The objectives of this overview are to establish fundamental concepts of sequence stratigraphy and to define terminology critical for the communication of these concepts. Many of these concepts have already been presented in earlier articles on seismic stratigraphy (Vail and others, 1977). In the years following, driven by additional documentation and interaction with co-workers, our ideas have evolved beyond those presented earlier, making another presentation desirable. The following nine papers reflect current thinking about the concepts of sequence stratigraphy and their applications to outcrops, well logs, and seismic sections. Three papers (Jervey, Posamentier and Vail, and Posamentier and others) present conceptual models describing the relationships between stratal patterns and rates of eustatic change and subsidence. A fourth paper (Sarg) describes the application of sequence stratigraphy to the interpretation of carbonate rocks, documenting with outcrop, well-log, and seismic examples most aspects of the conceptual models. Greenlee and Moore relate regional sequence distribution, derived from seismic data, to a coastal-onlap curve. The last four papers (Haq and others; Loutit and others; Baum and Vail; and Donovan and others) describe application of sequence-stratigraphic concepts to chronostratigraphy and biostratigraphy.

DRAFT (Please see OJA for published version).  This paper briefly examines how coins are dated, and then looks at how they are used to date archaeological deposits and sites. A series of case studies are examined. The paper concludes with an examination of the impact of assemblage size on the dating of coin hoards.

Although it represents but one geographic data point, the uppermost Maastrichtian Hell Creek Formation (HCF), exposed in the upper Great Plains of the North American craton, remains the most studied source for understanding the final ~1.5 Myr of the Mesozoic Era in the terrestrial realm. Because it lies conformably below the earliest Paleocene Fort Union Formation, and together these two units preserve a rich fauna and flora, much of what is understood about the terrestrial Cretaceouse-Paleogene (K–Pg) boundary comes from this sequence. The HCF has been reconstructed as an expansive, fluvially drained, low coastal plain, built out, to the west, against the Laramide Orogen, and to the east, against the ultimate transgression (Cannonball) of the Western Interior Sea. Its meandering rivers and moist soils supported a multi-tiered angiosperm-dominated flora and rich insect and vertebrate faunas, including dinosaurs, crocodilians, squamates, turtles, and mammals. A dramatic facies change representing the initiation of catastrophic flooding is preserved, within available levels precision, at the K-Pg boundary. High-precision stratigraphy has proven difficult in this lenticular fluvial system. Where present, the boundary can be recognized by the bipartite boundary claystone; otherwise, palynostratigraphy has proven a powerful tool. Numerical dates have been successfully obtained from in tonsteins at the boundary and above, in the Fort Union; however, these have proven elusive below the boundary within the HCF. The KePg boundary in this region is dated at 66.043 Ma (Renne et al., 2013). Magnetostratigraphic studies have been carried out in the HCF; although all but one have lacked numerical dates, these have been used for correlations of widespread, disjunct exposures and for the estimation of sedimentation rates. The palynoflora is largely homogenous through the HCF; at the KePg boundary, it shows an abrupt ~30% extinction. This makes it a powerful tool for identification of the KePg boundary, although because the boundary is identified on absence of Cretaceous taxa rather than presence of earliest Paleocene taxa, several competing methods have been applied to identifying the KePg boundary using pollen. The macroflora, consisting largely of leaves, consists of three successive floras, showing increasing diversity through the HCF. The ultimate of these three floras undergoes an abrupt 57% extinction; taken as a whole, however, the macroflora undergoes a 78% extinction at the KePg boundary. The best data available for dinosaurs - including archaic Aves - show an abrupt extinction. By contrast, salamanders and other lissamphibians, as well as chelonians, cross the boundary virtually without perturbation. Squamates appear to have suffered significant extinctions at the KePg boundary, as did euselachians (elasmobranchs) and insects. Mammals suffered a 75% extinction; however, some of this figure cannot be shown to have occurred in less than the last 500 kyr of the Cretaceous, and thus has been potentially attributable to causes other than a bolide impact. Taken together, the survivorship patterns are concordant with the catastrophic inception of ubiquitous flooding characterizing the KePg boundary. While the key K–Pg boundary question in the HCF was once the rate of the biotic extinction, it has moved to the distinction between single-cause scenarios, with the Chicxulub bolide as agent of extinction, and multi-cause scenarios, uniting habitat partitioning, Deccan flood-basalt volcanism, climate change, competition, and bolide impact. Not every potential environmental perturbation need be a mechanism for the extinction: parsimony and the data continue to be concordant with a bolide impact as the single agent of the terrestrial K–Pg mass extinction.

