deliver meteorites are LL chondrites 1,2 . This suggests that the current meteorite flux is dominated by fragments from recent asteroid breakup events 3,4 and therefore is not representative over longer (100-Myr) timescales. Here we...

Sub-millimetre-sized phosphatic spherules are often found in acetic acid-insoluble residues produced for microfossil extraction. As they are typically associated with conodont elements and have a similar chemical composition, they are informally known as ‘conodont pearls’. Still, the origin of these micro-spherules has been controversial, and autho...

A large abundance of L-chondritic material, mainly in the form of fossil meteorites and chromite grains from micrometeorites, has been found in mid-Ordovician 470 Ma old sediments globally. The material has been determined to be ejecta from the L chondrite parent body breakup event, a major collision in the asteroid belt 470 Ma ago. In this study w...

Synchrotron radiation X-ray tomographic microscopy (SRXTM) was used to virtually dissect and peel the shields off of the microscopic, bivalved phosphatocopine crustaceans in the Cambrian ‘Orsten’ type of preservation of Sweden. Doing so opened up for an array of concealed internal structures to be observed in a fully enclosed specimen of Hesslandon...

Except for the scattered cephalopod conchs that have given the rock type its name, mollusk fossils are relatively rare in the Middle Ordovician ‘orthoceratite limestone’ of Sweden. However, an interval in the Darriwilian stands out as being unusually rich in various types of mollusks. Throughout southern Sweden, gastropods became relatively abundan...

The onset of Earth's present icehouse climate in the Late Eocene coincides with astronomical events of enigmatic causation. At ∼36 Ma ago the 90–100 km large Popigai and Chesapeake Bay impact structures formed within . Enrichments of 3He in coeval sediments also indicate high fluxes of interplanetary dust to Earth for . Additionally, several medium...

The concept of the agnostoid arthropod species Lotagnostus americanus (Billings, 1860), which has been reported from numerous localities in the upper Furongian Series (Cambrian) of Laurentia, Gondwana, Baltica, Avalonia, and Siberia, is reviewed with emphasis on morphologic and taphonomic information afforded by large collections from Hunan in Sout...

About a quarter of all meteorites falling on Earth today originate from the breakup of the L-chondrite parent body ∼470 Ma∼470 Ma ago, the largest documented breakup in the asteroid belt in the past ∼3 Ga∼3 Ga. A window into the flux of meteorites to Earth shortly after this event comes from the recovery of about 100 fossil L chondrites (1–21 cm in...

The traditional Furongian trilobite biozones of Scandinavia, recently proposed abandoned due to inconsistent boundary definitions [Terfelt, F., Eriksson, M.E., Ahlberg, P. & Babcock, L.E., 2008: Furongian Series (Cambrian) biostratigraphy of Scandinavia – a revision. Norwegian Journal of Geology 88, 73–87], are resurrected and elevated to superzona...

The Cambrian–Ordovician boundary interval in Scandinavia is characterized by largely endemic trilobite species and fossil-meager intervals within the Alum Shale Formation. Previous investigations of this interval in Scandinavia, based on drill cores, are rather sketchy. In order to characterize the faunal signature in a largely dysoxic setting duri...

Out of the 14 agnostoid species/subspecies so far recorded from the Furongian of Scandinavia, seven are excellent biostratigraphical indices and important for correlation between Baltica and other palaeocontinents. Glyptagnostus reticulatus, Aspidagnostus lunulosus and Agnostus (Homagnostus) obesus first appear at the base of the G. reticulatus Zon...

The world-famous 'Orsten' Konservat-Lagerstätte has yielded detailed information about Cambrian arthropods and their morphology. Internal organs or soft tissues have, however, rarely been reported, an obvious palaeobiological drawback. In this study, we employed synchrotron radiation X-ray tomographic microscopy (SRXTM) to study microscopic 'Orsten...

The Cambrian 'Orsten' fauna comprises exceptionally preserved and phosphatised microscopic arthropods. The external morphology of these fossils is well known, but their internal soft-tissue anatomy has remained virtually unknown. Here, we report the first non-biomineralised tissues from a juvenile polymerid trilobite, represented by digestive struc...

