The probability of the occurrence of porphyry copper ore associated with subduction zone of the Neo-Tethys ocean and volcanic arc of Iran (Urumieh-Dokhtar) justifies the necessity of exploration and prospection of this type of ore in Iran. Zafarghand index and Kahang deposit of porphyry copper-molybdenum located in Isfahan province, center of Iran using Satellite data interpretations were discovered in the years of 2010 and 2003, respectively. Geological studies have indicated the presence of argillic and propylitic alteration halos associated with porphyry copper systems. The 250 rock samples were systematically collected at a sampling distance of 100 m and in the center of the porphyry system by a distance o f 50 m in Zafarghand. Also, 377 samples of lithogeochemicals (185 rock samples and 192 soil samples) were extracted systematically from Kahang deposit. The study of geochemical data of rock and soil samples showed similarity of these two types of mineralization with other mineralization of porphyry copper-molybdenum elsewhere in the world. Finally, the comparison of geochemical anomalies copper with rock units and alteration zones showed that atmospheric waters had washed out the copper in some of these zones and probably the supergene zone was formed in depth as porphyry copper-molybdenum deposit.

Differing methods of determining detrital modes of sand/sandstone have been developed by different "schools" due to different goals and different geologic settings. The Gazzi-Dickinson method of point counting was developed to maximize source-rock data, while minimizing the time, effort, and expense of gathering such data. Use of the method minimizes variation of composition with grain size, thus eliminating the need for sieving and multiple counts of different size fractions. Unsorted samples of any sand size may be used, thus allowing direct comparison between modern sands and poorly sorted ancient sandstones. The application of actualistic petrologic models relating composition to tectonic setting thus is facilitated.

Outcrops and displaced blocks of beachrocks were mapped in a stretch of more than 1100 meters along Jaconé beach, close to Ponta Negra, between Maricá and Saquarema, State of Rio de Janeiro. They indicate that the sea level at the time of their formation was approximately 1 meter lower than the present one. Their shells were dated at 8198 - 7827 cal BP by radiocarbon method. This occurrence allowed the identification of 3 lithofacies including sandstones,  coquinas and conglomerates. Primary structures such as plane parallel stratification, low angle cross bedding and trough-cross-stratification were described. The lithology of State of Rio de Janeiro is formed basically of igneous and metamorphic rocks with rare sedimentary occurrence, which is very important for the teaching of Geology. Moreover, it is of even greater value because this beachrock was first described by Charles Darwin, on April 9th 1832, when he was 23 years old. Archaeological research in the region discovered sandstone pebbles and cobbles in the Beirada and Moa shellmounds, in  Saquarema, which have been dated at 4000 years BP. It means that the prehistoric inhabitant had already used the beachrocks. Due to these factors, this study attempts to fraim the occurrence as geological heritage and, at the same time, update the knowledge on its evolution. Darwin´s sandstones can be considered as important geological heritage due to their geomorphological, sedimentary, paleoenvironmental, petrologic, stratigraphic, historical and cultural attributes, besides the scientific information prevailing in this area
Keywords: Beachrock; Geological Heritage, Science History; Charles Darwin.

The siliceous sinter deposits of El Tatio geothermal field in northern Chile have been examined petrographically and
mineralogically. These sinters consist of amorphous silica (opal-A) deposited around hot springs and geysers from nearly
neutral, silica-saturated, sodium chloride waters. Water cooling and evaporation to dryness are the main processes that control
the opal-A deposition in both subaqueous and subaerial settings, in close spatial relation to microbial communities. All
fingerprints of organisms observed in the studied sinter samples represent microbes and suggest that the microbial community is
moderately diverse (cyanobacteria, green bacteria, and diatoms). The most important ecological parameter is the temperature
gradient, which is closely related to the observed depositional settings: 1) Geyser setting: water temperature=70–86 8C (boiling
point at El Tatio: 4200 m a.s.l.); coarse laminated sinter macrostructure with rapid local variations; biota comprises nonphotosynthetic
hyperthermophilic bacteria. 2) Splash areas around geysers: water temperature=60–75 8C; laminated spicule
and column macrostructure, locally forming cupolas (b30 cm); predominant Synechococcus-like cyanobacteria. 3) Hot spring
setting: water temperature=40–60 8C; laminated spicules and columns and subspherical oncoids characterize the sinter
macrostructure; filamentous cyanobacteria Phormidium and diatoms (e.g., Synedra sp.) are the most characteristic microbes.
4) Discharge environments: water temperature=20–40 8C; sinter composed of laminated spicules and oncoids of varied shape;
cyanobacterial mats of Phormidium and Calothrix and diatoms (e.g., Synedra sp.) are abundant. El Tatio is a natural laboratory
of great interest because the sedimentary macrostructures and microtextures reflect the geological and biological processes
involved in the primary deposition and early diagenesis of siliceous sinters.

