Swift Formation Research Articles

コイ・ミオシン加熱時のＳＳ結合によるタンパク質の高分子化機構

The polymer of protein through SS bonding on the top of 5% SDS-PAGE gel was found to be made up of only a myosin heavy chain from the analysis of two-step SDS-PAGE, and from the results it was a dimer, trimer, tetramer, and above-decamer with 1.8% SDS-PAGE gel. The polymerization was suppressed in the presence of N-ethylmaleimide, dithiothreitol, or EDTA. The polymerization of myosin light chains as well as myosin heavy chain was promoted in the presence of transition ion (Cu+, Cu2+), while Ca2+ and Mg2+ did not affect the polymerization. From the above results, it was made clear that the polymerization of protein through SS bonding during the heating of myosin is the reaction that the SH groups of myosin heavy chain are oxidized in the presence of catalysts such as copper ion, and contribute to the smooth and swift formation of the polymer larger than decamer.

Stratigraphy and Petroleum Potential of the Swift Formation (Upper Jurassic), Southern Alberta and North-Central Montana

ABSTRACT Marine strata of the Upper Jurassic Swift Formation underlie a large area of the Western Interior Plains of the United States and pinch out to an erosional edge in southern Alberta. Two informal members can be distinguished over the study area in southern Alberta and northern Montana: a basal glauconitic shale member, and an upper member, composed of interbedded sandstone, siltstone, and shale, with lithotypes ranging from mudstones with lenticular silt beds to flaser-bedded sandstones. An initial marine transgression resulted in deposition of the basal shale, and was followed by gradual regression and episodic deposition of the ribbon sand member in shallow-marine, bar and interbar facies. Erosion during the latest Jurassic and earliest Cretaceous, particularly valley cutting, determined the distribution of the Swift. Correlation of the Swift with equivalent units throughout the Western Interior of North America provides the basis for a regional reconstruction of Late Jurassic depositional patterns and environments. Insight into erosional patterns and environments during Early Cretaceous time can also be gained. Although potential reservoir strata are widespread in the Swift, poor predictability of sand body distribution and trapping mechanisms make the Swift a low-priority target for hydrocarbon exploration.

Dynamic analysis of deformed quartz and calcite from the Dry Creek Ridge Anticline, Montana

Dynamic analyses of deformed quartz and calcite from the Swift Formation at Dry Creek Ridge anticline, Montana, were made to test the method for determining orientations of principal stress directions from microstructures produced by intragranular flow in quartz and the homogeneity of principal stress orientations around a fold. Close correspondence of results with Turner9s (1953) calcite technique indicates that quartz may be used independently for dynamic analysis. Arguments presented suggest that under the ambient conditions of deformation (about 1 kb overburden pressure, 100 degrees to 150 degrees C), the stress difference of slip in quartz was probably as low as that for deformation of the calcite aggregate. Orientations of deduced principal stress axes around the fold are remarkably consistent. In consideration of regional structure, the orientations of principal stress directions probably reflect bending stresses in the compressive part of a very thick plate.

