378 research outputs found
Ep. #031 - Jan Zalasiewicz
No full textThis recording and transcript form part of a collection of podcasts conducted by the Cultures of Energy at Rice University. Cultures of Energy brings writers, artists and scholars together to talk, think and feel their way into the Anthropocene. We cover serious issues like climate change, species extinction and energy transition. But we also try to confront seemingly huge and insurmountable problems with insight, creativity and laughter.Big news this week, friends, it turns out we’re living in the Anthropocene after all. The Anthropocene Working Group (AWG) of the International Union of Geological Sciences released its report at the International Geological Congress in Cape Town that we have left the Holocene behind. Cymene and Dominic find themselves more melancholy than they expected to be about this. But fortunately we’re able to talk it over (12:50) with Jan Zalasiewicz, Professor of Paleobiology at the University of Leicester, author of the marvelous The Planet in a Pebble (Oxford, 2010), and the Chair of the AWG. Jan walks us through the Working Group’s process of investigation, the forms of evidence that mattered to them and the ensuing debate over whether to make the Anthropocene a new geological time unit. We discuss the early history of climate science, the origin of the Anthropocene concept, what skeptics of the concept are thinking, and the study of deep time as a labor of love that may be able to help us all with the transition to a new sense of time. Is the Anthropocene an age or an epoch, when exactly did it begin, what are its key markers? What is the “golden spike” we are now hearing about? Even if we can’t make anyone feel better about the Anthropocene, we can at least answer some of your questions about it :
Evolutionary significance of the retiolitine Gothograptus (Graptolithina) with four new species from the Silurian of the East European Platform (Baltica), Poland and Lithuania
No full textKozłowska, Anna, Bates, Denis, Zalasiewicz, Jan, Radzevičius, Sigitas (2019): Evolutionary significance of the retiolitine Gothograptus (Graptolithina) with four new species from the Silurian of the East European Platform (Baltica), Poland and Lithuania. Zootaxa 4568 (3): 435-469, DOI: 10.11646/zootaxa.4568.3.
The Goldilocks Planet: The Four Billion Year Story of Earth\u27s Climate
No full textn this remarkable new work, Jan Zalasiewicz and Mark Williams demonstrate how the Earth\u27s climate has continuously altered over its 4.5 billion-year history. The story can be read from clues preserved in the Earth\u27s strata - the evidence is abundant, though always incomplete, and also often baffling, puzzling, infuriating, tantalizing, seemingly contradictory. Geologists, though, are becoming ever more ingenious at interrogating this evidence, and the story of the Earth\u27s climate is now being reconstructed in ever-greater detail - maybe even providing us with clues to the future of contemporary climate change.https://scholar.dominican.edu/cynthia-stokes-brown-books-personal-research/1109/thumbnail.jp
Gothograptus diminutus Kozłowska & Bates & Zalasiewicz & Radzevičius 2019, n. sp.
No full textGothograptus diminutus n. sp. Fig. 23 1999 Gothograptus nassa (Holm, 1890), Kozłowska-Dawidziuk, p. 156, fig. 3B. 2016 Gothograptus nassa (Holm, 1890), Kozłowska, p. 535, fig. 1b. Type material. Holotype ZPAL G.29/21, mature specimen with six pairs of thecae (Fig. 23B, C, E); paratype ZPAL G.55/34, mature tubarium with six pairs of thecae and appendix (Fig. 23D). Bartoszyce IG-1well, depth 1659.9 m, Poland, parvus / nassa Biozone. Etymology. Latin diminutus— relating to the small size of the finite tubarium. Diagnosis. Small finite tubarium reaching six or seven pairs of thecae and appendix. Genicular structures of the nassa type of hood are usually developed on medial and distal thecae. It differs from other Gothograptus species in the small hoods and small number of thecae. Material. Bartoszyce IG-1 core, Poland, parvus / nassa Biozone, depths 1659.9 m; five mature specimens, and about 60 young tubaria or fragments; 1658.8 m, a few specimens. Description. Tubaria of G. diminutus n. sp. are small; length of mature tubarium with six pairs of thecae and appendix is about 5.0– 5.5 mm. Nema short. Length of appendix is about 0.6 mm. Width of proximal end above the ancora umbrella rim is 0.7 mm. Maximum width of tubarium reaches about 0.9 mm at the level of second and third pairs of thecae. The tubarium slowly tapers distally; below the appendix it is 0.4–0.5 mm wide. Mid-ventral lists are slightly longer in medial thecae, about 0.7 mm. Length of mid-ventral list of th1 1 is 0.35 mm. Mature tubaria have nassa - type hoods developed on medial and distal thecae. The biggest hoods are in distal thecae. Mature tubaria usually have thin lists and poorly developed reticulum (Fig. 23A, D). Some membrane of the metasicula is observed (Fig. 23B, F). The outer ancora is not observed. Remarks. Gothograptus diminutus n. sp. is the smallest form among the Gothograptus species. It is distinctive in that its mature tubaria do not have thick lists and dense reticulum, characteristic of mature colonies of all other Gothograptus species. This form is comparable in size to the dwarf monograptid, Pristiograptus parvus. It is noteworthy that both species occur at the same stratigraphical level, in the parvus / nassa Biozone. This material comes only from the Bartoszyce IG-1core of Poland.Published as part of Kozłowska, Anna, Bates, Denis, Zalasiewicz, Jan & Radzevičius, Sigitas, 2019, Evolutionary significance of the retiolitine Gothograptus (Graptolithina) with four new species from the Silurian of the East European Platform (Baltica), Poland and Lithuania, pp. 435-469 in Zootaxa 4568 (3) on page 466, DOI: 10.11646/zootaxa.4568.3.2, http://zenodo.org/record/260160
