Microfacies of Carbonate Rocks: Analysis, Interpretation and Application

1005 Pages·2010·596.401 MB·English

by  Erik Flügel (auth.)

Microfacies of Carbonate Rocks
Erik Flu¨gel
Microfacies
of Carbonate Rocks
Analysis, Interpretation
and Application
Second Edition
WithacontributionbyAxelMunnecke
123
ISBN978-3-642-03795-5 e-ISBN978-3-642-03796-2
DOI10.1007/10.1007/978-3-642-03796-2
SpringerHeidelberg DordrechtLondonNewYork
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IX
Preface to the Second Edition
A second editon of this book - yes or no - or not yet? Most of the pictures in this book were collected
Are changes necessary or would it be enough if minor during Erik Flügel’s scientific work, some are from
errors in the text were corrected? papers that were published in the journal Facies, then
So I asked for help and I got answers from friends published by the Institute of Paleontology (now Geo-
and colleagues. I wish to thank W.Ch. Dullo (Kiel), A. zentrum Nordbayern), University Erlangen-Nürnberg, and
Freiwald (Erlangen), H.-G. Herbig (Cologne), W. Piller last not least, some were graciously provided by col-
(Graz), W. Schlager (Amsterdam), R. J. Stanton (Thousand leagues.
Oaks, USA) for their excellent and friendly advice. The author had hoped to include an additional
They were in agreement that not enough has changed chapter with plates that would provide the reader with
in the scientific field of ‘Microfacies of Carbonate Rocks’ an expanded range of information about microfacies.
since 2004 when the first edition was published for a This task has been accomplished by A. Munnecke
new edition to be necessary, but they all believed that (Erlangen). Chapter 20 contains plates and figures that
an update of the references on the CD going with the have been used successfully in the Course on Micro-
volume would be useful. facies held every year or two at the University in
Therefore, the reference section has been updated Erlangen.
to April 2009. Most of the new references are since I wish to thank all of my colleagues at the institute
2002, but a few are earlier. The reference file now in Erlangen, and especially A. Munnecke for the
contains more than 16,000 references. In connection compilation of Chapter 20.
with the keywords used throughout the book these Ch. Schulbert was most helpful in solving software
references can help the reader locate special subjects problems with the text and CD.
or overviews of interest. I thank Ch. Bendall (Springer Verlag Heidelberg)
When Erik wrote this book during his last years, for overseeing the printing of this new edition.
his primary goal was to provide students and all those
interested in and working with microfacies a helpful Erlangen, June 2009
und useful resource that contained many plates and Erentraud Flügel-Kahler
figures.
V
Preface
The objective of this book is to provide a synthesis of • presents diagnostic features and highlights the sig-
the methods used in microfacies studies of carbonate nificance of microfacies criteria,
rocks and to show how the application of microfacies • stresses the biological controls of carbonate sedi-
studies has contributed to new developments in car- mentation and provides an overview on the most
bonate geology. In contrast with other textbooks on car- common fossils found in thin sections of limestones,
bonate sedimentology this book focuses on those com- • discusses the relationships between diagenetic pro-
positional and textural constituents of carbonates that cesses, porosity and dolomitization,
reflect the depositional and diagenetic history and de- • demonstrates the importance of microfacies for es-
termine the practical usefulness of carbonate rocks. tablishing and evaluating sequence stratigraphic
The chapters are written in such a way, that each frameworks and depositional models,
one can be used as text in upper level undergraduate • underlines the potential of microfacies in differenti-
and graduate courses. The topics of the book also ap- ating paleoclimate changes and tracing platform-ba-
ply to research workers and exploration geologists, sin relationships, and
looking for current information on developments in the • demonstrates the value of microfacies analysis in
use of microfacies analysis. evaluating reservoir rocks and limestone resources,
Since microfacies studies are based on thin sections, as well as its usefulness in archaeological prov-
instructive plates showing thin-section photographs ac- enance studies.
companied by thorough and detailed explanations form
a central part of this book. All plates in the book con-
Structure of the Book
tain a short summary of the topic. An –> sign leads the
reader to the figures on the plate. The description of Microfacies of Carbonate Rocks starts with and in-
the microphotographs are printed in a smaller type. Care troductory chaper (Chap.1) and an overview of mod-
has been taken to add arrows and/or letters (usually the ern carbonate deposition (Chap. 2) followed by 17 chap-
initials of the subject) so that the maximum informa- ters that have been grouped into 3 major parts.
