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In search of the first animals

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thesis
posted on 28.03.2022, 12:16 by Shirin Baydjanova
The earliest proven fossils of multicellular animals are accepted to be those of the Ediacaran biota (ca 580 - 541 Ma), although some pre-Ediacaran samples from the Rasthof Formation of the Congo craton, Namibia, and from the Balcanoona Formation in the Northern Flinders Ranges, South Australia, have been claimed to contain fossils of the proto-sponges. The current study assesses samples from the above localities for the thermal maturity of the organic matter and the presence of sponge biomarkers. A combination of SEM, Raman and FTIR spectroscopy, and GC-MS techniques shows that the organic matter in the studied samples is over-mature for oil generation, with an equivalent vitrinite reflectance (R0) ≥ 1.4%. The Namibian samples (three dolostones from the Rasthof and Berg Aukas Formations) are more mature than the Australian samples (two siltstones from the Tapley Hill Formation and a dolomitic limestone from the Balcanoona Formation).The former are of chlorite zone metamorphic grade, while the latter exhibit characteristics of both pre-greenschist and greenschist (chlorite zone) metamorphism. No samples yielded sterane biomarkers specific to sponges, or any other biomarkers,including the normally ubiquitous hopanes. The absence of intact biomarkers can be attributed to their thermal destruction during late catagenesis and early metamorphism.

History

Table of Contents

Chapter 1. Introduction -- Chapter 2. Geological settings of the samples -- Chapter 3. Methods -- Chapter 4. Results -- Chapter 5. Discussion -- Chapter 6. Conclusions.

Notes

Bibliography: pages 56-61 Macquarie Organic Geochemistry Laboratory ARC Centre of Excellence for Core to Crust Fluid Systems (CCFS)" -- title page. Empirical thesis. "Macquarie University, Department of Earth and Planetary Sciences

Awarding Institution

Macquarie University

Degree Type

Thesis MRes

Degree

MRes, Macquarie University, Faculty of Science and Engineering, Department of Earth and Planetary Sciences

Department, Centre or School

Department of Earth and Planetary Sciences

Year of Award

2016

Principal Supervisor

Simon George

Rights

Copyright Shirin Baydjanova 2016. Copyright disclaimer: http://www.copyright.mq.edu.au

Language

English

Jurisdiction

Namibia

Extent

1 online resource (71 pages) illustrations (some colour), maps (some colour)

Former Identifiers

mq:47887 http://hdl.handle.net/1959.14/1095437