Gothograptus velo Kozłowska & Bates & Zalasiewicz & Radzevičius 2019, n. sp.
No full textGothograptus velo n. sp. Fig. 22 1990. Gothograptus (Gothograptus) sp. A. Kozłowska-Dawidziuk, pp. 202–203, pl. 24: 2; fig. 6A–E. Type material. Mature tubarium, holotype ZPAL G.XIII/35, Zawada 1 core, depth 1533.3–1540 m, Poland, upper part of lundgreni Biozone. Material. One finite tubarium with nine pairs of thecae. Diagnosis. Proximal thecae with no genicular structures, successive medial and distal thecae have genicular veils. The veils are built of thin reticular lists; there are no thicker lists at the end of the veil as in G. obtectus. Reticulum below thecal lip undergoes reduction in distal thecae. Description. The mature tubarium has nine pairs of thecae. The distal end is slightly damaged, together with the appendix (Fig. 22). The tubarium length is 10.1 mm, together with the extending nema. The width of the tubarium at the level of the first pair of thecae is 0.8 mm. The widest part of the tubarium is 1.2 mm at the level of the fifth thecal pair. The tubarium tapers distally to a width of 0.6 mm at the level of the ninth pair of thecae. The sicula length is 1.5 mm; the prosicula apex is connected to the lateral wall of the tubarium at the level of the lip of th1 2. The thecal lips are thick whereas the genicular lists are thinner in distal thecae but well developed and easy to distinguish (Fig. 22B). The two first pairs of thecae do not have genicular structures. The first well-developed veil is on the fifth pair of thecae. Some reticular lists of the veil of th6 1 are connected to the geniculum of th5 1, and to the reticulum of the th5 1 veil (Figs 9C, 22B). The reticulum of the ventral thecal wall is well-developed up to the fifth pair of thecae, but distally, below the long veils, it become poorly developed, eventually disappearing under the veils of the last thecal pairs. The genicular and mid-ventral lists below the veils exhibit a similar decrease in thickness, becoming as thin as some lists of the veil (Figs 9C, 22B). The outer ancora is well-developed in the mature tubarium, and built of thick reticulum (Fig. 22D). Some membrane of the metasicular wall is connected to the virgella (Fig. 22C). Proximal internal structures typical of the genus Gothograptus are present, but they are difficult to distinguish in the flattened material to hand. The nema is distinctively thicker than other lists of the tubarium, and the thickest part starts at the level of th5 1. Remarks. G. velo n. sp. differs from Gothograptus obtectus in the development of veils. The veils of G. velo are built of a delicate reticulum with no thick transverse lists as in G. obtectus. Some of the veils are connected to the veil of the previous theca, forming an external layer above the thecal orifices and thecae (Fig. 9C).Published as part of Kozłowska, Anna, Bates, Denis, Zalasiewicz, Jan & Radzevičius, Sigitas, 2019, Evolutionary significance of the retiolitine Gothograptus (Graptolithina) with four new species from the Silurian of the East European Platform (Baltica), Poland and Lithuania, pp. 435-469 in Zootaxa 4568 (3) on pages 462-466, DOI: 10.11646/zootaxa.4568.3.2, http://zenodo.org/record/260160
The Planet in a Pebble: A Journey into Earth\u27s Deep History
No full textThis is the story of a single pebble. It is just a normal pebble, as you might pick up on holiday - on a beach in Wales, say. Its history, though, carries us into abyssal depths of time, and across the farthest reaches of space.This is a narrative of the Earth\u27s long and dramatic history, as gleaned from a single pebble. It begins as the pebble-particles form amid unimaginable violence in distal realms of the Universe, in the Big Bang and in supernova explosions and continues amid the construction of the Solar System. Jan Zalasiewicz shows the almost incredible complexity present in such a small and apparently mundane object. Many events in the Earth\u27s ancient past can be deciphered from a pebble: volcanic eruptions; the lives and deaths of extinct animals and plants; the alien nature of long-vanished oceans; and transformations deep underground, including the creations of fool\u27s gold and of oil.Zalasiewicz demonstrates how geologists reach deep into the Earth\u27s past by forensic analysis of even the tiniest amounts of mineral matter. Many stories are crammed into each and every pebble around us. It may be small, and ordinary, this pebble - but it is also an eloquent part of our Earth\u27s extraordinary, never-ending story.https://scholar.dominican.edu/cynthia-stokes-brown-books-personal-research/1106/thumbnail.jp
Gothograptus auriculatus Kozłowska & Bates & Zalasiewicz & Radzevičius 2019, n. sp.