tion can be extracted from the figures. Microfacies Analysis (Chap. 3 to Chap. 10) summa-
Rather than being a revised version of ‘Microfacies rizes the methods used in microfacies studies followed
Analysis of Limestones’ (Flügel 1982) ‘Microfacies of by discussions on descriptive modes and the implica-
Carbonate Rocks’ is a new book, based on a new con- tions of qualitative and quantitative thin-section crite-
cept and offering practical advice on the description ria.
and interpretation of microfacies data as well as the Microfacies Interpretation (Chap. 11 to Chap. 16)
application of these data to basin analysis. Microfacies demonstrates the significance of microfacies studies
analysis has the advantages over traditional sedimen- in evaluating paleoenvironment and depositional sys-
tological approaches of being interdisciplinary, and in- tems and, finally,
tegrating sedimentological, paleontological and geo- Practical Use of Microfacies (Chap. 17 to Chap. 19)
chemical aspects. demonstrates the importance of applied microfacies
‘Microfacies of Carbonate Rocks’: studies in geological exploration for hydrocarbons and
• analyses both the depositional and the diagenetic his- ores, provides examples of the relationships between
tory of carbonate rocks, carbonate rock resources and their facies and physical
• describes carbonate sedimentation in various ma- properties, and also illustrates the value of microfacies
rine and non-marine environments, and considers studies to archaeologists.
both tropical warm-water carbonates and non-tropi- Important references are listed at the end of chap-
cal cool-water carbonates, ters or sections under the heading ‘Basics’. The code
VIII Preface
numbers K... are keywords leading to references on
Chapter 6: Quantitative Microfacies Analysis. Whilst
specific fields of interest (see CD), e.g. K021 (cold-
previous chapters focused on qualitative criteria this
water carbonates), K078 (micrite), or K200 (hydrocar-
chapter deals with quantitative data including grain size
bon reservoir rocks).
analysis, frequency analysis and multivariate studies.
The book is also accompanied by a CD containing Constituent analysis and the distribution patterns of spe-
• an alphabetical list of about 16,000 references cific grain types are valuable tools in the reconstruc-
(updated in this version up to April 2009) on carbonate tion of paleoenvironmental controls and depositional
rocks (see also Appendix) as word document, settings.
and
Chapter 7: Diagenesis, Porosity and Dolomitization.
• visual comparison charts for percentage estimation.
Understanding diagenetic processes and their products
is of high economic importance. The diagenetic micro-
facies of a rock reflects changes in the course of its
Synopsis of the Book‘s Contents
lithification history. The main topics discussed in this
chapter are porosity types, carbonate cements, diage-
Chapter 1: New Perspectives in Microfacies. Micro-
netic textures including compaction and pressure solu-
facies studies, which were originally restricted to the
tion, and dolomitization/dedolomitization and dolomite
scale of thin sections, provide an invaluable source of
textures. The last part of the chapter deals with thin-
information on the depositional constraints and envi-
section criteria for metamorphic carbonates and
ronmental controls of carbonates, as well as on the prop-
marbles.
erties of carbonate rocks. Microfacies studies assist in
understanding sequence stratigraphic patterns and are Chapter 8: Classification – chosing a name for your
of economic importance both in reservoir studies and sample. A classification is simply a tool for organizing
in the evaluation of limestone resources. information, and should not be the only source of con-
clusions. Whilst a name based on texture and compo-
Chapter 2: Modern Depositional Environments. Knowl-
sition can not replace a well-defined microfacies type,
edge of modern carbonates is a prerequisite for under-
rock names are essential for the categorization of
standing ancient carbonate rocks. Modern carbonates
samples. Textural classifications proposed by Dunham
are formed both on land and in the sea, in shallow- and
and by Folk have proven to be the most practical. Spe-
in deep marine settings, and in tropical and non-tropi-
cific concepts must be adhered to in the naming of reef
cal regions, but the present is only part a key to the
limestones, non-marine carbonates, recrystallized car-
Past.
bonates rocks and mixed siliciclastic-carbonate rocks.
