This illustrated survey covers what Nicholas Wade calls the "observational era of vision," beginning with the Greek philosophers and ending with Wheatstone's description of the stereoscope in the late 1830s.
For over thirty years, Latin American Politics and Development has kept instructors and students abreast of current affairs and changes in Latin America. Now in its ninth edition, this definitive text has been updated throughout and features contributions from experts in the field, including twenty new and revised chapters on Mexico, Central America,the Caribbean, and South America.
Understanding Central America explains how domestic, global, political and economic forces have shaped rebellion and regime change in Costa Rica, Nicaragua, El Salvador, Guatemala, and Honduras throughout their histories, during the often-turbulent 1970s and since. The text provides students a comprehensive coverage of Central America, political science, and international relations. The authors explain the origins and development of the region's political conflicts, their resolution and ongoing political change. This Sixth Edition provides the most up-to-date information on the recent political changes in each of the five countries presented.
In this seventh edition, John A. Booth, Christine J. Wade, and Thomas W. Walker update a classic in the field which invites students to explore the histories, economies, and politics of Costa Rica, Nicaragua, El Salvador, Guatemala, and Honduras. Covering the region's political and economic development from the early 1800s onward, the authors bring the Central American story up to date. New to the 7th Edition: Analysis of trends in human rights performance, political violence, and evolution of regime types; Updated findings from surveys to examine levels of political participation and support for democratic norms among Central Americans; Historical and current-era material on indigenous peoples and other racial minorities; Discussion of popular attitudes toward political rights for homosexuals, and LGBTQ access to public services; Discussion of women’s rights and access to reproductive health services, and women’s integration into elective offices; Tracing evolving party systems, national elections, and US policy toward the region under the Obama and Trump administrations; Central America’s international concerns including Venezuela’s shrinking role as an alternative source of foreign aid and antagonist to US policy in the region, and migration among and through Central American nations. Understanding Central America is an ideal text for all students of Latin American politics and is highly recommended for courses on Central American politics, social systems, and history.
Vision is our most dominant sense. From the light that enters our eyes to the complex cognititve provesses that follow, we derive most of our information about what thigns are, where they are and how they move from our vision.
El Salvador is widely considered one of the most successful United Nations peacebuilding efforts, but record homicide rates, political polarization, socioeconomic exclusion, and corruption have diminished the quality of peace for many of its citizens. In Captured Peace: Elites and Peacebuilding in El Salvador, Christine J. Wade adapts the concept of elite capture to expand on the idea of “captured peace,” explaining how local elites commandeered political, social, and economic affairs before war’s end and then used the peace accords to deepen their control in these spheres. While much scholarship has focused on the role of gangs in Salvadoran unrest, Wade draws on an exhaustive range of sources to demonstrate how day-to-day violence is inextricable from the economic and political dimensions. In this in-depth analysis of postwar politics in El Salvador, she highlights the local actors’ primary role in peacebuilding and demonstrates the political advantage an incumbent party—in this case, the Nationalist Republican Alliance (ARENA—has throughout the peace process and the consequences of this to the quality of peace that results.
Vision is our most dominant sense, from which we derive most of our information about the world. From the light that enters the eye and the processing in the brain that follows we can sense where things are, how they move and what they are. The first edition of Visual Perception took a refreshingly different approach to perception, starting from the function that vision serves for an active observer in a three-dimensional environment. This fully revised and expanded new edition continues this approach in contrast to the traditional textbook treatment of vision as a catalogue of phenomena. Following a general introduction to the main theoretical approaches, the authors discuss the historical basis of our current knowledge. Placing the study of vision in its historical context, they look at how our ideas have been shaped by art, optics, biology and philosophy as well as psychology. Visual optics and the neurophysiology of vision are also described. The core of the book covers the perception of location, motion and object recognition. There is a new chapter on representation and vision, including a section on the perception of computer generated images. This readable, accessible and truly relevant introduction to the world of perception aims to elicit both independent thought and further study. It will be welcomed by students of visual perception and those with a general interest in the mysteries of vision.
