Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols Used xiii 1. The Importance of Islands 3 2. Area and Number of Speicies 8 3. Further Explanations of the Area-Diversity Pattern 19 4. The Strategy of Colonization 68 5. Invasibility and the Variable Niche 94 6. Stepping Stones and Biotic Exchange 123 7. Evolutionary Changes Following Colonization 145 8. Prospect 181 Glossary 185 References 193 Index 201

The Theory of Island Biogeography

Successful petroleum exploration relies on detailed analysis of the petroleum system in a given area. Identification of potential source rocks, their maturity and kinetic parameters, and their regional distribution are best accomplished by rapid screening of rock samples (cores and/or cuttings) using the Rock-Eval apparatus. The technique has been routinely used for about fifteen years and has become a standard tool for hydrocarbon exploration. This paper describes how the new functions of the latest version of Rock-Eval (Rock-Eval 6) have expanded applications of the method in petroleum geoscience. Examples of new applications are illustrated for source rock characterization, reservoir geochemistry, and environmental studies, including quantification.

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Rock-Eval 6 Applications in Hydrocarbon Exploration, Production, and Soil Contamination Studies

Cretaceous eustasy revisited

The recurrence of the same types of sequence stratigraphic surface through geologic time defines cycles of change in accommodation or sediment supply, which correspond to sequences in the rock record. These cycles may be symmetrical or asymmetrical, and may or may not include all types of systems tracts that may be expected within a fully developed sequence. Depending on the scale of observation, sequences and their bounding surfaces may be ascribed to different hierarchical orders. Stratal stacking patterns combine to define trends in geometric character that include upstepping, forestepping, backstepping and downstepping, expressing three types of shoreline shift: forced regression (forestepping and downstepping at the shoreline), normal regression (forestepping and upstepping at the shoreline) and transgression (backstepping at the shoreline). Stacking patterns that are independent of shoreline trajectories may also be defined on the basis of changes in depositional style that can be correlated regionally. All stratal stacking patterns reflect the interplay of the same two fundamental variables, namely accommodation (the space available for potential sediment accumulation) and sediment supply. Deposits defined by specific stratal stacking patterns form the basic constituents of any sequence stratigraphic unit, from sequence to systems tract and parasequence. Changes in stratal stacking patterns define the position and timing of key sequence stratigraphic surfaces. Precisely which surfaces are selected as sequence boundaries varies as a function of which surfaces are best expressed within the context of the depositional setting and the preservation of facies relationships and stratal stacking patterns in that succession. The high degree of variability in the expression of sequence stratigraphic units and bounding surfaces in the rock record means ideally that the methodology used to analyze their depositional setting should be flexible from one sequence stratigraphic approach to another. Construction of this framework ensures the success of the method in terms of its objectives to provide a process-based understanding of the stratigraphic architecture. The purpose of this paper is to emphasize a standard but flexible methodology that remains objective.

/pdf/sequence-stratigraphy-methodology-and-nomenclature-4wbzs4vy4t.pdf

Sequence stratigraphy: methodology and nomenclature

Mass extinctions and sea-level changes

A new record of carbon isotopes, nannofossil biostratigraphy, gamma-ray and Fe content variations is presented for the upper Campanian of the Adda-3 core, Danish Central Graben, North Sea. The studied interval provides a revision of previously assigned late Coniacian to early Santonian ages. New biostratigraphic data indicate a late Campanian age for the 60 m thick studied interval. The Late Campanian Event (LCE) is well recorded by a 1.5‰ negative excursion in the bulk δ 13 C, along with two stepwise pre-excursion negative shifts (defining the pre-LCE). The amplitude of the LCE appears higher in the North Sea than in other areas as seen from the correlation to Germany, the UK and France. This correlation allows identification of a new 0.4‰ negative excursion (defined as the conica event). Fe and gamma-ray variations are used to calibrate the record with cyclostratigraphy. Fourteen 405 kyr cycles identified in the upper Campanian of Adda-3 can be correlated to North Germany. The compilation of previous results from North Germany and correlation to Adda-3 shows that the Boreal upper Campanian spans a total of 17 cycles each of 405 kyr; that is, 6.885 myr. The duration of the LCE is estimated to be c . 1 myr at Adda-3 and in North Germany. Supplementary materials: Calibration of the HH-XRF data is available at https://doi.org/10.6084/m9.figshare.c.2134362.

