Tectonics of Sedimentary Basins

Recent Advances

Cathy Busby, Antonio Azor Pérez, Cathy Busby, Antonio Azor Pérez

• Publisher: Wiley-Blackwell
• Year: 2011
• Print ISBN: 9781405194655
• eBook ISBN: 9781444347142
• Edition: 1
• Topic: Physical Sciences
• Subtopic: Geology & Earth Sciences

Investigating the complex interplay between tectonics and sedimentation is a key endeavor in modern earth science. Many of the world's leading researchers in this field have been brought together in this volume to provide concise overviews of the current state of the subject.

The plate tectonic revolution of the 1960's provided the framework for detailed models on the structure of orogens and basins, summarized in a 1995 textbook edited by Busby and Ingersoll. Tectonics of Sedimentary Basins: Recent Advances focuses on key topics or areas where the greatest strides forward have been made, while also providing on-line access to the comprehensive 1995 book.

Breakthroughs in new techniques are described in Section 1, including detrital zircon geochronology, cosmogenic nuclide dating, magnetostratigraphy, 3-D seismic, and basin modelling. Section 2 presents the new models for rift, post-rift, transtensional and strike slip basin settings. Section 3 addresses the latest ideas in convergent margin tectonics, including the sedimentary record of subduction intiation and subduction, flat-slab subduction, and arc-continent collision; it then moves inboard to forearc basins and intra-arc basins, and ends with a series of papers formed under compessional strain regimes, as well as post-orogenic intramontane basins. Section 4 examines the origin of plate interior basins, and the sedimentary record of supercontinent formation.

This book is required reading for any advanced student or professional interested in sedimentology, plate tectonics, or petroleum geoscience.

Additional resources for this book can be found at: www.wiley.com/go/busby/sedimentarybasins.

Part 1

Introduction

Chapter 1

Tectonics of Sedimentary Basins, with Revised Nomenclature

Raymond V. Ingersoll

Department of Earth and Space Sciences, University of California, Los Angeles, California

ABSTRACT

Actualistic plate-tectonic models are the best framework within which to understand the tectonics of sedimentary basins. Sedimentary basins develop in divergent, intraplate, convergent, transform, hybrid, and miscellaneous settings. Within each setting are several variants, dependent on type(s) of underlying crust, structural position, sediment supply, and inheritance. Subsidence of sedimentary basins results from (1) thinning of crust (2) thickening of mantle lithosphere (3) sedimentary and volcanic loading (4) tectonic loading (5) subcrustal loading (6) asthenospheric flow, and (7) crustal densification. Basins vary greatly in size, life span, and preservation potential, with short-lived basins formed in active tectonic settings, especially on oceanic crust, having low preservation potential, and long-lived basins formed in intraplate settings having the highest preservation potential.

Continental rifts may evolve into nascent ocean basins, which commonly evolve into active ocean basins bordered by intraplate continental margins with three types of configurations: shelf-slope-rise, transform, and embankment. Continental rifts that do not evolve into oceans become fossil rifts, which later become sites for development of intracratonic basins and aulacogens. If all plate boundaries within and around an ocean basin become inactive, a dormant ocean basin develops, underlain by oceanic crust and surrounded by continental crust.

Sites for sedimentary basins in convergent settings include trenches, trench slopes, forearcs, intra-arcs, backarcs, and retroarcs. Complex dynamic behavior of arc-trench systems results in diverse configurations for arc-related basins. Most notable is the overall stress regime of the arc-trench system, with resulting response along and behind the magmatic arc. Intra-arc rifting in highly extensional arcs commonly evolves into backarc spreading to form new oceanic crust. Backarcs of neutral arcs can contain any type of preexisting crust that was trapped there at the time of initiation of the related subduction zone. Highly compressional arcs develop retroarc foldthrust belts and related retroforeland basins, and may develop hinterland basins; in extreme cases, broken retroforelands may develop in former cratonal areas.