The life of Jan Evangelista Purkinje (1787-1869) has fascinated students from many disciplines. Histologists marvel at his early descriptions of cells; physiologists admire his attempts to relate structure to function; pharmacologists view in awe his heroic experiments on self-administered drugs; forensic scientists acknowledge his role in the use of fingerprints for identification; and Czech patriots salute his awakening of pride in their nation. Yet all these achievements followed his initial enquiries into vision. It is this psychological dimension that fostered this collaboration. As the title suggests, the present volume is bifocal. In the narrow sense it refers to Purkinje's studies of vision, but in its broader view it concerns Purkinje's anticipation of neuroscience. Purkinje provided evidence to support both its cellular and its conceptual base. At the cellular level his acute vision is immortalized within our bodies. At the conceptual level, he sought to relate subjective phenomena to their objective underpinnings--to link psychology to physiology. Vision provides a bond that unites psychology and physiology, and it is this bond that was strengthened by Purkinje's enquiries. The authors have tried to provide a context in which Purkinje's descriptions of visual phenomena can be placed. In some cases this exposes clear precursors of research for which Purkinje has been credited. In others, there was nothing to suggest the phenomena that he exposed. The book translates Purkinje's initial masterpiece on subjective vision and places it in the context of emerging views of neuroscience.
Nicaragua: Emerging from the Shadow of the Eagle details the country's unique history, culture, economics, politics, and foreign relations. The thoroughly revised and updated sixth edition features new material covering political, economic, and social developments since 2011.
The 2nd Edition of Carbonate Reservoirs aims to educate graduate students and industry professionals on the complexities of porosity evolution in carbonate reservoirs. In the intervening 12 years since the first edition, there have been numerous studies of value published that need to be recognized and incorporated in the topics discussed. A chapter on the impact of global tectonics and biological evolution on the carbonate system has been added to emphasize the effects of global earth processes and the changing nature of life on earth through Phanerozoic time on all aspects of the carbonate system. The centerpiece of this chapter—and easily the most important synthesis of carbonate concepts developed since the 2001 edition—is the discussion of the CATT hypothesis, an integrated global database bringing together stratigraphy, tectonics, global climate, oceanic geochemistry, carbonate platform characteristics, and biologic evolution in a common time framework. Another new chapter concerns naturally fractured carbonates, a subject of increasing importance, given recent technological developments in 3D seismic, reservoir modeling, and reservoir production techniques. Detailed porosity classifications schemes for easy comparison Overview of the carbonate sedimentologic system Case studies to blend theory and practice
This newly revised volume details Nicaragua's unique history, culture, economics, politics, and foreign relations. Its historical coverage considers the country's early and recent history, from pre-Columbian and colonial times through the nationalist liberal era, the U.S. marine occupation, the Somoza dictatorship, the Sandinista regime, the conservative restoration, and the Sandinista comeback. The fifth edition includes a new chapter detailing the reelection of Daniel Ortega and the irony of his current role in undercutting the rule of law and democracy that he helped institute in his earlier administration. This edition also documents what may be the more enduring reality of this Central American country: the historical and ongoing interventions by which the United States - the ''eagle'' to the north - continues to shape Nicaraguan political, economic, and cultural life.
