Permian Series Research Articles

Palaeozoic deformation and magmatism in the northern area of the Anatolide block (Konya), witness of the Palaeotethys active margin

The study area, located north of Konya (Central Turkey), is composed of Silurian to Cretaceous metamorphosed rocks. The lower unit of the oldest formation (Silurian-Early Permian) is mostly made up of Silurian-Early Carboniferous metacarbonates. These rocks pass laterally and vertically to Devonian-Early Permian series having continental margin, shallow water and pelagic characteristics. They are intruded or juxtaposed to different kinds of metamagmatic rocks, which show MORB, continental arc and within plate characteristics. The Palaeozoic units are covered unconformably by Triassic-Cretaceous metasedimentary units. All these rocks are overthrusted by Mesozoic ophiolites. The Palaeozoic sequence can be seen as a northern Palaeotethys passive, then active margin. The northward subduction of the Palaeotethys ocean during the Carboniferous-Triassic times, induced the development of a magmatic arc and fore-arc sequence (Carboniferous-Permian). Before the Early Triassic (?Late Permian) time, the fore-arc sequence was uplifted above sea level and eroded. The Triassic sequences are regarded as marking the onset of back-arc opening and detachment of the Anatolian Konya block from the active Eurasian margin. Finally, a suture zone formed during the Carnian between the Konya region and the Menderes- Tauride Cimmerian block due to the closing of Palaeotethys. This geodynamic evolution can be correlated with the evolution of the Karaburun sequence in western Turkey.

Control of Permian and Triassic faults on Alpine basement deformation in the Argentera massif (external southern French Alps)

Abstract Structural investigations reveal intense and heterogeneous deformation of the sedimentary cover attached to the basement complex of the southern Argentera and Barrot massifs (southernmost External Basement Massifs of the French Alps). Permian and early Triassic syn-depositional extensional tectonics imparted a tilted block pattern to the massifs. An early Miocene first stage of Alpine compression caused pervasive cleavage. This cleavage was controlled by the former pre-existing faults but is nevertheless consistent with NNE contraction. Where regional shortening is orthogonal to the trend of pre-existing faults the pervasive deformation produced either irrotational compressional strain (where no fault inversion occurred), or rotational compressional strain involving syn-cleavage shearing (where faults with favorable paleo-dip were inverted). Where the shortening direction is oblique to the paleo-fault trends, a component of strike-slip movement may locally prevail. A 22 %, N020o directed horizontal shortening, of 11 km, has been calculated based on deformed sedimentary markers in the Permian series and parallel folds in Lower Triassic quartzite. A shallower deformation as brittle reverse faults postdates the cleavage at the southwestern tip of the Argentera Massif and accounts for 4 km of extra shortening. Both types of deformation are connected at depth to a crustal blind thrust system and the Argentera Massif is over-thrust to the south-southwest. The observed strain indicates the Argentera Massif area underwent, from earliest Miocene to Present, a NNE to N rotating compression at distance from the left-lateral southwestern boundary of the Adria block.

Some developments of Upper Permian beds in the area west of Škofja Loka (Western Slovenia)

The article deals with three cross-sections of the Upper Permian beds in the area west of Škofja Loka. On the western slope of the Križna gora there is a limestone-dolomite development of the Upper Permian series. The limestone-dolomite development is exposed in the village Planica area at Čepulje as well. However, the most complete development of the Upper Permian can be followed in the Zadnja Smoleva valley.