No full textGothograptus auriculatus n. sp. Figs 13–14 2006 Gothograptus nassa, Calner, Kozłowska, Masiak & Schmitz, p. 80, fig. 1E. Type material. Holotype ZPAL G.55/23, mature specimen with six pairs of thecae and distal end broken off (Fig. 13 B); paratype ZPAL G.55/24, distal end of mature tubarium with five pairs of thecae and appendix (Fig. 13 C, F). Bartoszyce IG-1well, depth 1645.2 m, Poland, lower part of praedeubeli Biozone. Etymology. Latin auriculatus —relating to the earlobe shape of the genicular structures. Diagnosis. Tubarium with genicular structures formed by the nassa type of hood, and paired vertical auriclelike structures bordering both sides of the thecal orifices. Auricle structures are characteristic only of Gothograptus auriculatus n. sp. In mature colonies the auricles bend towards the mid-ventral list below the thecal lip and nassa hood. Remarks. G. auriculatus n. sp. differs from G. nassa in having two lateral auricles, as additional elements located on the lateral sides of the thecal orifices and below the lips. Young colonies of the new species have nassa hoods; the auricles appear later in astogeny. Material. The material studied comes from Poland, Lithuania and Germany. The most abundant material comes from the Bartoszyce IG- well, ranges from 1649.0 to 1645.2 m, praedeubeli Biozone, yielding about 1300, mostly young, specimens. Two fragments of G. auriculatus come from Lithuania, Pilviskiai-141 core, depth 842.2 m, nassa / praedeubeli Biozone. Description. Tubaria slightly widening up to th1 2, then parallel-sided and gently tapering distally, ended by an appendix. Most of the specimens are represented by fragments of tubaria up to the 11th thecal pair. Tubarium width at the level of the first thecal pair is about 1.5 mm, and in the middle part of the tubarium 1.2 mm. The longest fragment of tubarium, comprising 11 pairs of thecae, is 10 mm long. The lists of the young stages of colony are very thin, about 15 µm across, while the lists of the mature tubarium are about five times thicker, at 75 µm. The thickening of lists starts from the proximal end. The looping meshes of the ancora umbrella are overgrown by a reticulum in the mature colonies. The ancora prongs below the lateral proximal orifices and the lists surrounding the proximal lateral orifices are extremely wide in mature specimens (Fig. 14 C–F).The reticular lists also become very wide in mature colonies, making the reticulum meshes very small. In the most mature specimens the reticulum lists reach similar thicknesses to those of the main lists of the tubaria (Fig. 13D). Based on well-preserved specimens representing the young tubaria, the sicula length is estimated at 1.4 mm, the length of the prosicula at 400 µm (Fig. 2). The nema starts at the level of the th1 2 geniculum and is connected to the obverse lateral wall of the tubarium. The typical genicular structures are well developed in mature specimens. During astogeny the auricles, typical of this species, are first developed in more distal thecae (Fig. 13 A–C). The longest hoods in mature specimens are about 370 µm long, and extend below the lips. As a consequence the thecal orifices are not visible. The hoods of astogenetically old tubaria may be elongated in the centre of their lower parts (Fig. 13E). The distal thecae are shorter and their genicular structures are usually irregular and shorter horizontally (Fig. 13E). In mature specimens, the nema widens distally to about 67 µm across at the most distal end of the tubarium and in the appendix (Figs 3, 13C). A nematularium was not identified. Remarks. Gothograptus auriculatus n. sp. has been described from the praedeubeli Biozone of Sweden, and published as G. nassa (Calner et al. 2006, fig. 1E). This taxon, also found in erratic boulders from Germany, has been illustrated and identified by Jaeger as Gothograptus nassa late form (Maletz 2010, figs 1, 2). The specimens, stored in the Museum für Naturkunde, Berlin, come from a fauna containing the type material of Colonograptus praedeubeli.Published as part of Kozłowska, Anna, Bates, Denis, Zalasiewicz, Jan & Radzevičius, Sigitas, 2019, Evolutionary significance of the retiolitine Gothograptus (Graptolithina) with four new species from the Silurian of the East European Platform (Baltica), Poland and Lithuania, pp. 435-469 in Zootaxa 4568 (3) on pages 451-454, DOI: 10.11646/zootaxa.4568.3.2, http://zenodo.org/record/260160
Gothograptus domeyki Kozłowska & Bates & Zalasiewicz & Radzevičius 2019, n. sp.