Three economically important case histories serve as illustrations of the integration of analyses of depositional environments, sequence stratigraphic architecture, and porosity evolution during diagenesis, as a means of maximizing effectiveness of reservoir production and/or modelling: (1) the Paleozoic Madison Formation of central Wyoming, (2) the Upper Jurassic Smackover Formation of the central Gulf of Mexico, and (3) the Tertiary Malampaya buildup, offshore Philippines. The three embody a broad range of geologic contexts (e.g., icehouse versus greenhouse during deposition) and different approaches for optimizing development programs (e.g., use of surface analogs, 3D seismically based reservoir modelling). High drilling costs during development of the deep (23,000ft.) Madden Field in the Wyoming Madison Formation (due to high temperature, pressure, and H2S content of the gas) mandated high efficiency during development. Meticulous evaluation of a surface outcrop analog and maximized collection of analog data were the primary means of assuring optimal reservoir development. The Upper Jurassic Smackover trend in the central Gulf of Mexico illustrates revitalization of a mature petroleum fairway through application of sequence stratigraphic interpretation. Previously overlooked lowstand siliciclastic slope fans become geographically and stratigraphically predictable reservoir targets when understood in their proper sequence stratigraphic framework. The 3D seismic grid over the drowned isolated Oligocene–Miocene Malampaya platform, offshore Philippines, is integrated with geologic and petrophysical data from sparse well control and field-wide depositional and diagenetic models in order to develop a reservoir simulation model of the reservoir.
Shallow-marine carbonate sequences commonly undergo exposure to meteoric waters. These waters are chemically aggressive toward sedimentary carbonate minerals, capable of rapidly dissolving grains and generating secondary porosity. The carbonate derived from dissolution can precipitate as cement, either nearby or hydrologically downstream, decreasing porosity. Thus the potential for restructuring of original depositional porosity is very high in the meteoric diagenetic environment. Chemical signatures of meteoric pore waters and meteoric carbonate cements are distinct and reflect kinetics of the CaCO3–H2O–CO2 system, climatic effects, and hydrologic setting. The meteoric diagenetic environment is subdivided into vadose and phreatic diagenetic zones. Caliches/calcretes are distinctive diagenetic profiles of uppermost vadose zones in semi-arid climates. Porosity development in vadose diagenetic zones is to a large degree a function of relative sea level, which controls the occurrence of localized floating freshwater lenses (during highstands) versus regional meteoric water systems (during lowstands). Detailed examples presented include Quintana Roo (Mexico) strandplains and Oaks Field (North Louisian Jurassic), both highstand prograding shoreline systems, and Great Bahama Bank and Barbados (lowstand platform-wide aquifer systems). Geochemical trends in calcite cements and porosity development patterns characteristic of regional meteoric aquifer systems are illustrated from Mississippian Lake Valley Formation grainstones (southwest New Mexico). Karst processes and porosity styles are described in order that paleokarst features in reservoirs can be recognized and/or predicted. Detailed evaluations of paleokarsted reservoirs include Yates and Ellenburger fields (Permian and Ordovician of West Texas, respectively) and Rospo Mare Field (Cretaceous), Adriatic offshore, Italy. Lastly, the validity and significance of dolomitization associated with meteoric and especially mixed meteoric–marine waters (Dorag model) is evaluated and found to be lacking.
All organisms live in clusters, but such fractured local populations, or demes, nonetheless maintain connectivity with one another by some amount of gene flow between them. Most such metapopulations occur naturally, like clusters of amphibians in vernal ponds or baboon troops spread across the African veldt. Others have been created as human activities fragment natural landscapes, as in stands of trees separated by roads. As landscape change has accelerated, understanding how these metapopulations function—and specifically how they adapt—has become crucial to ecology and to our very understanding of evolution itself. With Adaptation in Metapopulations, Michael J. Wade explores a key component of this new understanding of evolution: interaction. Synthesizing decades of work in the lab and in the field in a book both empirically grounded and underpinned by a strong conceptual framework, Wade looks at the role of interaction across scales from gene selection to selection at the level of individuals, kin, and groups. In so doing, he integrates molecular and organismal biology to reveal the true complexities of evolutionary dynamics from genes to metapopulations.