Abstracts of Acta Geologica Sinica (Chinese Edition): Vol. 73, No. 4, 1999

The Reservior Characteristics of Lower Ordovician Dolomites Below Pre‐Mesozoic Unconformity in Yakela Fault‐convex, Tarim BasinThe Blueschist Belt in the Shuanghu Region, Central‐Northern Tibet and Its Tectonic ImplicationsReef Palaeopool and Prediction of Buried Reefs in the Lower Permian Series from Shiwandashan Basin of Guangri ProvinceGeochemistry of Rare Earth Elements in Late Paleozoic Coals in the North ChinaPhase Transition and Composition Change of Minerals from Melting Experiment of Two Kinds of Metamorphics in Fuping Group, Pingshan, Hebei Province, ChinaPalaeoecology and Palaeoenvironment of the Jehol Biota — A Palaeoecological and Palaeoenvironmental Reconstruction of Conchostracan Palaeocommunities in the Northern Hebei‐Western Liaoning AreaResearch on Micro‐FT.IR of Macerals of C‐P Coals in the Bohal Bay BasinSelf‐similar Texture of the Mid—Longling—Ruili Strike‐Slip System and the Location of Hydrothermal DepositsMetamorphism of the Eclogites from the ZK703 drillhole in Donghai, South Sulu (Jiangsu‐Shandong) Ultrahigh‐pressure Metamorphic Belt, Eastern China

Discovery of the Upper Permian series in Cuoqin Basin, Xizang (Tibet) and its geological significance

During the field work, one assumption has been made according to the lithologic, especially the paleotogic characteristics observed. The assumption is that the Upper Permian series should exist in Aduogabu which is in Xiadong Town, Gaize County, Tibet. This assumption was verified by the results of paleontologic identification. Accordingly it can be concluded that the idea of the lacuna of the Upper Permian series in Gangdise-Nyainqentanylha stratigraphie area should be reconsidered. There also exist abundant fossils such as coral, foraminifera, brachiopada and algae, which are representative of the result from warm water fauna. There exist some pinnacle reels consisting of coral and/or stramatopora. All this reflects the location evolution of Tibet in the area from high to low latitudes.

Palaeostress analysis, a contribution to the understanding of basin tectonics and geodynamic evolution. Example of the Permian/Cenozoic tectonics of Great Britain and geodynamic implications in western Europe

Microtectonic analysis in association with tectonic-sedimentological observations enables us not only to define palaeostress tensors but also to date each of them. Such a study, carried out in central and northeastern England and in southernmost Wales has permitted us to point out several tectonic stages during the Permian-Cenozoic period. (1) Inferred from syn-sedimentary faulting in the Late Permian series, the Permian/Early Triassic tectonic regime is characterised by a NNW-SSE-oriented extension. (2) During the Late Triassic to the early Late Jurassic, an E-W- to ENE-WSW-oriented extension was acting as suggested by syn-sedimentary normal faulting in Keuper, Lias and Middle Dogger sediments and post-sedimentary normal faulting in Oxfordian sediments. (3) The following tectonic event probably started during the Malm and was particularly active during the Early Cretaceous. It was characterised by a N-S- to NNE-SSW-oriented extension and was associated with an E-W- to WNW-ESE-oriented strike-slip tectonic regime (transtension). (4) A locally observed NW-SE-oriented transpressional strike-slip tectonic regime is thought to correspond to the ‘Laramide’ inversion phase of the Middle Paleocene. (5) The later tectonic event is characterised by a N-S-oriented transpressional strike-slip regime and affects a Paleocene tholeiitic dyke (‘Cleveland dyke’). It is supposed to be synchronous with the so-called Eocene ‘Pyrenean’ to the Early Miocene ‘Helvetic’ compressional stages. These paleostress tensors are compared with others defined in France, the Benelux countries and Germany and are also collated to the tectonic evolution of oil basins assessed from geophysical analyses. These comparisons raise discussions about the paleostress distribution within the geodynamic evolution of the West European shelf.

95/01040 Study of iterative characteristics of convective-diffusive and conjugate heat transfer problems

