Strata Dip Research Articles

Water Flooding at Inclined Reservoirs (No. 1)

It is characteristic of the oil fields in Japan that strata are steep and reservoirs are limited. Therefore, the study of water flooding at limited and steep oil reservoirs is very significant, especially in our country. The writer tried to analyse the up-dip flooding where producers are directly opposite to injection wells (cf. Fig. 1.) from the viewpoint of solving the boun-dary-value problem for the 2-dimensional, steady flow of single and incompressible fluid through porous media. Thus the derived results for the pressure distribution; the relation between well pressures, injection (or production) rate and dip of strata; the loss of flow capacity against the gravity; and the sweep efficiency are (6) or (7); (10), (15) or (16); (17) or (18); and (24) or (25), respectively.

Intraformational Contorted Rocks in the Upper Carboniferous of the Southern Pennines

Summary Beds of contorted shale, both overlain and underlain by normally bedded shale, occur in the Millstone Grit and Lower Coal Measures of the Goyt Trough to the west of Buxton. A brief synopsis of the geology of this area is given. The beds of contorted shale, usually from 6 inches to 2 feet 6 inches in thickness, are remarkably constant in horizon throughout the area; the majority directly overlie marine bands, but at least two are unassociated with these fosailiferous shales. Structures discernible within the contorted beds comprise sheer-planes and small folds. On each limb of the Goyt Syncline both the axial planes of the small folds, and the shear-planes, clip towards the major axis at an angle greater than the stratal dip. Wherever the pitch of the small folds can be observed it is northerly, in the same direction as the pitch of the major fold. Contacts of the contorted beds are almost invariably plane surfaces, often polished or bearing slickensides running along the line of dip. The contorted shsles are considered to be of tectonic origin and to be an expression of adjustment through bedding-plane slip during the folding of a succession of rocks of varying competency. It is thought that shearing, resulting from bedding-plane slip, affected the least competent beds in the succession. Shear-planes are interpreted as fracture cleavage and the small folds as congruous drag-folds. Similar beds of contorted shale occur at some of the same horizona on the borders of the North Staffordshire Coalfield and in Lancashire.

Survival and Growth of Shrubs Planted for Wildlife in New York

The ability to control plant cover is a basic requirement for successful wildlife management. Such control implies not only the power to maintain cover types already in occupancy, but to replace one type with another at reasonable cost and with certainty of results. Based on long experience, in both the United States and Europe, there have been developed satisfactory techniques for planting the hardier softwood species. The site requirements of the more exacting hardwoods, especially foodbearing trees and shrubs necessary for development of good wildlife habitats, are imperfectly understood. Some of the most serious wildlife management problems are presented by 3,000,000 acres of abandoned farmland scattered through the Allegheny Plateau in New York State. This is a deeply-dissected tableland west of the Hudson Valley and Catskill Mountains and south of the Mohawk Valley and Lake Ontario plain (Fig. 1). The region is underlaid by unaltered sedimentary rocks-shale, sandstone and some limestone-and the flat-bedded strata dip gently to the southwest. Much of the drainage follows the tilt of the rocks southward, into the Delaware, Susquehanna and Allegheny river systems; the remainder flows north into the Finger Lakes, Lake Ontario, and the Mohawk River. The broad, flat-topped summits seldom exceed 2,000 feet in elevation and are separated by narrow and steep-sided valleys. The soils are mostly stony loams, derived from the underlying rocks and altered by glaciation, and are acid save where modified locally by calcareous material in the subsoil or substratum. Exploitive agriculture has

Influence of Contrasted Soil Types Upon Changing Land Values Near Grapevine, Texas

L fe FIG. 1. Location of the Grapevine Area. Grapevine, the two lower members of the Upper Cretaceous system outcrop in parallel north-south beds. The strata dip southeasterly exposing the younger Eagle Ford shale along the eastern border of the county and bringing to the surface the underlying Woodbine sandstone immediately west of the shale (Fig. 2). The soils that have developed from these two formations contrast widely in appearance and composition. The shale constitutes the parent material for a black, calcareous, clayey soil, while the sandstone holds a similar relation to a reddish, non-calcareous, sandy and stony soil. The contact between the formations is clearly marked by a change in soil color and an equally striking contrast in natural vegetation. In their virgin condition the calcareous, clayey soils were occupied by tall prairie grass studded with scattered clumps of mesquite trees; the non-calcerous, sandy soils were heavily timbered with post oaks and black-jack oaks.