/pdf/orbital-calibration-of-the-late-campanian-carbon-isotope-5f7aj0a8pl.pdf

Orbital calibration of the late Campanian carbon isotope event in the North Sea

The basinal geochemical signature and platform margin geometries in the Upper Devonian mixed carbonate-siliciclastic system of Western Canada

The Natih Formation in Oman is an exceptionally well–exposed and studied example of a large (>1000 km [621 mi]) epeiric, shallow marine, tropical carbonate platform system with adjacent organic-rich intrashelf basins. It serves as an outcrop analog for many of the mid-Cretaceous giant oil reservoirs as well as for unconventional reservoirs in the Mesozoic of the Arabian plate. A key feature of the Natih Formation is its strict hierarchical stratigraphic organization at multiple orders of depositional sequences (third to fifth), which was first demonstrated in outcrop and subsequently adopted in the seismic and log data sets of the nearby subsurface. It has provided a high-resolution time framework for the robust sequence stratigraphic model that has been developed for an area of 6000 km2 (2317 mi2). Deposited in a calm tectonic setting, the Natih Formation provides an excellent example to demonstrate the principles of carbonate systems’ response to eustatic sea level change and some fundamental differences with siliciclastic systems. Key aspects that are addressed include the influence of the rate of sea level rise on the transition from ramp to platform, the creation of organic-rich intrashelf basins through differential accumulation rates, changing facies models within third-order sequences, and the importance of different platform top channel types. The economic relevance of this case study is the improved prediction of reservoir, seal, and source rock facies distribution and the associated early diagenetic overprint, insights that have been applied in the reservoir modeling of nearby oil fields as well as in exploration-scale studies.

The mid-Cretaceous Natih Formation in Oman: A model for carbonate platforms and organic-rich intrashelf basins

The Lower Cretaceous of northern Oman consists of a large carbonate platform that prograded over a distance of 280 km (174 mi) in approximately 23 m.y. The seismic stratigraphic interpretation of this system, based on a regional three-dimensional survey (40,000 km2 [15,400 mi2]), revealed a complicated organization of nested clinoforms with changing depositional dips. The tectonic setting and stratal patterns suggest that different orders of sea-level fluctuations, ranging from 20 to 150 m (66–492 ft) in amplitude, have controlled the overall sedimentation. The Lower Cretaceous Lekhwair, Habshan, and Salil Formations form the lithofacies of this carbonate platform that prograded in a northeastward direction from the United Arab Emirates and Oman to northern Oman, filling in the Rayda Basin. The majority of this system is documented in seismic and well data, whereas the final part of the progradation is visible on outcrops in the Oman Mountains. Cored wells and outcrops have been dated with calpionellids, echinoids, and calcareous algae biostratigraphy; 14 sequences have been identified and are grouped into four sequence sets based on their seismic stratigraphic organization. The differences in stratal patterns between the sets are interpreted to be caused by variations in the amplitude of sea-level fluctuations. The sequence sets indicate a general increase of the amplitude of sea-level fluctuations to a maximum of 150 m (492 ft) in the early Valanginian, followed by a general highstand and low-amplitude fluctuations (20 m [66 ft]) in the late Valanginian. The Oman relative-sea-level curve shows similarities with the one proposed for the Vocontian Basin in France, providing strong evidence for the eustatic nature of these fluctuations. A glacio-eustatic control is invoked to explain this global trend.

Seismic stratigraphy of a Lower Cretaceous prograding carbonate platform (Oman) and implications for the eustatic sea-level curve

In order to facilitate the search for new play concepts and exploration opportunities, a sequence stratigraphic synthesis of the Cenomanian–Turonian interval of the Arabian Plate has been compiled. The synthesis is based on published datasets which have been analysed within a temporal framework constrained by biostratigraphy and isotope stratigraphy. The high stratigraphic resolution allows the palaeogeography of the study area to be mapped within 3rd order depositional sequences, and the relative influence of eustacy and tectonics on basin development to be evaluated. This significantly improves the prediction of stratigraphic architecture and depositional morphology at the scale of the entire tectonic plate.

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Frans S.P. van Buchem

Papers

Orbital calibration of the late Campanian carbon isotope event in the North Sea

The basinal geochemical signature and platform margin geometries in the Upper Devonian mixed carbonate-siliciclastic system of Western Canada

The mid-Cretaceous Natih Formation in Oman: A model for carbonate platforms and organic-rich intrashelf basins

Seismic stratigraphy of a Lower Cretaceous prograding carbonate platform (Oman) and implications for the eustatic sea-level curve

Sequence stratigraphy, palaeogeography and petroleum plays of the cenomanian – turonian succession of the arabian plate: an updated synthesis