Petrophysical characteristics of Wakar Formation, Port Fouad marine field, north Nile Delta, Egypt

Petrophysical characteristics of the late Miocene Wakar Formation of Port Fouad Marine Field have been evaluated through the analysis of well-logging records of nine exploratory and development wells, distributed in the northeastern offshore area of the Nile Delta. These records have been analyzed through utilizing the ELAN Plus petrophysics software in order to identify the lithological constituents and fluid saturation parameters. The gas potentialities of the studied formation have been evaluated through number of isoparameteric maps. The litho-saturation analysis indicates that the Wakar Formation in the studied wells is mainly gas-bearing with some water-bearing sand levels. The analytical formation evaluation reveals that the lithological facies consists mainly of sandstone, shale, and siltstone. The disseminated shale is mainly of dispersed type and some of laminated habitat. It also points to the dominance of the intergranular porosity. The isoparametric maps of the petrophysical parameters show that the level S1 of Wakar Formation is the main reservoir.     

The geology of the Llanuwchllyn to Llanymawddwy area,south gwynedd,north wales

A geological map of the Caradoc rocks of the Llanuwchllyn to Llanymawddwy area is presented and the geology of the area described in detail. Hitherto unrecorded outcrops provide important stratigraphical evidence which is used to redraw the Caradoc-Ashgill Series boundary and many of the formational boundaries within the Caradoc Series. The stratigraphy of the area is revised to conform with the standard classification of the Caradoc Series in the Bala region. The only modifications are as follows: the Llaethnant Siltstone is proposed as a formational name for a group of beds which are broadly equivalent to the Glyn Gower Formation but which represent a distinct facies. The greater part of the Nod Glas Formation north of Dinas Mawddwy is shown to be laterally equivalent to the upper part of the Gelli-grin Formation; it is also subdivided into two members, the Dyfi Mudstone and the Corris Shale, differentiated on lithological and faunal grounds. The stratigraphy of the Dinas Mawddwy area is also amended. Faunal elements (genera) new to the Caradoc Series of this area, and to Wales, are noted.     

Discovery and Analysis of Shale Gas in a Carboniferous Reservoir and its Enrichment Characteristics in the Northern Nanpanjiang Depression,Guizhou Province,China

Shale gas resources are considered to be extremely abundant in southern China, which has dedicated considerable attention to shale gas exploration in recent years. Exploration of shale gas has considerably progressed and several breakthroughs have been made in China. However, shale gas explorations are still scarce. Summary and detailed analysis studies on black shale reservoirs are still to be performed for many areas. This lack of information slows the progress of shale gas explorations and results in low quantities of stored black shale. The Carboniferous Dawuba Formation, which is widely distributed and considerably thick, is one of the black shale formations targeted for shale gas exploration in southern China in the recent years. The acquisition and analysis of total organic carbon, vitrinite reflectance,types of organic matter, mineral composition, porosity, and permeability are basic but important processes. In addition, we analyzed the microscopic pores present in the shale. This study also showesd the good gas content of the Dawuba Formation, as well as the geological factors affecting its gas content and other characteristics. To understand the prospect of exploration, we compared this with other shale reservoirs which have been already successfully explored for gas. Our comparison showesd that those shale reservoirs have similar but not identical geological characteristics.     

Provenance,weathering, and paleoenvironment of the Upper Cretaceous Duwi black shales,Aswan Governorate,Egypt