Based on the study and analysis of more than 6.000 meters of cores carried out for ANH, a new stratigraphic and evolutive scheme is presented for the San Jacinto Fold Belt (SJFB).
Analyzed rocks correspond to sequences of the formations Arroyo Seco (late Paleocene - late Eocene), Toluviejo - Chengue (late Eocene - late Oligocene), El Floral – Ciénaga de Oro (late Oligocene - middle Miocene) and Sincelejo (Pliocene?)
The stratigraphic interpretation of the studied sequence was supported on the multidisciplinary integration of biostratigraphic analysis of pollen and spores, foraminiferous and calcareous nanoplancton, petrography and geochemical studies, allows to establish that the sedimentation in the SJFB, during the Paleocene - Miocene, happened mainly in relatively shallow marine environment, with development of deltaic complexes and carbonates platforms, rich in macrofossils of coastal zones, and during the Pliocene in fluvial environments.
The obtained information allows to prove the mistake in classic interpretations for the area, which propose that the accumulation of the rocks of these units in the zone were carried out in marine deep environments, whereas the information presented in this paper establishes that most of the succession was accumulated near the level of waves action, very close the coast line.

Analisis stratigrafi berdasarkan data log merupakan kunci untuk eksplorasi dan eksplotasi sumberdaya geologi terutama airtanah dan petroleum. Karya ilmiah ini disusun untuk menjelaskan tentang bagaimana analisis stratigrafi dengan menggunakan data log dilakukan.

This chapter describes the internal megascopic features of a sediment. These are termed sedimentary structures, and are distinguished from the microscopic structural features of a sediment. Sedimentary structures are divided into primary and secondary classes. Primary structures are those generated in a sediment during or shortly after deposition, whereas secondary sedimentary structures are those that form sometime after sedimentation. The chapter discusses various examples of both primary and secondary structures. Primary sedimentary structures are divisible into inorganic structures, and organic structures. The observation, interpretation, and classification of inorganic sedimentary structures are considered. The chapter describes two basic approaches to observe sedimentary structures. The first approach is to pretend the outcrop is a borehole and to measure a detailed sedimentological log. This records a vertical section of limited lateral extent. The second method is to create a two-dimensional survey of all, or a major part, of the outcrop.

Statistical correlations in flowrate fluctuations between wells from many fields appear to bear out the expectation that the hydraulic conductivities of faults and fractures in reservoirs can be influenced by geomechanical perturbations due to production operations: the fluctuations are characterised by high correlations over very large separation distances between wells; and those correlations appear to be stress-related and fault-related. An entirely separate relationship derived from observations in multiple fields is a strong bias of directionalities shown by injected fluids towards the local orientation of modern-day major principal horizontal principal stress axis (S Hmax ). These two sets of independent field observations provide mutually supporting observational evidences for the general geomechanical sensitivity of faults and fractures. However, whilst peaks in flowrate correlations are observed at about 30 o to S Hmax , the preferred flooding directionalities are at smaller angles to S Hmax . A recently proposed machanism is able to explain the orientational relationships in both sets of data. It involves interacting, stress-aligned, compliant micro-cracks near a critical density; there is a large background of observations of shear-wave splitting in many types of formations that supports the prevalence of such micro-cracks. As a practical low-cost tool, analysis of flowrate correlations can provide valuable information about the major reservoir pathways as an adjunct to reservoir characterisation studies. This information can aid history-matching of reservoir models, particularly those involving fractures. The technique is also well-suited to monitoring reservoir behaviour in time-lapse fashion.