The Raman Maturity Method (RaMM) is a non-graphical technique for thermal maturity determination based on the multi-linear regression analysis of parameters derived from carbon Raman spectra of humic macerals. It is calibrated against vitrinite reflectance with a suite of Australian mostly Permian coals. In a previous communication an equation to cover the range 0.4–1.2% equivalent vitrinite reflectance was derived. In this report we extend the range with a second equation for the range 1.0–2.5%, and validate its use by testing a series of Australian Permian and German Carboniferous coals. The special features of the technique are that it is equally applicable to vitrinite and inertinite, it corrects internally for the suppression of vitrinite reflectance effect, grains as small as 5 μm are suitable, and it does not require well depth information to be available.The technique has been applied to two wells, Cape Range-2 and Dampier-1, from the rift margin of the North West Shelf of Australia. Both wells intersect large thicknesses of fine-grained marine Jurassic and Cretaceous sediments including the major source rock formation of the Carnarvon Basin. There are no terrestrial sediments for control. There is good agreement between RaMM and VR results for VR > 1.2% for Cape Range-2. However within the oil window in both wells RaMM results indicate the vitrinites in many of the samples have reflectance suppression to such a degree that the VR results would be misleading or useless for maturity modeling. It is likely that this problem, which is well documented for marine influenced coals, to some degree affects organic matter in marine source rocks worldwide.

Structural evolution of the Alaska Juneau lode gold deposit, southeastern Alaska

The Alaska Juneau lode gold deposit is hosted by a series of polydeformed Permian to Late Triassic volcanic, pelitic, volcaniclastic, and mafic intrusive rocks. Rocks in the mine area have been sheared and metamorphosed to greenschist grade. Interpretation of rock fabrics indicates several generations of ductile and brittle deformation. Prior to mineralization, reverse shear occurred along northwest-striking and northeast-dipping ductile shear zones. Mineralization consists of Eocene auriferous quartz–carbonate veins, which cut the regional metamorphic fabrics. Mineralization was followed by reverse right-lateral shear along northwest-trending ductile–brittle shear zones. Two northwest-striking and steeply dipping vein sets host the bulk of the ore. Orientation of carbonate fibers within the quartz veins were used to determine the deformation regime that existed during mineralization. Plunge of the fibers indicate that down-to-the-northeast extension occurred synchronous with mineralization. Structural data support a model whereby the Alaska Juneau deposit formed after the peak of ductile deformation during a period of local extension. Localization of veins to areas of infolded phyllite and gabbro suggests that competency contrasts within host rocks enhanced vein emplacement. Veining may have been facilitated by a change from a contractional to a transpressive deformational regime which may have led to local extension and fluid migration to favorable deposition sites.

Micropalaeontology of the Permian Marls of Merbah el Oussif (Jebel Tebaga, Tunisia) with special emphasis on the Ostracods

Abstract. The Marls of Merbah el Oussif are part of the Permian series of the Jebel Tebaga of Médénine in Tunisia. They belong to the uppermost Murghabian, a stage intermediate between the Wordian and the Capitanian. These green marls were deposited in lows at the base of sponge bioherms. The sedimentation rate was high and the environment well oxygenated. The marls contain a relatively rich assemblage of isolated sponges, gastropods, smaller foraminifera, fusulinids, dasycladacean algae and ostracods. Amongst those, for the first time reported from the Permian of Tunisia, 14 species have been identified and one new species described, Bairdiacypris postrectiformis sp. nov. The geographic and stratigraphic distribution of several species are discussed. This ostracod fauna indicates a shallow nearshore environment and suggests a western, not eastern connection between the Tethys and the Texas Sea.

Palaeomagnetism of the Permian Volcanic Rocks of Moissey (French Jura): Implications For the Palaeofield and Tectonic Evolution

Rocks from the Massif de la Serre in the French Jura (latitude: 47.3°N longitude: 5.6°E) belonging to an ignimbritic assemblage dominated by vitrophyric rhyolites, and whose age of formation is probably Permian (Autunian to Saxonian) have been studied by applying thermal and alternating field demagnetization. the characteristic magnetization has a mean direction derived from 89 samples of D= 170°, I= - 16°, k= 26.2°, α95= 3° and a corresponding north palaeopole at 41°N, 172°E, A95= 5°. the pole, which is very close to the Permian European poles, can thus be considered as a new contribution. Some samples are found to carry a unique normal polarity magnetization, others carry both normal and reverse polarities. It therefore seems that, similar to Permian series in the USSR, these west European rocks have registered a normal event in the Kiaman interval. From a structural point of view, we may conclude that during the Alpine tectonic phases the Massif de la Serre has not been subjected to substantial rotation.

