Tephrostratigraphy of Pliocene Drill Cores from Kenya and Ethiopia, and Pleistocene Exposures in the Ledi-Geraru Research Project Area, Ethiopia: Geological Context for the Evolution of Australopithecus and Homo

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Description
East African extensional basins have played a crucial role in revealing the evolution and characteristics of the early stages of continental rifting and for providing the geological context of hominin evolution and innovation. The numerous volcanic eruptions, rapid sedimentation and

East African extensional basins have played a crucial role in revealing the evolution and characteristics of the early stages of continental rifting and for providing the geological context of hominin evolution and innovation. The numerous volcanic eruptions, rapid sedimentation and burial, and subsequent exposure through faulting and erosion, provide excellent conditions for the preservation of tectonic history, paleoenvironment data, and vertebrate fossils. The reconstruction of depositional environments and provision of geochronologic frameworks for hominin sites have been largely provided by geologic investigations in conjunction with paleontological studies, like the Ledi-Geraru Research Project (LGRP). High-resolution paleoclimate records that can be directly linked to hominin fossil outcrops have been developed by the Hominin Sites and Paleolakes Drilling Project (HSPDP) which collected sedimentary-paleolake cores at or near key hominin fossil sites.

Two chapters of this dissertation are a result of research associated with the HSPDP. For HSPDP, I establish a tephrostratigraphic framework for the drill cores from the Northern Awash (Afar, Ethiopia) and Baringo-Tugen Hills-Barsemoi (Kenya) HSPDP sites. I characterize and fingerprint tephra through glass shard and feldspar phenocryst geochemistry. From tephra geochemical analyses, I establish chronostratigraphic ties between the HSPDP cores’ high-resolution paleoclimate records to outcrop stratigraphy which are associated with hominin fossils sites.

Three chapters of this dissertation are a result of field work with the LGRP. I report new geological investigations (stratigraphic, tectonic, and volcanic) of two previously unmapped regions from the eastern Ledi-Geraru (ELG), Asboli and Markaytoli. Building upon this research I present interpretations from tephra analyses, detailed stratigraphic analyses, and geologic mapping, of the Pleistocene (~2.6 to < 2.45 Ma) basin history for the LGRP. My work with the LGRP helps to reconstruct a more complete Early Pleistocene depositional and geologic history of the lower Awash Valley.

Overall, this dissertation contributes to the reconstruction of hominin paleoenvironments and the geochronological framework of the Pliocene and Pleistocene faunal/hominin records. It further contributes to rift basin history in East Africa by elaborating the later structural and stratigraphic history of the lower Awash region.
Date Created
2019
Agent

Comparing the Influence of True Information and False Information on Climate Change Policy Preferences

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Description
This past summer, Pew Research Center conducted a ten-question survey to test Americans' knowledge on current events. Questions ranged from how Zika virus is transmitted, to the name of the current president of France. A majority of the participants were

This past summer, Pew Research Center conducted a ten-question survey to test Americans' knowledge on current events. Questions ranged from how Zika virus is transmitted, to the name of the current president of France. A majority of the participants were unable to answer half of the questions correctly (Pew Research Center, 2017). While previous Pew knowledge surveys saw a majority of Americans answer only one quarter of the questions correctly (2014), it is clear that Americans today are still not completely up-to-date on current affairs. Along with Americans lacking knowledge of current affairs, the recent election saw the rise in accusations of "fake news." These calls inspired me to undertake my thesis project to try to answer the question: "does fake news actually impact the public's policy preferences, and if so, by how much?" While studies have been conducted to test the relationship between policy misperceptions and policy preferences, there have not been many studies released to directly test the impact of incorrect information on policy preferences. The underlying purpose of this study is to test how introduction of new information, particularly falsehoods, influences policy preferences. Specifically, I focus on policy preferences related to anthropogenic climate change . Any valid research that seeks to analyze the effect of political information on policy preferences needs to starts by discovering how much the public knows about the particular policy issue that the researcher is focusing on. Without explicitly saying as much, all of the research on the subject that I have read has come to the same conclusion: American's are indeed politically unaware on a wide array of issues. The areas of policy that Americans lack knowledge on are widespread: education (Howell and West, 2009), welfare (Gilens, 2001), the war in Iraq (Berinsky, 2007; Kull, 2003), and facts about political candidates (Nyhan and Reifler, 2012) are just some of the issues that Americans seem to know little about. Literature discussed in the following section shows how researchers have tried to understand how policy knowledge impacts policy opinions. Researchers primarily collected their data either one of two ways: by analyzing existing survey data or by conducting their own survey.
Date Created
2018-05
Agent

The Hominin Sites and Paleolakes Drilling Project: Inferring the Environmental Context of Human Evolution From Eastern African Rift Lake Deposits

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Description

The role that climate and environmental history may have played in influencing human evolution has been the focus of considerable interest and controversy among paleoanthropologists for decades. Prior attempts to understand the environmental history side of this equation have centered

The role that climate and environmental history may have played in influencing human evolution has been the focus of considerable interest and controversy among paleoanthropologists for decades. Prior attempts to understand the environmental history side of this equation have centered around the study of outcrop sediments and fossils adjacent to where fossil hominins (ancestors or close relatives of modern humans) are found, or from the study of deep sea drill cores. However, outcrop sediments are often highly weathered and thus are unsuitable for some types of paleoclimatic records, and deep sea core records come from long distances away from the actual fossil and stone tool remains. The Hominin Sites and Paleolakes Drilling Project (HSPDP) was developed to address these issues. The project has focused its efforts on the eastern African Rift Valley, where much of the evidence for early hominins has been recovered. We have collected about 2 km of sediment drill core from six basins in Kenya and Ethiopia, in lake deposits immediately adjacent to important fossil hominin and archaeological sites. Collectively these cores cover in time many of the key transitions and critical intervals in human evolutionary history over the last 4 Ma, such as the earliest stone tools, the origin of our own genus Homo, and the earliest anatomically modern Homo sapiens. Here we document the initial field, physical property, and core description results of the 2012–2014 HSPDP coring campaign.

Date Created
2016-02-19
Agent