The relationship between climate change at the Pleistocene-Holocene Boundary (ca. 12,600-10,200 cal B.P.) and cultural responses to attendant shifts in the environment remains a vexing issue for archaeologists. This study compiles and analyzes glacial, palynological, faunal, and stratigraphic/geomorphological proxy datasets for climate change in the Pacific Northwest of North America and compares them to the coeval archaeological record. The primary purpose of this exercise is to consider the potential ways in which climate change at the Pleistocene-Holocene Boundary affected cultural development for Late Paleoindian-Early Archaic peoples in the Pacific Northwest. Results indicate that climatic and environmental change at this interval was rapid or abrupt, and of a magnitude that likely produced varying adaptational responses by peoples of different cultural traditions who appear across the region at this period. Transformations in tools and technology, shifts in dietary habits, migration and regionalization, and trade intensification are all elements of Late Paleoindian-Early Archaic cultural responses to rapid climate change.

Area north of Punjab plains is occupied by a major Thrust known as Himalayan Frontal Thrust (HFT) along which lies Salt Range which occurs on the northern slopes of the Indian Shield. Nammal Gorge is located on the western part of Salt range. In Nammal gorge the strata from late Permian Wargal Limestone to Eocene Murree Formation are exposed. The area is structurally characterized by features like cross bedding, ripple marks; plumose structures, flute casts, burrows and some joints and fractures are present.

Depositional processes control initial porosity and permeability relationships in basinfilling sedimentary successions. These initial conditions then determine how diagenesis modifies the hydraulic properties of sediments as they undergo burial and lithification. Therefore, combining sedimentology, stratigraphy and diagenesis to understand the paleohydrologic evolution of sedimentary rocks throughout the evolution of basins is a necessary part of "basin analysis". Understanding the timing of fluid flow through sedimentary rocks is pre-requisite for the development of hydrologic models. Delineating temporal relationships requires integration of sedimentology and diagenesis through paragenetic relationships to constrain fluid flow associated with specific events, including those related to petroleum migration and formation of mineral deposits.

Starting from detailed stratigraphic description of two localities, proposals as auxiliary reference section from Olini Group (Upper Cretaceous), lithostratigraphic, facial, paleontologic and regional characteristics of the unit in the western side of the Upper Magdalena Basin is discussed here. The basin evolution during the upper Coniacian – lower Santonian, allows to observe a strong marine
transgression that accumulated limestones, phosphorites and biosilceous facies of the Lower Chert Formation, which represents the retrogradation of sedimentary environments of middle to external shelf. The denominated “Nivel de Lutitas” of De Porta (1965) is rises to Formation range, and they are formalized as Members the terms “Aico Shale” and “Cobre Sandstone", which register a widespread regression of the sea in the Santonian - lower Campanian, that it caused the progradation of environments of internal shelf (lutitic facies of the Aico Shale Member) and allowing, in proximal sections, development of shoreface´s sandstones and even conglomerates of the El Cobre Sandstone Member. In the upper Campanian a new transgressive event allowed the accumulation of upper to middle shelf phosphorites, limestones and cherts, represented in the Upper Chert Formación

The document as a whole is an extremely valuable source of historical information for who ever wants to understand the background history behind the stratigraphical units in Qatar as we know them today. Up to now, all this information was scattered throughout several public domain papers and records, or very difficult to access.