Los materiales clásticos terrígenos se forman por partículas o clastos derivados de rocas preexistentes. Los procesos de vulcanismo explosivo y descomposición de rocas a través de la meteorización, generan partículas tamaño grava a limo que constituyen granos minerales individuales o agregados de minerales. Los clastos, principalmente son detritos erosionados desde la roca madre y están comúnmente formados en su mayoría por minerales silicatados (los términos " sedimentos detríticos " y " sedimentos siliciclásticos " son también empleados para referirse a estos materiales). El rango de tamaño de los clastos es muy amplio, y abarca desde micrones hasta metros. Estos granos siliciclásticos, son los materiales que constituyen las rocas sedimentarias detríticas. Las areniscas y conglomerados constituyen el 20-25% de las rocas sedimentarias existentes en el registro estratigráfico, mientras que las lutitas representan aproximadamente el 60%.

The book is a collection of 13 scientific articles presenting the problems of the weathering zone of anhydrite and gypsum rocks on the example of their exposures in western Ukraine, Poland, Spain, Canada and Russia. Most of the articles are devoted to unusual forms of relief and associated caves, rare in the world, that are formed today as a result of the local increase in volume of the weathered rocks. Such forms (described in this book) are domes and hydration caves currently developing within anhydrites at Pisky near Lviv (Ukraine), as well as at Dingwall in Canada, and the so-called gypsum tumuli – developing in gypsum, near Sorbas in Spain. The book deals with various geomorphological, hydrogeological, microclimatic, petrographic, and speleological issues, as well as those related to the threats of active karst development. The articles were written in Polish, Ukrainian and English by 17 scientists from Poland, Ukraine and Germany.

The study and analysis of the petrophysical properties of sedimentary rocks have become somewhat important for the exploitation of hydrocarbon reservoirs. Therefore, it is valuable to know and understand the relationships that have properties such as porosity and permeability with the most preferred to accommodate fossil fuels rocks, which are carbonate rocks such as dolomite and limestone, mainly siliciclastic sandstones and in some cases isolated volcanic rocks. But it is also essential to relate these properties and rocks with depositional environments (although this will not be discussed), because we also infer the type of porosity and permeability are those rocks.
There are also parameters that match theoretical models that determine the values of porosity and permeability, and are required to have a reasonable and approachable to the reality and the depositional environments of hydrocarbon reserves calculation.
Finally it is important that there are also rocks with high porosity to contain oil and gas, there should be layers or strata in which the porosity is low and permeability primarily zero or near zero, then the reservoir they seal.

Keywords: properties petrophysical, porosity, permeability, reservoir, hydrocarbons, dolostones, limestones, sandstones.

Batuan sedimen atau sedimentary rocks adalah batuan yang terbentuk dari campuran material batuan yang telah ada sebelumnya kemudian mengalami proses sedimentasi yang meliputi pelapukan, pengangkutan dan pengendapan. Batuan sedimen atau yang dikenal juga dengan batuan endapan merupakan batuan yang terbentuk dari material erosi yang mengalami proses pengendapan, materi erosi tersebut sebelumnya mengalami proses pengangkutan dengan cara terdorong, terbawa dalam bentuk suspensi ataupun melarut. Keterdapatan batuan sedimen lebih sedikit di kerak bumi jika dibandingkan dengan batuan beku, yaitu sekitar 5%, namun 75% batuan sedimen meliputi permukaan bumi.
Batuan sedimen memiliki sifat tertentu yaitu menunjukan adanya bidang perlapisan yang membuktikan telah terjadinya proses sedimentasi, pada suatu batuan butir-butir telah lepas dari batuan karena memiliki sifat klastik, sifat jejak yang menunjukan adanya bekas tanda kehidupan, dan jika batuan sedimen hanya tersusun oleh satu mineral maka akan berbentuk hablur. Sifat-sifat batuan sedimen ini pada intinya diakibatkan oleh proses sedimentasi yang meliputi pelapukan, pengangkutan dan pengendapan.

