Facies Analysis

In 1932, the Esera river was dammed at the foothills of the Pyrenean External Ranges; since then, sedimentation has reduced its water storage capacity by a third. This study of the sediments in the Joaquín Costa reservoir has been based on detailed sedimentological examination and other analysis of mineralogy, grain size distribution and the chemical components of the materials accumulated at the bottom of the reservoir. Interpretations are based on results from four sediment cores collected at sites representative of the main environments in the reservoir. Records of known flood events and of reservoir management data have been combined with a 137 Cs-derived chronology. Thus, it has been possible to ascribe the sedimentary record at the different reservoir environments to specific years, as well as some main changes in the facies types and sediment components. This methodology is a first approach to assessing siltation processes and dynamics in Mediterranean mountain reservoirs.

In this study, the effects of petroleum generation and expulsion on shale porosity is explored by evaluating the compaction of the Kimmeridge Clay Formation (KCF) within the oil window using log data and shale samples from the KCF within the depth and temperature range of ~1.5-5.0 km and 90-157ºC, respectively. Petrophysical properties e.g porosity and pore-size distribution were measured, and permeability was calculated using empirical models based on the measured porosities. Transit-time values from the sonic logs recorded at depths in the wells were the cores were recovered were calibrated against the porosities determined from the core samples. Bulk geochemical parameters e.g., Total Organic Carbon (TOC), Hydrogen Index (HI) were determined. The volume reduction in the KCF within the oil window due to petroleum generation and expulsion, and compaction due to loss of pore space was determined using the geochemical and log derived porosity data emplaced into empirical relations. Porosities above the oil window range from ~15-20%, but decreased to <5% at the end of the oil window. Pore-sizes decrease from ~11 nm to between 6-8 nm at the depth range of 1.5-5.0 km. Permeability decreased from 4.8 nD to ~0.095 nD. The quantitative estimations of volume reduction within the oil window indicate that for ~8.0wt% initial TOC sediment, a bulk volume reduction of 13% of the initial volume is due to oil expulsion, and ~12% is due to loss of pore space.

Applied organic geochemistry provides the information needed to make maps of the richness, type, and thermal maturity of a source rock. These maps are a necessary step toward determining the stratigraphic and geographic extent of a pod of active source rock in a petroleum system, and they are based on geochemical analyses of rock samples from outcrops and wells that are displayed on logs. These geochemical well logs are based on Rock-Eval pyrolysis, total organic carbon, vitrinite reflectance, and other rapid, inexpensive "screening" methods. The logs define (1) potential, effective, and spent petroleum source rock; (2) the thermal maturation gradient, including immature, mature, and postmature zones, and (3) in situ and migrated petroleum shows. Useful geochemical logs require proper sample selection, preparation, analysis, and interpretation. Detailed studies, including oil-source rock correlations by biomarker and supporting techniques, are undertaken on selected samples only after the screening methods are completed.

The Sandakan Formation of the Segama Group is exposed across the Sandakan Peninsular in eastern Sabah. This Upper Miocene part of the Segama Group unconformably overlies the Garinono Formation and is conformably overlain by the Bongaya Formation. This formation was investigated with detailed logging of outcrops and microfossils analysis in order to map the depositional facies and sedimentary environment. This study showed the presence of seven lithofacies: Thick amalgamated sandstone; thin, lenticular interbedded HCS sandstones and mudstone; laminated mudstone with Rhizophora; trough cross-bedded sandstone; laminated mudstone; strip mudstone with thin sandstone and siltstone; and interbedded HCS sandstone and mudstone. Based on the presence of Rhizophora, Brownlowia, Florchuetia sp., Polypodium, Stenochleana palustris, Ascidian spicule low angle cross bedding, very fine grained sandstone, thin alternations of very fine sandstone, silt and clay layers showing cyclicity (muddy rhythemites), rocks in the Sandakan Formation are interpreted as mangal estuary and open marine facies. Three facies associations could be deduced from the seven lithofacies: Gradual coarsening upwards shoreface; abrupt change facies and prograding estuary facies association.

Atal Sagar Hydroelectric Dam (Madikheda Dam) is major project in Shivpuri district of Madhya Pradesh. It comes under the Sindh project phase-II. Atal Sagar Hydroelectric Dam (Madikheda Dam) is constructed over the Sindh River. It is multi purposes uses dam. The dam world over has been playing dual role of harnessing the river waters for accelerating socioeconomic growth and mitigating the miseries of large population of the world suffering from the vagaries of floods and droughts. Since the advent of civilization, man has been constructing dams and reservoirs for storing surplus water available during wet periods and for utilization of the same during lean periods. Energy plays a key role for socioeconomic development of a country. Hydro power provides a cheap, clean and renewable source of energy.

geomorphic concept of the 'orderly sequence of landforms' (Thornbury 1954). Generally, fluvial systems show a downstream increase in channel width, discharge and hydraulic radius, and a decrease in channel gradient, and grain size (Schumm 2005; Bradshaw et al. 1978). However, rivers sometimes show unusual and complex behaviour (Malik et al. 2024), contrary to established trends. Complexity is a situation between 'order' and 'chaos' (Richards 2002), where difficulty is faced in describing the system characteristics (Manson 2001). The word 'complexity' has been used in different ways with rivers (Sivakumar et al. 2007; Zhou et al. 2012; Kourgialas et al. 2012; Zhang et al. 2017), but here, it is related to the geomorphological characteristics of the river. There are different interpretations of complexity in geomorphology (Keiler 2011). According to Phillips (2003), complexities are complications in the prediction of different facets of geomorphology, but they provide an

Although trophic position or level is one of the most basic aspects of a benthic marine species&#39; ecology, its evolutionary significance remains obscure. Gastropods offer a suitable model for examining the relationship between trophic level and evolution since they exhibit a wide variety of trophic strategies and their mode of life is often reflected in their shell form. We examined 196 genera of Paleozoic gastropods (≈ 1/3 of known genera) for which first appearance and last appearance could be specified to stage level and for which trophic strategy could be inferred with a reasonable degree of confidence. We classified these genera into four trophic categories on the basis of shell characters relating to locomotion and clamping. These trophic categories are: Suspension feeders, Grazers on firm substrata, Soft substrate Grazers/Detritivores, and Carnivores. Suspension feeders are the most unambiguously recognizable category, marked by clear indicators of a sessile mode of life s...

From two horizons in the lower Aptian Peñascal limestone Formation south of Bilbao 22 coral species are reported. The corals belong to the scleractinian families Actinastraeidae, Eugyridae, Haplaraeidae, Latomeandridae, and Solenocoeniidae, and the octocorallian family Helioporidae. The stratigraphic distribution of the species lies between the Berriasian to Cenomanian, but most species have a distribution between the Barremian and Albian. The faunas show most palaeobiogeographical relationship to faunas from the Hauterivian to Albian of the European Boreal, the Western Atlantic and the Western Tethys.