Jurassic Stratigraphy of Williston Basin Area

Rocks of known Jurassic age in the Williston Basin area are included in five formations which from oldest to youngest are Gypsum Spring, Piper, Rierdon, Swift, and Morrison. A sequence of red silty shales termed the Jura-Triassic redbeds underlies these formations, but is of uncertain age. In the eastern part of the area the Swift, Rierdon, and formations can not be differentiated and strata equivalent to these formations are combined to form a single formation herein identified as the Sundance. An arbitrary cut-off line is used to limit the area in which the Swift, Rierdon, and formations are recognizable units. The Jura-Triassic redbeds are correlated over the entire area and consist essentially of red silty shales, grading into argillaceous siltstone near the base but becoming progressively less silty upward in the section. The Gypsum Spring formation can be traced over the entire area and commonly consists of two members, a basal evaporite member and an upper normal marine member consisting of limestone, dolomite, and shale. In Montana and western Saskatchewan the two members grade into each other and division into members is not possible. A continuous unit serves to indicate the upper boundary of the formation. The Piper, Rierdon, and Swift formations can be traced only over the western half of the area. The can be divided into three members. The lower member is a heterogeneous unit consisting of limestone, sandstone, and shale in which facies changes are abrupt and individual beds can not be traced over great distances. The middle member is of consistent lithologic character, being composed almost entirely of and is commonly known in the area as the Piper limestone. This is confined to the western part of the area and is a different stratigraphic unit from the so-called Piper limestone of North Dakota and Manitoba. The upper member of the formation consists of shales and sandy limestones. A continuous bed of sandy marks the top of this formation. The Rierdon consists primarily of greenish gray calcareous shales which are sandy in the eastern and northern part of the area. End_Page 367------------------------------ The Swift formation is divided into three members. The lower member consists predominantly of greenish gray shale, the middle member is sandstone, and the upper member greenish gray shale locally becoming variegated near the top of the formation. The middle sandstone member does not appear to represent a continuous sheet of sand, and at least two separate sandstone units occur. The Sundance formation represents equivalents of the Swift, Rierdon, and formations in the eastern half of the area and consists of a marine series of shales, sandstones, and limestones. The Morrison formation is a non-marine series of shales and sandstones which overlies the Swift formation in Montana and the Sundance formation in North Dakota.

Jurassic Subsurface in Southern Alberta: ABSTRACT

Jurassic rocks underlie all of southern Alberta from its eastern and southern boundaries to the Rocky Mountain front on the west. The northern boundary is roughly crescent shape, approximately coinciding with the South Saskatchewan River and its tributary, the Oldman River, to within a few miles of Lethbridge. From that point the boundary trends northwest, passing a few miles east of Calgary. On Alberta plains, Jurassic strata are readily divisible into three formations, which were originally described and named in Montana, and which are, in ascending order, Sawtooth, Rierdon, and Swift. In Alberta Foothills, Jurassic strata are called the Fernie formation, which is roughly the equivalent of the three formations of the Plains. Jurassic strata in southern Alberta rest unconformably on the Rundle formation of Mississippian age. On the Plains they are overlain unconformably by the basal sandstones of the Blairmore formation which have been correlated with the Cutbank and Sunburst sands of Montana. The unconformity at the top of the Jurassic truncates the formations so that they wedge out northward; consequently, the Swift, being the uppermost, has a very limited distribution in Alberta having been eroded completely from the crest of the Sweetgrass arch and remaining only in the extreme southeastern corner of Alberta and in a narrow belt paralleling the Foothills. The Rierdon and Sawtooth formations extend northward approximately to the limits of the Jurassic as defined. In the Foothills the Fernie is overlain y Kootenay sandstone and shale. The Sawtooth formation consists of two sandstone members, separated by green, pyritic, non-calcareous shale. The upper sand is a reservoir for oil and gas in several small fields in Alberta. The formation has a maximum thickness of about 235 feet. The Rierdon formation is made up of an alternation of gray calcareous shale and greenish gray limestone with some pyrite, glauconite, and iron-stone, and has a maximum thickness of 200 feet. The Swift formation lies unconformably on the Rierdon and has a maximum thickness of 150 feet. It consists of glauconitic sandstone, siltstones, concretions, dark gray shale, and usually has chert pebbles at the base. Facies changes take place from west to east in the Sawtooth, Rierdon, and Swift formations so that at the eastern boundary of Alberta they may be readily correlated with the Gravelbourg, End_Page 414------------------------------ Shaunavon, and Vanguard formations of Saskatchewan. However, they are not the exact equivalents of these formations since some overlapping occurs. End_of_Article - Last_Page 415------------

Marine Upper Jurassic, Eastern Wyoming

The Swift-Rierdon nomenclature of the Ellis group in Montana is applied in eastern Wyoming to formational units of the group. Indications are that the names are applicable to the marine Upper Jurassic throughout most of Wyoming and western South Dakota, but the term Sundance should be retained because of historical significance. Thickness maps indicate that the distribution of the Rierdon sediments in eastern Wyoming was influenced by a minor depositional basin, the River embayment, corresponding in general with the present Powder River Basin, and a positive-trending feature, the arch, present across north-central Wyoming during the early part of Upper Jurassic time. Micropaleontologic studies indicate the presence of two distinct Rierdon ostracode biofacies whose distribution is apparently governed by environmental factors associated with presence of the Sheridan arch. The Swift sediments are lithologically and paleontologically distinct from those of the Rierdon, but show a less definite pattern of distribution, probably because of ineffectiveness of the Sheridan arch during their deposition. For a similar reason, only a single ostracode assemblage is present in the Swift formation. Two ostracode zones are recognized in this assemblage.