The mineralogy and geochemistry of the Upper Cretaceous Duwi black shales of Nile Valley district, Aswan Governorate, Egypt, have been investigated to identify the source rock characteristics, paleoweathering, and paleoenvironment of the source area. The Duwi Formation consists mainly of phosphorite and black shales and is subdivided into three members. The lower and upper members composed mainly of phosphorite beds intercalated with thin lenses of gray shales, while the middle member is mainly composed of gray shale, cracked, and filled with gypsum. Mineralogically, the Duwi black shales consist mainly of smectite and kaolinite. The non-clay minerals are dominated by quartz, calcite, phosphate, dolomite, feldspar, with little gypsum, anhydrite, iron oxides, and pyrite. Based on the CIA, PIA, and CIW values (average?=?84, 94, 95, respectively), it can be concluded that the litho-components of the studied shales were subjected to intense chemical weathering and reflect warm/humid climatic conditions in the depositional basin. The provenance discrimination diagram indicates that the nature of the source rocks probably was mainly intermediate and mafic igneous sources with subordinate recycled sedimentary rocks (Nubia Formation). Geochemical characteristics indicate that the Duwi black shales in Nile Valley district were deposited under anoxic reducing marine environments.     

Catastrophic movement of rocks and proposed solutions to avoid its risks in the Abu El-Reesh area, northeast Aswan City, Egypt

Catastrophic mass movement of rocks and torrents affected the Abu El-Reesh area, northeast of Aswan City. The present article aims to evaluate the potential catastrophic movement of rocks, delineate the risk zones, and suggest suitable solutions to avoid the potential risks in this area. The sedimentary succession of Abu El-Reesh area is mainly represented by the Nubian sandstone sequence of Upper Cretaceous (up to 60?m thick) forming a huge scarp at the eastern border of the study area. This sequence comprises two vertically successive rock formations: Timsah Shale Formation and Umm Barmil Sandstone Formation. The Timsah Shale Formation forms the lower part of the sedimentary succession with a thickness of 6?C40?m. It is composed of shale beds with intercalations of sandstones, siltstones, and mudstones. This formation is overlain by the Umm Barmil Sandstone Formation, representing the cap rock of the succession, with a thickness of 4?C20?m. The western scarp face has an irregular concave slope, with slope angles ranging from 22° to 46° in the lower part of scarp and become steep (60°?C86°) at its upper part. The drainage patterns are mainly coarse dendritic and discharge into the Nile River, passing through densely populated zones. These zones are exposed to the torrents during rare rainfall events. Three sets of vertical joints (trending NNW, NNE, and WNW) dissect the cap rocks and intersect with the horizontal bedding planes to form separated cubes and polygonal blocks. Potential catastrophic movement of rocks in Abu El-Reesh area is related to several reasons, including: existence of competent sandstones underlain by incompetent shales, dissection of the coherent cap rock due to intersection of vertical joint sets and bedding planes, presence of exposures with steep slopes, rainfall, and human activities (mining works, sewage water, and irrigation). Based on the dominance of either one or more of these reasons, three subareas (El-Khalasab, El-Shadeeda and El-Aqaba) represent the main risk zones, subjected to rock movements and torrents in the study area. Several solutions have been suggested for avoiding the risks related to the potential catastrophic movement of the rocks and torrents in the study area. The fractured rock masses at the top of scarp should be released either mechanically or manually. All buildings that were built on the slope surface of the scarp should be removed. Also, buildings which were constructed in the inlets of wadis and through the rain spillways should be removed. An unsafe boundary separating safe building borders from unsafe zone (with average width 50?m from the base of scarp) is delineated. As a result, resettlement for people living in this unsafe zone should be transferred to another safe area.     

Mode of formation of the Nile Gorge in northern Egypt: a study by DEM‐SRTM data and GIS analysis

This is an overview of the mode of formation of the Nile Gorge in northern Egypt. It is based on the interpretation of the Shuttle Radar Topography Mission (SRTM) data along with detailed analysis of landsat image, geological map and seismic data. The results show that the current course of the Nile was caused by a differential uplift of two plateaus: Ma'aza, to the east, and Western Desert plateau, to the west of the river. This uplift is caused by dynamic forces resulting from subsurface convection processes. It also contributed to the formation of several drainage systems, basins and structural features. Abundant faults and fractures that are parallel to the Nile Valley on both flanks that are associated with uplift are proven to be contemporaneous with formation of the river. We conclude that understanding of the uplift is crucial to visualizing the Nile course and its geodynamic formation. The information derived from the SRTM data reveals invaluable knowledge in support of the presented remotely sensed geological features. The paper clearly explains the stages of formation of the Nile segments in space and time and structural controls on the path of the Nile River in Egypt. Copyright © 2015 John Wiley & Sons, Ltd.     