Fluvial red beds containing anatomically preserved large woody debris shed new light on seasonally dry biomes of the Pennsylvanian–Permian transition and elucidate the concurrence of river depositional systems and vegetation. As a result, the occurrence, distribution and preservation of petrified large woody debris accumulations are considered crucial to understanding the role of arborescent vegetation in shaping fluvial environments. This study reports sizeable silicified trunks and corresponding fluvial architectures from the uppermost Pennsylvanian (upper Gzhelian) Siebigerode Formation (Kyffhäuser, central Germany). The origin, taphonomy and depositional environment of the fossil woods are elucidated by using a multidisciplinary approach including geological mapping, lithofacies analysis, sediment petrography, wood anatomical studies and microstructure analyses. Results reflect the gradual burial of a gentle basement elevation by sand‐bed to gravel‐bed braided rivers at the nort...

Volcanism on Montserrat (Lesser Antilles arc) has migrated southwards since the formation of the Silver Hills ~2.5 Ma, and has formed three successively active volcanic centres. The Centre Hills volcano was the focus of volcanism from ~1-0.4 Ma, before activity commenced at the currently active Soufrière Hills volcano. The history of activity at these two volcanoes provides an opportunity to investigate the pattern of volcano behaviour on an andesitic arc island over the lifetime of individual volcanoes. Here, we describe the pyroclastic stratigraphy of subaerial exposures around central Montserrat; identifying 11 thick (>1 m) pumiceous units derived from sustained explosive eruptions of Centre Hills from ~0.8-0.4 Ma. Over 10 other, less well-exposed pumiceous units have also been identified. The pumice-rich units are interbedded with andesite lava breccias derived from effusive, dome-forming eruptions of Centre Hills. The stratigraphy indicates that large (up to magnitude 5) explosive eruptions occurred throughout the history of Centre Hills, alongside effusive activity.

A study of large benthic foraminifera from the 147 m-thick Qom Formation in the Chenar area (northwestern Kashan) is reported. One hundred and twelve thin sections were prepared and the distribution of benthic foraminifera was analyzed to reconstruct paleoenvironmental conditions. Study of these sections led to the identification of 28 genera and 38 species. On the basis of the recognized foraminifera, the section is comparable to Lepidocyclina-Operculina-Ditrupa Assemblage zone, and the age of the Qom Formation in the studied section is assigned to the Oligocene. Evidence of sea level changes is observed from bottom to top of the studied section. On the basis of large benthic foraminifera assemblages and microfacies features, three major depositional environments (inner shelf, middle shelf and outer shelf) were defined. The inner shelf facies is characterized by wackstone-packstone, dominated by miliolid and small perforate foraminifera. The middle shelf facies is represented by packstone-grainstone with diverse assemblage of large perforate benthic foraminifera. Outer shelf facies is dominated by large perforate benthic foraminifera as well as planktic foraminifera. The distribution of the Oligocene large benthic foraminifera in the studied area indicates that shallow marine carbonate sediments of the Qom Formation were deposited in a photic zone of tropical to subtropical environments. Finally, the correlation between the study area and some other sections of Central Iran indicates that sedimentation of the Qom Formation is continued from Late Rupelian to Chattian in northwest and Late Rupelian to Aquitanian in southeast direction.

A study of large benthic foraminifera from the 147 m-thick Qom Formation in the Chenar area (northwestern Kashan) is reported. One hundred and twelve thin sections were prepared and the distribution of benthic foraminifera was analyzed to reconstruct paleoenvironmental conditions. Study of these sections led to the identification of 28 genera and 38 species. On the basis of the recognized foraminifera, the section is comparable to Lepidocyclina-Operculina-Ditrupa Assemblage zone, and the age of the Qom Formation in the studied section is assigned to the Oligocene. Evidence of sea level changes is observed from bottom to top of the studied section. On the basis of large benthic foraminifera assemblages and microfacies features, three major depositional environments (inner shelf, middle shelf and outer shelf) were defined. The inner shelf facies is characterized by wackstone-packstone, dominated by miliolid and small perforate foraminifera. The middle shelf facies is represented by packstone-grainstone with diverse assemblage of large perforate benthic foraminifera. Outer shelf facies is dominated by large perforate benthic foraminifera as well as planktic foraminifera. The distribution of the Oligocene large benthic foraminifera in the studied area indicates that shallow marine carbonate sediments of the Qom Formation were deposited in a photic zone of tropical to subtropical environments. Finally, the correlation between the study area and some other sections of Central Iran indicates that sedimentation of the Qom Formation is continued from Late Rupelian to Chattian in northwest and Late Rupelian to Aquitanian in southeast direction.

The 5th International Meeting on Global Continental Palaeohydrology (GLOCOPH) was held in Pune, between 2 and 7, December 2002. T'le meeting hosted by the Geological Society of India and INQUA Commission on Global Continental Palaeohydrology (GLOCOPH) comprised of -paper and poster presentations, and special lectures (2-4 December, 2002) and field excursion in the Deccan Traps region and Goa (5-7 December, 2002). Dr. Vishwas S. Kale, University of Pune was the Convener of the GLOCOPH-2002 meeting. historicaI records, (5) Response to climatic and hydrological changes during late Quaternary in the monsoon regions, and (6) Hydro-geomorphological response to climate change in relation to human activity. Thirty-one research papers and eleven posters were presented during the conference. Out of the thirty-one papers presented, about twentythree were related to the focal theme of the conference. Four special lectures by eminent scholars from India and abroad were organized during the meeting. The conference GLOCOPH-2002 meeting at Pune. The meeting was attended by earth scientists with an interest in palaeohydrology, Quaternary studies and environmental change during the late Quaternary period. The focal theme of the symposium was: Palaeohydrology and monsoons: Past records and future implications. Other general themes were: (1) Palaeohydrological techniques and approaches, (2) Global climate changes and environmental changes during the last 20 Ka, (3) Palaeohydrological changes in the tropical, temperate and cold regions, (4) Flaad reconstruction -geological and was attended by 14 overseas delegates from UK, USA,

This paper investigates thylacocephalan (?Crustacea) carapaces from the lower Famennian of the Holy Cross Mountains, Poland in order to check whether predation-related activities has influenced the mode of carapace preservation. Analysis of 225 specimens reveals that 71% of carapaces consist of complete/ nearly complete specimens, and those that are incomplete have experienced purely taphonomic processes. The remaining 29% of specimens, are damaged and fragmented carapaces, the preservation patterns of which point to biological modifications due to predation. These damaged carapaces range from those that have some portions missing, to those totally fragmented into small pieces scattered on bedding planes. The damaged specimens lacking some portions of the carapace are similar to those described previously from the Frasnian of Australia, where they are interpreted to evidence fish predation. The loosely scattered cuticle fragments are very similar to those reported from the Pennsylvanian of the USA that are interpreted as shark regurgitates. We interpret the damaged and fragmented thylacocephalans from Poland as evidence for fish predation, consistent with previous evidence from fragmented cuticle preserved within coprolites. However, as the majority of cuticle fragments occurring within coprolites in previous studies are difficult to distinguish, the simple calculation of predation intensity is much lower (13%) to that obtained in the present study (29%). Thus, analysis of thylacocephalan carapace preservation conducted here, may serve as a calibrating tool for the assessment of a general predation intensity in a given palaeoenvironment based solely on coprolite data.