Marine Jurassic Formations of Southern Alberta Plains

The Jurassic sediments of the Southern Alberta Plains, known only from subsurface work, are described as to lithology, thickness, distribution, stratigraphic relationships, and geologic history. The three-fold subdivision of the Ellis group into Swift formation, Rierdon formation, and Sawtooth formation, established in Montana, is recognizable and applicable in Alberta. A major unconformity between the Jurassic beds and the underlying Paleozoic limestone influences the distribution of the Sawtooth formation. Late Jurassic or early Cretaceous erosion truncating the Jurassic formations from south to north has determined the present extent and northern boundaries of these formations in Southern Alberta.

Marine Jurassic of Black Hills Area, South Dakota and Wyoming

In the Black Hills area the marine Jurassic rocks comprising the Gypsum Spring and formations represent the upper Bajocian, Bathonian, Callovian, and Oxfordian stages of the Middle and Jurassic. A minor disconformity was developed during the upper Bathonian and a major, regional disconformity during the middle to upper Callovian. Subdivisions of the formation from base to top are herein defined as the Canyon Springs sandstone member, the Stockade Beaver shale member, the Hulett sandstone member, the Lak member, and the Redwater shale member. Sandy sediments in the lower four members were probably derived locally from the east or southeast, in the upper member mainly from the west. The Gypsum Spring formation represents the first widespread invasion and withdrawal of marine waters during the Jurassic in the Western Interior region. It is Middle Jurassic in age and correlative with the Gypsum Spring and Sawtooth formations farther west. The Canyon Springs sandstone member and the Stockade Beaver shale member represent a widespread marine invasion at the beginning of the Jurassic and are correlative with the lower part of the formation of north-central Wyoming, the Lower Sundance of central Wyoming, and the Rierdon formation of Montana. The overlying marine Hulett sandstone member is correlative with similar sandstone in the Lower Sundance formation in central Wyoming. It is probably present in North Dakota and southeastern Montana. It is missing in the outcrop in Montana but may be represented there by shale or sha y limestone at the top of the Rierdon formation. It probably passes westward in Wyoming into the upper part of the Twin Creek limestone. The Lak member consists of redbeds, is apparently non-marine, and is correlative at least in part with the Entrada and Preuss sandstones farther west. It is possibly present in North Dakota but has not been identified in Montana. The Redwater shale member represents the last Jurassic marine invasion in the Western Interior region of the United States. It is mainly or entirely Oxfordian in age and correlative with highly glauconitic sandstone and shale farther west, variously called Swift formation, Stump sandstone, Curtis formation, and Upper Sundance formation.

