Chemical Evolution of the Early Precambrian

Contents

List of Contributors

Preface


1 Origin of the Atmosphere: History of the Release of Volatiles from the Solid Earth

I. Introduction

II. Secondary Origin of the Atmosphere

III. Evidence for Early Degassing

IV. Evidence for Continuing Release of Volatiles from the Upper Mantle

V. Degassing and Recycling

VI. Conclusion


2 Early Precambrian Weathering and Sedimentation: An Impressionistic View

I. Temperatures of the Early Precambrian

II. Weathering at 4.3 Billion Years before the Present

III. Sedimentation at 4.3 Billion Years before the Present


3 Very Old ( > 100 Million Years) Rocks in North America


4 Three Arguments for Continual Evolution of Sial throughout Geologic Time

I. Introduction

II. Proterozoic Shields

III. Phanerozoic Continental Growth

IV. Composition of Graywackes


5 Archean Geology and Evidence of Ancient Life in the Slave Structural Province, Canada

I. Yellowknife-Hearne Lake Area

II. Nature of the Archean Crust in the Slave Province

III. The Extent of the Archean Record in the Slave Province

IV. Evidence of Ancient Life in the Archean of the Slave Province


6 Carbon Contents of Early Precambrian Rocks


7 Condensed Phosphates from Abiotic Systems in Nature

I. Introduction

II. The Formation of Condensed Phosphates

III. Examples of the Formation of Condensed Phosphates

IV. The Preparation of P4Oi0

V. The Removal of M2 0 from Orthophosphate

VI. The Removal of Water of Constitution

VII. Oxygen Substitution Reaction

VIII. The Decomposition of Salts of Lower Oxides

IX. Condensed Phosphate Minerals

X. Conclusion


8 Hydrocarbons and Fatty Acids in Oil Shale of Permian Irati Formation, Brazil

I. Introduction

II. Experimental

III. Results

IV. Discussion


9 The Stable Isotopes of Hydrogen in Precambrian Organic Matter

I. Introduction

II. Experimental

III. Discussion


10 Evolution of the Terrestrial Oxygen Budget

I. Introduction

II. Geochemical Carbon Cycle and Terrestrial Oxygen Budget

III. Terrestrial 13C Mass Balance

IV. Stationary Sedimentary Mass and Evolution of Photosynthetic Oxygen

V. Paleoenvironmental Implications of the Model


11 Evidences of Archean Life

I. Chemical Evidence

II. Morphological Evidence


12 Earliest Evidence of Fossil Eucaryotes


13 Paleobiology of Stromatolites

I. Introduction

II. The Stromatolites

III. Stromatolite Biostratigraphy

IV. Paleobiology of Stromatolites

V. Gunflint Stromatolites

VI. Conclusions


14 Natural Mechanisms of Protection of a Blue-Green Alga against Ultraviolet Light

I. Introduction

II. Materials and Methods


15 Kakabekia, a Review of Its Physiological and Environmental Features and Their Relation to Its Possible Ancient Affinities

I. Material and Methods

II. Results and Discussion


16 A Discussion of Biogenicity Criteria in a Geological Context with Examples from a Very Old Greenstone Belt, a Late Precambrian Deformed Zone, and Tectonized Phanerozoic Rocks


17 Synthetic Organic Microstructures as Model Systems for Early Protobionts

I. Synthesis of Organic Microstructures

II. Morphology by Light Microscopy

III. Morphology by Transmission Electron Microscopy

IV. Chemical Studies

V. Catalytic Properties

VI. Kinetics of Synthesis

VII. Discussion


18 Comparison of Laboratory Silicified Blue-Green Algae with Precambrian Microorganisms


19 Eoastrion and the Metallogenium Problem


20 Evolution of Mitosis and the Late Appearance of Metazoa, Metaphyta, and Fungi


21 Iron-Sulfur Proteins and Superoxide Dismutases in the Evolution of Photosynthetic Bacteria and Algae

I. The Iron-Sulfur Proteins

II. Superoxide Dismutases


22 Low Oxygen Levels and the Pabnitoyl CoA Desaturase of Yeast: Relation to Primitive Biological Evolution

Subject Index