Fossil abundance data on foraminifer communities were collected in marginal marine sediments of the Pliocene Valdelsa succession, in Tuscany, Italy. This succession is organized in a hierarchy of elementary and composite depositional sequences. Multivariate techniques allowed to analyse the dataset and reconstruct gradients in species distributions. Species-level data available on modern environmental distributions were used to reconstruct Pliocene environmental gradients and to infer absolute palaeodepths and palaeosalinities. Estimates were then compared with the sequencestratigraphic interpretation to check for consistency. The high-resolution stratigraphic framework allowed us to test the stability of foraminifer communities against ecological variations related to high-frequency glacio-eustatic cycles. The results confirm that fossil distributions of foraminifer species can be used as a fine tool to detect environmental change and that multivariate techniques allow their interpretation in terms of absolute variations of controlling parameters. Salinity is the main contributor to the sum of depth-related factors that regulate foraminifer distributions in coastal facies. In the same setting, nutrient levels and the presence of a sea grass cover are responsible for secondary changes in shallow-water distributions. Below the wave base, however, depth-related parameters other than salinity explain the largest variations. This study indicates that foraminifer communities are random associations of species that respond individualistically to environmental change. ᮀ Community stability , foraminiferal palaeoecology , gradient analysis , sequence stratigraphy .

Lithofacies analysis of the upper part of the Pliocene succession of the Valdelsa basin (central Italy) unravelled a number of depositional environments, ranging from alluvial plain to coastal, to marine. Strata are arranged in a hierarchy of elementary and composite unconformitybounded units. A palaeoecological study of macro-(molluscs) and microfossils (pollen, dinocysts, foraminifera) allowed to finely reconstruct subenvironments within fine-grained terrestrial, coastal and marine deposits and thence to track the spatial and temporal change of physical conditions. The stacking pattern of sedimentary units highlights the lateral switching of onshore-offshore gradients and documents relative sea-level changes. These units are interpreted in a sequence stratigraphic framework. Elementary depositional sequences are arranged to form six composite depositional sequences, in turn encased within two major synthems. This hierarchy of unconformity-bounded sedimentary units suggests that sealevel variation has occurred at different time-frequencies. Glacio-eustasy and active tectonism are discussed as the main forcing factors regulating the different scales of sedimentary cyclicity.

Organised mineralised structures observed in large inoceramids (valves on a metre scale) from the Late Albian, Toolebuc Formation, Australia (Inoceramus sutherlandi McCoy, 1865), and the Santonian, Niobrara Formation, USA (Platyceramus sp.), were investigated using variable pressure scanning electron microscope (SEM) with energydispersive X-ray spectroscopy (EDX), X-ray microcomputed tomography (micro-CT) and X-ray diffraction (XRD) analyses. These indicate that the structures comprised a phosphate framework of aligned tubes and shallow troughs overlain perpendicularly by evenly spaced structures. In the Toolebuc Inoceramus, these are U-shaped cross-structures, whilst in the Niobrara Platyceramus, they comprise bundled fibre elements. Comparison with modern bivalves indicates that the observed phosphatised structures represent soft-tissue preservation of the gills, as suggested in earlier publications. The tubes and troughs are remnants of a filamental support framework comprising ordinary and primary filaments, whilst the U-shaped cross-structures (I. sutherlandi) and fibrous bands (Platyceramus) represent preserved longitudinal gill musculature. Internal perforate and strand-like fabric observed on the internal surface of some Platyceramus tubular structures suggests that the framework comprised collagen. The presence of primary and ordinary filaments in numerous unusually large plicae, in at least two lamellae, indicates that the gill structures were heterorhabdic. Each plica has at least 40 ordinary filaments, an exceptional number when compared with the maximum of 20 present in modern heterorhabdic gills. The

Deep neural networks (DNNs) can learn accurately from large quantities of labeled input data, but often fail to do so when labelled data are scarce. DNNs sometimes fail to generalize ontest data sampled from different input distributions. Unsupervised Deep Domain Adaptation (DDA) techniques have been proven useful when no labels are available, and when distribution shifts are observed in the target domain (TD). In the present study, experiments are performed on seismic images of the F3 block 3D dataset from offshore Netherlands (source domain; SD) and Penobscot 3D survey data from Canada (target domain; TD). Three geological classes from SD and TD that have similar reflection patterns are considered. A deep neural network architecture named EarthAdaptNet (EAN) is proposed to semantically segment the seismic images when few classes have data scarcity, and we use a transposed residual unit to replace the traditional dilated convolution in the decoder block. The EAN achieved a pixel-level accuracy >84% and an accuracy of ~70% for the minority classes, showing improved performance compared to existing architectures. In addition, we introduce the CORAL (Correlation Alignment) method to the EAN to create an unsupervised deep domain adaptation network (EAN-DDA) for the classification of seismic reflections from F3 and Penobscot, to demonstrate possible approaches when labelled data are unavailable. Maximum class accuracy achieved was ~99% for class 2 of Penobscot, with an overall accuracy>50%. Taken together, the EAN-DDA has the potential to classify target domain seismic facies classes with high accuracy.

This study was carried out to better understand the geology and depositional environments of rock units in the Ede-Oballa - Orba  axis of southeastern Nigeria. The integration of outcrop data, facies and sedimentological analyses aided the interpretation of the depositional setting of the sediment packages. Geologic mapping showed that the area is underlain by the Ajali Formation and Nsukka Formation of the Anambra Basin. Three outcropping lithologies were identified namely: sandstone, siltstone and mudstone. Facies analysis revealed eight (8) lithofacies namely: Conglomeritic Sandstone (CS) facies, Structureless sandstone (Ss) facies, Heterolith (H) facies, Siltstone (Si) facies, Mudstone (Fm) facies, Interbedded Sandstone and Mudstone (SM) facies, Cross-bedded sandstone (Cbs) facies and Ferruginized Sandstone (IS) facies. These lithofacies were further grouped into four facies associations; FA1 - prodelta deposits, FA2 - delta front deposits, FA3 - distributary channel-fill deposits and FA4 - fluvial channel deposits. Result from sieve analysis data indicates that the sands are generally medium to coarse-grained, but dominantly medium-grained, poorly to moderately sorted, due to fluctuations in energy of depositional agent, albeit with dominance of high energy. Bivariate discriminant plots of Mean vs Sorting and Sorting vs Skewness indicate fluvial – shallow marine environments. In addition, paleocurrent analysis showed unimodal, low variance pattern and vector strength of (0.94) suggesting fluvial environment of deposition. Overall, the rock units of the study area were deposited generally within the environments that span from continental through marginal marine setting.