Wilmington Oil Field, Los Angeles County, California

The Wilmington oil field, located 20 miles south of Los Angeles and adjacent to the Los Angeles Harbor, is one of the largest oil fields discovered in California. Oil was first produced in January, 1932, from the Lower Pliocene formation. The General Petroleum Corporation's Terminal No. 1 was the first large well and was completed in December, 1936, with an initial production of 1,500 barrels per day, 20.5° A.P.I. gravity, from the Puente formation (Upper Miocene) at a depth of 3,625 feet. Discovery was made by correlation of outpost wells together with a seismograph survey which added materially to the general outline of the structure. The structure is an irregular-shaped dome with faulting transverse to the principal axial trend. The dip of strata ranges from 2° to 15°. The major faulting apparently occurred near the close of Miocene time and continued progressively throughout deposition of the Repetto formation (Lower Pliocene). Production is obtained from the Repetto formation (Lower Pliocene) and the Puente formation (Upper Miocene). There are five producing zones: Tar, Ranger, upper Terminal, lower Terminal, and Ford. The gravity of oil ranges from 12° to 31°. The lower 700-800 feet of Pliocene and 2,500 feet of Miocene formation contain oil and gas at different stratigraphic levels. The field has produced a total of 17,608,495 barrels of crude oil from discovery date, December 7, 1936, to February 15, 1938, inclusive. Recent development in the City of Long Beach has increased the proved area from 2,100 acres to 3,200 acres. Production on March 2, 1938, was 101,382 barrels daily from 374 wells with a large part of proved area undeveloped.

The Geology of the Eastern Half of the San Joaquin Hills, Orange County, California: ABSTRACT

With the exception of the Pleistocene terrace deposits, all of the sedimentary rocks exposed in the San Joaquin Hills are Tertiary in age. The Tertiary section has a thickness of about 5,000 feet and is correlated with rocks of Sespe, Vaqueros, Topanga, San Onofre, and Puente formations. The dip of strata is thought to be largely due to the action of normal faulting, rather than folding. Basic lavas are found intruded as dikes along or near the planes of many of the larger faults. While the age relationship between the faulting and the intrusion is not clear, it is thought that they are in part contemporaneous and that both are, at least, pre-Pleistocene in age. It is suggested that the present topography of the hills has resulted from a gentle northward tilting of the ar a occurring in Pleistocene and Recent time End_of_Article - Last_Page 1519------------

A semigraphical method of determining depths of multilayer dipping strata from seismic time-travel curves

A semigraphical method of determining depths of multilayer dipping strata from seismic time-travel curves

The Pleistocene Crustal Movements and the Inclination of Coastal Terraces on the Southeastern Kyûsyû

In his previous papers, the writer has shown a peculiar contrast of the geoglogic structures of the lower Pliocene strata inn the Fossa Magna and in the outer zone of southwest Japan. And' he has concluded that. the structural lines of the.. lower Pliocene deposits do not conform with the general trend lines of the Honsyu arc or with the main structural lines of the outer zone of southwest Japan, but with the trend of the contour lines of the summit level in the outer zone of southwest Japan, and that the attitude of the lower Pliocene strata wasere made by the Pliocene crustal movements. From the above conclusions, . he has called in question that the crust deformation of the similar tendency as in the Pliocene crustal movements may have been continued during the later geologic period. In this paper he takes note of attitude of the. lower Pleistocene deposits and the inclinations of 4 coastal terraces arranged in step. on the southeastern coast of Kyusyu. And he points out that the dips of strata and the inclinations of the terraces are the older, the steeper they incline towards E. or EES., and the crustal movements of the similar tendency have been continued or repeated in these districts since the early Pliocene age. And he inclines to conclude that the recent structural features of the lower Pliocene deposits in the outer zone of southwest Japan may represent the total result of the crust deformations accumulated slowly since the early Pliocene age.

On the Nature and Origin of the Stylolitic Structure in Tennessee Marble

The stone known commercially as constitutes what the government geologists have called the Holston formation, which is of Ordovician age. The quarries are located chiefly in the central portion of the East Tennessee Valley with Knoxville as a center. The marble is sub-crystalline to crystalline in texture and varies in color from light pink and gray to differing shades of red, dark chocolate, and cedar. At present the light pink and gray are the varieties most in demand. The formation is from 200 to 400 feet thick, though by no means is all of this suitable for decorative purposes. As a result of folding, accompanied in places by faulting, the outcrops occur in belts extending from northeast to southwest. The strata dip usually 25 to 35 'Read before the Tennessee Academy of Science, November 26, 1915, and the American Association for the Advancement of Science, Pittsburgh, December, 1917. (Abstract, Science, New Series, XLVII [1918], 492.)