No full text<i>Gothograptus domeyki</i> n. sp. <p>Figs 15–16</p> <p> ?1952 <i>Gothograptus nassa</i>, Bouček & Münch, pp. 11–15, fig. 2, a–i.</p> <p> <b>Type material</b>. Holotype number VU RET-13, mature specimen with seven pairs of thecae and appendix (Fig. 16 A–B), Šiupyliai-69 core, 1009,1 m, <i>lundgreni</i> Biozone, <b>paratype</b> number VU RET-14, finite tubarium (Fig. 16 C–E), Šiupyliai-69 core, depth 1010.0 m, <i>lundgreni</i> Biozone, Lithuania.</p> <p> <b>Etymology.</b> Ignacy Domeyko (1802–1889) was a Polish geologist, mineralogist and educator; most of his life was spent in Chile.</p> <p> <b>Diagnosis</b>. <i>Gothograptus</i> with genicular hoods of <i>nassa</i> type developed on the first pair of thecae; second pair of thecae may have paired spines with seams or remnants of reticulum between them; subsequent thecae lacking genicular processes except for the last theca with a reticulated hood. Distinctively thicker thecal lips than pleural and genicular lists. G <i>othograptus domeyki</i> differs from other <i>Gothograptus</i> species in the lack of genicular structures in the medial and distal thecae.</p> <p> <b>Remarks.</b> <i>Gothograptus domeyki</i> <b>n. sp.</b> differs from other <i>Gothograptus</i> species in the lack of any genicular processes in most thecae as well as in having thick lips. <i>G. domeyki</i> <b>n. sp.</b> is similar to <i>G. kozlowskii</i> in having <i>nassa</i> type hoods on the first pair of thecae and reticulated hoods on the last pair of thecae. Similar reticulated hoods on the last thecae are also found in G. <i>storchi</i>. <i>G. domeyki</i> <b>n. sp.</b> is so far known only from Lithuania.</p> <p> Bouček & Münch (1952) described some retiolitines as <i>Gothograptus nassa</i>, from the Czech Republic, <i>lundgreni</i> Biozone. Their drawings show some tubaria with thick lips, and without genicular <i>nassa</i> hoods, similar to those described herein for the first time in <i>G. domeyki</i> <b>n. sp.</b> Proper recognition of this form needs some detailed study.</p> <p> <b>Material</b>. Two cores from Lithuania: Šiupyliai-69 core, depths: 1009.7 m 30 young, 12 mature; 1009.1 m 50 young, 31 mature; Vilkaviškis-131 core, depth 1095.8 m four fragments of mature specimens. Upper part of <i>lundgreni</i> Biozone.</p> <p> <b>Description.</b> Mature tubaria usually have seven or eight pairs of thecae and appendix. The total length of the tubarium is about 7.0 mm, together with the appendix. The tubarium is almost parallel-sided, widest at 0.83 mm at the level of the first thecal pair, and then it slowly narrows to 0.4 mm just below the appendix.</p> <p>In some mature specimens the prongs of the ancora, as well as the sicular rim and lists above the proximal lateral orifices, are extremely thick ((Fig. 16A, B, E, H, I). An outer ancora is well developed in mature specimens. The proximal ventral orifices are overgrown by reticulum in mature colonies. Mid-ventral lists are 0.5 mm long in the first and last thecae, the rest are about 0.7 mm long.</p> <p> Genicular structures start to develop when the colony reaches about five thecal pairs. There are three types of genicular structures in mature tubaria of <i>G. domeyki</i> <b>n. sp.</b> The first pair of thecae have <i>nassa</i> hoods; usually they are small and do not cover the orifices of thecae or they are slightly larger than the thecal orifice.</p> <p> The second and third thecal pairs have a pair of curved spines grown on the pleural lists, extending horizontally. Seams on the inner sides of the spines indicate that there was a thin membrane between them, so that the spines form the sides of a hood. The bases of the spines in the mature tubaria are of triangular shape (Fig. 16G). Similar spines forming hoods are also found in <i>Gothograptus kozlowskii</i> (see below).