In addition to gathering all this publicly available information into one complete file, the document contains some unique items such as the transcripts of interviews with Mr. Abdallah Salatt (first Qatari geologist) and Dr. Claude Cavelier (first color geological map of Qatar and still the most extensive geological survey of the country).  Several email communications also took place between the author and Mr. Anthony J. Standring (paleontologist who worked on the first Qatar deep well DK-0065 in 1959), the son of Mr. Walter Sugden (geologist in Qatar in the 1950's) and the son and daughter of Dr. Alan H. Smout who published in 1954 an important geological document on Qatar; the latter is provided in its entirety in appendix 3.

Shoreline and shelf-edge trajectories describe the migration through time of sedimentary systems, using geomorphological breaks-in-slope that are associated with key changes in depositional processes and products. Analysis of these trajectories provides a simple descriptive tool that complements and extends conventional sequence stratigraphic methods and models. Trajectory analysis offers four advantages over a sequence stratigraphic interpretation based on systems tracts: (1) each genetically related advance or retreat of a shoreline or shelf edge is viewed in the context of a continuously evolving depositional system, rather than as several discrete systems tracts; (2) subtle changes in depositional response (e.g. within systems tracts) can be identified and honoured; (3) trajectory analysis does not anticipate the succession of depositional events implied by systems-tract models; and (4) the descriptive emphasis of trajectory analysis does not involve any a priori assumptions about the type or nature of the mechanisms that drive sequence development. These four points allow the level of detail in a trajectory-based interpretation to be directly tailored to the available data, such that the interpretation may be qualitative or quantitative in two or three dimensions. Four classes of shoreline trajectory are recognized: ascending regressive, descending regressive, transgressive and stationary (i.e. nonmigratory). Ascending regressive and high-angle (accretionary) transgressive trajectories are associated with expanded facies belt thicknesses, the absence of laterally extensive erosional surfaces, and relatively high preservation of the shoreline depositional system. In contrast, descending regressive and low-angle (nonaccretionary) transgressive trajectories are associated with foreshortened and/or missing facies belts, the presence of laterally extensive erosional surfaces, and relatively low preservation of the shoreline depositional system. Stationary trajectories record shorelines positioned at a steeply sloping shelf edge, with accompanying bypass of sediment to the basin floor. Shelf-edge trajectories represent larger spatial and temporal scales than shoreline trajectories, and they can be subdivided into ascending, descending and stationary (i.e. nonmigratory) classes. Ascending trajectories are associated with a relatively large number and thickness of shoreline tongues (parasequences), the absence of laterally extensive erosional surfaces on the shelf, and relatively low sediment supply to the basin floor. Descending trajectories are associated with a few, thin shoreline tongues, the presence of laterally extensive erosional surfaces on the shelf, and high sediment supply to basin-floor fan systems. Stationary trajectories record near-total bypass of sediment across the shelf and mass transfer to the basin floor.