As nonsubductable continental or arc crust is carried toward a subduction zone, collision generally initiates at one point and the resulting suture propagates away from this point of initial impact. Remnant ocean basins form on both sides of the initial impact point, and rapidly fill with sediment derived from the suture zone. As collision continues, the flux of sediment into the remnant ocean basin(s) increases concurrently with shrinkage of the basin until final suturing and obduction of the accreted sediment occur. Concurrently with collision, proforeland basins form on continental crust of the subducting plate and collisional retroforeland basins form on the overriding plate. Impactogens, broken forelands, and hinterland basins also may result.

In transform settings and along complex strike-slip fault systems related to convergent settings, changing stress regimes related to irregularities in fault trends, rock types, and plate motions result in transtension, transpression, and transrotation, with associated complex, diverse, and short-lived sedimentary basins.

Two previously unnamed basin types that have received increasing attention recently are halokinetic basins (related to salt tectonics, especially along intraplate margins with embankment configurations) and bolide basins (resulting from extraterrestrial impacts). Sediment accumulates in successor basins following cessation of basin-controlling processes, whether in divergent, convergent, transform, or hybrid settings.

The ultimate goal of classifying and reviewing all types of sedimentary basins is the improvement of paleotectonic and paleogeographic reconstructions through the application of actualistic models for basin evolution. Interdisciplinary studies that test and refine these models will improve our knowledge of Earth history.

Keywords: basin nomenclature; plate-tectonic settings; subsidence mechanisms; preservation potential; paleotectonic reconstruction

Introduction

It has been more than a decade since I reviewed and revised my original basin classification (i.e., Ingersoll, 1988; Ingersoll and Busby, 1995), which was based primarily on Dickinson's (1974b, 1976a) statement of fundamental principles that should guide discussion of the tectonics of sedimentary basins. Many new insights and models have been developed recently; in addition, nomenclature has evolved in complex ways. Therefore, now is an appropriate time to consolidate, revise, and discuss how to communicate about the tectonics of sedimentary basins.

As in my previous papers on this subject, I follow Dickinson's (1974b, 1976a) suggestions that nomenclature and classification be based on the following actualistic plate-tectonic processes and characteristics, which ultimately control the location, initiation, and evolution of sedimentary basins in diverse tectonic settings. Horizontal motions of plates, thermal changes through time, stretching and shortening of crust, isostatic adjustments, mantle dynamics, surficial processes, and even extraterrestrial events influence sedimentary basins. Additional study of sedimentary basins, inevitably, leads to greater complexity of models to explain them. Although we should search for unifying principles that lead to deeper understanding of processes and results, the complexity of the real world dictates that enhanced knowledge about sedimentary basins results in more complex models. Thus, new types of sedimentary basins are added to the list provided in Ingersoll and Busby (1995) because these are actual features that need to be understood. Gould (1989, 98) stated, “Classifications are theories about the basis of natural order, not dull catalogues compiled only to avoid chaos.” I hope that my discussion serves the dual purposes of reducing nomenclatural chaos and suggesting a framework within which to understand the complex controls on the origin and evolution of sedimentary basins.

Nomenclature

First-order criteria for classifying sedimentary basins (Dickinson, 1974b, 1976a) are (1) type of nearest plate boundary(ies) (2) proximity of plate boundary(ies), and (3) type of substratum. Thus, the first-order classification, based on criteria (1) and (2) is divergent, intraplate, convergent, transform, hybrid, and miscellaneous settings (Table 1.1). Within each of these categories are several variants, dependent on type of substratum (oceanic, transitional, continental, and anomalous crust), as well as structural position, sediment supply, and inheritance.

Table 1.1 Basin classification with modern and ancient examples Modified after Ingersoll and Busby (1995)(1995).

Basin classification and nomenclature are based on characteristics of a basin at the time of sedimentation. Thus, many stratigraphic successions are multidimensional and multigenerational in terms of plate-tectonic controls on their evolution. A single stratigraphic succession may represent several different tectonic settings. “The evolution of a sedimentary basin thus can be viewed as the result of a succession of discrete plate-tectonic settings and plate interactions whose effects blend into a continuum of development” (Dickinson, 1974b, 1).