Microfacies Analysis
Chapter 9: Limestones are Biological Sediments. In
Chapter 3: Methodology. Which methods can be used
contrast to siliciclastic rocks, both the formation and
in the field? Which sampling strategy should be ap-
the destruction of most limestones is directly or indi-
plied and how many samples are required? Which labo-
rectly influenced and controlled by biological pro-
ratory techniques are useful in microfacies analysis?
cesses. This chapter stresses the biological controls on
Which other techniques should be combined with
carbonate sedimentation. Microbes, encrusting organ-
microfacies studies?
isms, and macro- and microborers can yield useful in-
Chapter 4: Microfacies Data: Matrix and Grains. This formation on paleoenvironment, depositional con-
chapter offers practical advice on how to handle micro- straints and carbonate production.
facies data, and deals with how to describe and inter-
Chapter 10: Fossils in Thin Sections. It Is Not That
pret thin-section characteristics. Matrix types and grain
Difficult. The recognition of fossils in thin sections is
categories are discussed with regard to their diagnostic
not so difficult once the diagnostic criteria for the main
criteria, origin and significance.
groups have been understood, particularly for algae and
Chapter 5: Microfacies Data: Fabrics. Typical deposi- foraminifera, sessile invertebrates, and organisms with
tional and diagenetic fabrics in limestones reflect the shells. This chapter provides an overview of the most
history of the rock. Microfacies criteria indicating common fossils found in thin sections of limestones.
breaks and changes in sedimentation (discontinuity sur- The text concentrates on identification criteria, envi-
faces) are of specific interest in refining sequence strati- ronmental and temporal distribution, and on the sig-
graphic boundaries. Variously sized fissures, micro- nificance of the fossils. Numerous instructive plates
cracks and breccias can be used in deciphering syn- are included to aid in the recognition and differentia-
and post-depositional destructive processes. tion skeletal grains in thin sections.
Preface IX
Microfacies Interpretation stones of different carbonate systems? Case studies for
Chapter 11: Summarizing Microfacies Criteria: Micro- non-marine and marine carbonate rocks demonstrate
facies Types. How can microfacies data be combined how to translate microfacies into ancient depositional
in sensitive and practicable microfacies types? Which settings. Non-marine settings can be successfully re-
criteria should be used, which grain types are of par- constructed for pedogenic carbonates, paleokarst de-
ticular importance and, how many microfacies types posits and ancient speleothems, travertine deposits, and
are reliable? The creation of microfacies types is illus- lacustrine carbonates, these can be characterized by spe-
trated by means of examples. cific microfacies types. Marine settings can be differ-
entiated into peritidal carbonates, platforms and ramps,
Chapter 12: Recognizing Paleoenvironmental Condi-
platform-slope-basin transects, and pelagic deep-ma-
tions. Carbonate sediments are particularly sensitive
rine carbonates. Grain Composition Logs are particu-
to environmental changes. Microfacies and organisms
larly effective in tracing platform-basin relations.
are excellent paleoenvironmental proxies as they re-
flect hydrodynamic conditions, the impact of storms, Chapter 16: Recognizing Depositional Constraints and
substrate conditions, light, oxygenation, seawater tem- Processes. Selected case studies are used to demon-
perature and salinity. Significant differences between strate the value of microfacies data in interpreting depo-
the compositions of skeletal grain associations for sitional controls.
warm-water and cold-water carbonates provide a use- • How can microfacies be used in sequence stratigra-
ful tool for estimating paleoclimatic changes. How deep phy? Cyclic depositional patterns and sequence strati-
was the sea? Microfacies studies provide an answer. graphic constraints are documented by microfacies data
that assist in recognizing sequence boundaries, para-
Chapter 13: Integrated Facies Analysis. Understand- sequences, high-frequency sea-level changes, and sys-
ing the formation and diagenesis of carbonate rocks tems tracts.
requires the combination of microfacies with mineral- • Which criteria characterize reef limestones? Major
ogical and geochemical data. The chapter deals with reef types differ in biota, matrix, sediment, and cements.
acid-insoluble residues and authigenic minerals in car- Which methods should be employed in reconstructing
bonate rocks, discusses the value of minor elements former platforms and reefs that are only recorded by
and stable isotopes in tracing the depositional and di- eroded relicts deposited on slopes and in basins? Clast
agenetic history of limestones, and deals with the po- analysis can solve this puzzle.
tential of organic matter in carbonate rocks for facies • Which criteria define ancient cold-water carbonates?
analysis. Ancient cool-water shelf and reef carbonates are typi-
fied by specific biotic, compositional and diagenetic
Chapter 14: Depositional Models, Facies Zones and
features.