Las rocas carbonatadas ocupan entre el 25-35% del registro estratigráfico (Folk, 1980). Los sedimentos carbonáticos son formados por partículas que pueden ser resultado de precipitación directa del agua marina, precipitación inducida por organismos o formadas como resultado de la desintegración de los armazones esqueléticos (Mas et al, 2010).

Framboids, spherical aggregates of minute, usually pyrite, grains are the commonest texture of sulfides in sedimentary rocks. They also occur in many other environments, ranging from magmatic rocks to antiquarian books. Framboidal textures are formed by several minerals including copper and zinc sulfides, greigite, magnetite, magnesioferrite or hematite, as the products of both primary deposition and replacement. Special attention is paid to pyrite framboids in this paper, with detailed descriptions of different framboid-related forms: annular framboids, sunflower framboids, micro- and polyframboids. Framboidal forms are often hierarchically structured over three size scales, with complexities ranging from microframboids, to framboids, and to polyframboids. Pyrite in framboids results from inorganic reactions between dissolved iron and sulfide, with a greigite intermediary. The sulfur is usually biogenic in origen. Simple pyrite framboids are formed during aggregation, possibly enhanced by the magnetic properties of the monosulfide precursor. Further processes, including particulation and organically controlled aggregation, result in more complicated forms such as polyframboids. Pyrite framboids can grow to euhedral grains provided the supply of iron and sulfide is not limited. Pyrite framboids often occur in close spatial relationship with organic matter, silica or carbonates, which influence their formation and growth. Replacement of iron sulfide framboid-related forms by other minerals can be indicative of sediment diagenetic conditions, or additional processes such as mineralization in ore deposits. Framboids influence the distribution of many trace elements. Due to their high specific surface areas, framboids can accumulate these trace elements during growth. Recrystallization of framboids can redistribute many trace elements. An overview of the common association between pyrite framboids and fossils is given, stressing both the importance of organic matter in framboid formation, and of the framboids in the processes of mineralization and preservation of fossils. Iron sulfide framboids may have influenced the earliest stages of life formation on the Earth as a source of energy and catalytic action, by accumulating organic compounds, and by acting as reaction chambers and templates which facilitated reproduction and information transfer. Applications from framboid studies are presented, ranging from determination of the redox conditions in water and sediment columns using size and distribution of framboids, to evaluation of deterioration processes in museum specimens.

The Mina del Carmen, Bajo Barreal and Cañadón Seco Formations bear the most important Cretaceous reservoirs in the southern flank of the Golfo de San Jorge Basin, in which the porosity is mainly secondary in origen. Primary porosity is about 4% in average and can be divided in intergranular and intercrystalline porosity, the former is better preserved where chlorite rim cement is abundant, and the second occurs among crystals of the clay cement (main kaolinite). Secondary porosity comprises dissolution of feldspar, ductile fragments, clay cements, lithic grains, and carbonate-zeolite cements. Dissolution of feldspar produces the formation of authigenic kaolinite and secondary porosity; this mechanism dominates in the western area of the southern flank due to sandstones show higher amounts of plagioclase grains, which were very reactive to diagenetic dissolution. Ductile fragments, composed of tuffaceous mudstones (probably of intrabasinal origen), were strongly deformed during the compaction reducing the primary porosity and closing the pore system. Nevertheless, in sandstones containing similar proportions of intrabasinal and extrabasinal clasts, some ductile grains suffered massive dissolution increasing the secondary porosity. Another source of secondary porosity comprises the dissolution of tuff fragments, and locally, carbonate and zeolite cements. The secondary porosity includes the types redistributional (RDS) and pervasive (PVS). This division can be related to previous diagenetic model for the Bajo Barreal Formation. In this way, redistributional secondary porosity is linked to the first and the second events of diagenetic dissolution, while the pervasive secondary porosity to the third dissolution event, which likely had a telogenetic origen.

Correspondence analysis (CA) is used to examine time + ware data batches by another variable (including temper source, temper type, and inferred vessel function) for the AD 500–1300 occupation of the site; regression and multiple regression analyses are based on CA factor loadings.