Superficial dip of marine limestone strata; a factor in petroleum geology

Superficial dip of marine limestone strata; a factor in petroleum geology

I.—The Gulf of Suez

In a previous paper published in this Magazine, I gave reasons for the belief that neither the Gulf of Suez nor the valley of the Nile owes its origin to trough-faulting, as was at that time generally supposed. The skeleton of the argument was as follows:—1. Extensive faulting at the faces of the scarps of the Nile Valley and Gulf of Suez cannot be held to be evidence of trough-faulting, since the same can be observed along the scarps of the Wadi Araba, the structure of whose floor shows it to be an eroded anticline, and the faults along its scarp-faces to be merely huge landslips.2. The faulting observable immediately along the coast of the Gulf of Suez is of an exactly similar nature to that above mentioned, and along part at least of the gulf the strata dip away from the sea on the opposite coasts, leading to the inference that the Gulf of Suez is, like the Wadi Araba, an eroded anticline.3. If it be granted that the Gulf of Suez is not a trough-fault, the argument against the Nile Valley being a trough-fault is strengthened, the support of parallelism being removed.

III. Researches on the structure, organization, and classification of the fossil reptilia.—Part IX., section 6. Associated remains of two small skeletons from Klipfontein, Fraserburg

In 1888, in the ‘Phil. Trans,' B, vol. 179, I described some parts of the skeleton of Theriodesmus phylarchus . Its geological horizon was then unknown. In the following year I visited the locality where it was found, at Klipfontein, near Fraserburg, in Cape Colony, on the summit of the volcanic series of rocks the escarpment of which forms the Neiuwveldt range. As the base of the Karroo rocks at Prince Albert is fully sixty miles south, and the same strata dip towards the north, over all that distance, with some minor undulations in the southern part of the area, while the elevation of the surface of the country augments northward, Klipfontein holds a high position in the deposits of Permian age which are comprised in the Karroo formation. I had the advantage of the company of the late Mr. Thomas Bain, who conducted me to the farm of two brothers, E. and O. Erasmus, where the Theriodesmus was collected. But after an interval of more than twelve years, the effects of atmospheric forces in breaking and removing the surface rocks made it impossible to discover additional remains of that animal. We carefully explored the banks and bed of a dried stream which drains into the Orange River, where I met with fragments of two species of the ganoid fish, Atherstonia , which have been regarded by Mr. A. Smith Woodward as new species, but found nothing resembling Theriodesmus . Along that stream I found and collected fragments of two skeletons which appear to me to be referable to Theriodonts, though their position in the group is not certain. These fossils show the association of limb bones and vertebrae; and with them I found fragments of skulls, which may have belonged to the same animals; but the association should be made with caution, since it is unsafe to put together disconnected fragments of skeletons which may have been associated by transport, unless there is corroborative evidence that they belong to the same type of organization. These small animals in the character of the humerus are Marsupial in type. This character being associated with carnivorous dentition among existing animals, led me to anticipate the discovery of a skull showing canine teeth. Such dentition though poorly preserved, I found near by, in the bed of the river, associated with the back of the skull.

V.—On some Physical Changes in the Earth's Crust

On the western flanks of the Malverns, the Upper Silurians are folded in several great anticlinals and synclinals, formed parallel to the axis of the Hill itself. To the west of Ledbury and again near Woolhope these contorted strata dip beneath the Old Red Sandstone, which, as computed by Phillips, has a maximum thickness of 8000 feet, that of the Upper Silurians being 2690 feet.The thickness of the strata of which the Longmynd is formed has been estimated by the Government Surveyors at not less than 26,000 feet, as exposed in their highly inclined edges; the beds dipping at an average inclination of 60° to the W.N.W. They thus appear as if they had been tilted by pressure against the more ancient rocks of the Caer Caradoc Range.

II.—Graphical Methods in Field-Geology

In determining the actual position of strata from the appearances presented by their exposed edges in natural and artificial sections, certain mathematical problems are of constant occurrence. To a field-geologist who is not content with rough guesses founded on judgments by eye, the solution of these problems is a matter of importance, and methods have accordingly been given for some of those most frequently met with. These solutions take the form of (1.) trigonometrical formulæ, which can be applied only with the aid of trigonometrical and logarithmic tables; (2.) tables specially prepared from these formulæ for use in the field; (3.) graphical methods, requiring only a ruler, scale and protractor, which may be conveniently combined in one instrument. Of the first kind is the formula for deducing the true dip of strata from two apparent dips, given in Green's Geology (p. 341, 1st ed.), etc. Among special tables are those of Mr. Jukes for finding the apparent dip in any direction from the true dip, and for connecting the dip, thickness and depth of beds: these tables are given in the appendix to the Survey Memoir on the Geology of the South Staffordshire Coal-field, and reproduced in Jukes's “Manual of Geology.” Graphical methods have been used for finding the true dip from two apparent dips: a method partly graphical but requiring a table of cotangents is given in Phillips's “Treatise on Geology” (p. 298, 5th ed.), and also by the Rev. E. Hill (Geol. Mag. 1876, p. 334); a purely graphical method by Mr. W. H. Dalton (Geol. Mag. 1873, p. 332); and an approximate method by Mr. Penning (Geol. Mag. 1876, p. 236), reproduced in his “Field Geology.” As Prof. Green has pointed out (ib. p. 377), the last-named method is equivalent to taking the angle for its tangent, and so applicable only to small angles of dip. Mr. Dalton's solution (loc. cit. p. 334) of another question, to find the effect on strata already inclined of a second tilt in a new direction, is only an approximation, and cannot be applied if the dips are considerable. It is erroneously assumed that the inclination of the strata in a direction at right angles to that of the second tilt is unaltered by the tilting.

