Książki

Preface to Second Edition

It has been more than a decade since the appearance of the First Edition of this book. Much progress has been made, but some controversies remain.
The original idea of Sloss and of Vail (building on the early work of Blackwelder, Grabau, Ulrich, Levorsen and others) that the stratigraphic record could be subdivided into sequences and that these sequences store essential information about basin-forming and subsidence processes remains as powerful an idea as when it was first formulated. The definition and mapping of sequences has become a standard part of the basin analysis process. Subsurface methods make use of advanced seismic-reflection analysis methods, with three-dimensional seismic methods, and seismic geomorphology adding important new dimensions to the analysis. Several advanced textbooks have now appeared that deal with the recognition and definition of sequences and their interpretation in terms of the evolution of depositional systems, the recognition and correlation of bounding surfaces, and the interpretation of sequences in terms of changing accommodation and supply. This is not one of these books.
The main purpose of this book remains the same as it was for the first edition, that is, to situate sequences within the broader context of geological processes so that geoscientists might be better equipped to extract the maximum information from the record of sequences in a given basin or region. The following are the main themes of the book:

Central to the concept of the sequence is the deductive model that sequences carry messages about the "pulse of the earth". In the early modern period of sequence stratigraphy (the late 1970s and 1980s) the model of global eustasy was predominant, and it was to offer a critique of that model that provided the impetus for developing the first edition of this book. Model-building has been central to the science of geology from the beginning it was certainly a preoccupation of such early masters of the science as Lyell, Chamberlin, Barrell and Ulrich. A historical evaluation of the contrasting deductive and inductive approaches to geology has been added to this edition of the book, in order to provide a background in methodology and a historical context.

Standard sequence models have become very well described and understood for most depositional settings, and are the subject of several recent texts. Two chapters are provided in this edition in order to outline modern ideas, and to provide a framework of terminology and illustration for the remainder of the book.

A major component of the first edition was devoted to a documentation and illustration of the main types of sequence in the geological record, ranging from those representing hundreds of millions of years of geological evolution to the high-frequency sequences formed by rapid cyclic processes lasting a few tens of thousands of years. Such documentation remains a major component of the book, and has been updated with new examples.

The central core of the first edition was composed of a detailed description and evaluation of the major processes by which sequences are formed. This remains the central focus of the book and has been updated.

Perhaps partly in response to this book, many geoscientists have recognized the complexity of the geological record, have adopted a rigorous inductive approach to their analyses and remain committed to a multi-process interpretation of their rocks. Such an approach can provide a rich array of ideas regarding regional tectonics and basin analysis. However, the original Vail model of global eustasy remains convincing to many, and a powerful guide to interpretation. This writer finds that much of the work in this area retains a flavour of "working backwards from the answer" that was already troubling twenty years ago. The practical, theoretical and methodological issues surrounding this still controversial area comprise a concluding section of the