Two marine evaporative settings are presented in detail: the sabkha and the evaporative lagoon/salina. In each, diagenetic pathways affect porosity evolution in associated marine carbonate sequences, with common dolomitization being a principal factor. Dolomitization is favored where hypersaline waters possess high Mg/Ca ratios (postprecipitation of Ca-bearing evaporites) and potential for hydrologic drive (high fluid densities). Surficial dolomites in modern environments are poorly ordered “protodolomites”. Modern marginal marine sabkha diagenetic environments are thin (
The three diagenetic realms in which porosity modifications (e.g., dissolution, cementation, compaction) take place are the marine, meteoric, and subsurface environments. The meteoric environment—with its dilute waters, easy access to CO2, and wide range of saturation states with respect to carbonate phases—has high potential for porosity modification, including destruction by cementation and generation of secondary porosity by dissolution. Modern shallow-marine environments are particularly susceptible to porosity destruction by cementation due to high levels of supersaturation of marine waters relative to metastable carbonate minerals. Decreasing saturation with depth can lead to development of secondary porosity by dissolution of aragonite. In the geologic past, shallow-marine waters were often undersaturated with respect to aragonite. The subsurface environment is marked by loss of porosity through compaction and related cementation. Thermal maturation and degradation of hydrocarbons and the slow flux of basinal fluids during progressive burial drive later porosity modification by cementation and modest local dissolution. Recognition and differentiation of the porosity modification history of carbonate rocks is aided by a number of analytical tools. Petrography enables us to reconstruct the sequence of relatively timed diagenetic events responsible for porosity modifications. Trace element and stable isotope analyses of cements and dolomites provide insight into the types of waters involved in these events. Two-phase fluid inclusions are used to estimate temperatures of cement or dolomite formation and the composition of precipitating or dolomitizing fluids. The definitiveness of trace element analysis is often limited by uncertainties in distribution coefficients, temperature fractionation effects, or low concentration values. Two-phase fluid inclusion studies also pose significant problems (e.g., stretching of inclusions during burial, recognition of primary inclusions, and accuracy of pressure corrections). Therefore, these tools should be used to provide constraints on assessing environments of diagenetic events, within an appropriate petrographic/geologic framework. The continuing development of new instruments and techniques (e.g., the ion probe, clumped isotope analysis) holds great promise for the future of geochemical analyses in diagenetic studies.
Major porosity-modifying processes operating in the marine diagenetic realm are (1) cementation in shallow warm waters, (2) dolomitization accompanied by minor porosity enhancement in deep waters below the aragonite and calcite lysoclines, and (3) dolomitization associated with organic degradation during early burial. In shallow, normal marine environments, porosity is lost through abiotic and microbially mediated cementation. Such cementation is most abundant in shelf-margin reefs, high-energy intertidal zones, and isolated hardgrounds. Abiotic and microbial cementation in reefs—in combination with bioerosion and internal sedimentation—can totally destroy high initial reef framework porosities. Although intertidal and hardground cements tend to be vertically and laterally restricted, these zones can act as permeability barriers in reservoirs. Deep marine slope and basin environments can experience significant porosity modification. Aragonite cementation on the upper slope extends to 60m depth at present. During the Paleozoic and Mesozoic eras, carbonate mud mounds developed on upper shelf slopes and distal ramps. Microbial processes in these mounds contributed to both early cementation and dissolution. Many such mounds formed in conjunction with hydrothermal and cold petroleum vents on the seafloor; some of these mud mounds are significant reservoirs. Where the thermocline and carbonate lysoclines impinge on steep carbonate platform margins that front oceanic basins, dissolution of aragonite and/or calcite, precipitation of radiaxial calcite cement, and dolomitization can occur. Kohout thermal convection and mixing-zone-induced seawater circulation are the most likely hydrologic pumps driving large volumes of marine water through steep platform margins. At relatively shallow depths in the sediment/rock column, decomposition of organic matter mediated by sulfate-reducing bacteria can promote dissolution of aragonite and Mg-calcite, calcite cementation, and massive dolomitization.