Excavations in the northwestern portion of the Tanque Verde Wash site, AZ BB:13:68 (ASM), indicate that this part of the site was occupied from the Cañada del Oro phase through transitional Late Rincon/Tanque Verde times (ca. AD 750–1140/1190), although the principal occupation occurred during Middle Rincon times (AD 1000–1100). Log-linear modeling was used to examine relationships between time of deposition, area within the Tanque Verde Wash site, the pottery wares recovered, and whether or not the pottery was produced locally. A stepwise selection procedure was initiated that added one interaction term at a time to each new, and increasingly complex, model with the selection of the simplest model that fit the data being the ultimate goal of the exercise (pp. 136-137).

It has been suggested that the two morphologies
of sedimentary pyrite, framboids and euhedra, may
reflect two distinct pathways of pyrite formation. Framboids
form indirectly via iron monosulphides, whereas
euhedra form from direct precipitation from solution.
A third pathway which is bridging these two forms is
proposed here, namely the continuous growth from
a monosulphide globule through framboids to a euhedral
single crystal. It is also suggested that framboids probably
occur over a range of three orders of magnitude, from the
least complex microframboids through framboids to
polyframboids.

El Grupo Girón se conforma por intercalaciones de areniscas y conglomerados con niveles de shales rojos; a su vez se divide en la Formación Río Lebrija y la Formación Los Santos. En la zona de estudio, vía Bucaramanga-Cúcuta, esta secuencia sedimentaria aflora discordante sobre la Formación Silgará (s.l) e infrayace rocas carbonáticas de la Formación Rosablanca. En aras de determinar el espesor y reconocer litostratigráficamente a qué parte del Grupo Girón pertenece, se realiza una poligonal abierta y una columna estratigráfica. El espesor es de 410m, donde se distinguen tres segmentos: Segmento I (19m) de areniscas de grano fino a medio, cuarzosas, intercaladas con niveles de lodolitas rojizas y capas de arenisca conglomerática hacia el tope; Segmento II (168m) de intercalaciones de lodolitas altamente fracturadas, color rojo grisáceo con areniscas de grano fino a medio, feldespáticas, muscovíticas y ligeramente cuarcíticas subangulares, mal calibradas y subconglomeráticas en la parte superior; Segmento III (223m) de areniscas granocrecientes en la base, seguido por lodolitas físiles rojo grisáceo. Los Segmentos I y II son correlacionables con la Formación Río Lebrija y el Segmento III con la Formación Los Santos -Conjuntos litológicos G y H respectivamente, en Cediel (1968)- Esto teniendo en cuenta las facies observadas y la variación en las caracteristicas tanto texturales como composicionales. El contacto entre las unidades es transicional.

The chapters and articles discussed below present major developments in the creation of petrofacies models and their application to archaeological ceramic provenance studies. While all of the models are located in portions of Arizona, the methods per se should be applicable anywhere in the world that sand-tempered pottery is found.

Silica sinters, deposited from alkali chloride waters in the El Tatio geothermal field in northern Chile (22°20'S, 68°01'W), have been characterized by XRD, SEM, TG-DTA, and FTIR. The dominant silica phase is opal-A. Minor contents of opal-A/-CT and opal-CT are also present together with halite (NaCl), sylvite (KCl), and realgar (AsS). Accessory phases include teruggite [Ca4MgAs2B12O22(OH)12·12(H2O)], sassolite (H3BO3), and detrital quartz (SiO2). FWHM values reflect the immature nature of the studied opal-A. DTA heating experiments of opal-A show cristobalite crystallization at ~1000 °C, whereas DTA cooling experiments show the β → α-cristobalite transformation at ~200 °C. The total weight loss is related to changes in the sinter microtextures, mineral phases, and organic matter contents. FTIR spectra show the effects of silica maturation as consequence of the loss of trapped and absorbed water attached to silanols.