</p> <p>The next thecae have no hoods; their lips are thick, about twice as thick as the geniculum list. The genicular lists became significantly thinner in the last thecae. The last pair of thecae have reticulated hoods covering orifices; the genicular list is not developed. The reticulum of these hoods is connected with the appendix (Fig. 16A).</p> <p>umbrella, outside view.</p> <p> Some young tubaria with five pairs of thecae have reticulum up to the third pair of thecae, small <i>nassa</i> hoods on the first thecae, the two next pairs of thecae having thin genicular spines. A specimen with seven pairs of thecae has a well-developed reticulum, except on the two last thecae. The lists of young colonies are thin; the thickest is the nema (Fig. 15A, D). During astogeny the next thicker lists are the lateral apertural rods.</p> <p>The lips and genicular lists are so thick that the thecal orifice is very narrow (Fig. 15E, 16E). The thecal orifices vary in shape from nearly rectangular to pyramidal with rounded corners (Fig. 7A, 16C, E). Mature colonies have a dense reticulum of similar thickness to the clathrial lists, thus the structures formed by clathrial lists are difficult to distinguish.</p>Published as part of <i>Kozłowska, Anna, Bates, Denis, Zalasiewicz, Jan & Radzevičius, Sigitas, 2019, Evolutionary significance of the retiolitine Gothograptus (Graptolithina) with four new species from the Silurian of the East European Platform (Baltica), Poland and Lithuania, pp. 435-469 in Zootaxa 4568 (3)</i> on pages 454-457, DOI: 10.11646/zootaxa.4568.3.2, <a href="http://zenodo.org/record/2601607">http://zenodo.org/record/2601607</a>
A stratigraphical basis for the Anthropocene?
No full textRecognition of intimate feedback mechanisms linking changes across the atmosphere, biosphere, geosphere and hydrosphere demonstrates the pervasive nature of humankind's influence, perhaps to the point that we have fashioned a new geological epoch, the Anthropocene. To what extent will these changes be evident as long-lasting signatures in the geological record?
To establish the Anthropocene as a formal chronostratigraphical unit it is necessary to consider a spectrum of indicators of anthropogenically induced environmental change, and to determine how these show as stratigraphic signals that can be used to characterize an Anthropocene unit and to recognize its base. It is important to consider these signals against a context of Holocene and earlier stratigraphic patterns. Here we review the parameters used by stratigraphers to identify chronostratigraphical units and how these could apply to the definition of the Anthropocene. The onset of the range of signatures is diachronous, although many show maximum signatures which post-date1945, leading to the suggestion that this date may be a suitable age for the start of the Anthropocene
FIGURE 3. Gothograptus auriculatus n in Evolutionary significance of the retiolitine Gothograptus (Graptolithina) with four new species from the Silurian of the East European Platform (Baltica), Poland and Lithuania
No full textFIGURE 3. Gothograptus auriculatus n. sp., fragments of distal parts of tubaria showing a thick nema, Bartoszyce IG-1, depth 1647.2 m, praedeubeli Biozone, Poland. A–B, distal end of tubarium with broken appendix, ZPAL G.55/4, A, fragment with beginning of appendix, B, enlargement of last thecal region showing thick nema. C, lateral view of fragment of medial part of tubarium, ZPAL G.55/5.Published as part of Kozłowska, Anna, Bates, Denis, Zalasiewicz, Jan & Radzevičius, Sigitas, 2019, Evolutionary significance of the retiolitine Gothograptus (Graptolithina) with four new species from the Silurian of the East European Platform (Baltica), Poland and Lithuania, pp. 435-469 in Zootaxa 4568 (3) on page 440, DOI: 10.11646/zootaxa.4568.3.2, http://zenodo.org/record/260160
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