William Charles Wells (1757-1817) was one of the foremost, and forgotten, American scientists of the eighteenth century. He should be acknowledged as laying the foundations for modern studies of vestibular function as well as eye movements. This book reprints his Essay on single vision with two eyes (1792) and his own Memoir of his life (1818). Wells’ essay on natural selection is reprinted as an Appendix. Wells' experiments and observations on natural phenomena will surprise students of science because of their modernity.
In a fascinating and accessible style, Marco Piccolino and Nick Wade analyse the scientific and philosophical work of Galileo Galilei from the particular viewpoint of his approach to the senses (and especially vision) as a means of acquiring trustworthy knowledge about the constitution of the world
Carbonate reservoirs are prone to natural fracturing. Fractures can act as enhanced permeability pathways, which may increase, decrease, or complicate reservoir production and development; healed fractures contribute to reservoir compartmentalization. A primary focus is placed upon the predictability of fracture set patterns and orientations, which vary according to carbonate lithofacies and the stress field(s) under which different types of fractures form. Extension fractures can form at the surface or at reservoir depths. Certain types of extension fracture sets (e.g., syndepositional, regional, and—to a lesser extent—karst-related fracture sets) exhibit predictable patterns and orientations with respect to the stress field under which they originated. Surface outcrops commonly exhibit multiple fracture sets; these are most frequently related to relaxation of compaction and/or thermal cooling. Such fracture sets are considered unlikely to resemble fracture sets in nearby reservoirs at depth; therefore, the use of surface fracture patterns as analogs for same-formation reservoirs, without comparative analysis of burial stress histories, is risky. Fault-related fractures have very high permeability potentials when newly formed, but their resulting role as fluid conduits typically leads to rapid healing, and therefore a higher likelihood of causing reservoir compartmentalization. These fractures typically cut across multiple beds. Fold-related fracture patterns are complex, typically consisting of both extension and conjugate shear-pair fractures, and show variable orientations in space and/or over time. However, they tend to follow the geometries of individual beds and are often confined to single beds, rather than aligning according to overall structural axes. Ekofisk Field, a naturally fractured North Sea chalk reservoir, is presented as an illustrative case of fold-related fracture abundance and effectiveness in enhancing fieldwide permeability parameters, without the drawback of creating major production problems during waterflooding.
The overarching diagenetic drive during progressive burial of carbonate rocks is toward the loss of porosity through mechanical and chemical compaction (the latter consisting of pressure solution plus related cementation). The passive margin diagenetic regime is marked by relatively rapid burial with steadily rising temperatures and pressures. Once a mechanically stable grain framework is achieved, the effective stress from sediment loading can eventually suffice to cause chemical compaction. Early cementation, the presence of organic frameworks, overpressuring, dolomitization, and especially the filling of reservoir pores with oil all act to retard the onset and efficiency of chemical compaction. Aggressive pore fluids, the presence of metastable mineral phases, and admixtures of siliciclastics or other insolubles tend to accelerate the process. Catagenesis of organic matter in source rocks yields aggressive formation waters capable of calcite dissolution just prior to hydrocarbon maturation. But despite evidence of local late secondary porosity generation, theoretical considerations lead to the conclusion that such evidence represents limited and local porosity rearrangement. Hydrocarbon-filled deep carbonate reservoirs experience progressive loss of porosity with increasing depth, due to precipitation of pyrobitumen as circumgranular linings, and also—during very deep burial—by renewed precipitation of calcite cement (with carbon derived from destruction of methane) and resumption of mechanical and/or chemical compaction. The active margin diagenetic regime is characterized by rapid movement of large volumes of warm-to-hot basinal fluids, mobilized by tectonism, through complex subsurface conduits. Reactions between expelled fluids and conduit carbonates include recrystallization of earlier dolomites and calcites, replacement dolomitization, dissolution of calcite, dolomite and/or evaporites, and sulfide mineralization. Ascending hydrothermal fluids associated with wrench faults and rifting may result in fault-localized leaching of calcite, dolomitization, and dolomite cementation capable of creating or enhancing “hydrothermal dolomite” reservoirs. The most abundant diagenetic product is saddle dolomite. The postorogenic diagenetic regime is characterized by topographically driven meteoric recharge into deeply buried aquifers. There is minimal impact on carbonate porosity unless meteoric waters are dissolving anhydrite/gypsum. Where this occurs, a chemical drive can promote dissolution of dolomite and precipitation of calcite, accompanied by porosity enhancement. In the absence of evaporite dissolution, meteoric waters equilibrate with carbonate aquifers and minimal porosity modification occurs downstream. Crossplots of porosity versus thermal maturity appear to possess porosity predictive capability. Carbonate reservoirs are relatively prone to souring at depth; hydrocarbons in sour reservoirs can be partially or entirely consumed by destructive redox reactions with sulfur in the forms of H2S and S0. The initiation and extent of these reactions depend upon the availability of reactant sulfur (from evaporites and organosulfur compounds) and dissolved iron (derived from Fe-rich siliciclastics, if proximal).