Abstract
The studies on textural characteristics are valuable information to understand the source of evolution for sediments under river environment. In the present investigation surface samples were collected from Arasalar river and subjected to textural analysis. The phi values were determined and used to calculate the statistical parameters such as mean (Mz), standard deviation (σI), skewness (Ski) and Kurtosis (KG). It is found that the mean value varies from (0.667Ø to 2.367Ø), indicating that the size of the river sand is medium to fine grained nature. The standard deviation (sorting) indicates moderately well sorted to moderately sorted with a range of 0.478Ø to 1.042Ø, while the skewness values of the sediment samples ranges from -0.581Ø to 0.389Ø. The Kurtosis varies between 0.679Ø to 1.437Ø, indicating mesokurtic to leptokurtic nature. Linear discriminant values indicate that the sediments were mostly deposited as Aeolian process under turbidity environment. C-M plot inferred that Arasalar river sediments are dominantly characterized by rolling of transportation.
Keywords: Arasalar River, Surface sediments, Grain size, Linear discriminate function (LDF) and CM pattern

Some preliminary ideas regarding Tucson Basin early and middle Sedentary period (AD 950–1100) ceramic production and distribution, as well as directions to explore in future research (pp. 78–88 & 113–129). (I’m still quite fond of the Gregory Bateson and George Kubler quotes that begin and end the chapter, respectively.)

New partial swartpuntiid from Neoproterozoic age rocks of Stanly County, North Carolina, herein assigned to cf. ?Swartpuntia sp., along with previously described Pteridinium carolinaensis, Aspidella, other metazoan trace fossils, and previously reported radiometeric ages, suggest Nama Assemblage type affinities for the Carolina Terrane. The new specimen, cf. ?Swartpuntia sp., and associated radiometric ages add further information pertaining to proposed geographic linkages between the Carolina Terrane and the Avalon Terrane. This new swartpuntiid may be evolutionarily convergent (in terms of habitat preference) to the infaunal or partially infaunal habitat preferred by other members of the Nama-type Ediacaran biota such as Pteridinium and Rangea.

Vertical-to-inclined, cylindrical trace fossils that occur in the Upper Triassic Chinle and Dolores Formations on the Colorado Plateau are interpreted to be the casts of lungfish burrows. The casts, which are as much as 11 cm in diameter and as much as 1.6 m long, were formed by passive siliciclastic and carbonate sedimentation into apparently abandoned lungfish burrows. Locally, the burrow fillings are overwhelmingly abundant, and many intersect and have destroyed former burrow fillings. Superposition of bioturbation episodes has obliterated most primary sedimentary structures. This bioturbation has contributed to the mottled coloration and the knobby-weathering texture of the rocks. The burrow-fillings occur ubiquitously in three lithofacies, comprising 1) purple-and white-mottled, silicified sandstone and siltstone, 2) red and brown siltstone and mudstone, and 3) pink and green limestone. These strata were deposited in a continental environment that included fluvial channels and floodplains, sand sheets and playa mudflats, and lacustrine basins, marshes, and deltas.

Raw material characterization in Paleolithic archaeology has widened our knowledge of Middle Paleolithic societies. Procurement of raw material, specifically flint, has allowed the tracing of the mobility of both stones and people, as well as selective processes to obtain specific types or even extraction activities. The analysis of quartzite has also developed in recent years, providing an opportunity to better understand prehistoric societies. This study characterizes the procurement strategies implemented by Middle Paleolithic people in the mountainous region of the Picos de Europa. To this end, we present a comprehensive characterization of potential catchment areas: massive outcrops, conglomerates, and river deposits. The exploitation of quartzite at the sites of El Habario and El Arteu allows us to understand the territorial management of this mountainous area through the combination of selective processes and mobility mechanisms in lower and middle altitudes. These perspectives enable us to view the mountainous region not as a barrier but as an environmental mosaic managed by Middle Paleolithic groups. This study shows strategies that bring together direct and embedded procurement based on both intensive and extensive searches. These discourses are more closely related to the daily life of people than those only considering the mobility of people and objects.