Standard Microfacies. Microfacies are essential for de-
• Which facies criteria are diagnostic of ancient vent-
fining depositional models and recognizing facies
and seep carbonates? Case studies provide answers.
zones. Facies models assist in understanding deposi-
• How to handle mixed carbonate-siliciclastic sedi-
tional history. Changes in sedimentological and bio-
ments and interpret limestone-marl successions?
logical criteria across shelf-slope-basin transects form
• Constraints on carbonate deposition exhibit secular
the basis of generalized models for carbonate platforms,
variations, which are discussed in the last section.
ramps and shelves. Facies belts are reflected by their
biotic zonation patterns and the distribution of Stan-
dard Microfacies Types (SMF Types). The latter are
Practical Use of Microfacies
virtual categories that summarize microfacies with iden-
Chapter 17: Reservoir Rocks and Host Rocks. Carbon-
tical criteria. Which criteria are used in differentiating
ates are the most important reservoir rocks for hydro-
the SMF Types of platform and ramp carbonates? What
carbons as well as forming important host rocks for
are the problems involved in the SMF concept? Re-
ores. Limestones and dolomites contain more than 50%
vised and refined SMF types are a meaningful tool in
of the world’s oil and gas reserves. Reservoir potential
tracing facies belts, but must be used with care. Com-
differs for carbonates formed in different depositional
mon microfacies of carbonate ramps (Ramp Micro-
settings and depends on the interplay of depositional
facies Types) show only partial correspondence to the
processes and diagenetic history. The microfacies of
SMF Types of rimmed platforms.
cores and cuttings assist in the translation of lithological
Chapter 15: Basin Analysis: Recognizing Depositional data into petrophysical information. Facies-based out-
Settings. Which diagnostic criteria characterize lime- crop-analogue studies indicate the scale of porosity and
X Preface
permeability variations within carbonate bodies. Micro- (Erlangen), Markus Geiger (Bremen), Gisela Gerdes
facies analysis also assists in the genetic interpretation (Oldenburg), Eberhard Gischler (Frankfurt), Dirk von
of carbonate-hosted base metal deposits controlled by Gosen (Erlangen), Jürgen Grötsch (Damascus). Hans-
specific facies patterns. Georg Herbig (Köln), Richard Höfling (Erlangen),
Bernhard Hubmann (Graz), Andi Imran (Makassar),
Chapter 18: Carbonate Resources, Facies Control and
Michael Joachimski (Erlangen), Josef Kazmierczak
Rock Properties. Carbonate rocks are important raw
(Warszawa), Martin Keller (Erlangen), Stephan Kempe
materials for chemical and construction industries and
(Darmstadt), Helmut Keupp (Berlin), Wolfgang
are high on the list of extracted mineral resources, both
Kiessling (Berlin), Roman Koch (Erlangen), Karl
in terms of quantity and of value. Both exploration and
Krainer (Innsbruck), Jochen Kuss (Bremen), Michael
exploitation can be enhanced by taking into account
Link (Erlangen), Heinz Lorenz (Erlangen), Ulrich
the relationships between depositional and diagenetic
Michel (Nürnberg), Axel Munnecke (Erlangen), Fritz
facies that control technologically relevant chemical
Neuweiler (Göttingen), Alexander Nützel (Erlangen),
and physical parameters, as well as the weathering and
Joachim Reitner (Göttingen), Jürgen Remane
decay properties of carbonate rocks. Conservation and
(Neuchâtel), Elias Samankassou (Genéve), Diethard
preservation of works of art and building stones should
Sanders (Innsbruck), Chris Schulbert (Erlangen), Baba
start with thin-section studies of the textural and di-
Senowbari-Daryan (Erlangen), Robert J. Stanton
agenetic criteria that describe the porosity and perme-
(Thousand Oaks, California), Torsten Steiger (Bad
ability of the material.