Chemical composition of water‐bodies in the English Lake District: relationships between chloride and other major ions related to solid geology, and a tentative budget for Windermere

SUMMARY. Mean tarnwater concentrations of CI‐ and other ions (Na +, K+, Ca2+, Mg2+, SO42‐+ NO3‐) decrease with increasing distance from the sea and altitude but are also related to solid geology. Lowest concentrations occur on slow‐weathering igneous rocks (Borrow‐dale Volcanics); minima of c. 100 μequiv. CI‐I‐1 are similar to the volume‐weighted mean for bulk precipitation. At least 10–20% of Na+ is leached from upland catchments, giving Na+/CI‐ ratios greater than the equivalent ratio (0.86) in seawater and precipitation. Evapotranspiration at 20–30% annual rainfall accounts for CI‐ concentrations in many tarns on igneous rocks but not all; some CI‐ may be leached from the rocks in upland catchments and come from groundwaters at low altitudes near the sea. Sea‐spray has little influence on tarnwaters near the coast. On sedimentary rocks overall mean CI‐ concentrations are 27–73% higher than equivalent means on Borrowdale Volcanics; concentrations of other ions are also higher. A 5‐fold to 10‐fold range of CI‐concentrations is not simply due to increased evapotranspiration. Na+/CI‐ ratios are < 0.86, especially on Skiddaw Slates where tarnwaters contain 10% or more excess CI‐ balanced by Ca2+, apparently derived from groundwaters rich in CaCI2. On other sedimentary rocks (Silurian Slates and Carboniferous, Triassic and Permian series) tarn waters display a similar but less pronounced excess of CI‐ and Ca2‐+ relative to Na+. Some extra CI‐ may be captured by dry deposition on vegetation but a portion, perhaps 15–30% of the total, apparently comes from the rocks or from groundwaters via deep aquifers in contact with seawater or connate water. Anthropogenic sources on the catchments are also considered: deicing salt used on highways in winter accounts for a 27% increase of CI‐ in Windermere South Basin over a 20‐year period.

Some Field Permeation Properties of Fractured Permian and Triassic Sandstones in Northwest England

The 1000 m thick series of Permian and Triassic sandstones in Northwest England exhibit both intergranular and fissure flow. However, estimates of their relative importance can be distorted by the statistical manipulation of test data. Additional parameters which are believed to independently identify the mechanism of flow are examined. These include variation of field permeability in 171 boreholes with respect to depth and radius of the pumped bore, distance from tectonic zones and consideration of the regional distribution of fluid bodies. Interpretation suggests that intergranular flow is dominant despite the fractured nature of the rock mass.

Geology and hydrocarbon provinces of the North Sea

The technically recoverable hydrocarbon reserves of the North Sea are currently estimated at 23 × 109 bbls of oil, condensate and NGL and 90 × 1012 scf of gas. The North Sea underwent a complex geological evolution. The oil and gas occurrences in the central and northern North Sea are tied to Mesozoic and Tertiary sediments; the gas fields of the southern North Sea are mainly contained in Permian series. The proven hydrocarbon provinces cover at best one third of the total area of the North Sea. It is estimated that in the early 1980's the oil production from the North Sea will meet 22% of the oil demand of Western Europe.

Conocardium langenheimi Sp. N. (Mollusca: Bivalvia) in the Lower Permian Series of the McCloud Limestone, northern California

Conocardium langenheimi Sp. N. (Mollusca: Bivalvia) in the Lower Permian Series of the McCloud Limestone, northern California

Pennsylvanian and Lower Permian of Northern Denver Basin, Colorado, Wyoming, and Nebraska