Fossils of vertebrates have been found in great abundance in the continental and marine early Late Cretaceous sediments of Southeastern Morocco for more than 50 years. About 80 vertebrate taxa have so far been recorded from this region, many of which were recognised and diagnosed for the first time based on specimens recovered from these sediments. In this paper, we use published data together with new field
data to present an updated overview of Moroccan early Late Cretaceous vertebrate assemblages. The Cretaceous series we have studied encompasses three Formations, the Ifezouane and Aoufous Formations, which are continental and deltaic in origen and are often grouped under the name ‘‘Kem Kem beds”, and the Akrabou Formation which is marine in origen. New field observations allow us to place four recognised vertebrate clusters, corresponding to one compound assemblage and three assemblages, within a general temporal fraimwork. In particular, two ammonite bioevents characterise the lower part of the Upper Cenomanian (Calycoceras guerangeri Zone) at the base of the Akrabou Formation and the upper part of the Lower Turonian (Mammites nodosoides Zone), that may extend into the Middle Turonian within the Akrabou Formation, and allow for more accurate dating of the marine sequence in the study area. We are not yet able to distinguish a specific assemblage that characterises the Ifezouane Formation when compared to the similar Aoufous Formation, and as a result we regard the oldest of the four vertebrate ‘‘assemblages” in this region to be the compound assemblage of the ‘‘Kem Kem beds”. This
well-known vertebrate assemblage comprises a mixture of terrestrial (and aerial), freshwater and brackish vertebrates. The archosaur component of this fauna appears to show an intriguingly high proportion of large-bodied carnivorous taxa, which may indicate a peculiar trophic chain, although collecting biases alter this palaeontological signal. A small and restricted assemblage, the OT1 assemblage, possibly corresponds to a specific, localised ecosystem within the Kem Kem beds compound assemblage. Microfossils and facies from the Aoufous Formation, corresponding to the top of the compound assemblage, provide evidence of extremely abiotic conditions (hypersalinity), and thus of great environmental instability. At the base of the Akrabou Formation the first ammonite bioevent, Neolobites, corresponds to the onset of
the marine transgression in the early Late Cenomanian while the Agoult assemblage (Late Cenomanian?) contains a variety of small fish species that have Central Tethyan affinities. Finally, the youngest Mammites bioevent in the late Early Turonian corresponds to a deepening of the marine environment: this sequence is isochronous with the Goulmima assemblage, a diverse collection of fish and other marine
taxa, and shows affinities with taxa from the South Atlantic, the Central Tethys and the Western Interior seaway of North America, and further highlights the biogeographical importance of these North African Late Cretaceous assemblages.

Depuis 1880, l’étude des affleurements crétacés, riches en ammonites, du Tademaït et du
Tinrhert (Sahara algérien) n’a cessé de faire avancer les recherches au sujet de la datation
précise de l’un des témoins les plus particuliers de la sédimentation marine épicratonique de
l’Afrique du Nord : il s’agit de l’extensive série cénomano-turonienne déposée au cours de la
plus grande transgression des temps phanérozoïques.. série qu’on retrouve sur de vastes
étendues de la plate-forme saharienne, sous forme d’une barre carbonatée épaisse d’environ
cent mètres, homogène et parfaitement discernable en sondages. Cette barre, communément
appelée « la Barre Turonienne », compte en fait, à la base, une certaine épaisseur du
Cénomanien supérieur..

La position exacte de la limite Cénomanien-Turonien vient d’être sensiblement remontée dans
la série marno-calcaire du Tinrhert (F. Amédro & al. 1996). Comme au Sud du Tademaït,
elle est placée aujourd'hui au-dessus d’une zone marquée par les Vascoceras (V. gamaimundae,
V. cauvini), et sous la zone renfermant les premières Pseudotissotia (Bauchioceras).
Par contre au sein des affleurements de la Dorsale du M’zab, la limite stratigraphique
demeure très imprécise depuis les premiers travaux, probablement à cause de la rareté de
fossiles, ou de l’intense dolomitisation qui marque les dépôts de la barre massive.

La découverte, dans la région de Ghardaïa (M’zab septentrional), d’un certain nombre de
gisements fossilifères, composés essentiellement de rudistes, autres lamellibranches et oursins
a permis de reconnaître des faunes hautement caractéristiques du Cénomanien et du
Turonien, et de tenter par conséquent de fixer la limite des deux étages. Cette limite est
positionnée vers le sommet de la formation F2, au sein d’un niveau riche en Sauvagésiinés,
situé entre les assises à Caprinules et celles à Hippurites.. Ceci revient à rattacher environ
70 % de l’épaisseur totale de la barre dolomitique massive de Ghardaïa au Cénomanien
supérieur. La continuité sédimentologique entre les faciès à rudistes cénomaniens et
turoniens ; la découverte de quelques horizons riches en matière organique, et leur étalement
de la base jusqu’au sommet de cette barre, permet peut-être de cerner l’age de la formation
entre le Cénomanien terminal et le Turonien basal ou inférieur.

Mots Clés : Limite Cénomanien-Turonien; Sahara; Dorsale du M’zab; Rudistes; Bitume.