The Geology of Stratigraphic Sequences

Contents

Part I

THE EMERGENCE OF MODERN CONCEPTS

1 HISTORICAL AND METHODOLOGICAL BACKGROUND

1.1 introduction

1.2 Methodologies in geology

1.2.2 The significance of sequence stratigraphy

1.2.3 Data and argument in Geology

1.2.4 The hermeneutic circle and the emergence of sequence stratigraphy

1.2.5 Paradigms and exemplars

1.3 The development of descriptive stratigraphy

1.3.1 The growth of modern concepts

1.3.2 Do stratigraphic units have "time" significance?

1.3.3 The development of modern chronostratigraphy

1.4 The continual search for a "pulse of the earth"

1.5 Problems and research trends: the current status

1.6 Current literature

1.7 Stratigraphic terminology

2 THE BASIC SEQUENCE MODEL

2.1 Introduction

2.2 Elements of the model

2.2.1 Accommodation and supply

2.2.2 Stratigraphic architecture

2.2.3 Depositional systems and systems tracts

2.3 Sequence models in clastic and carbonate settings

2.3.1 Marine clastic depositional systems and systems tracts

2.3.2 Nonmarine depositional systems

2.3.3 Carbonate depositional systems

2.3.3.1 Breaks in sedimentation in carbonate environments

2.3.3.2 Platform carbonates: catch-up versus keep-up

2.4 Sequence definitions

Figures

3 OTHER METHODS FOR THE STRATIGRAPHIC ANALYSIS OF CYCLES OF BASE-LEVEL CHANGE

3.1 Introduction

3.2 Facies cycles

3.3 Areas and volumes of stratigraphic units

3.4 Hypsometric curves

3.5 Backstripping

3.6 Sea-level estimation from paleoshorelines and other fixed points

3.7 Documentation of metre-scale cycles

3.8 Integrated tectonic-stratigraphic analysis

Figures

Part II

THE STRATIGRAPHIC FRAMEWORK

4 The major types of stratigraphic cycle

4.1 Introduction

4.2 Sequence hierarchy

4.3 The supercontinent cycle

4.4 Cycles with episodicities of tens of millions of years

4.5 Cycles with million-year episodicities

4.6 Cycles with episodicities of less than one million years

Tables

Figures

5 CYCLES WITH EPISODICITIES OF TENS TO HUNDREDS OF MILLIONS OF YEARS

5.1 Climate, sedimentation and biogenesis

5.2 The supercontinent cycle

5.2.1 The tectonic-stratigraphic model

5.2.2 The Phanerozoic record

5.3 Cycles with episodicities of tens of millions of years

5.3.1 Regional to intercontinental correlations

5.3.2 Tectonostratigraphic sequences

5.4 Main conclusions

Figures

6 CYCLES WITH MILLION-YEAR EPISODICITIES

6.1 Continental margins

6.1.1 Clastic platforms and margins

6.1.2 Carbonate cycles of platforms and craton margins

6.1.3 Mixed carbonate-clastic successions

6.2 Foreland basins

6.2.1 Foreland basin of the North American Western Interior

6.2.2 Other foreland basins

6.3 Arc-related basins

6.3.1 Forearc basins

6.3.2 Backarc basins

6.4 Cyclothems and mesothems

6.6 Conclusions

Figures

7 CYCLES WITH EPISODICITIES OF LESS THAN ONE MILLION YEARS

7.1 Introduction

7.2 Neogene clastic cycles of continental margins

7.2.1 The Gulf Coast basin of the United States

7.2.2 Wanganui Basin, North Island, New Zealand

7.2.3 Other examples of Neogene high-frequency cycles

7.2.4 The deep-marine record

7.3 Pre-Neogene marine carbonate and clastic cycles

7.4 Late Paleozoic cyclothems

7.5 Lacustrine clastic and chemical rhythms

7.6 High-frequency cycles in foreland basins

7.7 Main conclusions

Figures

Part III

MECHANISMS

8 SUMMARY OF SEQUENCE-GENERATING MECHANISMS

Figures

9 LONG-TERM EUSTASY AND EPEIROGENY

9.1 Mantle processes and dynamic topography

9.2 Supercontinent cycles

9.3 Cycles with episodicities of tens of millions of years

9.3.1 Eustasy

9.3.2 Dynamic topography and epeirogeny

9.3.3 The origin of Sloss sequences

9.4 Main conclusions

Figures

10 TECTONIC MECHANISMS

10.1 Introduction

10.2 Rifting and thermal evolution of divergent plate margins

10.2.1 Basic geophysical models and their implications for sea-level change

10.2.2 The origins of some tectonostratigraphic sequences

10.3 Tectonism on convergent plate margins and in collision zones

10.3.1 Magmatic arcs and subduction

10.3.2 Rates of uplift and subsidence on convergent margins

10.3.3 Tectonism versus eustasy in foreland basins

10.3.3.1 The North American Western Interior Basin;

10.3.3.2 The Appalachian foreland basin.

10.3.3.3 Pyrenean and Himalayan basins

10.4 Intraplate stress

10.4.1 The pattern of global stress

10.4.2 In-plane stress as a control of sequence architecture

10.4.3 In-plane stress and regional histories of sea-level change

10.5 Basement control

10.6 Sediment supply and the importance of big rivers

10.7 Environmental change

10.8 Main conclusions

Figures

11 ORBITAL FORCING

11.1 Introduction

11.2 The nature of Milankovitch processes

11.2.1 Components of orbital forcing

11.2.2 Basic climatology

11.2.3 Variations with time in orbital periodicities

11.2.4 Isostasy and geoid changes

11.2.5 Nonglacial Milankovitch cyclicity

11.2.6 The nature of the cyclostratigraphic data base

11.3 The geologic record

11.3.1 The sensitivity of the earth to glaciation

11.3.2 The Cenozoic record

11.3.3 Glacioeustasy in the Mesozoic?

11.3.4 Late Paleozoic cyclothems

11.4 Distinguishing between orbital forcing and tectonic driving mechanisms

11.5 Main conclusions

Figures

Part IV

CHRONOSTRATIGRAPHY AND CORRELATION: AN ASSESSMENT OF THE CURRENT STATUS OF "GLOBAL EUSTASY"

12 THE CONCEPT OF THE GLOBAL CYCLE CHART

12.1 From Vail to Haq

12.2 The two-paradigm problem

12.3 Defining and deconstructing global eustasy and complexity texts

12.4 Invisible colleges and the advancement of knowledge

12.5 The global-eustasy paradigm-a revolution in trouble?

12.6 Conclusions

Figures

13 TIME IN SEQUENCE STRATIGRAPHY

13.1 Introduction

13.1 Hierarchies of time and the completeness of the stratigraphic record

13.2 Main conclusions

14 CHRONOSTRATIGRAPHY, CORRELATION, AND MODERN TESTS FOR GLOBAL EUSTASY

14.1 Introduction

14.2 Chronostratigraphic models and the testing of correlations

14.3 Chronostratigraphic meaning of unconformities

14.4 A correlation experiment

14.5 Testing for eustasy: the way forward

14.5.1 Introduction

14.5.2 The dating and correlation of stratigraphic events: potential sources of uncertainty

14.5.2.1 Identification of sequence boundaries

14.5.2.2 Chronostratigraphic meaning of unconformities

14.5.2.3 Determination of the biostratigraphic framework

14.5.2.4 The problem of incomplete biostratigraphic recovery.

14.5.2.5 Diachroneity of the biostratigraphic record.

14.5.3 The value of quantitative biostratigraphic methods

14.5.4 Assessment of relative biostratigraphic precision

14.5.5 Correlation of biozones with the global stage framework

14.5.6 Assignment of absolute ages and the importance of the modern time scale

14.6 Modern tests of the global eustasy paradigm

14.6.1 Cretaceous-Paleogene sequence stratigraphy of New Jersey

14.6.2 Other modern high-resolution studies of Cretaceous-Paleogene sequence stratigraphy

14.6.3 Sequence stratigraphy of the Neogene

14.6.4 The growing evidence for glacioeustasy in the Mesozoic and Cenozoic

14.7 Cyclostratigraphy and Astrochronology

14.7.1 Historical background of cyclostratigraphy

14.7.2 The building of a time scale

14.8 Main conclusions

Tables

Figures

15 FUTURE DIRECTIONS

15.1 Research methodology

15.2 Remaining questions

15.2.1 Future advances in cyclostratigraphy?

15.2.2 Tectonic mechanisms of sequence generation.

15.2.3 Orbital forcing

15.2.4 The codification of sequence nomenclature

Figures.