Blankenburg), Thomas Steuber (Bochum), Harald
Chapter 19: Archaeometry. Microfacies analysis, com- Tragelehn (Köln), Jörg Trappe (Bonn), Dragica Turnsek
bined with geochemical data has considerable poten- (Ljubljana), Andreas Wetzel (Tübingen).
tial in provenance analysis of archaeological materi- I am indebted to Birgit Leipner-Mata and Marieluise
als. Thin sections reveal the source of building stones Neufert (Institute of Paleontology Erlangen) for labo-
and of material used for mosaics and works of arts. ratory work and photography.
The microfacies of temper grains in ancient pottery Chris Schulbert (Institute of Paleontology) was a
helps in understanding the source and production ar- valuable help with all computer problems.
eas for ceramics. Last but not least, microfacies stud-
ies can throw new light at the love affair between I am sincerely grateful to my friend Johann Georg
Antony and Cleopatra.... Haditsch (Graz) for critical reading the text of the book.
Special thanks go to Karen Christenson (Nürnberg-
Kraftshof) who took care of linguistic problems and
Acknowledgments
pitfalls.
Thanks are due to many people who have provided
photographs, information and advice: Editing, layout, drawings and the preparation of
Gernot Arp (Göttingen), Martina Bachmann (Bre- plates and figures have been carried out by my wife
men), Benoit Beauchamp (Calgary), Thilo Bechstädt Erentraud Flügel-Kahler. I am most grateful for her en-
(Heidelberg), Michaela Bernecker (Erlangen), Joachim couragement and constant help.
Blau (Giessen), Florian Böhm (Kiel), Thomas Brachert
(Mainz), Ioan Bucur (Cluj-Napoca), Werner Buggisch Finally, I am obliged to all institutions who gave
(Erlangen),Thomas Clausing (Halle), Wolf-Christian permission to use published material and to the staff of
Dullo (Kiel), Paul Enos (Lawrence, Kansas), Gerd Flajs Springer Verlag, especially to Dr. Wolfgang Engel for
(Aachen), Christof Flügel (München), Helmut Flügel his constant encouragement and to Dr. J. Witschel for
(Graz), Beate Fohrer (Erlangen), Holger Forke (Ber- assistance with the book.
lin), André Freiwald (Erlangen), Robert van Geldern
XI
Contents
1 New Perspectives in Microfacies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1 The Microfacies Concept. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 New Perspectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
2 Carbonate Depositional Environments . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.1.1 Carbonates are Born not Made. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.1.2 The ‘Sorby Principle’: Limestones are Predominantly Biogenic
Sediments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.1.3 Modern Carbonates: Obligatory Reading . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.2 Carbonate Sediments Originate on Land and in the Sea . . . . . . . . . . . . . . . 8
2.3 Classification of Marine Environments . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.3.1 Boundary Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.3.2 Vertical and Horizontal Zonations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.3.2.1 Vertical Zonations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.3.2.2 Horizontal Zonations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.4 Review of Modern Carbonate Depositional Environments . . . . . . . . . . . . . 10
2.4.1 Non-Marine Carbonate Environments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.4.1.1 Pedogenic Carbonates, Paleosols, and Caliche/Calcretes . . . . . . . . . . . . . . 10
2.4.1.2 Palustrine Carbonates. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.4.1.3 Cave Carbonates, Speleothems and Karst . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.4.1.5 Glacial Carbonates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.4.1.6 Travertine, Calcareous Tufa and Calcareous Sinter. . . . . . . . . . . . . . . . . . . 14
2.4.1.7 Lacustrine Carbonates: Lakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2.4.1.8 Fluvial Carbonates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2.4.2 Transitional Marginal-Marine Environments: Shorelines and
Peritidal Sediments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
2.4.2.1 Beach (Foreshore), Barriers and Coastal Lagoons. . . . . . . . . . . . . . . . . . . . 24
2.4.2.2 Peritidal Environments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
2.4.3 Shallow-Marine Sedimentary Environments: ‘Shallow’ and ‘Deep’. . . . . . 25
2.4.3.1 Pericontinental vs Epicontinental Shallow Seas . . . . . . . . . . . . . . . . . . . . . 26
2.4.3.2 Carbonate Shelves, Ramps and Platforms . . . . . . . . . . . . . . . . . . . . . . . . . . 26
2.4.3.3 Shelf Margins. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
2.4.3.4 Reefs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
2.4.4 Tropical and Non-Tropical Carbonates: Different in Composition,
Controls and Significance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