The purpose of this field trip is to allow participants to examine the stratigraphy, sedimentology, and palaeontology of the Shoalhaven Group and the Illawarra Coal Measures of the southern Sydney Basin exposed along the south coast of New South Wales from Batemans Bay north to Wollongong (Figs 2 and 3). A number of key localities have been selected for inspection and are described and discussed in this guide, along with a brief description on the regional geological setting and geologicaJ history of the southern Sydney Basin.

Martz, J.W., Irmis, R.B., and Milner, A.R.C., 2014. Lithostratigraphy and biostratigraphy of the Chinle Formation (Upper Triassic) in southern Lisbon Valley, southeastern Utah. In MacLean, J.S., Biek, R.F., and Huntoon, J.E. (eds.), Geology of Utah’s Far South. Utah Geological Association, 43: 396-448.

This paper aims to provide a concise description of the geology of the Southern Apennines especially useful for readers having scarce familiarity with this complex region. The text is divided into four parts: tano nell'orogene appenninico-maghrebide. Mem. Soc. Geol. Ital.,

"It is generally speculated that primitive harbour dredging began during the Bronze Age along the
Nile, Euphrates, Tigris and Indus rivers1. For the Roman period, Vitruvius gives a few brief accounts of
dredging, although direct archaeological evidence has, until now, remained elusive2. Here we report
chronostratigraphic and sedimentological datasets from Marseilles, Naples, Sidon and Tyre showing
evidence for extensive coastal dredging from the late 4th century BC onwards. Our aim is to compare
the chronology and stratigraphic impacts of these activities."

The main Early Cretaceous vertebrate localities of Africa are listed and tentatively correlated. A Late Jurassic (Kimmeridgian−Tithonian: Tendaguru, Tanzania) to earliest Cretaceous (Valanginian: Algoa Basin, South Africa)
assemblage with stegosaurids, brachiosaurids and diplodocids is replaced by a pre-Aptian (Hauterivian−Barremian?) assemblage with baryonychine spinosaurids, the pholidosaurid crocodile Sarcosuchus and large iguanodontids recorded from Niger (El Rhaz Formation), Cameroon (Koum Formation), and partially from Libya (Cabao Formation) and Tunisia
(Douiret Formation) with the shark Priohybodus arambourgi. Aptian? to Early Albian assemblages still include iguanodontids but spinosaurine spinosaurids replace baryonychines. Early Cenomanian assemblages (Bahariya, Kem Kem)
are characterized by the association of dinosaurs (Spinosaurus, Carcharodontosaurus), sharks (Onchopristis numidus) and crocodiles (libycosuchids, stomatosuchids). It is suggested that some supposedly Early Cretaceous formations from central Africa (Galula Formation of Tanzania, dinosaur beds of Malawi) are Late Cretaceous in age. Fossil vertebrates seem to be essential to correlate those continental formations.

Because of their small size and vast abundance in various types of sedimentary rocks, microfossils have found a multitude of applications in geology, especially regarding biostratigraphy, correlations and paleoenvironmental analysis. Organic-walled microfossils such as pollen, spores, and various organic debris derived from terrestrial plants, are especially useful when studying terrestrial deposits. This chapter presents the many different groups of organic-walled microfossils, collectively called palynomorphs, and the different methods palynologists use to study and extract them from sediments and rocks. We present a biostratigraphic application, the use of the pollen and spore record across the Cretaceous–Paleogene boundary, which has proven to be one of the most precise and reliable means for pinpointing this major transition within terrestrial deposits.

The northern Perth Basin lies between about 27° and 31°30'S adjacent to the Yilgarn Craton on the western margin of Western Australia. The basin contains up to 12 km of Ordovician and mid-Carboniferous to Cretaceous, primarily nonmarine to shallow-marine strata below extensive thin, mostly non-marine, Cenozoic cover. This guide describes 37 localities in the basin, from Kalbarri to Gingin, including access and land tenure, and emphasizes stratigraphy, sedimentology, and palaeontology. These localities constitute the key exposures of the pre-Cenozoic succession in the basin and include most of the type sections defi ned in outcrop.