Permo-Pennsylvanian sedimentation in the northern Denver basin was influenced by the positive areas of Frontrangia (ancestral Front Range) and the Cambridge arch. Near these sources, coarse clastics interfinger with shales and limestones of the basin. The Cambridge arch was first covered by marine Pennsylvanian sediments during Desmoinesian time. Frontrangia contributed coarse arkosic sediments from Morrowan into Leonardian time. A northwest trend of Frontrangia and the Cambridge arch is indicated by isopach and lithofacies data. The Transcontinental arch was a positive pre-Morrowan feature which also was very slightly positive during Desmoinesian and Missourian time and at the end of the Pennsylvanian Period. The Hartville, Wyoming, area was basinal until uplifted near the end of Wolfcampian time as indicated by truncated Wolfcampian sediments. lsopach maps indicate that the Las Animas arch was mildly positive during Morrowan, Atokan, and Desmoinesian time. On the east flank of the Laramie Mountains the Casper Formation includes sediments of Atokan through Wolfcampian Age. Sediments of questionable Morrowan Age may be present in the basal Casper or in underlying tongues of the Fountain. At the type locality strata as young as Leonardian are believed to be present in the upper Casper. The Ingleside Formation is the Colorado equivalent of the Casper and near the Wyoming-Colorado boundary line also includes sediments of Atokan through Wolfcampian Age. South of the Wyoming-Colorado boundary line basal Ingleside intertongues with the Fountain Formation and at the type locality the Ingleside is entirely Wolfcampian. The Hartville Formation is divided into seven members ranging in age from Atokan to Leonardian, inclusive. Wolfcampian fusulinids occur 70-80 feet below the subsurface shale marker in Cheyenne County, Nebraska. The Satanka Formation consists of the predominantly red sediments that lie between the Casper or Ingleside Formation below and the Opeche Shale or the Lyons Sandstone above. Lateral equivalents of the Satanka are the uppermost Casper of the type locality, the Cassa Member of the Hartville Formation, the middle part of the Lyons Sandstone at the type locality and rocks of Leonardian Age in northwestern Kansas. Lithofacies maps of Pennsylvanian and early Permian sediments indicate decreasing clastic ratios in progressively younger strata. Pre-Desmoinesian clastics decrease in particle-size toward the center of the Denver basin, whereas in sediments deposited following burial of the Cambridge arch, during Desmoinesian time, the clastic particles become smaller eastward across the basin. The present structure of the northern Denver basin is abruptly asymmetrical, much steeper on the west than on the east side, and slightly elongate in a northerly direction. The deepest part of the basin lies only 18-20 miles east of the Permo-Pennsylvanian outcrop. Isopach maps of the Pennsylvanian and Lower Permian Series show relatively greater subsidence in the center of the basin than on the flanks, and also indicate a general southward tilting. About one well per 400 square miles has penetrated the Lower Permian-Pennsylvanian section. These objectives in the northern Denver basin must be considered largely unexplored.

CORRELATION OF ROCK DENSITY DETERMINATIONS FOR GRAVITY SURVEY INTERPRETATION*

ABSTRACTThe results of field and laboratory methods of density determination on a series of Coal Measure, Permian and Triassic rooks are presented and the different methods compared. It is concluded that the most satisfactory method is that of measuring the vertical change of gravity in a mine shaft. Nettleton's method is unsatisfactory to us, due to weathering of the rocks (particularly Magnesian Limestone) and possible effects from drift. Laboratory measurements are of variable value depending on the lithology and source of the samples.A method adopted to solve the problem of finding the true densities for use in a local gravity survey in N.E. England is given.

Geology of the Miharaiyama District, Yabu-gun, Hyogo Prefecture, Japan, with Special Reference to the Triassic Miharaiyama Group : A Study on the Stratigraphy and Geologic Structure of the "Maizuru Zone" (Part 2)

The Paleozoic rocks which occur in the Miharaiyama district belong to the Minamitani group., They are correlated with the rocks of Kuma series (Upper Permian), which are typically expose in Kumamoto Pref., The Minamitani group contains special deposits such as the so-called Yasuba conglomerate., The Mesozoic Miharaiyama group is correlated with the lower part of the Inai series and is considered Scythian in age., It is subdivided as follows: Gannosudani formation G3 bluish grey siltstone -200m G2 bluish grey sandstone -80∼95m G1 conglomerate-50∼80m Niikuradani formation N2 bluish grey sandstone -30∼60m N1 basal conglomerate -15∼30m Minamitani group (Upper Permian) The Niikuradani formation contains no fossils, but the Gannosudani formation, especially G2 is rich in fossils which are listed below., G3: Nuculana sp., Myophoria aff., laevigata G2: Neobakevellia kambei M., S., M., aff laevigata (abundant) Neob., kambei sakaigawensis M., S., Nuculana sp., Rhynchonella sp., Terebratula? sp., etc., (rare) An unconformity was discovered between the Miharaiyama group and the underlying Paleozoic rocks., The Lower Triassic formations in Japan are local and very limited in occurrence., They are generally jammed into others formations by faults., Previously, the disconformable relation of the Lower Triassic with the Upper Permian Series (≒Kuma series), had beenknown only in the Kitakami Mountains, Miyagi Prefecture., The discovery of the unconformity mentioned above may be important in the study of the late Paleozoic crustol movement in Japan.,

