Number Of Thin Sections Research Articles

Porosity and Permeability Measurements Integration of The Upper Cretaceous in Balad Field, Central Iraq

The corrected porosity image analysis and log data can be used to build 3D models for porosity and permeability. This can be much realistic porosity obtainable because the core test data is not always available due to high cost which is a challenge for petroleum companies and petrophysists. Thus, this method can be used as an advantage of thin section studies and for opening horizon for more studies in the future to obtain reservoir properties. Seventy-two core samples were selected and the same numbers of thin sections were made from Khasib, Sa`di, and Hartha, formations from Ba-1, Ba-4, and Ba-8 wells, Balad Oilfield in Central Iraq to make a comprehensive view of using porosity image analysis software to determine the porosity. The petrophysical description including porosity image analysis was utilized and both laboratory core test analysis and well log analysis were used to correct and calibrate the results. The main reservoir properties including porosity and permeability were measured based on core samples laboratory analysis. The results of porosity obtained from well log analysis and porosity image analysis method are corrected by using SPSS software; the results revealed good correlation coefficients between 0.684 and 0.872. The porosity range values are 9-16% and 9-27% for Khasib and Sa’di in Ba-1 Well, respectively; 10-21%, 9-25%, and 16-27% for Khasib, Sa’di and Hartha in Ba-4 Well, respectively; and 11-24% and 15-24% for Khasib and Hartha in Ba-8 Well, respectively according to petrographic image analysis. By using the laboratory core analysis, the porosity range values are 12-26% and 17-24% for Khasib and Sa’di in Ba-1 Well, respectively; 6-28% and 14-27% for Sa’di and Hartha in Ba-4 Well, respectively; and 17-19% and 15-24% for Sa’di and Hartha in Ba-8 Well, respectively. Finally, the well log analysis showed that the porosity range values are 11-16% and 7-27% for Khasib and Sa’di in Ba-1 Well, respectively; 4-18%, 21-26%, and 16-19% for Khasib, Sa’di and Hartha in Ba-4 Well, respectively; and 9-24% and 15-23% for Khasib and Hartha in Ba-8 Well, respectively. The permeability range values based on laboratory core analysis are 1.51-8.97 md and 0.29-2.77 md for Khasib and Sa’di in Ba-1 Well, respectively; 0.01-24.5 md and 0.28-6.47 md for Sa’di and Hartha in Ba-4 Well, respectively; and 0.86-2.25 md and 0.23-3.66 for Sa’di and Hartha in Ba-8 Well, respectively.

Entire-volume Serial Histological Examination for Detection of Micrometastases in Lymph Nodes of Colorectal Cancers

The purpose of this study was to accurately detect lymph-node micrometastases, i.e., metastatic cancer foci that have a size between 2.0 and 0.2 mm, in nodes excised from colorectal cancer (CRC) patients, and to determine how frequently micrometastases might be missed when standard histological examination procedures are used. A total of 311 lymph nodes were removed and examined from 90 patients with Stage I to IV CRC. The number of slices of histology sections ranged from 6 to 75 per node (average = 25.5; SD = 11.1), which provided a total of 7,943 slices. Lymph nodes were examined in their entire volume at every 50-μm and 100-μm intervals for nodes smaller and larger than 5 mm respectively. The total number of thin sections examined in each node and the number of thin sections where metastatic foci were present were counted. The number of thin sections with metastatic foci and the total number of slices was determined for each node. In addition, the presence or absence of metastatic foci in the "central" slice was determined. Micrometastases were found in 12/311 (3.9%) of all lymph nodes. In the 12 lymph nodes with micrometastases, the rate of metastatic slices over all slices was 39.4% (range = 6.3 to 81.3%; SD = 25.8%) In the central slice of each node, micrometastases were present only in 6 of 12 lymph nodes (50%); accordingly, they were not present in the central slice for half the micrometastatic nodes. These 6 nodes represented 1.9% of the 311 nodes and 11.1% of the 54 metastatic nodes. This study suggests that a significant fraction of micrometastases can be missed by traditional singleslice sectioning; half of the micrometastases would have been overlooked in our data set of 311 nodes.