Sequence stratigraphic principals can be applied to carbonate rock sequences. Typical tropical shallow-water carbonate shelves lead to sequence boundary exposure across carbonate platforms, and carbonate deep water deposits during highstands. Rapid carbonate sedimentation across a shelf leads to vertical accretion during the TST and progradation during the HST. Reef-bound shelf margins tend to evolve into escarpment margins with megabreccia development on the slope. Examples are the Devonian of the Canning Basin and the Cretaceous of Mexico. Carbonate ramps typically develop lowstand prograding complexes. Cool-water carbonates develop ramp morphology, independent of light with no framework reefs, and parallel the sequence stratigraphic framework of siliciclastics. The cool water sediments of the Great Australian Bight is an example Mud mound sequences as seen in Morocco are generally independent of sea-level changes, so most sequence stratigraphic concepts are not applicable. In mixed carbonate-siliciclastic situations reciprocal sedimentation results with HST carbonates dominating in the basin and LST clastics dominating in the basin. Sequence stratigraphic concepts are generally not applicable to lacustrine carbonates, but lake dessication cycles present a similar stratigraphic framework as seen in the Tertiary Green River of the Western United States.
The biological influence over the origin, distribution, composition, texture, and mineralogy of carbonate sediments is stressed. Environmental factors such as light, temperature, and water depth directly affect these biological processes. Abiotic carbonate precipitation is discussed. Three carbonate factories are identified: shallow water tropical; deep water mud mound; cool-water factory developed in high and low latitudes. Basic attributes of each factory are developed. The rimmed shelf and ramp facies models of the tropical factory are detailed with the Belize shelf and Middle East Abu Dhabi as examples. The facies tract of the mud mound factory is detailed and the Devonian Canning Basin used as an example. The role of sea-level changes and carbonate sedimentation in platform development is discussed. High sea-level carbonate sediment shedding combined with lowstand sediment starvation is opposite to what is seen in regions of siliciclastic sedimentation. The dominance and importance of the Dunham rock classification is stressed. Finally, lacustrine carbonates are discussed using the African rift lakes as modern examples and developing a simple model of continental rift lake carbonate sedimentation emphasizing potential source rock and reservoir facies. The Brazil Cretaceous subsalt play of the south Atlantic rift and the potential of its African counterpart are discussed.
The porosity of carbonates as compared to sandstones is vastly more complex with simple intergrain porosity dominates sandstones while carbonates commonly exhibit complex secondary pore systems that may evolve during burial. Initial porosity of carbonates is much greater than that seen in sandstones due to common intragranular porosity. Fractures, both natural and induced, are much more important in carbonates. Diagenesis is a major factor in the development of ultimate pore systems in carbonates. The geologically based Choquette–Pray carbonate porosity classification is the most commonly used scheme. Their 15 different pore types are based on fabric selectivity. A major feature of the classification is its recognition of the potential of porosity evolution through time and burial. Three porosity development zones are recognized: eogenetic, dealing with surface processes; mesogenetic, dealing with burial processes; and telogenetic, exhumed rocks dealing again with surface processes. This classification is best used during exploration, while other engineering-based classifications such as the one developed by Lucia should be used in reservoir characterization and as input for reservoir modeling. Examples of all 15 pore types are given.