Verden Sandstone of Oklahoma--an Exposed Shoestring Sand of Permian Age

The Verden sandstone is a remarkable narrow elongated body of sandstone which crops out in a long line of flat-topped buttes extending northwestward a distance of 75 miles from Stephens County, through southwestern Grady and northeastern Caddo counties, into Canadian County, Oklahoma. It has long been of interest to petroleum geologists because of the similarity of many of its features to those of the shoestring oil-producing sands of northeastern Oklahoma and southeastern Kansas. The Verden sandstone body is only 10 feet thick and less than 1,000 feet wide at most places. It lies in the redbeds portion of the Permian series. The sandstone occupies everywhere the same stratigraphic position within a range of a few feet, in the redbeds, and lies within a sequence of regula ly bedded thinly laminated silty sandstone, silt, and gypsum of the Marlow formation. It is characterized by relatively thick beds of medium- to coarse-grained sandstone which are steeply cross-bedded with northwest dips, and are interbedded with thin beds of fine-grained horizontally laminated sandy shale. The sand grains have a wide range in size but are sorted into layers in which grains of a single size predominate. The fine-grained beds contain wave ripple marks and giant ripple marks that trend nearly parallel with the sandstone belt. The sandstone is a firm hard rock composed of well rounded quartz and subangular chert grains and of calcium carbonate which makes up 50 per cent of the rock. Marine fossils are common. That the Verden sandstone was deposited as some form of a barrier beach, probably as one or more spits that extended across the mouth of a broad shallow bay, near the shore of a shallow marine sea, is indicated by the evidence collected during this investigation. Apparently the coarse-grained cross-bedded sandstone was deposited by longshore currents that flowed northwestward and the fine-grained beds were deposited during quiescent periods when gentle waves and tides spread fine mud over the nearshore bottom. The coarse material in the sandstone was probably derived from beds of conglomerate in the underlying Duncan sandstone which were exposed near the southeast end of the sandstone belt and probably in other localities in the region. Most of the calcium carbonate in the bed was pro ably deposited originally as granular material composed of shell fragments, and was later dissolved and redeposited; a part may have been precipitated directly out of solution in the sea water and a part may have been precipitated out of water that passed from the lagoons and estuaries seaward through the sand bar soon after it was formed.

Relation of Permian Sedimentation to Tectonics in Guadalupe Mountain Region: ABSTRACT

Relation of Permian Sedimentation to Tectonics in Guadalupe Mountain Region: ABSTRACT

Permian stratigraphy of trans-Pecos Texas

INTRODUCTION GENERAL FEATURES OF THE PERMIAN SERIES The Permian series of North America attains its greatest development in trans-Pecos Texas. Strata of this age have an important influence on the geography of the region. Permian limestones, sandstones, and shales constitute many of the mountain ranges and plateaus, and the more resistant rocks crop out in bold cliffs and ledges on numerous escarpments. The highest peak in Texas, El Capitan (8750 feet), is the summit of a cliff of Permian limestone at the crest of the Guadalupe Mountains (Fig. 13 A). In New Mexico, not far northeast of this peak, is the great Carlsbad Cavern, which is carved from limestones of the same age. Permian strata beneath the plains east of the mountains have produced vast quantities of oil, and contain large deposits of valuable potash salts. Strata of the Permian series in trans-Pecos Texas reach a thickness of about 7000 . . .