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Alexander P. Wolfe
University of Alberta
181Publications
47H-index
7,780Citations
Publications 181
Newest
Published on Oct 1, 2018in Geochimica et Cosmochimica Acta 4.69
Gabriela González Arismendi (University of Alberta), Ralf Tappert16
Estimated H-index: 16
(University of Alberta)
+ 2 AuthorsKarlis Muehlenbachs41
Estimated H-index: 41
(University of Alberta)
Abstract Deuterium exchange experiments on modern and fossil plant resins (amber) were conducted to assess to what extent diagenetic alteration can overprint the stable hydrogen ( δ 2 H) and carbon ( δ 13 C) isotopic composition of these materials. Pairs of resins and amber fragments were placed together with deuterated water in sealed quartz-glass tubes to assure that all samples were exposed equally to the chosen experimental conditions. Experiments lasting up to one year were carried out at t...
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Kaarel Mänd2
Estimated H-index: 2
(University of Tartu),
Karlis Muehlenbachs41
Estimated H-index: 41
(University of Alberta)
+ 2 AuthorsKurt O. Konhauser48
Estimated H-index: 48
(University of Alberta)
Abstract Ambers—fossilized plant resins—are a rich and unique source of paleoecological data due to their ability to preserve soft body fossils. However, interpretations concerning their environmental context are often hampered by uncertainties in the relationship between assemblages of inclusions and geological context, particularly in the case of secondarily redeposited ambers such as those from the Paleogene of Central Europe. Here we use stable carbon and hydrogen isotope analyses, as well a...
5 Citations Source Cite
Published on Sep 1, 2017in Anthropocene
Jan Zalasiewicz35
Estimated H-index: 35
(University of Leicester),
Colin N. Waters24
Estimated H-index: 24
(British Geological Survey)
+ 22 AuthorsAgnieszka Gałuszka20
Estimated H-index: 20
(Jan Kochanowski University)
Abstract Since 2009, the Working Group on the ‘Anthropocene’ (or, commonly, AWG for Anthropocene Working Group), has been critically analysing the case for formalization of this proposed but still informal geological time unit. The study to date has mainly involved establishing the overall nature of the Anthropocene as a potential chronostratigraphic/geochronologic unit, and exploring the stratigraphic proxies, including several that are novel in geology, that might be applied to its characteriz...
31 Citations Source Cite
Published on Jul 1, 2017in Geology 5.07
Alexander P. Wolfe47
Estimated H-index: 47
(University of Alberta),
Alberto V. Reyes18
Estimated H-index: 18
(University of Alberta)
+ 5 AuthorsJohn A. Westgate43
Estimated H-index: 43
(University of Toronto)
Eocene paleoclimate reconstructions are rarely accompanied by parallel estimates of CO 2 from the same locality, complicating assessment of the equilibrium climate response to elevated CO 2 . We reconstruct temperature, precipitation, and CO 2 from latest middle Eocene (ca. 38 Ma) terrestrial sediments in the posteruptive sediment fill of the Giraffe kimberlite in subarctic Canada. Mutual climatic range and oxygen isotope analyses of botanical fossils reveal a humid-temperate forest ecosystem wi...
9 Citations Source Cite
Published on Apr 1, 2017in Newsletters on Stratigraphy 3.63
Jan Zalasiewicz35
Estimated H-index: 35
,
Colin N. Waters24
Estimated H-index: 24
+ 24 AuthorsJacques Grinevald8
Estimated H-index: 8
A range of published arguments against formalizing the Anthropocene as a geological time unit have variously suggested that it is a misleading term of non-stratigraphic origin and usage, is based on insignificant temporal and material stratigraphic content unlike that used to define older geological time units, is focused on observation of human history or speculation about the future rather than geologically significant events, and is driven more by politics than science. In response, we conten...
22 Citations Source Cite
Published on Apr 1, 2017
Jan Zalasiewicz35
Estimated H-index: 35
(University of Leicester),
Mark Williams36
Estimated H-index: 36
(University of Leicester)
+ 22 AuthorsErle C. Ellis37
Estimated H-index: 37
(University of Maryland, College Park)
We assess the scale and extent of the physical technosphere, defined here as the summed material output of the contemporary human enterprise. It includes active urban, agricultural and marine components, used to sustain energy and material flow for current human life, and a growing residue layer, currently only in small part recycled back into the active component. Preliminary estimates suggest a technosphere mass of approximately 30 trillion tonnes (Tt), which helps support a human biomass that...
23 Citations Source Cite
Published on Mar 1, 2017in Current Biology 9.25
Lida Xing18
Estimated H-index: 18
(China University of Geosciences),
Ryan C. McKellar5
Estimated H-index: 5
(University of Regina)
+ 11 AuthorsAlexander P. Wolfe47
Estimated H-index: 47
(University of Alberta)
Summary In his correspondence, Markus Lambertz [1] raises some concerns about the phylogenetic placement and feather development of DIP-V-15103, the amber-entombed tail section that we recently reported [2] as fragmentary remains of a non-pygostylian coelurosaur (likely within the basal part of Coelurosauria). We here would like to respond to these concerns.
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Published on Dec 1, 2016in Current Biology 9.25
Lida Xing18
Estimated H-index: 18
(China University of Geosciences),
Ryan C. McKellar5
Estimated H-index: 5
(University of Regina)
+ 11 AuthorsAlexander P. Wolfe47
Estimated H-index: 47
(University of Alberta)
Summary In the two decades since the discovery of feathered dinosaurs [1–3], the range of plumage known from non-avialan theropods has expanded significantly, confirming several features predicted by developmentally informed models of feather evolution [4–10]. However, three-dimensional feather morphology and evolutionary patterns remain difficult to interpret, due to compression in sedimentary rocks [9, 11]. Recent discoveries in Cretaceous amber from Canada, France, Japan, Lebanon, Myanmar, an...
32 Citations Source Cite
Published on Dec 1, 2016
Andrzej Pisera15
Estimated H-index: 15
(Polish Academy of Sciences),
Renata Manconi12
Estimated H-index: 12
(University of Sassari)
+ 1 AuthorsAlexander P. Wolfe47
Estimated H-index: 47
(University of Alberta)
The freshwater sponge species Ephydatia cf. facunda Weltner, 1895 (Spongillida, Spongillidae) is reported for the first time as a fossil from middle Eocene lake sediments of the Giraffe kimberlite maar in northern Canada. The sponge is represented by birotule gemmuloscleres as well as oxea megascleres. Today, E. facunda inhabits warm-water bodies, so its presence in the Giraffe locality provides evidence of a warm climate at high latitudes during the middle Eocene. The morphological similarity o...
2 Citations Source Cite
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