福建明溪寒塘组地质特征及时代归属

福建明溪北部寒塘地区出露一套低绿片岩相浅变质岩系，原划分为中-上元古界下峰（岩）组。经1：5万区调和剖面研究，现已查明其空间层位在万全（岩）群之上，并伏于盖洋群之下，其岩石组合，原岩建造与其上覆及下伏岩石地层差异明显，具自身特点，厚度较大，且区内有一定延伸性，因此，作者新创建寒塘组，据其与上覆，下伏地层关系及及取得的930Ma单颗粒锆石U－Pb同位素年龄资料，将其时代归属青白口纪，该岩石地层单位的的建立及其时代确定，对闽西北前寒武纪变质岩地层划分，区域对比及构造研究具有重要意义。     

滇西保山地块南部公养河群研究新进展

保山地块是滇西特提斯多岛洋的重要组成部分,属滇-缅-马-泰微大陆的北端。出露的最老地层被称为公养河群,主要分布于保山地块南部酒房—旧城—大汪塘和镇安街—绕廊街—公养河—芒海—瑞丽2个片区,为一套厚度巨大的砂岩、长石石英砂岩-砂质板岩-泥质板岩组合,夹硅质岩、泥质硅质岩、薄层灰岩,具有典型的浊流沉积特征,部分地段有低级变质现象。公养河群中生物化石稀少,缺乏年代学依据,其时代被推测为震旦纪—中寒武世。近年来的1:25万、1:5万区域地质调查项目对公养河群进行了深入研究,在新发现的中酸性火山熔岩、凝灰岩夹层中获得了一批可靠的LA-ICP-MS锆石U-Pb年龄(925.0±9.2~499.2±2.1Ma)。结合岩性组合、沉积环境的差异,建议将公养河群自下而上细分为青白口—南华系大汪塘组、震旦系—中寒武统公养河组、上寒武统—奥陶系蒲满哨组3个组级岩石地层单元。主要介绍大汪塘组的分布、岩性组合、沉积环境、时代依据。     

Distribution of the energy release, b-values and seismic hazard in Egypt

A review of the seismicity and seismic history of Egypt indicates areas of high activity concentrated along Oligocene-Miocene faults. This supports the idea of recent activation of the Oligocene-Miocene stress cycle. There are similarities in the spatial distribution of recent and historical epicenters. Destructive earthquakes in Egypt are mostly concentrated in the highly populated areas of the Nile Valley and Nile Delta. Some big earthquakes located near the plate boundary as far away as Turkey and Crete were strongly felt in Egypt. The distribution of the energy release shows a possible tectonic connection between active zones in Egypt and the complicated tectonic zones in Turkey and Crete through geologically verified fault systems. The distribution of intensity shows a strong directivity along the Nile Valley. This is due to the presence of a thick layer of loose sediments on top of the hard rock in the Nile Valley graben. The distribution of b-values indicates two different zones, comparable with stable and unstable shelf areas. Stress loads in the northern Red Sea and northern Egypt are similar. Geologically, northern Egypt is a part of the Unstable Shelf area. The probability to have an earthquake with intensity V or larger within 94 years is more than 80% in the Nile Valley and Nile Delta areas, Egypt-Mediterranean coastal area, Aswan High Dam area, Gulf of Aqaba-Levant Fault zone and in the oil fields of the Gulf of Suez. The maximum expected intensity in these areas and within the same period is V–VI for a 80% probability and VII–VIII+ for a 10% probability. Intensity VIII–IX has been reported for several earthquakes in both historical and recent time.     

