Category Archives: Geology

Paleogene Mountains, Rivers, Lakes,… and Isotopes – #365papers – 2017 – 46

#365papers for February 15, 2017

Davis, Mulch, Carroll, Horton, and chamberlain, 2009, Paleogene landscape evolution of the central North American Cordillera: Developing topography and hydrology in the Laramide foreland: Geological Society of America Bulletin, v. 121, p. 100-116.

What’s it about?

This paper uses isotopes of oxygen, carbon, and strontium from multiple areas along the east edge and middle of the Rocky Mountains to explore the timing of the uplift of the Rockies, and to understand how the new mountains affected climate locally.Continue reading “Paleogene Mountains, Rivers, Lakes,… and Isotopes – #365papers – 2017 – 46”

Doctoral Day! – Mammals of the Torrejonian-Tiffanian (Paleocene) Transition – #365papers – 2017 – 45

#365papers for February 14, 2017

Higgins, 2003, A Wyoming succession of Paleocene mammal-bearing localities bracketing the boundary between the Torrejonian and Tiffanian North American Land Mammal “Ages”: Rocky Mountain Geology, v. 38.

What’s it about?

This paper discusses the nature of the boundary between two adjacent North American Land Mammal “Ages” (NALMAs). NALMAs are defined by the presence or absence of certain mammal species and are usually quite different in species composition. The 136 localities studied here bracket the Torrejonian-Tiffanian boundary, so we can examine the transition more closely.Continue reading “Doctoral Day! – Mammals of the Torrejonian-Tiffanian (Paleocene) Transition – #365papers – 2017 – 45”

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”

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”

Correlation and Earth’s History

One of those things we do as geoscientists is try to figure out if the rocks in one place are the same as the rocks in another place. While it seems a very easy question to ask, it’s not so easy to answer.

This determination of ‘sameness’ is called correlation. But before we can do any correlating, we have to get more specific in our question. Do we want to know if rocks here and there are the same age, or do we want to know if they represent the same environment?

Cartoon showing rock correlation (solid line) and fossil correlation (dashed line)
Cartoon showing rock correlation (solid line) and fossil correlation (dashed line) between layers of rock in three different areas.
Continue reading “Correlation and Earth’s History”

Field Work Travelogue: Day 2 – Arrival At Natural Trap Cave #NTCave15

This is really the fourth day of my field season, but day two in which the Principal Investigator has been on the road, so we’ll call it day two.

One might consider today day one, because today is the day that we made it to the field site and pitched our tents.

The drive was lovely. We had to cross the Bighorn Mountains.

High Altitude Meadows
High Altitude Meadows

Continue reading “Field Work Travelogue: Day 2 – Arrival At Natural Trap Cave #NTCave15”