Video clip showing the hypostome with digestive system (LO 11348t). Semi-transparent (voltex) with clipping plane transecting the specimen from posterior to anterior. (MP4)

Video clip showing the hypostome with digestive system (LO 11348t). External morphology (isosurface). (MP4)

Terfelt, F, Bagnoli, G. & Stouge, S. 2011: Re-evaluation of the conodont Iapetognathus and implications for the base of the Ordovician System GSSP. Lethaia, Vol. 45, pp. 227–237. In 2000, the International Union of Geological Sciences (IUGS) ratified the decision from the International Working Group on the Cambrian–Ordovician Boundary (COBWG) to pl...

Enclosed in the Darriwilian (Middle Ordovician) part of the reddish ‘orthoceratite limestone’ of Baltoscandia is a conspicuous c. 1.5 m thick unit colloquially known as the ‘Täljsten’ interval. It has a wide geographical distribution in the Baltoscandian paleocontinent but is particularly well exposed in south-central Sweden. The unit is characteri...

Pseudagnostus rugosus Ergaliev, 1980 is described from the Furongian Ctenopyge tumida Zone at Gislövshammar, Scania, southern Sweden. This is the first record of this distinctive agnostoid in Scandinavia. The species is known previously from Malyi Karatau, Kazakhstan, and northwestern Hunan and western Zhejiang, South China, and provides a newly re...

Terfelt, F., Ahlberg, P. & Eriksson, M.E. 2011: Complete record of Furongian polymerid trilobites and agnostoids of Scandinavia – a biostratigraphical scheme. Lethaia, Vol. 44, pp. 8–14. So far, 112 polymerid trilobite species/subspecies and 13 agnostoid species/subspecies have been recorded from the Furongian (upper Cambrian) of Scandinavia. For t...

A core drilling (Andrarum-3), from the classical locality at Andrarum, Scania, southernmost Sweden, penetrated a 28.90-m-thick Cambrian succession. The core comprises dark grey to black, finely laminated mudstones and shales with early concretionary carbonate lenses (stinkstones or orsten) and a few primary carbonate beds. The middle Cambrian (prov...

The furongian of Mount Kinnekulle, Vastergotland, Sweden (Fig. 1) is exposed in a number of road cuts, stream cuts, and abandoned alum shale quarries scattered around the mountain (e.g., Westergard, 1922, fig. 18; Muller and Hinz, 1991, fig. 2). Stratigraphically, the exposed successions span the Olenus gibbosus Zone through the Peltura paradoxa Zo...

The Furongian Series (Cambrian) biostratigraphy of Scandinavia is revised. We propose a two-fold trilobite zonation based on agnostoids and polymerids respectively. The agnostoid zonation includes four zones, in ascending order: the Glyptagnostus reticulatus, Pseudagnostus cyclopyge, Lotagnostus americanus, and the Trilobagnostus holmi Zone. The po...

Macropyge (Promacropyge) scandinavica new species is described from the Furongian Peltura minor Zone on northwestern Mount 14 Kinnekulle, southcentral Sweden. It represents the first macropyginid trilobite recorded in Baltica. M. (P.) scandinavica closely resembles other species of the same subgenus from southeast China, suggesting a correlation be...

The middle Cambrian–Furongian transitional interval was a time of significant biotic and environmental changes. Strata of this age in Scania, southern Sweden, contain two interlayered biofacies, a normal one dominated by trilobites and an anomalous one dominated by phosphatocopines (small bivalved arthropods). In places these biofacies are separate...

  The Scandinavian trilobites described in the classical papers by Moberg and Möller (1898) and Moberg (1898) are reviewed, based on the original type collections. The ten species and subspecies originally described are here considered to represent 12 species and subspecies, ranging in age from the latest Furongian (late Cambrian) through the Trema...

A drilling made in 1972 at Håslöv, Scania, southern Sweden, penetrated a 2572 m thick succession of Phanerozoic strata. The only cored parts of the succession derive from the Upper Ordovician and the Furongian (upper Cambrian) series. Merely the uppermost part of the Furongian was recovered, comprising eight metres of Alum Shale with limestone conc...

A section through the Upper Cambrian black shales and limestones at Kakeled on Kinnekulle, Västergötland, Sweden, extends from the lower-middle part of the Agnostus pisiformis Zone into the Peltura scarabaeoides Zone. Fossils are usually preserved only in the stinkstones, but in the A. pisiformis Zone trilobites can be found also in the shales. Lit...

Thesis (doctoral)--Lunds Universitet, 2006. Includes bibliographical references.