Category Archives: Stable Isotopes

How Do the Early Processes of Fossilization Affect the Chemistry of Bones and Teeth? – #365papers – 2017 – 41

#365papers for February 10, 2017

Tutken, Vennemann, and Pfretzschner, 2008, Early diagenesis of bone and tooth apatite in fluvial and marine settings: Constraints from combined oxygen isotope, nitrogen and REE analysis: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 266, p. 254-268.

What’s it about?

This paper discusses how we can determine how altered a geochemical signal in a fossil bone or tooth might be, comparing bones and teeth that fossilized in both freshwater (river) and marine (ocean) environments. The authors used collagen content, nitrogen content, and the abundance of Rare Earth Elements (REEs) to attempt to estimate alteration.Continue reading “How Do the Early Processes of Fossilization Affect the Chemistry of Bones and Teeth? – #365papers – 2017 – 41”

Fresh water and marine snails from 55 million years ago – #365papers – 2017 – 39

#365papers for February 8, 2017

Schmitz and Andreasson, 2001, Air humidity and lake δ18O during the latest Paleocene-earliest Eocene in France from recent and fossil fresh-water and marine gastropod δ18O, δ13C, and 87Sr/86Sr: Geological Society of America Bulletin, v. 113, p. 774-789.

What’s it about?

This paper describes oxygen isotope ratios from modern freshwater snails and how the values and patterns of intra-shell analyses relate to the overall climate of a region. These patterns are then compared with Paleocene-Eocene aged gastropods to get at ancient climate. Some marine snails were also studied to see how they compare with freshwater snails. Strontium was also used to help get at the amount and timing of precipitation and weathering  in a region.Continue reading “Fresh water and marine snails from 55 million years ago – #365papers – 2017 – 39”

Snail Shells, Climate, and Weather – #365papers – 2017 – 35

#365papers for February 4, 2017

Yanes, Izeta, Cattaneo, Costa, and Gordillo, 2014, Holocene (~4.5-1.7 cal. kyr BP) paleoenvironmental conditions in central Argentina inferred from entire-shell and intra-shell stable isotope composition of terrestrial gastropods: The Holocene, v. 24, p. 1193-1205.

What’s it about?

This paper discusses the use of geochemistry (specifically stable isotopes) of fossil snail shells to understand past environments. It looks especially on comparing results from whole shell analysis (grinding the whole shell up and putting it into the mass spectrometer) against serial or intra-shell analyses, where multiple samples are collected from a single shell.Continue reading “Snail Shells, Climate, and Weather – #365papers – 2017 – 35”

More Tales from Land Snails – #365papers – 2017 – 34

#365 papers for February 3, 2017

Prendergast, Stevens, Barker, and O’Connell, 2015, Oxygen isotope signatures from land snail (Helix melanostoma) shells and body fluid: Proxies for reconstructing Mediterranean and North African rainfall: Chemical Geology, v. 409, p. 87-98.

What’s it about?

This paper seeks to show that what we’ve been saying we can do with the geochemistry of snail shells (especially oxygen isotopes) can actually be done. This paper shows that there is a relationship between oxygen isotopes in rainfall and those of snail body fluids. The relationship between isotopic signatures of body fluids and shells is then shown.Continue reading “More Tales from Land Snails – #365papers – 2017 – 34”

Snails Tell Tales of Past Climate – #365papers – 2017 – 33

#365papers for February 2, 2017

Abell and Hoelzmann, 2000, Holocene palaeoclimates in northwestern Sudan: stable isotope studies on molluscs: Global and Planetary Change, v. 26, p. 1-12

What’s it about?

By measuring isotopes of carbon and oxygen from fossil snails, the authors were able to determine what the past climate in Sudan was like.Continue reading “Snails Tell Tales of Past Climate – #365papers – 2017 – 33”

Growing Up Andes – #365papers – 2017 – 28

#365papers for January 28, 2017

Quade, Dettinger, Carrapa, DeCelles, Murray, Huntington, Cartwright, Canavan, Gehrels, and Clementz, 2015, The growth of the central Andes, 22*S–26*S: GSA memoir 212, p

What’s it about?

This paper applies the method described in yesterday’s #365papers, along with other methods to explore the uplift history of the central Andes.Continue reading “Growing Up Andes – #365papers – 2017 – 28”

From Volcanic Glass We Can Estimate Ancient Elevation – #365papers – 2017 – 27

#365papers for January 27, 2017

Dettinger and Quade, 2015, Testing the analytical protocols and calibration of volcanic glass for the reconstruction of hydrogen isotopes in paleoprecipitation: GSA Memoir 212, p. 261-276.

What’s it about?

This paper discussed in detail the protocol necessary to get reliable hydrogen isotopic data from volcanic glass. The authors check many variations and possible ways to isolate and clean the glass to determine which is the best way to do it.Continue reading “From Volcanic Glass We Can Estimate Ancient Elevation – #365papers – 2017 – 27”

You Are What You Eat, Plus a Few Permil – #365papers – 2017 – 20

#365papers for January 20, 2016

Passey, Robinson, Ayliffe, Cerling, Sponheimer, Dearing, Roeder, and Ehleringer, 2005, Carbon isotope fractionation between diet, breath CO2, and bioapatite in different mammals: Journal of Archaeological Science, v. 32, p. 1459-1470.

What’s it about?

This paper discusses how carbon from food becomes incorporated into the tooth enamel of mammals. More specifically, it examines the fractionation in isotopic ratios from food to enamel based upon groups of mammals having different sizes and physiologies.
Continue reading “You Are What You Eat, Plus a Few Permil – #365papers – 2017 – 20”

Back and Forth on the Oxygen Train – #365papers – 2017 – 19

#365papers for January 19, 2017

Kipp, Stueken, Bekker, and Buick, 2017, Selenium isotopes record extensive marine suboxia during the Great Oxidation Event: Proceedings of the National Academy of the Sciences.

What’s it about?

Sometime longabouts 2.3 and 2.1 billion years ago, Earth’s atmosphere became oxygenated and organisms came about that utilized oxygen extensively in their metabolic processes. However, these organisms did not come to dominate on the Earth until a billion years later. During this Great Oxidation Event, despite increases in oxygen overall in the atmosphere and the oceans, there were periods of more or less oxygen, which made it hard to oxygen-dependent organisms to proliferate.

Continue reading “Back and Forth on the Oxygen Train – #365papers – 2017 – 19”

Hot Times in the Eocene – #365papers – 2017 – 12

#365papers for January 12, 2017

Methner, Mulch, Fiebig, Wacker, Gerdes, Graham, and Chamberlain, 2016, Rapid Middle Eocene temperature change in western North America: Earth and Planetary Science Letters, v. 450, p. 132-139.

What’s it about?

This paper discusses the use of multiple geochemical methods to study an episode of extreme warmth in Earth’s history. The authors were able to determine the magnitude of the warming and used multiple methods to assign ages to the rocks involved. Using other chemical and geological methods, the authors were also able to show how this warming and subsequent cooling changed the overall climate in the interior of North America.Continue reading “Hot Times in the Eocene – #365papers – 2017 – 12”