Based on mapping of laterally traceable stratigraphic discontinuities, we propose a highresolution allostratigraphic scheme for one of the world's foremost fossil marine vertebrate Lagerstätten: the lower Miocene strata of the Chilcatay Formation exposed along the Ica River near Zamaca, southern Peru. Measured sections combined with 1:10,000 scale mapping of a 24 km 2 area provide an overview of the stratal architecture, as well as a general facies framework and interpretation of the various depositional settings. As a whole, the Chilcatay alloformation is bounded by the CE0.1 unconformity at the base and the PE0.0 unconformity at the top. An internal Chilcatay surface, termed CE0.2, splits the alloformation into two distinct allomembers (Ct1 and Ct2). The Ct1 allomember comprises three facies associations recording deposition in shoreface, offshore, and subaqueous delta settings. The Ct2 allomember comprises two facies associations, recording deposition in shoreface and offshore settings. Using these data, we place the rich marine vertebrate assemblage in a precise spatial and stratigraphic framework. The well-diversified vertebrate assemblage is dominated by cetaceans (mostly odontocetes) and sharks (mostly lamniforms and carcharhiniforms); rays, bony fish, and turtles are also present. Taxonomic novelties include the first records of baleen whales, platanistids, and eurhinodelphinids from the Chilcatay Formation.

The Shiranish Formation represents one of the most important fractured reservoirs in northern Iraq. In this work, the petrophysical properties of the formation have been fully characterised using microscopy, core analysis, and well log analysis using conventional methods as well as new quantitative diagenetic approaches. During this work we have developed methods to quantify a petrophysical heterogeneity index (χ), reservoir quality indicator (RQI), and fracture effect index (FEI) for each of the stratigraphic units of the formation. The FEI was calculated by dividing the difference between the mean permeability of the wireline log data and the mean permeability of the unfractured core plug samples by the difference between the mean porosity of the wireline log data and the mean porosity of the unfractured core plug samples. This study shows that the Shiranish Formation has a fracturing pore system in all the characterised units, but it is particularly well developed in U.4, which shows the best reservoir quality (A and B). The new methods developed in this study can be applied to any carbonate formation to provide a trustworthy way to obtain a reservoir quality indicator linked to the petrophysical heterogeneity of the studied formation.

Alberta Geological Survey completed field programs in June 2007 and October 2008 near Cardston, Taber and Fort McLeod. We described outcrops of Upper Cretaceous and Tertiary formations in the field, took radioactivity measurements onsite, and collected 122 samples for determination of multiple elements. Representative thin sections were prepared and detailed petrographic descriptions, including point counts, were made. We conducted a radiometric survey along the St. Mary, Waterton and Oldman rivers. The most notable result of the 2007 and 2008 field programs was the discovery of a new radioactive occurrence, consisting of anomalous uranium content (158 ppm) in the siltstones of the Willow Creek Formation along the Oldman River. An automated evaluation of tens of thousands of digital logs from oil and gas wells, and subsequent detailed analysis of 1800 well logs, outlined areas for future assessment. We selected anomalous gammaray intervals in the upper 550 m for determination of rock type and formation. Eighty-two per cent of the high-gamma intervals occur within shaly units with a high organic content (e.g., Base of Fish Scales and Second White Specks formations). Clusters of wells with high gamma readings in sandstone occur in NTS areas 82O, 83G, 84D and 83O. In the Claresholm area, multiple wells with high gamma readings in sandstones of the Willow Creek and St. Mary River formations occur within the upper 500 m. Testing drill cuttings from oil and gas wells that cover radioactive intervals was unable to confirm the source rocks for the radioactive anomalies but provided insight into the rock types of these intervals. We collected 109 and 18 rock samples during 2007 and 2008, respectively. All samples were analyzed using inductively coupled plasma (ICP-OES) following HNO 3 /HCl partial digestion and HF/HNO 3 /HClO 4 total digestion. Uranium was also analyzed by the more sensitive fluorimetry method.

A high-level coastal deposition feature at the southern tip of Ap Lei Chau, Hong Kong Island, is studied in this report to understand its paleo-depositional environment. Previous systematic surveys for similar deposits in Hong Kong were conducted between 1986 and 1996 during the production of fifteen 1:20,000 scale geological maps, and subsequently reviewed wholistically by Wong & Shaw in 2009. Studies of specific sites were conducted by different parties as well such as at Po Chue Tam, Lantau Island in 2000 and 2003. Possible formation processes for these features such as eustatic changes in sea level, local variations in sea level, extreme wave events, high waves and wind action, winnowing, and neotectonic activity were proposed by the Wong & Shaw (2009) study. In this study, literature reviews are carried out to understand the existing models for Quaternary sea level changes in Hong Kong, methods for quantifying clast size, sphericity and roundness, findings from previous studies on similar site in Hong Kong, and the ground model of the site. Field studies comprising joint set survey, vertical photographic scan line assessment of 198 clasts and general observations such as grain sizes and shape distribution, clasts preferred orientations, are conducted and discussed to deduce the possible mode of deposition, potential sources, and likely age of the site. It is concluded in this study that the site consists of five layers exhibiting fluvial depositional processes at the lower three layers and colluvial processes for the upper two layers. A joint set bounded wave-cut notch was formed after the uplifting of the area and favors the deposition of coarse grain material on a beachor tombolo-like environment. Subsequent debris slide and collapse of the wavecut notch formed the colluvial layers of the site.

Synthesis of sedimentologic, paleocurrent, and organic geochemistry data of the Lower Permian Ga'ara Formation from the Western Desert, western Iraq, shows good hydrocarbon potentiality and deposition by high sinuosity and mixed-load channels, likely by a meandering river system. The Ga'ara Formation includes kaolinitic mudstone beds of various colors and channelized quartzitic sandstone beds. Based on the lithofacies identification, five lithofacies associations have been recognized: channel-floor, point-bar, abandoned channel plug, crevasse splay, and interchannel flood basin. In addition, the paleocurrent analysis and sandstone percentage map indicate a variation of the paleoflow spatially and temporally with a general direction range between NE and Sw, and the depositional environment has been interpreted as a meandering river system. To unravel the hydrocarbon potentiality of the Ga'ara Formation deposits, Pyrolysis and TOC% analyses were conducted on selected samples. The studies indicated that the Ga'ara Formation in western Iraq could be a moderate to excellent rock source. The PCI agrees with TOC content, suggesting that the generation potentiality of the mudstones as a source rock is poor and poor to excellent. All the analyzed samples show that their hydrocarbons are indigenous. The Ga'ara mudstones of the Nijili and West Tayyarah have very good generative potential, whereas the Ubairan samples have excellent generation potentiality. The Nijili and Ubairan samples are at an early stage of oil generation, i.e., immature. In contrast, the Tayyarah sample represents a postmature phase at the end of oil generation. Collectively, these new data on spatial distribution, geologic characters, and organic geochemistry propose that the Ga'ara Formation in western Iraq could be a valuable economic asset with good hydrocarbon potentiality .