On the Passage-beds from the Upper Silurian Rocks into the Lower Old Red Sandstone, at Ledbury, Herefordshire

T he transition, or passage-rocks, which connect the Upper Silurian deposits with the basement-beds of the Old Red Sandstone epoch, are most interesting to the geologist; and as a very remarkable section of these rocks is now visible on the line of railway near Ledbury, in Herefordshire, a few notes with a sketch and section may be acceptable. In my communication on “The Old Red Sandstone of Herefordshire,” published in the Edinburgh New Philosophical Journal (April 1, 1859, p. 232), I expressed my opinion that the Ludlow sections on the horizon of the passage-beds above the Downton Sandstone are broken by faults, and that the true succession is therefore destroyed. I had come to this determination long before the beds now developed in the railroad-cutting at Ledbury were exposed to view; and, having again lately visited Ludlow, and compared the passage-rocks of that district with those of Ledbury, I am convinced that nowhere perhaps in the world is there such an exhibition of passage-beds presented to the eye of the geologist as at the Ledbury tunnel, on the Worcester and Hereford Railway. Fortunately most of the passage-beds are laid open to the sunlight, and the important points exposed. When engaged upon the section, I was accompanied by my friends Mr. Edmond Richards, and the Messrs. Ballard, the Engineers on the Worcester and Hereford Railway, to whom I return my best thanks for their hearty and efficient cooperation. The strata dip at an angle of 71° north-by-west. The accompanying sketch (see fig.

On the Geology of Lycia.

The district explored by the authors extends over two degrees of longitude and one of latitude. It is chiefly occupied by a series of alpine plains and mountain ridges, broken up by four great valleys, which open seawards. The mountain mass of Cragus rises to 7500 feet, that of the Lycian Taurus to 7000 feet, that of Massicytus to 10,000, Soosoos-Dagh to 7000, and Mount Solyma to 7000. The plains or yailahs which these mountain ridges wall in, vary in elevation from 2000 to 6000 feet above the sea. They have no outlets; the rivers which water them pour into caverns, and reappear again at the bases of the mountains in the low country near the sea. Geologically, they appear to be valleys of elevation. sedementary rocks .—The oldest stratified rock in Lycia si the Scaglia or Apennine limestone , usually referred to the cretaceous epoch. It forms the great mass of the country and the highest mountains, 10,000 feet above the sea; it is usually a cream-coloured compact limestone, sometimes a gray or pink stone of looser texture, and in place brecciated. In Milyas it degenerates into soft chalky limestone, resembling chalk, and difficult to distinguish from the freshwater tertiary limestones. Near Lake Caralitis the harder and softer beds of the scagli are interstratified : the more compact scaglia is usually very thick-bedded. The strata dip at all possible angles, and are often much disturded and contorted : the dip is generallyfrom the axis of the mountain chains. Fossils are very

VI. Description of a Fossil Tree found in a Quarry at Niteshill, the Property of Colonel Dunlop of Househill

The quarry of Niteshill, from which this very interesting petrifaction was taken, lies about three miles south-east of Paisley, and is part of a coal formation. It consists of white sandstone, which in many parts is deeply stained by an impregnation of iron. Two very thin seams of excellent coal occur immediately under the sandstone, with the intervention of a few feet of till or blaize. The strata dip to the south, and crop out about a hundred yards north of the spot from whence the tree was taken. At this spot the face of rock is about sixteen feet; fourteen feet above the tree, and one under; another foot being occupied by the stem itself.The part which has been detached from the rock consists of stem and roots, five feet of stem, and two of roots, different views of which I have endeavoured to represent in figures 1, 2, & 3.

LXV. On the impropriety of assigning new meanings to the established Marks used in science: and on observing the directions and dips of Strata

"LXV. On the impropriety of assigning new meanings to the established Marks used in science: and on observing the directions and dips of Strata ." The Philosophical Magazine, 38(163), pp. 356–357