Marine Jurassic Formations of Sweetgrass Arch, Montana

The marine Jurassic rocks of the Sweetgrass arch in western north-central Montana have been assigned to the Ellis formation. As a result of measuring and sampling eleven Jurassic sections around the Sweetgrass arch and from examining numerous well cuttings, the writer concludes that the Ellis consists of three major lithologic divisions that should be recognized as formations, and that the Ellis should be raised to group rank. The formations of the Ellis group from oldest to youngest are herein named Sawtooth, Rierdon, and Swift. The Sawtooth formation consists of three members, a basal fine-grained sandstone, a medial dark gray shale containing a few dark limestone beds, and an upper member of light gray calcareous siltstone, fine-grained sandstone, or sandy, oolitic limestone. The Sawtooth is as little as 8 feet in thickness on the Kevin-Sunburst dome. It thickens eastward to 200 feet in the Sweetgrass Hills and westward to about 200 feet along the Rocky Mountain Front. The formation is absent over most of the South arch. The lower two members pass into redbeds east of the Sweetgrass Hills and on the southeast flank of the South arch. The Rierdon formation consists mainly of gray limy shale and nodular limestone. It seems to overlie the Sawtooth formation conformably. It is as little as 72 feet in thickness on the Kevin-Sunburst dome, but thickens eastward to 180 feet in the Sweetgrass Hills and westward to about 200 feet along the Rocky Mountain Front. The formation is absent over most of the South arch. The Swift formation is composed of two members along the Rocky Mountain Front and eastward across the Kevin-Sunburst dome at least as far as the Sweetgrass Hills. The lower member is dark non-calcareous shale, highly glauconitic at the base. The upper member is gray fine-grained flaggy glauconitic sandstone containing abundant black-gray micaceous shale partings. On the South arch the formation consists of fine-grained flaggy sandstone which is locally pebbly at the base. In the vicinity of the Little Belt Mountains the formation is massive fine-grained sandstone containing a prominent basal conglomerate. The Swift attains its maximum thickness of 166 feet in the Pondera field. The formation has been removed by pre-Kootenai erosion from most of the Cut Bank area, and from a small area west of the Whitlash field. All the formations are fossiliferous. According to Imlay, the Sawtooth is upper Bathonian, the Rierdon is upper Bathonian and Callovian, and the Swift is Divesian and Argovian. The South arch was an island through most of the Bathonian and Callovian stages. At the close of the Callovian the marine waters retreated from the area. During the early Divesian the Sawtooth and Rierdon formations were locally thinned by erosion and possibly removed from some areas. Later in the Divesian marine waters transgressed the entire area and remained until the close of the Argovian.

Marine Jurassic Formations of Sweetgrass Arch, Montana

The marine Jurassic rocks of the Sweetgrass arch in western north-central Montana have been assigned to the Ellis formation. As a result of measuring and sampling eleven Jurassic sections around the Sweetgrass arch and from examining numerous well cuttings, the writer concludes that the Ellis consists of three major lithologic divisions that should be recognized as formations, and that the Ellis should be raised to group rank. The formations of the Ellis group from oldest to youngest are herein named Sawtooth, Rierdon, and Swift. The Sawtooth formation consists of three members, a basal fine-grained sandstone, a medial dark gray shale containing a few dark limestone beds, and an upper member of light gray calcareous siltstone, fine-grained sandstone, or sandy, oolitic limestone. The Sawtooth is as little as 8 feet in thickness on the Kevin-Sunburst dome. It thickens eastward to 200 feet in the Sweetgrass Hills and westward to about 200 feet along the Rocky Mountain Front. The formation is absent over most of the South arch. The lower two members pass into redbeds east of the Sweetgrass Hills and on the southeast flank of the South arch. The Rierdon formation consists mainly of gray limy shale and nodular limestone. It seems to overlie the Sawtooth formation conformably. It is as little as 72 feet in thickness on the Kevin-Sunburst dome, but thickens eastward to 180 feet in the Sweetgrass Hills and westward to about 200 feet along the Rocky Mountain Front. The formation is absent over most of the South arch. The Swift formation is composed of two members along the Rocky Mountain Front and eastward across the Kevin-Sunburst dome at least as far as the Sweetgrass Hills. The lower member is dark non-calcareous shale, highly glauconitic at the base. The upper member is gray fine-grained flaggy glauconitic sandstone containing abundant black-gray micaceous shale partings. On the South arch the formation consists of fine-grained flaggy sandstone which is locally pebbly at the base. In the vicinity of the Little Belt Mountains the formation is massive fine-grained sandstone containing a prominent basal conglomerate. The Swift attains its maximum thickness of 166 feet in the Pondera field. The formation has been removed by pre-Kootenai erosion from most of the Cut Bank area, and from a small area west of the Whitlash field. All the formations are fossiliferous. According to Imlay, the Sawtooth is upper Bathonian, the Rierdon is upper Bathonian and Callovian, and the Swift is Divesian and Argovian. The South arch was an island through most of the Bathonian and Callovian stages. At the close of the Callovian the marine waters retreated from the area. During the early Divesian the Sawtooth and Rierdon formations were locally thinned by erosion and possibly removed from some areas. Later in the Divesian marine waters transgressed the entire area and remained until the close of the Argovian.