The Central Asiatic (Tibet, Xinjiang, Pamir) petrological collections of Sven Hedin (1865–1952) — Swedish explorer and adventurer

During a 42 year period (1893–1935), the Swedish explorer Sven Hedin led and co-ordinated four expeditions to remote and inhospitable parts of Central Asia (Tibet, Xinjiang, Pamir). Along with collaborators he collected a diverse collection of just under 3100 petrological specimens. Petrographic examples of high pressure metamorphic blueschists, mantle peridotites and serpentinites, granitoids, K-rich alkaline lavas, mylonites, and a range of clastic and fossil rich carbonate sedimentary rocks are present. This collection is a major asset for scientists studying the history of continental collision between India and Asia, and the uplift of the Tibetan plateau.A spreadsheet listing all the samples collected during Hedin's first three expeditions into Tibet (commencing 1893, 1899, 1906) includes a brief description and location of each specimen, with additional information on the availability of thin sections. Samples are cross-referenced with the geographical position of Hedin's campsites indicated on maps published with his extensive reports. Most samples, and a number of thin sections, are available for loan from the Swedish Museum of Natural History, Stockholm. We also describe a smaller collection of specimens and thin sections from Hedin's fourth (1927–35, Sino-Swedish) expedition, currently housed at the Institute of Earth Sciences, Uppsala University. Hedin's career as an explorer, highlighting the geological significance of his work and the reasons that it has remained largely ignored by the majority of Himalayan and Central Asian researchers for so many years, is outlined.

CONGO RED STAINING ON 1 MICRON DE-PLASTICIZED SECTIONS FOR DETECTION OF LESIONS IN ALZHEIMER??S DISEASE AND RELATED DISORDERS

Neuritic plaques (NPs), neurofibrillary tangles (NFTs) and congophilic angiopathy (CA), the three characteristic lesions in Alzheimer's disease, are easily detected in paraffin sections using light microscopy and specific staining methods including Congo red and Thioflavin S. Identification of these lesions in plastic thick sections (1 micron) is more tedious and relies essentially on morphological criteria. This causes investigators to subsequently analyze large numbers of thin sections under the electron microscope. Since many researchers use electron microscopy for various aspects of Alzheimer's disease and related research, it would be advantageous to have a rapid method enabling the investigator to quickly and reliably identify in thick sections the characteristic NPs, NFTs and/or CA, which can then be used for further analysis at the ultrastructural level. In this context, the present study describes a dependable technique for identifying NPs, NFTs and/or CA in Alzheimer's disease and related disorders and involves Congo red staining on one micron sections after plastic removal.

Magnetic fabric analyses in the Gail Galley (Carinthia, Austria) for the determination of the sense of movements along this region of the Periadriatic Line

Magnetic fabric analyses on a large suite of rocks from the Gailtal (Gail Valley) crystalline basement (“Gailtalkristallin”) from Lesachtal (Lesach Valley) and upper Gailtal (Carinthia, Austria) have been carried out in order to determine the sense of movements along this east—west section of the Periadriatic Line. The magnetic fabric data indicate that this section of the Line is a shear zone with mean-susceptibility anisotropies around 30%. The susceptibility ellipsoids are strongly oblate with very accurately defined foliation planes and minimum axes orientations. These minimum axes orientations were compared with those of the mica c- axes , which are assumed to reflect the directions of maximum shortening, to verify that the magnetic fabrics reflect the strain fabric of the region. A number of thin sections from randomly selected cores were studied and the groupings of the mica c- axes were found to give excellent agreement with the magnetic minimum axes orientations. The fabric data were used to build up a piece-meal movement model of the shearing along the study profile. Localised units indicate sinistral movements along the shear zone but the overall movement along this section of the Periadriatic Line is dextral. The degree of deformation and the sense of action of the deforming forces are presented in a tectonic model of the Periadriatic Line.

Relationships between particle size, fabric and other factors in some Australian soils

Soil fabrics at the level of related distribution of f-matrix (usually finer material) to f-members (usually coarser units) are considered in relation to particle size distribution for a number of randomly selected Australian profiles. Three major fabric continua are recognized: the chlamydic iunctic and matrigranic sequences. The majority of samples in the first two sequences have ratios of clay to silt greater and less than one, respectively, and successive stages correlate with increasing proportions of silt plus clay; fabrics of samples that fall out of sequence in relation to percentage of silt plus clay are explained on the basis of composition and/or specific processes, especially fine-grained carbonates, organic matter, faunal activity, and illuviation. The matrigranic sequence does not correlate with particle size distribution, but seems to be related to composition and/or specific processes such as faunal activity. The usefulness of the results lies in the possibility of using the conclusions to reduce the number of thin sections required to characterize areas of soil, particularly within restricted areas.