It is important to realize that “basin,” as used herein, refers to any stratigraphic accumulation of sedimentary or volcanic rock; the three-dimensional architecture of basins may approximate saucers, wedges, sheets, and odd shapes. Also, basins may form by subsidence of a substrate, development of a barrier to transport of sediment, filling of a preexisting hole, or relative movement of source and sink.

Subsidence Mechanisms and Preservation Potential

Surfaces of deposition may subside due to the following processes (Dickinson, 1974b, 1976a, 1993; Ingersoll and Busby, 1995) (Table 1.2): (1) thinning of crust due to stretching, erosion, and magmatic withdrawal (2) thickening of mantle lithosphere during cooling (3) sedimentary and volcanic loading (local crustal isostasy or regional lithospheric flexure)(4) tectonic loading of both crust and lithosphere (5) subcrustal loading of both crust and lithosphere (6) dynamic effects of asthenospheric flow, and (7) crustal densification. Figure 1.1 illustrates that crustal thinning dominates during early stages of extension (e.g., rifts and transtensional basins), and mantle-lithospheric thickening dominates following the initiation of seafloor spreading (during the rift-to-drift transition along divergent margins which evolve into intraplate margins). Sedimentary loading dominates along continental-oceanic crustal boundaries which are supplied by major rivers and deltas (e.g., continental embankments and remnant ocean basins). Tectonic loading dominates in settings where crustal shortening dominates (e.g., trenches and foreland basins). The other three types of subsidence mechanisms are generally subordinate.

Table 1.2 Subsidence mechanisms.

Crustal thinning	Extensional stretching, erosion during uplift, and magmatic withdrawal
Mantle-lithospheric thickening	Conversion of asthenosphere to mantle lithosphere during cooling following cessation of stretching and/or heating
Sedimentary and volcanic loading	Local isostatic compensation of crust and/or regional lithospheric flexure during sedimentation and volcanism
Tectonic loading	Local isostatic compensation of crust and/or regional lithospheric flexure during overthrusting and/or underpulling
Subcrustal loading	Lithospheric flexure during underplating of dense lithosphere
Asthenospheric flow	Dynamic effects of asthenospheric flow, commonly due to descent or delamination of subducted lithosphere
Crustal densification	Increased density of crust due to changing pressure/temperature conditions and/or emplacement of higher-density melts into lower-density crust

Fig. 1.1 Suggested subsidence mechanisms for all types of sedimentary basins.

The diversity of tectonic and structural settings of sedimentary basins dictates that they vary greatly in size, life span, and preservation potential (Fig. 1.2) (Ingersoll, 1988; Ingersoll and Busby, 1995; Woodcock, 2004). Many sediment accumulations are destined to be destroyed relatively soon after deposition (e.g., most basins residing on oceanic crust or in rapidly uplifting orogenic settings). In contrast, basins formed during and following stretching of continental crust (e.g., continental rifts that either evolve into seafloor spreading or fail to do so) have high preservation potential because they subside and are buried beneath intraplate deposits following rifting. On the other hand, stratigraphic sequences along intraplate continental margins are destined to be partially subducted as they are pulled into trenches, thus preserving them at moderate to deep crustal levels as highly deformed and metamorphosed terranes. Such metasedimentary and metavolcanic terranes, along with voluminous sediments deposited in remnant ocean basins, are major rock bodies involved in the construction of continental crust, although their substrates (oceanic crust) are mostly subducted (e.g., Graham et al., 1975; Ingersoll et al., 1995, 2003).

Fig. 1.2 Typical life spans for sedimentary basins versus their post-sedimentation preservation potential, which refers to average time interval during which basins will not be uplifted and eroded during and following se...

Table of contents

• Cover
• Series Page
• Title Page
• Copyright
• Contributors
• Preface
• Part 1: Introduction
• Part 2: New Techniques and Modeling
• Part 3: Rift, Post-Rift, Transtensional, and Strike-Slip Basin Settings
• Part 4: Convergent Margins: Subduction and Collision, from Outboard to Inboard Settings
• Part 5: Plate Interior Basins and Widespread Basin Types
• Index