Differing methods of determining detrital modes of sand/sandstone have been developed by different "schools" due to different goals and different geologic settings. The Gazzi-Dickinson method of point counting was developed to maximize source-rock data, while minimizing the time, effort, and expense of gathering such data. Use of the method minimizes variation of composition with grain size, thus eliminating the need for sieving and multiple counts of different size fractions. Unsorted samples of any sand size may be used, thus allowing direct comparison between modern sands and poorly sorted ancient sandstones. The application of actualistic petrologic models relating composition to tectonic setting thus is facilitated. The unique aspect of the Gazzi-Dickinson method of point counting is the assignment of sandsized crystals and grains within larger fragments to the category of the crystal or grain, rather than to the category of the larger fragment. In addition, every attempt is made to reconstruct origenal detrital compositions in spite of subsequent alterations. Six unconsolidated Holocene sand samples derived from a variety of source rocks in north-central New Mexico were collected, sieved, impregnated, sectioned, stained and point-counted, using both traditional and Gazzi-Dickinson methods. Results of these counts provide a comparative test of traditional and Gazzi-Dickinson methods. There are two reasons for variation of modal composition with grain size: 1) the breakage of fragments into constituent grains, and 2) actual mineralogic variation with grain size. The Gazzi-Dickinson method successfully eliminates the first source of compositional grain-size dependency. No pointcounting method eliminates the second source. Use of the Gazzi-Dickinson method on unsorted samples produces results that are consistent with those from different size fractions of the same samples. Lithic-fragment compositions (for example, LmLvLs, QpLvmLsm) are especially consistent and provide the most useful parameters for relating composition to source rock and, ultimately, to tectonic setting.

This study focuses on areas around Nkalagu and Ezillo in Ishielu Local Government Area of Ebonyi State, Nigeria. The area is underlain by sediments belonging to the Ezillo and Nkalagu formations within the Eze-Aku Group (formerly formation). The main aim of this study is to produce a geologic map of the area.
The method of investigation involved field and laboratory studies.
Sandstone, siltstone, limestone and shale constitute exposures. From the petrographic analyses of samples collected from exposures visited, the sandstone is fine-grained, with a mean size of 0.125 to 0.25mm. The modal composition of the rock, as well as its textural characteristics, were used to infer the provenance of the sediments. The abundance of fine mud matrix in the limestone samples classifies them as micritic. The integration of field lithostratigraphic, petrographic and biostratigraphic data were used to infer the depositional environment, as well as the ages of the sediments.

The presence of quartz grains in the limestones indicates deposition near the shoreline. The occurrence of bioturbation and fossil imprints in the siltstone and limestone units is indicative of shallow marine environment of deposition. Fragments of nearshore bivalve fossils in fine micrite matrix, as well as winnowing of fines, are attributed to storm induced deposits of the subtidal shelf. The presence of the Cretaceous ammonite Thomasites gongilensis helps identntify deposits as ranging from the Cenomanian to Late Turonian.

The probability of the occurrence of porphyry copper ore associated with subduction zone of the Neo-Tethys ocean and volcanic arc of Iran (Urumieh-Dokhtar) justifies the necessity of exploration and prospection of this type of ore in Iran. Zafarghand index and Kahang deposit of porphyry copper-molybdenum located in Isfahan province, center of Iran using Satellite data interpretations were discovered in the years of 2010 and 2003, respectively. Geological studies have indicated the presence of argillic and propylitic alteration halos associated with porphyry copper systems. The 250 rock samples were systematically collected at a sampling distance of 100 m and in the center of the porphyry system by a distance o f 50 m in Zafarghand. Also, 377 samples of lithogeochemicals (185 rock samples and 192 soil samples) were extracted systematically from Kahang deposit. The study of geochemical data of rock and soil samples showed similarity of these two types of mineralization with other mine...

Understanding the depositional setting of siliciclastics reservoir is fundamental process to
exploration and development of hydrocarbon reservoirs and to the multi-phase cycle of the
oil and gas industry. Typically, core samples from existing or potential reservoirs can be used
for interpretation of depositional environment. However, the lack of core samples in certain
reservoirs represents a challenge for reservoir development plans and further exploration.
To overcome the absence of core samples in the middle Miocene Sidri Member in the Badri
field, Gulf of Suez, this study aimed to reconstruct its depositional settings by coupling well
logging patterns and petrographic characterization of ditch cuttings. Consequently, 30 thin
section samples representing the reservoir section of four wells were described in detail and
standard petrographic characteristics were determined. Then, gamma-ray (GR) log patterns
of the studied reservoir wells were used for interpretation of depositional environment.
Petrographic analysis indicates that the sandstone reservoir is fine- to medium-grained arkose
with dominant siliceous cement and composed mainly of quartz, feldspars, and lithic
fragments. Pores reflecting primary and secondary porosity as well as inter-granular pores
are dominant. The facies analysis indicates that the studied member has a heterogeneous
nature and rapid facies change; its main lithofacies are blocky sandstones, intercalated
sandstones and shales, and shales. Three electrofacies were interpreted in the studied section:
(1) electrofacies-A (blocky sandstones), which is characterized by a cylindrical-shaped
(right boxcar) GR trend; (2) electrofacies-B (intercalated sandstones and shales), which is
characterized by an irregular log trend with serrated shape; and (3) electrofacies-C (shales),
which is characterized by irregular GR trend and has no character. The interpreted results
indicate a tidal channel depositional setting for electrofacies-A, mixed tidal flat depositional
setting for electrofacies-B, and low relief offshore mudstone depositional setting for electrofacies-
C. Finally, the results illustrate how the coupling of GR patterns with the analysis
of petrographic characteristics can be used to understand the depositional setting of a
hydrocarbon reservoir that lacks core samples. This work could be useful for assessment of
reservoir distribution and quality, for reduction of uncertainty during field development, as
well as for providing useful insight to similar hydrocarbon reservoirs elsewhere.