Synthesis of sedimentologic, paleocurrent, and organic geochemistry data of the Lower Permian Ga'ara Formation from the Western Desert, western Iraq, shows good hydrocarbon potentiality and deposition by high sinuosity and mixed-load channels, likely by a meandering river system. The Ga'ara Formation includes kaolinitic mudstone beds of various colors and channelized quartzitic sandstone beds. Based on the lithofacies identification, five lithofacies associations have been recognized: channel-floor, point-bar, abandoned channel plug, crevasse splay, and interchannel flood basin. In addition, the paleocurrent analysis and sandstone percentage map indicate a variation of the paleoflow spatially and temporally with a general direction range between NE and Sw, and the depositional environment has been interpreted as a meandering river system. To unravel the hydrocarbon potentiality of the Ga'ara Formation deposits, Pyrolysis and TOC% analyses were conducted on selected samples. The studies indicated that the Ga'ara Formation in western Iraq could be a moderate to excellent rock source. The PCI agrees with TOC content, suggesting that the generation potentiality of the mudstones as a source rock is poor and poor to excellent. All the analyzed samples show that their hydrocarbons are indigenous. The Ga'ara mudstones of the Nijili and West Tayyarah have very good generative potential, whereas the Ubairan samples have excellent generation potentiality. The Nijili and Ubairan samples are at an early stage of oil generation, i.e., immature. In contrast, the Tayyarah sample represents a postmature phase at the end of oil generation. Collectively, these new data on spatial distribution, geologic characters, and organic geochemistry propose that the Ga'ara Formation in western Iraq could be a valuable economic asset with good hydrocarbon potentiality .

Lost circulation, the loss of drilling fluid into holes or
fractures throughout the geological formations being drilled,
is the most expensive problem encountered in drilling
operations for oil and gas wells. It is known that when there is
a loss of circulation during the drilling process, the operation
activities are delayed or stopped for curing or treatment,
resulting in extra time known as non-productive time (NPT).
The NPT issues during the drilling operations are the most
important priorities for planning any drilling program.
Therefore, the lost circulation is one of the main problems
which can control the NPT. To mitigate the lost circulation
problems, an integrated investigation is necessarily needed for
the main parameters which enhance/downgrade the rate of
lost circulation.
Drilling through the Dammam and Hartha formation is
typically accompanied with substantial nonproductive time
due to severe and often entire drilling fluid losses. The
majority of the curing this problem require time for
preparation, placement or setting. In this research, a field
study was carried out to investigate the effect of 6 drilling
parameters on the rate of the lost circulation. The investigated
parameters are the rate of penetration, weight on bit, stand
pipe pressure, mud weight, flow rate, and the equivalent
circulation density. Furthermore, the effect of lithology type
on the lost circulation rate was clearly determined and
correlated. In addition, a graphical representation of bit depth
vs the real drilling time/date was constructed to compare the
lossy wells vs non-lossy wells named frithogram. This study
was based on field data for 350 wells drilled in Rumaila
Oilfield, southern Iraq. The results of this study showed that if
these six operating parameters are standard and controlled, the
significance of lost circulation problems could be reduced.
However, the main factors which are responsible for the lost
circulation problems are lithology types, facies and/or
diagenesis process, which mainly distinguish the carbonate
formations.

The Mishrif Formation was studied in seven wells that were distributed in the Nasiriya Oil-
field, southern Iraq, well logs were obtained for these wells and included: Gamma ray,
Neutron, Density and Resistivity log. The Nasiriya Oil field is located at the unstable platform
Mesopotamian zone. The Mishrif Formation was divided into two rock units, the upper MA
and lower MB, separated by insulating shale rocks based on the gamma ray log. Furthemore,
the lower rock unit was also divided into two reservoir units MB1 and MB2. The petrophysical
properties of the formation were studied using various logs and through realationships
between the logs. The petrophysical study of the water and hydrocarbon saturations showed
that the formation contains varying proportions and quantities of water and hydrocarbons that
can be produced. The research also included a statistical study and calculation of reservoir
heterogeneity using two methods: first using the Dykstra-Parsons Coefficient, where the
results showed that is, the Lateral extension of the reservoir units of the study wells are
heterogeneous, and second using the Lorenz coefficient, where the results showed that wells
heterogeneous distribution, while Ns-9 and Ns-16 wells a homogeneous distribution.

One of the most useful logging tools for identifying losses and fractures is Formation Micro
Imager. Drilling through the Dammam Formation is typically associated with substantial
nonproductive time due to severe and often entire drilling fluid losses. The majority of
remedy this problem require time for preparation, placement or setting. Combining between
conventional well log and FMI log associated with drilling data, a special study of the
shallow Dammam carbonate formation penetrate by wells is accomplished. For a better
understanding of the loss mechanism, Image log study was highlighted to imagine the loss
zones and as such adapt data to advance loss prevention or cure future scenario. Five images
and conventional logs available data associated with drilling operation documents were
applied to suggest best subsurface stratigraphic facies in order to knowledge sediment
environment of Dammam Formation. Five image log facies were identified as representing
the different environments within the different depths, large, fine vugs, carbonate layers,
laminate interrupt and laminate. The stratigraphy succession reveals shallowing upward
from deep water represented by laminate facies to more disturbed water signified by vuggy
large facies. There are six internal picks zone according to GR log sign D90 at the top of
Rus Formation, D80, D70, D65, D60, D50 and D40. It has been clear that nearly severe or
complete losses events limit intensively in D60 and D65 based on logs interpretation
analysis associated with drilling data.

Stratigraphic and taphonomic analysis of Bonitasaura salgadoi Apesteguía (Sauropoda, Titanosauria) at «La Bonita» site (Upper Cretaceous, Rio Negro Province, Argentina). «La Bonita» is a fossiliferous locality close to the town of Cerro Policía, Río Negro Province, Argentina. At the quarry are exposed siliceous rocks belonging to the Bajo de la Carpa and Anacleto formations (Santonian-Campanian), separated by an unconformity from the Renteria Formation (Upper Pliocene-Pleistocene). The Bajo de la Carpa Formation is composed of sandstones, fine beds of conglomerates, alternate with pelites and wackes beds. The Anacleto Formation is composed of sandy to pelitic beds. The Renteria Formation is dominated by conglomerates with clasts that reach 15 cm in length, included in a sabullitic matrix. The facies analysis suggests a fluvial regime, with a subacuatic control with changes from mid to low energy. The lenticular-shaped sandy channels with crossed stratification point to an unidirectional flow in the transporting agent and bioclasts. The taphonomical analysis suggested that the dinosaur dies close to the river margins, being rapidly incorporated to the fluvial sediments that sepulted the specimen in successive events. The spatial distribution and bone relations suggest a very short transport from the source area, with a slight northward movement. The presence of two caudal vertebrae series with an opisthotonous articulation pattern, suggests that the animal was exposed long enough to permitt the rigor mortis and dissecation. The disarticulation degree also point to some amount of weathering of the skeleton before being sepulted. However, the exceptional periostium preservation in many cases suggests a very short subaerial exposure.