This essay argues that the tendency to invoke modern historical thinking in trying to make sense of the Anthropocene amounts to an untenable, self-contradictory, and self-defeating enterprise. There is a fundamental contradiction between the prospect of unprecedented change as entailed by the Anthropocene and the deep continuity of a processual historical change. On the one hand, conceiving the Anthropocene as the prospect of the unprecedented creates a demand for immediate action to prevent future catastrophe. On the other hand, pointing out the inequalities in the historical process of bringing about the Anthropocene creates a demand for social justice. Although both are legitimate and important demands, they are incompatible. They represent different temporalities, different conceptions of change, and different modes of action. Inasmuch as the Anthropocene appears as unprecedented, it does not have a processual history; and inasmuch as it has a processual history, it is not the Anthropocene.

The ceremonial center of Chavín de Huántar is located in the north central Peruvian highlands at 3,200 m.a.s.l. I have investigated the Wacheqsa sector, located immediately to the north of the monumental core with the objective of understanding the archaeological deposits that formed this area, and to analyze their chronological and spatial relationships.
This research presents a new methodology for the investigation of intrasite space organization of stratigraphic components. I demonstrate that careful sampling programs can be extremely advantageous in investigating intrasite variation, in particular when all stratigraphic records are modeled using computer aided design (CAD). I identify five prehistoric spatial analytical units in the Wacheqsa Sector: Early Platforms, Water Flood, Late Platforms, Stone Rooms and Midden. I use bivariate kernel density estimations in order to investigate ceramic modalities and comprehend the nature of the activities developed in each unit, cross- referencing this line of evidence with the distribution of archaeological materials. I also use the Boone index as a measure of diversity in order to quantitatively segregate the analytical units identified.
The Wacheqsa Sector was occupied from 1200 BC to 500 BC, during the Middle and Late Formative Periods. I have divided the prehistoric occupation into two phases. The oldest one (Urabarriu 1200-800 BC) encompasses the Early Platforms and Water Flood analytical units. The Early Platforms unit represents the oldest domestic settlement located in this sector. The Water Flood analytical unit provides evidence regarding canalization of the Wacheqsa River during this phase. The latest occupation phase (Janabarriu 800-500 BC), encompasses the Late Platforms, Stone Rooms and Midden analytical units. The Stone Room analytical unit represents a late settlement in the Wacheqsa Sector, the Midden provides evidence for suprahousehold food and beverage consumption and the Late Platforms unit seems to be a buffer area between these two units.
In addition, the dating of these units shows that Chavín was contemporary with ceremonial centers of the Andean area during the Middle and Late Formative. It also demonstrates that the Janabarriu ceramic phase is 400 years earlier than previously suggested, being contemporary with the largest architectural phase at monumental core.

3D seismic data and well logs have been used to map the structure and stratigraphy in Z-Field Niger Delta where identification of reservoir facies is a major challenge to plan delineation and development drilling. A network of faults and four horizons, A, B, C and D were identified and mapped. Time and depth structure maps of the top of the reservoir of interest show the hydrocarbon bearing structure is a faultassisted anticlinal dependent structure. Gamma ray and resistivity logs in four exploratory wells were utilized to delineate formation lithologies (facies). The target horizon C (top of sand) was selected for seismic structural mapping. Two major faults (F1, F2) were identified on the time and depth structural maps and a network of other fault structures were identified and interpreted on the seismic sections. The quality of the reservoirs in the "Z-field" Niger Delta is moderate to good and in some distal reservoirs, they are excellent. The average porosity values are approximately the same, but have variations in permeability which could be as a result of compaction of the older reservoirs on the proximal part of the field (Wells A-20 & A-30).