An oriented plastic slicing guide for facilitating stereotaxic interpretations in brain sections.

A rigid plastic cutting guide for whole brains in which the interior conforms to the contours of the interior base of the cranial cavity was molded from plastic that sets at room temperature. The mold was poured in a glass staining dish surrounding a wax-coated plaster cast of the floor of the skull. Both the casting and the molding processes were carried out in a stereotaxic apparatus to insure proper alignment. The molded box supports the brain in correct stereotaxic alignment, and vertical slits sawed at 5 mm intervals along the width of the box allow the passage of a blade through the brain. The resulting tissue slabs are of uniform thickness and can be easily correlated with the coronal planes shown in stereotaxic atlases. This inexpensive cutting device reduces the number of thin sections lost between tissue blocks, an important consideration when tracking degenerating nerves.

A petrochemical survey of plutonic intrusions in the Piedmont, Southeastern Appalachians, U.S.A.

This paper presents a summary of chemical and mineralogical data on intrusive igneous rocks in a segment of the Southern Appalachian orogenic be]~. The exposed crystalline part of the Southern Appalachians reaches a maximum width of about 300 km in North Carolina and South Carolina and narrows along strike to the northeast and southwest (Fig. I). We have attempted to delineate the major groups of intrusions in this segment. Few detailed studies or discussions of differentiation trends shown by intrusive rocks in this region have been published previously. The purpose of this paper is: (1) To give the general characteristics and distribution of major groups of p]utons. (2) To define the chemical trends in major elements that are exhibited by the groups and (3) to discuss the origin of the intrusive rocks and their role in the evolution of the Southern Appalachians. Major element analyses by rapid methods were made of 198 selected samples. Chemical methods, and precision and accuracy of analyses are the same as described by RAGLA~D et al. (1968). The chemical analyses were performed by a combination of atomic absorption and x-ray spectrometry. All chemically analyzed samples, except for 27 that are very fine-grained, were also modally analyzed. The point-count method of CHAu (1956) was used for fine- or medium-grained rocks. About 1500 points were counted over an area large enough to maintain an analytical error for major minerals of 2 % or less (CHAYES, 1956, p. 82). Where average grain size is greater than about 5 ram, the required number of thin sections becomes prohibitively large; therefore, slabs stained with sodium cobaltinitrite were also used. A slab area at least 100 times greater than the area of the largest mineral grain was used, and 1000 to 1500 points were counted. A point count of two to four thin sections was used to determine the approximate percentage of biotite, sphene, opaque minerals and other minerals in the "dark minerals" category obtained from the slab count. Rock names are used as defined in the descriptive modal classification of PETEI~SON (1961). Modern, large-scale geological maps are available for only a small percentage of total area in the c;ysta]line Southern Appalachians. It will take considerably more mapping, petrographic and chemical studies, and determination of radiometrie ages to decipher the complex intrusive history of the region. We present here a first approximation, which will undoubtedly be modified by later studies.

Some properties of resistance-grown pyrolytic graphite

A bar of pyrolytic graphite, grown at a constant surface temperature of 2200°c by resistance heating of the substrate, was cleaved into a number of thin sections; crystallographic and a-direction thermal and electrical measurements were made as a function of distance through the deposit. These properties were found to vary in a systematic way consistent with the increased substrate temperature to be expected in this method of growth. The temperature profile through the deposit was estimated, yielding a substrate temperature of 3050°c for a deposit 24 mm thick. Comparison of the electrical properties with other workers' results on pyrolytic graphites annealed at known temperatures gives adequate confirmation of the estimated temperatures and shows that resistance-grown graphites may be used to measure a-direction properties of material effectively annealed at temperatures much in excess of the surface deposition temperature.