Reefs are hotspots of diversity, modifying their surroundings and fostering numerous biotic interactions: in the fossil record, they preserve valuable paleoecologic and paleoenvironmental information. Early Cretaceous reefs are understudied; this paper analyzes the sclerobiont fauna of an Hauterivian patch-reef from the Neuquén Basin (Argentina) to interpret its life history and paleoenvironmental significance. Massive and ramose forms of paleoautoecologically homogeneous genera comprise this reef; corals bore zooxanthellae and presented features indicative of a tolerance for highsedimentary input. Sclerobionts were analyzed separately for ramose and massive corals. In addition, upper and lower surfaces of massive corales were also logged separately. The sclerobiont fauna comprised mainly thecideid brachiopods, oysters, serpulids, cyclostome bryozoans and calcareous sponges; in ramose corals only, microbial crusts are recorded and encrusted by sclerobionts. Massive corals presented lowered diversity indices and lacked microbial crusts. In both coral morphotypes, bioclaustrated sclerobionts were registered: in particular, serpulids established mutualistic relationships with the corals. Massive corals undersides hosted a much more abundant, sciaphyllous scleobiont fauna. This patch reef established in a mid-ramp setting under relatively high sedimentation rates; massive corals were buried more quickly than ramose forms. The microbialites on the latter indicate lowered sedimentation rates after the coral reef had already dwindled, likely due to nutrient enrichment, but with ramose corals mostly in life position. Thus, at Early Cretaceous mid-latitude settings, corals were adapted to suboptimal settings in settings with relatively high sedimentation, sustaining a moderately diverse and dynamic sclerobiont fauna composed of mostly heteretrophic organisms.

The integration of sedimentary facies analysis, ichnology and benthic mollusc quantitative paleoecology allowed interpretation of factors that have controlled the deposition of the alluvial to marine succession outcropping in Northwestern Sicily (Southern Italy) at Altavilla Milicia, near Palermo (Imerese Basin). Two main marine units are recognised, labelled CNM and ALT, separated by an angular unconformity and formed by elementary depositional sequences (CNM1-4, ALT1-5). The succession was subdivided by means of calcareous nannoplankton biostratigraphy into upper Pliocene (Piacenzian: CNM1-4 and ALT1-4) and lower Pleistocene (Gelasian, ALT4-5), covering the onset of the Quaternary glaciation. The main asset of the succession is driven by tectonic compression and accommodation by transpressional faults, a regime that led to a change in the direction of fluvial sediment delivery, from axial (mid-Piacenzian: CNM), to transverse with respect to the basin elongation (upper Piacenzian-Gelasian: ALT). High-frequency eustatic changes drove the formation of elementary depositional sequences, the building blocks of CNM and ALT. During the late Piacenzian, a phase of gradual passage from the mid-Piacenzian warm period to the Quaternary glaciation, bioclastic production was still high, characterising the maximum flooding intervals of the two composite depositional sequences CNM and ALT. Mixed carbonate-siliciclastic lithosomes of both CNM and ALT show a good correlation with shallow marine shell-rich detrital carbonates of Northern and Southern Italy and with Mediterranean deep-water sapropel clusters, suggesting common climatic forcing. Some tropical species thought to disappear from the Mediterranean at around 3.0 Ma, including Pecten bosniasckii, Macrochlamys latissima, Spondylus crassicosta, Lucina orbicularis, Isognomon maxillatus, Crassatina concentrica, Gastrana lacunosa, Callista italica, Circomphalus foliaceolamellosus and Persististrombus coronatus, are present in the upper Piacenzian of Sicily (top of the MN16a Zone and the MN16b/17 Zone of calcareous nannofossil biostratigraphy). More data are needed to reconstruct the geographic dimension in the disappearance of the Mediterranean Pliocene macrobenthos with tropical affinities.

The Eocene-Oligocene sand facies is well exposed around Osumenyi and Ukpor areas in the Anambra Basin of southeastern Nigeria. Outcrop sections were located, measured, described in detail and sampled so as to decipher the paleoenvironment of deposition, using an integration of sedimentary facies and grain size analyses. The sedimentary facies study suggests that the Eocene-Oligocene age in this area consist mainly of three facies association; sandstone, lignite and clay facies. The fine-grained sandstone sub-facies is indicative of shoreface, the medium grained sandstone sub-facies is indicative of estuarine, while the coarse-grained sandstone sub-facies suggests a fluvial environment. The lignite facies indicate a continental origin (swamp environment) while the clay facies are interpreted as fluvially intercepted shallow marine environment. Results of grain-size analysis for the Eocene-Oligocene age show that the sands are medium grained, moderately to poorly sorted, very negatively to positively skewed and very platykurtic to very leptokurtic. Bivariate plots of mean size against standard deviation and skewness against standard deviation support a fluvially dominated shallow marine environment with tidal crosscuts. Result of multivariate functions showed a fluvially intercepted shallow marine environment. This study is significant in providing evidence for the reservoir potentials and aquifer characteristics of the Eocene-Oligocene sand facies for petroleum accumulation and prolific water bearing units within the basin.

The Eocene-Oligocene sand facies is well exposed around Osumenyi and Ukpor areas in the Anambra Basin of southeastern Nigeria. Outcrop sections were located, measured, described in detail and sampled so as to decipher the paleoenvironment of deposition, using an integration of sedimentary facies and grain size analyses. The sedimentary facies study suggests that the Eocene-Oligocene age in this area consist mainly of three facies association; sandstone, lignite and clay facies. The fine-grained sandstone sub-facies is indicative of shoreface, the medium grained sandstone sub-facies is indicative of estuarine, while the coarse-grained sandstone sub-facies suggests a fluvial environment. The lignite facies indicate a continental origin (swamp environment) while the clay facies are interpreted as fluvially intercepted shallow marine environment. Results of grain-size analysis for the Eocene-Oligocene age show that the sands are medium grained, moderately to poorly sorted, very negatively to positively skewed and very platykurtic to very leptokurtic. Bivariate plots of mean size against standard deviation and skewness against standard deviation support a fluvially dominated shallow marine environment with tidal crosscuts. Result of multivariate functions showed a fluvially intercepted shallow marine environment. This study is significant in providing evidence for the reservoir potentials and aquifer characteristics of the Eocene-Oligocene sand facies for petroleum accumulation and prolific water bearing units within the basin.