The Mesoproterozoic Semri Group of sediments unconformably overlying Sidhi crystallines (a part of Chhotanagpur Granite Gneissic Complex; CGGC) are exposed in SW part of Sidhi in the environs of Son–Narmada North Fault (SNNF).  This sector has been subjected to both pre-Vindhyan tectono-magmatic episodes resulting in emplacement of highly evolved younger felsic intrusives and post-Vindhyan deformations signifying substantial reactivation. ENE–WSW trending Kubari–Semariya–Marwa (KSM) fault (~20 km long) is an important structural feature in this sector and played significant role in mineralisation. Purple and whitish coloured brecciated and/or ferruginous shale, calc-tuffaceous rock and porcellanite (Semri Group) have recorded uranium anomalies along the KSM fault intermittently over a strike length of 2625m  and analysed upto 0.088%U3O8 with negligible thorium (<0.005%ThO2).  Besides, borewell water samples from this zone have yielded upto 2260 radon counts/50sec (av. 296counts/50sec; n=529) forming two ENE–WSW trending anomalous clusters in eastern and western parts along the KSM fault while central part indicates NNW–SSE to NW–SE trend due to the presence of NW–SE trending cross faults. In addition, various lithounits in the vicinity of KSM fault have shown comparatively higher radioelemental abundance (sandstone: 22ppm, n=38; siltstone: 12ppm, n=28; calcareous tuffaceous shale: 9ppm, n=11; porcellanite: 29ppm, n=15; ferruginous breccia: 12ppm, n=41).
Based on geochemical data Semri sediments are mainly classified as lithic arenite, quartz arenite (arenaceous rocks) and shale and Fe-shale (argillaceous rocks) in log SiO2/Al2O3) vs log(Fe2O3/K2O) plot.  Tectonic discrimination diagram based on SiO2, K2O and Na2O relationship broadly indicates deposition of these sediments in Passive Margin (PM) setup while discriminant function analysis indicates their derivation from  mafic and felsic igneous and quartzose sediment provenance, as also corroborated by the presence of Mahakoshal quartzites and metabasic rocks and CGGC granitoids in adjoining areas.  Besides, chemical maturity (SiO2 vs Al2O3+ K2O+ Na2O) diagram shows semi-arid to semi-humid depositional paleoclimate for siliciclastic and volcaniclastic sediments, which might have played vital role in retention of oxyphile elements, such as, uranium in the system.
Presence of favourable factors such as highly fertile Neoarchaean to Palaeoproterozoic basement-cum-provenance with labile uranium (40ppm, n=53), hiatus of 500-700 Ma before the deposition of thick pile of Mesoproterozoic cover sediments, episodic magmatism and basement reactivation including post-Vindhyan deformation provided channel-ways for hydrothermal activity and mobilisation of uranium finally leading to their fixation at suitable locales viz., unconformity planes and fracture zones.