西昌盆地五峰组—龙马溪组页岩气保存条件研究

保存条件是影响页岩气富集高产的关键因素.本文综合利用地质、钻井等资料,分析了西昌盆地五峰组—龙马溪组的顶底板条件、构造特征、地层压力特征和气体组分,从宏观和微观两个方面对影响页岩气保存的主要指标进行了研究,在此基础上开展了西昌盆地保存条件综合评价.结果表明:盆地各凹陷主要由走滑-冲断带相隔,凹陷内地层缓倾,构造样式表现...     

老挝万象地区含盐系地层

老挝万象地区的含盐地层称为塔贡组(E1tg)。该组可划分为三个岩性段,每个岩性段均由下部膏盐层、上部陆源碎屑岩组成,均属湖泊沉积。该套地层的介形虫属Sinocypris—Cypris(Cristocypris)—Parailyocypris组合、轮藻属Peckichara—Obtusochara组合,属古新统。岩石地层、生物地层及年代地层上,该组与我国滇西地区的勐野井组(Em)较为相似。     

The Kalaktash and Halvan assemblages of Permian fusulinids from the Padeh and Sang-Variz sections (Halvan Mountains, Yazd Province, Central Iran)

New Permian sections have been studied in the Halvan Mountains of Iran, northwestward of Tabas. In addition to the Chili, Sartakht, and Hermez formations established here earlier, the new Rizi Formation is distinguished, underlying deposits of the Triassic Sorkh Shale Formation. Conodonts, fusulinids, and smaller foraminifers found in the rocks date the formations. In particular, it is demonstrated that the Chili Formation bearing the Kalaktash fusulinid assemblage is of Sakmarian age. The age of the Halvan fusulinid assemblage from clasts in the breccia-conglomerate at the Sartakht Formation base is reevaluated, and it is shown to be late Sakmarian but not Asselian in age. The Bolorian-Kubergandian age is established for the greater part of the Sartakht Formation. Correlation of the sections studied with the other Permian sections in different regions of Iran showed their lithological and paleontological specifics as compared to the latter. On the other hand, the sections in question are surprisingly similar in both respects to sections in the Central Pamirs. Fusulinids of the Kalaktash and Halvan assemblages are figured in four plates, and five new species belonging to the genera Rugosochusenella, Benshiella, Parazellia, and Nonpseudofusulina are described.     

浙江湖州太湖南岸地热资源研究

浙江湖州太湖南岸有多处地热异常显示,异常点水温为25℃～31℃,水中的氟、偏硅酸和游离二氧化碳达到或接近国家医疗热矿水标准值,具有一定的开发利用价值。通过大量调查和以往地质成果资料的分析研究,建立了地热形成模式和热储概念模型,认为区内存在二叠系栖霞组、石炭系船山组和黄龙组灰岩以及泥盆系五通组、志留系茅山组砂岩两个热储层;北东向的学川—湖州、北西向的长兴—奉化和东西向的湖州一嘉善大断裂是区内的主要导热热构造,且近期有活动迹象,为地下热水的形成创造了条件;石炭系上统高骊组、二叠系龙潭组与堰桥组的页岩、泥岩,第四系的粘土层是良好保温层。研究成果对开发本区的地热资源有一定的参考价值。     

甘肃酒泉盆地营尔凹陷层序地层特征与岩性勘探目标

甘肃酒泉盆地营尔凹陷发育中生代陆相断陷沉积,沉积构造研究表明下白垩统具备形成岩性油气藏的石油地质条件,但前人对该区岩性油气藏勘探领域的研究较少,目前尚未开展针对岩性油气藏的勘探。借助东部陆相断陷盆地的成功经验,利用钻井、地震等资料,开展了层序地层研究;将区内下白垩统划分为4个三级层序,自下而上依次为赤金堡组下段层序（Ⅰ）、赤金堡组上段层序（Ⅱ）、下沟组下段层序（Ⅲ）和下沟组上段层序（Ⅳ）;重点对区内主要勘探目的层段赤金堡组上段（层序Ⅱ）和下沟组下段（层序Ⅲ）进行了体系域划分。各层序及体系域具有不同的岩性、电性及地震反射波组特征响应,在体系域格架内利用三维属性反演、地震相分析、切片等手段开展了沉积相和岩性圈闭识别研究,发现3个岩性圈闭,综合评价认为1号岩性体是本区岩性勘探的有利目标。     