The correct determination of sedimentation processes in caves is often complicated by the unique characteristics of cave environments and their relationship to surface soil. A study at Cuvieri Cave has allowed new insights into the dynamics and evolution of these types of sedimentary facies and their relation to the nearby landscape. The cave is located in the Lagoa Santa Karst, eastern Brazil, and contains fossiliferous deposits of Pleistocene-Holocene age at the base of three vertical pits near the cave entrance. Facies analysis was applied to sediments to understand sedimentation process, and sediments were described according to their morphology, grain-size, micromorphology, chemical composition, paleontological content and age. Results indicate that all deposits present a soil-like aspect and although they record several depositional conditions, sedimentary structures and textures are similar among different facies. As such, facies were defined by a combination of matrix color, degree of cementation and sedimentological characteristics. Additionally, abundance of fauna remains, their taxonomic composition (extant vs extinct), completeness, and degree of individuals' articulation was evaluated. Differences between facies were produced by two main factors: (i) change in source area and transport route (from the epikarst to doline colluviation and back to epikarst) and (ii) change in type of sediment cover injected, from doline fed soils, followed by talus debris and finally soils from modern epikarst. The change in both factors is related to the landscape evolution, mainly with the development and progressive enlargement and deepening of the nearby doline. Additionally, the change in the type of sediment cover injected could also be related to climatic evolution. The complex evolution of Cuvieri Cave sediments occurred over at least the last 300 kyr and is marked by periods in which entrance opening allowed the incorporation of vertebrate (both extinct and extant) remains into the sediment. Detailed multidisciplinary field and laboratory analyses are essential in unraveling the long history of sedimentation in caves, providing a framework in which multiple events of sediment input and erosion can be correctly interpreted and related to the evolution of the landscape.

A este último agradecemos também pelas inúmeras contribuições em termos de cartografia geológica e geoprocessamento. Aos geólogos Inácio de Medeiros Delgado e Augusto Pedreira, da DIGEOB, agradecemos pela revisão do Mapa Geológico e da versão final deste Relatório, bem como pelas discussões e valiosas sugestões. Á Geóloga Adelina Arduíno de Magalhães, Elias Bernard do Espírito Santo e Leonardo Brandão Araújo, da DIGEOP, agradecemos pelo suporte na elaboração do SIG. Aos geólogos Ernesto Von Sperling e José Márcio Henrique Soares, da DIMARK, o nosso agradecimento pela concepção gráfica do SIG. As discussões estratigráficas e metodológicas com os colegas geólogos Eduardo Camozzato, Marco Aurélio Schneiders da Silva, Ricardo da Cunha Lopes e Wilson Wildner também foram de grande importância. Nos trabalhos de campo, o auxílio dos colegas Geólogo Carlos Alberto Kirchner e Técnico de Prospecção Edegar dos Santos Dias em muito contribuiu para a realização das campanhas num prazo otimizado. Também gostaríamos de agradecer aos colegas Técnico de Laboratório Valmor Justin pela confecção das lâminas delgadas, e Técnico de Prospecção Luiz Alberto da Costa e Silva pela coleta de zircões em algumas amostras. Á colega Bibliotecária Ana Lúcia Borges Fortes Coelho agradecemos pela normatização das referências bibliográficas e pelo auxílio na busca de material bibliográfico e aerofotográfico. Ao colega Geólogo Jorge Henrique Laux agradecemos pela revisão da versão preliminar deste Relatório. Ao Geólogo Johann Neveling (Council for Geoscience, South Africa) agradecemos pelo material bibliográfico sobre o Triássico da Bacia do Karoo. Á Bióloga Carolina Saldanha Scherer e à Geóloga Paula Camboim Dentzien Dias (Programa de Pós-Graduação em Geociências, UFRGS) agradecemos pelo empréstimo de material bibliográfico. Ao estagiário e graduando em geologia Jonathan Nereu Lisboa Rojas (Unisinos), pelo acompanhamento em campo, o nosso agradecimento.

In the Mount Messapion area (Chalkida, Greece) a continuous and expanded section of Triassic/Jurassic (T/J) limestone is exposed. This section consists of a 710 m thick pile of shallowing-upward peritidal cycles; the persistence of the facies and the lack of paleoenvironmental changes across the T/J boundary allowed studying the distribution of shallow water microfossils. The T/J boundary is placed in the upper part of the section defined by correspondence with (i) the last occurrence of Triasina hantkeni , (ii) the abrupt disappearance of megalodontid faunas and (iii) the presence of Early Jurassic microfossil assemblages. This paleontological reorganization happens suddenly, it is not controlled by any facies change, and surprisingly, it seems to produce no evident modification in the vertical stacking pattern of the cycles. A detailed facies analysis, performed along a 290 m thick stratigraphic interval (60 m above the T/J boundary and 230 m below), allowed the recognition of per...

The Homo erectus-like cranium from Buia (UA 31) was found in the Eritrean Danakil depression and dated to 1 million years. Its outer morphology displays archaic traits, as well as distinctive and derived characters. The present study provides the description and metric comparison of its endocranial anatomy. UA 31 was originally filled by a diffuse concretion. Following its removal and cleaning, the endocast (995 cc) was reconstructed after physical molding and digital scan. Its morphology is here compared with specimens belonging to different human taxa, taking into account endocranial metrics, cortical traits, and craniovascular features. The endocast is long and narrow when compared to the H. erectus/ergaster hypodigm, although its proportions are compatible with the morphology displayed by all archaic and medium-brained human species. The occipital areas display a pronounced bulging, the cerebellum is located in a posterior position, and the middle meningeal vessels are more deve...

Disponível on-line no endereço www.igc.usp.br/geologiausp -19 -Resumo Depósitos siliciclásticos da Formação Raizama de idade ediacarana-cambriana são expostos descontinuamente ao longo da margem sul do Cráton Amazônico e Faixa Paraguai Norte, centro-oeste do Brasil. Estes depósitos são interpretados por sucessões costeiras progradacionais, sobrepondo em conformidade os depósitos carbonáticos do Grupo Araras. A análise faciológica e estratigráfica da seção aflorante na região de Nobres, Estado do Mato Grosso, permitiu a individualização de dezessete fácies sedimentares agrupadas em cinco associações de fácies (AF): AF1) shoreface inferior consiste de arenitos com laminação plano -paralela e truncada por onda (microhummocky), intercalados por pelitos laminados, e com níveis bioturbados por tubos verticais perfurantes; AF2) shoreface superior, formada por arenitos com estratificação plano-paralela e cruzada swaley; AF3) submaré, composta por arenitos com estratificações cruzadas tangenciais e acanaladas com recobrimentos de siltito/arenito muito fino interpretados como depósitos de canal e barras; AF4) planície de maré é caracterizada por arenitos com estratificação cruzada tangencial e sigmoidal, laminação plano-paralela a cruzada de baixo ângulo, gretas de contração, intercalados por siltititos/arenito muito finos com acamamento flaser, organizados em ciclos de raseamento ascendente; e AF5) fluvial entrelaçado distal é constituída por arenitos com estratificação cruzada acanalada com lags lateralmente descontínuos, estratificações plano-paralelas e cruzadas de baixo-ângulo, parcialmente retrabalhadas por onda. A sedimentação da Formação Raizama indica que o fornecimento de sedimentos siliciclásticos estariam relacionado a soerguimentos no Cráton à noroeste da área estudada, sucedendo os depósitos carbonáticos do Grupo Araras. Traços fósseis tubulares descritos na AF1 indicam, pela primeira vez, a presença de traços fósseis perfurantes sugerindo uma idade deposicional para Formação Raizama mais próxima ao limite Ediacarano-Cambriano.