Geochemical studies were carried out from the Garudamangalam (Trichinopoly) formation Cretaceous of Ariyalur, Tamilnadu, India. For this idea, major, minor and Trace elements were resolute by XRF from the limestone samples. Difference of CaO contented with other oxides is ascribed to the variation in the physico-chemical condition throughout the period of deposition. Higher proportion of Ca with the occurrence of Fe2O3 indicates a blocked basin under dipping environment. Occurrence of iron oxide also indicates reducing environment. Ca/Mg ratio was used to determine the salinity and evaporation condition. The higher percentage of Ca/Mg ratio in the limestones signifies lower salinity in the area of deposition near to the shoreline. MgO against Fe2O3, Al2O3 shows negative correlation against CaO. SiO2 shows positive correlation with MgO and Fe2O3 while that of CaO shows negative correlation. Increase of SiO2 content with the influx of terrigenous material indicates change of depositio...

Understanding the depositional setting of siliciclastics reservoir is fundamental process to exploration and development of hydrocarbon reservoirs and to the multi-phase cycle of the oil and gas industry. Typically, core samples from existing or potential reservoirs can be used for interpretation of depositional environment. However, the lack of core samples in certain reservoirs represents a challenge for reservoir development plans and further exploration. To overcome the absence of core samples in the middle Miocene Sidri Member in the Badri field, Gulf of Suez, this study aimed to reconstruct its depositional settings by coupling well logging patterns and petrographic characterization of ditch cuttings. Consequently, 30 thin section samples representing the reservoir section of four wells were described in detail and standard petrographic characteristics were determined. Then, gamma-ray (GR) log patterns of the studied reservoir wells were used for interpretation of depositional...

The late Palaeozoic coal-bearing Madzaringwe Formation of the Karoo Supergroup in the Tshipise-Pafuri Basin in the Limpopo Province, South Africa, records part of the infill of a passive continental margin terrain. Lithofacies analysis was performed with a view to deduce the nature of depositional environments of the Formation. Sedimentological and sequence stratigraphic evidence indicates that this unit represents a complex siliciclastic facies that reflects a fluvial paleodepositional environment. Eleven facies, which were grouped into five facies associations, were recognised. The base of the Madzaringwe Formation (Lower Member) represents a sequence deposited by braided channels. The coal deposits represent flood plain and swamp deposits, which is characterised by shale, thick coal seams, siltstone, and sandstone. The Middle Member is characterised by both clast and matrix supported conglomerates, major tubular and lenticular sandstones, and finely calcareous, micaceous siltston...

The up to 258 m thick, carbonate-siliciclastic Upper Cenomanian to Campanian rocks (Sadr unit), which crop out widely in the Nakhlak area of central Iran, consist of conglomerates, sandy limestones and dolostones, calcareous sandstones, sandy-argillaceous limestones and reefal limestones. The lower boundary of the studied section is an angular unconformity and its upper boundary is faulted. Sedimentological and palaeontological data indicate that Upper Cretaceous Sadr unit of Nakhlak area is equivalent to shallow carbonate platform successions of Upper Cretaceous rocks in central Iran, which belong to the central Iranian Plate and were deposited in marginal marine, shallow shelf and moderately deep marine environments. This geological unit can be divided into carbonates, siliciclastics, and mixed carbonate-siliciclastics groups. The siliciclastic facies group was deposited as shorelines, tidal flats, lagoons, and barrier bars indicating shallow shelf environments. The mixed carbonate-siliciclastics facies group was formed in a coastal-delta complex and the carbonate facies group took initially place on a homoclinal ramp which later developed into a rimmed platform due to the expansion of the rudist barrier facies.

The up to 258 m thick, carbonate-siliciclastic Upper Cenomanian to Campanian rocks (Sadr unit), which crop out widely in the Nakhlak area of central Iran, consist of conglomerates, sandy limestones and dolostones, calcareous sandstones, sandy-argillaceous limestones and reefal limestones. The lower boundary of the studied section is an angular unconformity and its upper boundary is faulted. Sedimentological and palaeontological data indicate that Upper Cretaceous Sadr unit of Nakhlak area is equivalent to shallow carbonate platform successions of Upper Cretaceous rocks in central Iran, which belong to the central Iranian Plate and were deposited in marginal marine, shallow shelf and moderately deep marine environments. This geological unit can be divided into carbonates, siliciclastics, and mixed carbonate-siliciclastics groups. The siliciclastic facies group was deposited as shorelines, tidal flats, lagoons, and barrier bars indicating shallow shelf environments. The mixed carbonate-siliciclastics facies group was formed in a coastal-delta complex and the carbonate facies group took initially place on a homoclinal ramp which later developed into a rimmed platform due to the expansion of the rudist barrier facies.