The Valley and Ridge Province of eastern Pennsylvania—stratigraphic and sedimentologic contributions and problems

Many contributions that have led to a better understanding of Appalachian geology have resulted directly from work in the folded Appalachian Mountain and Great Valley sections of the Valley and Ridge physiographic province of eastern Pennsylvania. Disagreements have been common since H.D. Rogers first described the geology of the area in 1858. Many differing opinions still exist regarding the stratigraphy, structural geology, geomorphology, and glacial geology. The rocks in the area, which range from Middle Ordovician to Late Devonian in age, are more than 25000 feet (7620 m) thick. This diversified group of sedimentary rocks was deposited in many different environments, ranging from deep sea, through neritic and tidal, to alluvial. In general, the Middle Ordovician through Lower Devonian strata are a sedimentary cycle related to the waxing and waning of Taconic tectonism. The sequence began with a greywacke-argillite suite (Martinsburg Formation) representing synorogenic basin deepening. This was followed by basin filling and pro-gradation of a sandstone-shale clastic wedge (Shawangunk Formation and Bloomsburg Red Beds) derived from the erosion of the mountains that were uplifted during the Taconic orogeny. The sequence ended with deposition of many thin units of carbonate, sandstone, and shale on a shelf marginal to a land area of low relief. Another tectonic-sedimentary cycle, related to the Acadian orogeny, began with deposition of Middle Devonian rocks. Deep-water shales (Marcellus Shale) preceded shoaling (Mahantango Formation) and turbidite sedimentation (Trimmers Rock Formation) followed by another molasse (Catskill Formation).     

滇西南耿马弄巴地区南皮河组层型剖面地层层序、时代的重新认识

对前人建立的上二叠统南皮河组的层型剖面——弄巴剖面进行了详细研究 ,发现该地层属于一套被动大陆边缘浊积岩为主的沉积岩系 ,可概括为四种层序类型特征 :一为代表浊流沉积的鲍马序列 ;二为由泥质岩与岩屑石英 (杂 )砂岩透镜体 (层 )构成的水道沉积序列 ;三为由薄层状砂岩与泥岩呈韵律状互层构成的浊流远端低密度流序列 ;四为薄层状硅质岩与硅质泥岩呈韵律状组成的基本层序。该组中采获了低等蕨类植物、牙形石和笔石等化石 ,证实其时代属于早泥盆世—晚泥盆世。根据该地层的岩性组合、沉积环境等特征及区域对比 ,应归于泥盆系温泉组。     

The environment and evolution of an early egyptian urban center: Archaeological and geochemical investigations at hierakonpolis

We describe and summarize the results of new interdisciplinary techniques for recovering and analyzing historical and paleoenvironmental data from mid-Holocene archaeological and geological deposits in the modern Nile floodplain at the site of Hierakonpolis in Upper Egypt. Application of these techniques has produced the first stratigraphic link between historic (Early Dynastic) and late prehistoric (Predynastic) periods in the Nile Valley at a site which played a central role in the evolution of Egyptian civilization.     

Upper Ordovician chitinozoans from the Cedarberg Formation of South Africa. Preliminary note

Chitinozoans bracket the geological age of the Soom Shale at the base of the Cedarberg Formation of South Africa as Lower Silurian to Upper Ordovician whereby the oldest age is the more probable. On account of the organic eometamorphism the most likely maximum depth of burial of the Soom Shale was slightly in excess of 5000 meters.     