The depositional environment, climatic conditions, structural evolution, age, catchment area characteristics, and sequence stratigraphic arrangement along an early Cenozoic forelandhinterland boundary in northeastern Spain were determined from sedimentologic, palynologic, stratigraphic, structural, and paleomagnetic data. As the transpressional Catalan Coastal Ranges (characterized by NNW-verging folds and thrusts) rose during the Paleogene, two fan-deltas prograded into the Ebro basin. The syntectonic condition of the Paleogene deposits is evidenced by facies and geometries directly related to the growth of specific structures and tectonic activity in the catchment area. A tectonosedimentary evolution was deduced along the basin margin, clearly indicating a NE to SW migration of the deformation. In the present study, the effects of high rates of subsidence and sediment supply, associated with orogenic uplift and loading, on the sequence-stratigraphic organization of two fandelta cl...

O conhecimento geológico do território brasileiro constitui um instrumento indispensável para o plane- jamento e a implementação das políticas públicas voltadas para o desenvolvimento sustentável dos recursos minerais, petrolíferos e hídricos subterrâneos do país e, simultaneamente, fonte de dados imprescindível para o conhecimento do meio físico tendo em vista a execução de estudos de zoneamento ecológico-econômico e de gestão ambiental do território nacional. É com esta premissa que a Secretaria de Geologia, Mineração e Transformação Mineral do Ministério de Minas e Energia, através da CPRM -Serviço Geológico do Brasil têm a grata satisfação de disponibilizar à comunidade técnico-científica, aos empresários do setor mineral e à sociedade em geral os resultados alcançados pelo PROJETO BACIA DO TUCANO CENTRAL, que compreende as FOLHAS CAIMBÉ -SC.24-Z-A-I e JEREMOABO -SC.24-Z-A-II. Executado pela Superintendência Regional de Salvador da CPRM -Serviço Geológico do Brasil, o projeto apresenta o estado da arte do conhecimento geológico e de recursos minerais na escala 1:100.000 de uma área de 6.000 km2, abrangendo terras dos municípios de Adustina,

The Tithonian Pimienta Formation represents the main hydrocarbon source rock in Mexico, recently being targeted as an unconventional reservoir. This work shows the results of a detailed sedimentological characterization of the Pimienta Formation in the Tampico-Misantla Basin, Mexico.
This study integrates the well information, gamma ray log (GR), seismic interpretation and a high-resolution sedimentological analysis of an analogue outcrop core which involved facies identification, bio and chemostratigraphy. The continuous core covers the whole Pimienta Formation and its lower and upper stratigraphic boundaries (San Andres and Tamaulipas Inferior formations respectively).
Three stratigraphic members were recognized in the Pimienta Fm, the lower member consists mainly of saccocoma wackestone and calcispheres wackestone, with increasing GR values towards the top, suggesting a deposition on an outer platform to deep marine environment during early Tithonian time. The middle member comprises predominantly argillaceous carbonate mudstone and radiolarian wackestone, both with high organic matter, high V, Si and Al content and high GR values, indicating a deep marine environment and a middle Tithonian age. The upper member contains mainly bioclastic wackestone and mollusk-fragments wackestone with decreasing GR values towards the top and low organic matter content, implying an outer platform environment and a late Tithonian age.
According to their sedimentological features, both lower and middle members of the Pimienta Formation shows the best characteristics as an unconventional reservoir. This analysis contributed to identify sweet spots within the Pimienta Formation in the study area.

Tight sandstone reservoirs are widely distributed worldwide. The Upper Triassic Chang 6 member of the Yanchang Formation is characterized by low permeability and porosity. The facies model offers a unique approach for understanding the characteristics of various environments also heterogeneity, scale, and control of physical processes. The role of subsurface facies features and petrophysical properties was unclear. Notable insufficient research has been conducted based on facies and petrophysical modeling and that demands to refine the role of reservoir properties. To tackle this problem, a reservoir model is to be estimated using various combinations of property modeling algorithms for discrete (facies) and continuous (petrophysical) properties. Chang 6 member consists of three main facies, i.e., channel, lobe main body, and lobe margin facies. The current research is aimed at comparing the applicability and competitiveness of various facies and petrophysical modeling methods. Furt...

A este último agradecemos também pelas inúmeras contribuições em termos de cartografia geológica e geoprocessamento. Aos geólogos Inácio de Medeiros Delgado e Augusto Pedreira, da DIGEOB, agradecemos pela revisão do Mapa Geológico e da versão final deste Relatório, bem como pelas discussões e valiosas sugestões. Á Geóloga Adelina Arduíno de Magalhães, Elias Bernard do Espírito Santo e Leonardo Brandão Araújo, da DIGEOP, agradecemos pelo suporte na elaboração do SIG. Aos geólogos Ernesto Von Sperling e José Márcio Henrique Soares, da DIMARK, o nosso agradecimento pela concepção gráfica do SIG. As discussões estratigráficas e metodológicas com os colegas geólogos Eduardo Camozzato, Marco Aurélio Schneiders da Silva, Ricardo da Cunha Lopes e Wilson Wildner também foram de grande importância. Nos trabalhos de campo, o auxílio dos colegas Geólogo Carlos Alberto Kirchner e Técnico de Prospecção Edegar dos Santos Dias em muito contribuiu para a realização das campanhas num prazo otimizado. Também gostaríamos de agradecer aos colegas Técnico de Laboratório Valmor Justin pela confecção das lâminas delgadas, e Técnico de Prospecção Luiz Alberto da Costa e Silva pela coleta de zircões em algumas amostras. Á colega Bibliotecária Ana Lúcia Borges Fortes Coelho agradecemos pela normatização das referências bibliográficas e pelo auxílio na busca de material bibliográfico e aerofotográfico. Ao colega Geólogo Jorge Henrique Laux agradecemos pela revisão da versão preliminar deste Relatório. Ao Geólogo Johann Neveling (Council for Geoscience, South Africa) agradecemos pelo material bibliográfico sobre o Triássico da Bacia do Karoo. Á Bióloga Carolina Saldanha Scherer e à Geóloga Paula Camboim Dentzien Dias (Programa de Pós-Graduação em Geociências, UFRGS) agradecemos pelo empréstimo de material bibliográfico. Ao estagiário e graduando em geologia Jonathan Nereu Lisboa Rojas (Unisinos), pelo acompanhamento em campo, o nosso agradecimento.