2.4.4.1 Latitudinal Zonation and Diagnostic Criteria of Tropical and Non-Tropical
Carbonates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
2.4.4.2 Tropical and Subtropical Shallow-Marine Carbonates . . . . . . . . . . . . . . . . 34
2.4.4.3 Non-Tropical Shelf and Reef Carbonates . . . . . . . . . . . . . . . . . . . . . . . . . . 37
2.4.5 Deep-Marine Environments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
2.4.5.1 Settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
2.4.5.2 Sedimentation Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
2.4.5.3 Pelagic Sedimentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
2.4.5.4 Resedimentation (‘Allochthonous Carbonates’) . . . . . . . . . . . . . . . . . . . . . 49
XII Contents
2.4.5.5 Carbonate Plankton and Carbonate Oozes. . . . . . . . . . . . . . . . . . . . . . . . . . 49
2.4.5.6 Preservation Potential and Dissolution Levels. . . . . . . . . . . . . . . . . . . . . . . 49
2.4.5.7 Carbonate Slopes, Periplatform Carbonates and Caronate Aprons . . . . . . . 50
2.4.6 Seep and Vent Carbonates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Microfacies Analysis
3 Methods. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
3.1 Field Work and Sampling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
3.1.1 Field Observations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
3.1.1.1 Lithology, Texture and Rock Colors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
3.1.1.2 Bedding and Stratification, Sedimentary Structures and
Diagenetic Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
3.1.1.3 Fossils and Biogenic Structures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
3.1.1.4 Field Logs and Compositional Logs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
3.1.2 Sampling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
3.1.2.1 Search Sampling and Statistical Sampling. . . . . . . . . . . . . . . . . . . . . . . . . . 62
3.1.2.2 How Many Samples? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
3.1.2.3 Practical Advice for Microfacies Sampling . . . . . . . . . . . . . . . . . . . . . . . . . 63
3.2 Laboratory Work: Techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
3.2.1 Slices, Peels and Thin Sections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
3.2.2 Casts, Etching and Staining . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
3.2.3 Microscopy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
3.2.3.1 Petrographic Microscopy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
3.2.3.2 Stereoscan Microscopy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
3.2.3.3 Fluorescence, Cathodoluminescence and Fluid Inclusion Microscopy. . . . 67
3.2.4 Mineralogy and Geochemistry. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
3.2.5 Trace Elements and Stable Isotope Analysis . . . . . . . . . . . . . . . . . . . . . . . . 70
4 Microfacies Data: Matrix and Grains . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
4.1 Fine-Grained Carbonate Matrix: Micrite, Microspar, Calcisiltite . . . . . . . . 73
4.1.1 Micrite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
4.1.2 Modes of Formation of Micrite and Other Fine-Grained Matrix Types . . . 80
4.1.3 Microspar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
4.1.4 Calcisiltite. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
4.1.5 Practical Aids in Describing and Interpreting Fine-Grained Limestones . . 98
4.1.6 Significance of Fine-Grained Carbonates . . . . . . . . . . . . . . . . . . . . . . . . . . 98
4.2 Carbonate Grains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
4.2.1 Bioclasts (Skeletal Grains). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
4.2.2 Peloids: Just a Term of Ignorance?. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
4.2.3 Cortoids – Carbonate Grains Characterized by Micrite Envelope. . . . . . . . 118
4.2.4 Oncoids and Rhodoids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
4.2.4.1 Oncoids. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
4.2.4.2 Rhodoids and Macroids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
4.2.5 Ooids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
4.2.6 Pisoids and Vadoids – Simply ‘Larger Ooids’ or Carbonate Grains
on their Own? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
4.2.7 Aggregate Grains: Grapestones, Lumps and Other Composite Grains . . . . 163
4.2.8 Resediments: Intra-, Extra- and Lithoclasts – Insiders and Foreigners . . . . 166
4.2.8.1 Intraclasts: Origin and Facies-Diagnostic Types . . . . . . . . . . . . . . . . . . . . . 167
4.2.8.2 Extraclasts: Strange Foreigners . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172
4.3 Morphometry of Carbonate Grains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173
4.3.1 Intentions and Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174
4.3.2 Significance of Morphometric Data for Carbonate Grains . . . . . . . . . . . . . 175