TEXTURE AND TOPOGRAPHY OF VOLCANIC ASH BEDS

This paper deals with the effects of agency of soil erosion working on the texture of volcanic ash beds. The surveyed area is the northeastern foot of Asama Volcano. In this area, heavy rainfalls during the rainy season wash down large quantities of soils from the ground surface and deposit them in lower parts of the land. Minor external agencies such as corrasion and deposition due to rain wash accelerate erosion of soils, and degradation, though on a samall scale, is fairly active. As a result, perpetual cultivation becomes impossible where the topography is such that illustrated in Fig. 2 and 5. The writers selected some localities where the effects of such minor agencies are distinctly observed, and carried out topographic measurementand investigation of sedimentational conditions and texture of volcanic ash beds, and contem-pl.ated on the land degradation. The localities are indicated in Fig. 1 and 4. Samples of the black ash right below point A in Fig. 2 and Fig. 5 were collected in a vertical cylindrical form. After solidified, the samples were made into thin sections, which were prepared in the horizontal and the vertical (to the bedding plane) directions at 3 to 5cm intervals. Therefore, the number of thin sections merely for the samples below point D in Fig. 2 amounted to about 90. The study of the texture of these numerous thin sections has revealed the following facts. The black ash comprises several beds of a common texture. Apparently these beds constitute one stratum, but actually they are made of several thin layers differing in texture. The difference in texture has probably resulted from differing degrees of agency, i, e., extent of rain wash which takes place in every rainfall. The micrographic photo shows a thin section cut vertical to the bedding plane. The section represents the texture of the thin layer in the thick black ash. The layesrs are thicker at the base of the slopes and their texture is granular in most cases. Under the microscope, the layers are found to contain minute grain of brown volcanic ash. Thus, from the thickness of volcanic ash beds in outcrops, the status of cultivation on the ground surface (the number of years of cultivation), and from the environment of the black ash sedimentation as revealed by the texture, it has become known that the action of degradation is unexpectedly strong and quick in the areas composed of soft sedimentary beds.

The Occurrence of Authigenic Feldspars in Sediments

ABSTRACT Authigenic feldspars in sediments have been reported by a number of workers from many geologic horizons, but the opinion prevails that such feldspars are relatively uncommon. Most investigators have concluded that the authigenic growths occurred during the deposition or early consolidation of the containing sediments. The authors have studied a large number of thin sections and insoluble residues and conclude that authigenic feldspars occur in many types or rocks from Cambrian to Cretaceous in age, and that in certain instances the evidence indicates that growth occurred after consolidation of the rock and during a period of replacement by meteoric waters. Feldspars are common in limestone and dolomite, and in some arenaceous beds the feldspar is known to constitute about 30 per cent f the fine grades.

VI.—Notes on the Witwatersrand Beds, Transvaal

In discussing a paper by Mr. J. S. Curtis on the Witwatersrand Gold Deposits, Mr. George Denny has raised the point that the slates or shales of the Witwatersrand, which especially characterise, but are not confined to, the Lower Witwatersrand Beds (Hospital Hill Series), are not of sedimentary, but of igneous origin. He relies chiefly on the fact that he has observed in places that a so-called band of slate cuts across the bedding of the quartzites. I think we are all prepared to agree with him that, where he can point out that this occurs, the rock which traverses the bedded formation must be an igneous intrusion; but such cases are rare. In the vast majority of sections where the slates are exposed, they are found to occur truly bedded, and in conformable relation with the quartzites with which they are associated. It seems to me that, after all, this is in the main a petrological question, which can be easily settled by the examination of the rocks in question under the microscope.With this end in view I have examined a number of thin sections of these rocks, in all cases prepared from the cores of boreholes, on account of the difficulty of obtaining near the surface specimens sufficiently fresh and unweathered for microscopic examination; and I have selected geological horizons which are well known on the Witwatersrand. They are (1) the band of slates which occurs in the neighbourhood of the Bird Reef Series, and (2) the slates which occur in the footwall of the Main Reef itself, in both cases in the eastern portion of the Witwatersrand, as at Van Ryn and Geduld.

1. On the Structure of the Skeleton of Tubipora musica, and on the Relation of the Genus Tubipora to Syringopora

The object of the present communication is to briefly consider the general and minute structure of the corallum of the recent Tubipora musica, with special reference to the association of the genus Tubipora with the extinct genus Syringopora, as advocated by many modern naturalists. The method of inquiry that I have pursued in carrying out this investigation has been principally that of preparing similar thin and transparent sections of both the recent and the extinct types; and though there are special difficulties in the way of any examination of Tubipora by this method, I have been able to overcome these in a satisfactory manner, and to prepare a number of thin sections which answer all the requirements of the case.