How Aluminum in Zircon Can Tell Us What Happened Billions of Years Ago – #365papers – 2017 – 150

#365papers for May 30, 2017

Trail, Tailby, Wang, Harrison, and Boehnke, 2017, Aluminum in zircon as evidence for peraluminous and metaluminous melts from the Hadean to present: Geochemistry, Geophysics, Geosystems, v. 18, p. 1580-1593.

What’s it about?

Zircon is a mineral that forms in igneous rocks. As the rocks erode away, the zircons often survive and can be mixed into younger rocks, including new igneous rocks. Here, the authors use the concentration of aluminum in the zircons to determine the type of igneous rock the zircon originally formed in. Continue reading

Calcium Can Tell Us About Ancient Ecosystem Structure – #365papers – 2017 – 147

#365papers for May 27, 2017

Martin, Vincent, Tacail, Khaldoune, Jourani, Bardet, Balter, 2017, Calcium isotopic evidence for vulnerable marine ecosystem structure prior to the K/Pg extinction: Current Biology, v. 27

What’s it about?

The variations of the amounts of stable isotopes (that is non-radioactive) found in rocks and fossils can be used to help us understand patterns of weather, of vegetation, and of who’s eating whom in modern and fossil rocks, bones, teeth, and shells. Most of the time carbon, oxygen, and nitrogen are used for this.

The authors here show that calcium isotopes can be used to understand tropic level (where organisms are on the food chain) in modern and fossil animals. Their work shows that large marine reptiles likely went extinct at the end of the Permian Period because they all lived at the same trophic level. There was some sort of ecological change that eradicated their food supply and the marine reptiles could not recover. Continue reading

Because Isotopes of Carbon and Oxygen Are So Last Century… – #365papers – 2017 – 141

#365papers for May 21, 2017

Martin, Tacail, and Balter, 2017, Non-traditional isotope perspective in vertebrate palaeobiology: Palaeontology, p. 1-18.

What’s it about?

The authors discuss the utility of isotopes of calcium, magnesium, copper, iron, and zinc for study of ancient environments, dietary preferences, and food chains. Continue reading

Volcanoes and the Late Ordovician Extinction – #365papers – 2017 – 139

#365papers for May 19, 2017

Jones, Martini, Fike, and Kaiho, 2017, A volcanic trigger for the Late Ordovician mass extinction? Mercury data from south China and Laurentia: Geology,

What’s it about?

One of the “Big Five” mass extinctions that has affected life on this planet is the Late Ordovician mass extinction or LOME. The causes of such extinctions are topics of focused research efforts. Here, the authors show that pulses of volcanic activity may be related to the extinction events. Continue reading

Dinosaur Fossils: Dating the Rock to Date the Bones – #365papers – 2017 – 137

#365papers for May 17, 2017

An, Kuang, Liu, Peng, Xu, Xu, Zhang, Wang, Chen, and Zhang, 2016, Detrital zircon dating and tracing the provenance of dinosaur bone beds from the Late Cretaceous Wangshi Group in Zhucheng, Shandong, East China: Journal of Palaeogeography, v. 5, 72-99.

What’s it about?

Geochemical and sedimentological methods are used to determine the age and provenance (i.e. where did the sediments come from) of dinosaur-bearing rocks. The bones themselves could not be directly dated, but cannot be younger than the rocks they’re found in. Continue reading

How Did the Earth’s Crust Grow – #365papers – 2017 – 133

#365papers for May 13, 2017

Rozel, Golabek, Jain, Tackley, and Gerya, 2017, Continental crust formation on early Earth controlled by intrusive magmatism: Nature.

What’s it about?

The Earth didn’t always have continents. This paper explores how the planet’s first continents probably formed. The major hypotheses were that the continents formed by volcanic eruptions primarily, or by upwellings of magma that never erupted on the surface. It seems that the latter is most likely. Continue reading

Keratin Ain’t Gonna Make It – #365papers – 2017 – 132

#365papers for May 12, 2017

Saitta, Rogers, Brooker, Abbott, Kumar, O’Reilly, Donohoe, Dutta, Summons, and Vinther, 2017, Low fossilization potential for keratin protein revealed by experimental taphonomy: Palaeontology, p. 1-10.

What’s it about?

Keratin is a major protein making up hair and nails. The authors conduct experiments on modern keratin to emulate fossilization to test whether or not keratin is likely to fossilize. Based on these experiments, keratin should not survive the process of fossilization, though calcium phosphate and pigments might. Continue reading

Rock Weathering and its Influence on Climate – #365papers – 2017 – 125

#365papers for May 5, 2017

Godderis, Donnadieu, Carretier, Aretz, Dera, Macouin, and Regard, 2017 Onset and ending of the late Palaeozoic ice age triggered by tehtonically paced rock weathering: Nature Geoscience, doi:10.1038/ngeo2931

What’s it about?

Many hypotheses have been put forward to explain global glaciation that happened toward the end of the Paleozoic (started around 340-330 million years ago and ended around 290 million years ago). This paper explores the hypothesis that uplift and subsequent erosion of the ancient Hercynian orogeny (mountain belt) which once straddled the equator may have played an important role. Continue reading

What Happens to Make Fish Muscle Turn to Pyrite? – #365papers – 2017 – 124

#365papers for May 4, 2017

Oses, Petri, Boltani, Prado, Galante, Tizzutto, Rudnitzki, da Silva, Rodrigues, Rangel, Sucerquia, and Pacheco, 2017, Deciphering pyritization-kerogenization gradient for fish soft-tissue preservation: Nature Scientific Reports, v. 7, doi:10.1038/s41598-017-01563-0

What’s it about?

Fish fossils from the Santana Formation in northeastern Brazil are often exquisitely preserved, with soft-tissues (muscles, eyes, etc) often evident and available for study. The authors here are less concerned with what specifically was preserved, but how it was preserved. In some cases, the fossils were altered to pyrite; in others to kerogen. The path for alteration and preservation depended on minute details of the rocks and the geochemical environment in which the dead organisms were deposited. Continue reading

Highs and Lows of the Rocky Mountains in the Middle to Late Eocene – #365papers – 2017 – 97

#365papers for April 7, 2017

Fan, Constensius, and Dettman, 2017, Prolonged high relief in the northern Cordilleran orogenic front during middle and late Eocene extension based on stable isotope paleoaltimetry: Earth and Plantery Science Letters, v. 457, p. 376-384.

What’s it about?

The Rocky Mountains have been around for a long, long time. This study focuses on a part of the Rockies that was still growing between about 46 to about 34 million years ago. Through the study of fossil soils and fossil snails, the authors show that the difference between the lowest basins and the highest mountain peaks was around 4 km – which is a lot! Continue reading