Preface 1 Carbon, the Earth and life: 11 Carbon and the basic requirements of life12 Chemical elements, simple compounds and their origins13 The origin of life14 Evolution of life and the atmosphere15 Major contributors to sedimentary organic matter 2 Chemical composition of biogenic matter: 21 Structure of natural products22 Carbohydrates23 Amino acids and proteins24 Lipids25 Lignins, tannins and related compounds26 Nucleotides and nucleic acids27 Geochemical implicatiions of compositional variation 3 Production, preservation and degradation of organic matter: 31 How and why organic-rich deposits form32 Controls on primary production33 Preservation and degradation of organic matter34 Depositional environments associated with accumulation of organic matter 4 Long-term fate of organic matter in the geosphere: 41 Diagenesis42 Humic material43 Coal44 Kerogen45 Catagenesis and metagenesis46 Temporal and geographical distribution of fossil organic carbon 5 Chemical stratigraphy 51 Biologically mediated transformations52 Examples of source indicators in recent sediments53 Diagenesis at the molecular level54 Source and environment indicators in ancient sediments and oil55 Thermal maturity and molecular transformations56 Palaeotemperature and age measurement57 Maturity of ancient sedimentary organic matter58 Isotopic palaeontology 6 The carbon cycle and climate 61 Global carbon cycle62 Changes in carbon reservoirs over geological time63 Palaeoclimatic variations64 Isotopic excursions at period boundaries65 Human influence on the carbon cycle 7 Anthropogenic carbon and the environment 71 Introduction72 Halocarbons73 Hydrocarbon pollution in aquatic environments74 Endocrine disrupting chemicals75 Environmental behaviour of selected xenobiotic compounds76 Factors affecting the rate of anthropogenic components Appendix 1: SI units usedAppendix 2: SI unit prefixesAppendix 3: Geological timescaleReferencesIndex

An introduction to organic geochemistry

It is generally accepted that the formation of kerogens is the result of the so-called depolymerization-recondensation pathway (Tissot and Welte, 1984; Durand, 1980), Thus, naturally occurring macromolecular substances such as polysaccharides and proteins are enzymatically depolymerized to oligo- and monomers, which for the most part are mineralized. However, a small part of them are thought to condense with other substances such as low-molecular-weight lipids in a random way (Fig. 1). During diagenesis, the “geopolymers” thus formed continuously undergo chemical transformations by which they become more and more insoluble and resistant. Kerogens are being formed, which—depending on the nature of the original organic matter contributions—can generate various amounts and sorts of oil under thermal stress.

A Review of Macromolecular Organic Compounds That Comprise Living Organisms and Their Role in Kerogen, Coal, and Petroleum Formation

Organic residue analysis utilizes analytical organic chemical techniques to identify the nature and origins of organic remains that cannot be characterized using traditional techniques of archaeological investigation (because they are either amorphous or invisible). The field is founded upon the principle that the biomolecular, or biochemical, components of organic materials associated with human activity survive in a wide variety of locations and deposits at archaeological sites. The archaeological information contained in organic residues is represented by the biomolecular components of the natural products that contribute to the formation of a given residue. By applying appropriate separation (chromatographic) and identification (mass spectrometric) techniques, the preserved, and altered, biomolecular components of such residues can be revealed. Once identified, the Archaeological Biomarker Concept can be applied, wherein the structure and even isotopic composition(s) of a given biomolecule or suite of biomolecules (the ‘chemical fingerprint’) can be related to the compositions of organisms exploited by humans in the past. As the organic residue field emerges from its pre-paradigmatic phase, and the organic residue revolution gathers pace, the way is open for challenging many long-held archaeological hypotheses and offering new perspectives on the study of human activity in the past.

Laurence J. Gough

Papers

The chemical composition of Baltic amber