A comprehensive series of carbonate diagenesis/porosity models summarize the concepts developed in previous chapters, emphasizing the predictable loci of major porosity modification and enhancement. Each model refers to a specific combination of (1) setting (carbonate ramp, land-tied shelf, or isolated platform), (2) climate regime (humid or arid), and (3) sea-level cycle phase (TST, HST, or LST). Diagenetic processes at the parasequence scale reflect third-order sea-level cycles. During the TST and early HST, parasequences tend to be thick, with marine diagenesis dominating. Parasequences progressively thin during the HST, with exposure at cycle tops and meteoric influence becoming more important. During the late HST and the LST, subaerial diagenesis dominates. Third-order sedimentary sequences exhibit stacking geometries that reflect background second-order sea-level trends. Retrogradational sequence sets develop during second-order sea-level rise (e.g., in rift or foreland basins). Such sequence sets show relative domination by marine diagenesis. Aggradational sequence sets develop during second-order sea-level stillstand to moderate rise (e.g., early post-rift phase in extensional basins). Moderate meteoric water diagenesis and porosity modification occur at sequence boundaries, followed by burial diagenesis. Progradational sequence sets develop on passive margins during second-order sea-level stillstand to fall. This setting supports deep, amalgamated karstification, extensive phreatic meteoric diagenesis, and—under arid conditions—reflux dolomitization. First-order Icehouse conditions are characterized by high-frequency, high-amplitude sea-level cycles that favor development of rimmed carbonate shelves. The mainly aragonitic sediments deposited on these aggraded shelves experience high degrees of meteoric diagenesis and porosity modification. Greenhouse conditions are characterized by lower-frequency, low-amplitude sea-level cycles that favor development of carbonate ramps. The calcite sediments deposited here result in relatively muted meteoric diagenesis and porosity modifications. Two case histories illustrate the basic concepts of early diagenetic porosity evolution: (1) the Southwest Andrews Area, an Icehouse Permian–Pennsylvanian rimmed shelf margin reservoir (Permian, West Texas), and (2) ramp sequences of the Kwanza and Lower Congo basins, Greenhouse Albian Pinda Group (Cretaceous, offshore Angola).
Phanerozoic Global tectonic cycles (rifting of supercontinents, drifting and disassembly, closure and assembly) have a major impact of the development of the carbonate system. Volcanism during rifting affects global climate, leading to icehouse and greenhouse global climate conditions which affects marine abiotic carbonate mineralogy (aragonite seas during icehouse times, calcite seas during greenhouse times). During rifting and drifting stages, well-developed shelf margins and deep oceanic basins prevail, while during the assembly stage, shallow cratonic basins are characteristic. Ice house and greenhouse conditions impact the development of carbonate shelves. During icehouse conditions, high amplitude sea-level cycles favor development of rimmed shelves, thick fourth-order cycles, and deep karsting at sequence boundaries. Greenhouse conditions favor accretionary shelves with many thin parasequences and mild exposure surfaces. Biologic evolution also has a major impact on the carbonate system. The development of framework reefs is cyclical through the Phanerozoic as reef-building organisms evolve, leading to reef-free periods. The majority of carbonate sediments owe their mineralogy to the preferred mineralogy of the biota responsible for the sediments. As these groups evolve and become extinct, the sediment mineralogy mirrors these changes. A major carbonate database developed by Exxon/Mobil (termed the CATT hypothesis) has enormous potential as a tool to assist the exploration geoscientist in developing well-constrained conceptual geologic models and the development team to develop viable analogs for their reservoirs.
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