Environmental geological investigations at the Van open dump site, southeastern Turkey

 This study evaluates the geological, hydrogeological and hydrological conditions at the open waste dump site of the Van municipality in eastern Anatolia, Turkey. A geological map and a three-dimensional view of the project site have been prepared. All lithological units exposed at and near the dump site have been determined and their boundary relationships identified. Drainage basin characteristics of the dump site along with the water bearing properties of different lithological units have been assessed. For the rehabilitation of the existing dump site, material availability (clay as a liner, cap, and daily cover material; granular soil as a filter material) has been researched. Based on the geological, hydrogeological, morphological and hydrological conditions of the existing waste dump site, recommendations to minimize its environmental impact are presented. Received: 8 March 1999 · Accepted: 3 May 1999     

Rejuvenation of dry paleochannels in arid regions in NE Africa: a geological and geomorphological study

Although the River Nile Basin receives annually ca. 1600 billion cubic meters of rainfall, yet some countries within the Basin are suffering much from lack of water. The great changes in the physiography of the Nile Basin are well displayed on its many high mountains, mostly basement rocks that are overlain by clastic sediments and capped by volcanics in eastern and western Sudan. The central part of the Nile Basin is nearly flat including volcanics in the Bayuda Mountains and volcanic cones and plateaus in southwestern Egypt. The high mountains bordering the Nile Basin range in elevation from 3300 to 4600 m.a.s.l. in the Ethiopian volcanic plateau in the east to ca. 3070 m.a.s.l. in the western Gebel Marra, and 1310 m.a.s.l. in the Ennedi Mountains in northwestern Sudan. In central Sudan, the Nile Valley rises approximately 200–300 m.a.s.l. In Egypt, the River Nile is bounded by the Red Sea Mountains in the east, assuming ca. 1000–2600 m.a.s.l., mostly of basement rocks, which are covered to the north of Aswan by Phanerozoic sediments sloping to the west, passing by the Nile Valley and continuing through the Western Desert. The Phanerozoic cover on both sides of the Nile is known as the Eastern and Western Limestone Plateaus. These plateaus assume elevations varying from 300 to 350 m.a.s.l. near the eastern bank of the Nile to 400–500 m.a.s.l. south Luxor at Esna and west of Aswan. The nearly flat Sahara west of the Nile Valley rises gradually westward until it reaches Gebel Uweinat in the triple junction between Egypt, Sudan, and Libya. Gebel Uweinat has an elevation of 1900 m.a.s.l. sloping northward towards the Gilf Kebir Plateau, which is 1100 m.a.s.l. The high mountains and plateaus in the southern and western Egypt slope gradually northward where the Qattara Depression is located near the Mediterranean coast. The depression is ?134 m.b.s.l., which is the lowest natural point in Africa. All these physiographic features in Sudan and Egypt are related to (i) the separation of South America from Africa, which started in the Late Paleozoic and continued up to the Cretaceous, giving rise to several generally E–W-oriented tectonic features inside Africa, (ii) the uplift of the Red Sea Mountains and their continuation inside Africa resulted in the East African Rift System (EARS), (iii) the Guinea–Nubia Lineament crossing Africa from the Atlantic to the Red Sea where many havoc trends, mostly E–W-trending faults, and uplifted basement features pierce the overlying sediments, (iv) parallel and longitudinal structures associated with volcanic plateaus and cones extend from west Sudan (Gebel Marra) to Ethiopian Plateau, passing by volcanics and plume features in between and the basins in east Africa were subjected to wrench related inversions, and (v) the Sudd linear E–W area stretching more than 1000 km between Gebel Marra in the west, passing by South Sudan and reaching southwestern Ethiopia. Here, fluviatile and subsurface waters led to ponds, lakes, and wet areas that are hard to exploit. The impact of these features led to the present south to north River Nile, but passing by many changes in the direction of its many tributaries and slope reversal of some of the major extinct rivers, either sectors of the main Nile or the rivers once flowed into the main river. The paleoclimatic changes during the Quaternary period: wet and dry have a great effect on the physiographic features and slope reversal of the Nile Basin drainage system.