Download or read book Architectural Analysis and Fold Geometry of Syntectonic Fluvial Conglomerate in the Nanushuk Formation Brooks Range Foothills Alaska written by Emily Suzanne Finzel and published by . This book was released on 2004 with total page 460 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The fluvial style and syntectonic deposition of conglomerate in the upper part of the Nanushuk Formation are resolved using facies architectural analysis and structural geometry. Along the Kanayut River in the northern foothills of the Brooks Range, Alaska, fluvial conglomerate is exposed as benches on the north and south flanks of the Arc Mountain anticline. Photo mosaics of each bench on the north side, along with thirty-three detailed measured sections, were used to evaluate facies architecture. Eight lithofacies were described that characterize six facies associations including longitudinal and transverse gravel bars, diffuse gravel sheets, sediment gravity flow deposits, crevasse splay and floodplain deposits, and scour fills of a gravel-bed braided river. Strata on the south limb of the anticline show characteristics of syndeformational deposition during the growth of the south limb of the Arc Mountain anticline. These structural data provide new evidence for syndepositional contractional deformation during the mid-Cretaceous at this locality in the northern foothills of the Brooks Range. These results provide clues to the character and extent of potential reservoir rocks from the Nanushuk Group that are present in the subsurface of the National Petroleum Reserve in Alaska, which is important for continued recovery of natural resources on the North Slope"--Leaf iii.

Download or read book Architectural Analysis of Fluvial Conglomerate in the Nanushuk Formation Brooks Range Foothills Alaska written by Emily Suzanne Finzel and published by . This book was released on 2005 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this report is to present the results of a sedimentological study of Aptian-to Albian-age Nanushuk Formation rocks along the north limb of the Arc Mountain anticline at the Kanayut River, Alaska. The goal of this study is to define and interpret lithofacies and architectural elements for the conglomerate in the study area, and then use these interpretations to suggest a fluvial model for the river that deposited the conglomerate.

Download or read book Structural Geology of the Big Bend Anticline Brooks Range Foothills Alaska written by Cheryl M. Sanders and published by . This book was released on 2014 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt: Big Bend anticline is near the northern edge of the Brooks Range foothills of northern Alaska. The structure of the foothills is a low-taper triangle zone or passive-roof duplex within Brooks Range foreland basin deposits. The dominant structures are detachment folds locally cut by thrust faults and Big Bend anticline is one of these. This research combines detailed surface mapping (1:25,000) with interpretation of aerial photos and satellite imagery of the Big Bend anticline and seismic reflection data from the Umiat anticline to reconstruct its surface and subsurface geometry. The research area surrounds the Big Bend of the Chandler River and covers approximately 10 km2. The mechanical stratigraphy of the area consists of the competent Nanushuk sandstones between two incompetent units-the overlying Seabee and underlying Torok shales. The structure of the area consists of an east-trending anticline with a hinge that branches westward into two open, broad anticlines and an intervening syncline. A forethrust near the southern hinge and a backthrust near the northern hinge have broken through the anticline west of the branch point. Subsurface data of Umiat anticline combined with surface projected cross sections from the study area provide an analog of the subsurface structure in the Big Bend area. These cross sections show gentle anticlines separated by flat bottomed synclines in competent Nanushuk Formation sandstone. The anticlines overly Torok Formation thickened by north vergent folds and thrust faults above a detachment zone. Collectively, these structures form a low-taper triangle zone. Cross section restoration suggests more shortening in the Torok duplex than in the overlying folds and breakthrough faults. Results of this research provide an analog for other anticlines in the region that are currently the focus of oil and gas exploration.

Download or read book Architecture of the Central Brooks Range Fold and Thrust Belt Arctic Alaska written by John S. Oldow and published by Geological Society of America. This book was released on 1998-01-01 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 17 papers presented here introduce results on geological and geophysical research centred largely along a North-South transect through the central Brooks Range of Arctic Alaska. Investigations centre on a descripton of the rocks and their tectonic evolution from the foreland to the hinterland of the orogen, the geometry and kinematics of contractional and extensional structures, regional and local stratigraphic relations, thermochronology, and the deep crustal structure of the Brooks Range and parts of the North Slope, and descriptions of the major lithotectonic assemblages, composing the orogenic belt.

Download or read book A Geometric Analysis of Detachment Folds in the Northeastern Brooks Range Alaska and a Conceptual Model for Their Kinematic Evolution written by Paul Kirtley Atkinson and published by . This book was released on 2001 with total page 418 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Detailed measurements of six detachment folds in the northeastern Brooks Range, Alaska, show that the competent Lisburne Limestone, which overlies a regional décollement in the Kayak Shale, varies considerably in structural thickness across folds, with substantial thickening in both the crest and trough panels. Several factors appear to influence this thickening, including variations in mechanical stratigraphy, relative stratigraphic thicknesses of the competent and incompetent units, and structural relief of the underlying basement. My observations indicate that these detachment folds formed in a manner significantly different from that predicted by existing geometric and kinematic models. Thus, I propose a new conceptual model which allows variable amounts of bed shortening and thickness changes in both the competent and incompetent units, thereby opening up an infinite array of possibilities for the development of a fold. My analyses demonstrate that this model provides a better fit to these natural folds than do other models"--Leaf iii.

Download or read book Variations in Structural Geometry Across the Continental Divide Thrust Front Northeastern Brooks Range Alaska written by A. V. Anderson and published by . This book was released on 1994 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Structural Geometry of Detachment Folds Above a Duplex in the Franklin Mountains Northeastern Brooks Range Alaska written by Thomas X. Homza and published by . This book was released on 1994 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Preliminary Observations of the Straight Creek Detachment Anticline Northeastern Brooks Range Alaska written by Thomas X. Homza and published by . This book was released on 1993 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Geometric Analysis of Thrust truncated Asymmetric Folds Upper Marsh Fork Area Eastern Brooks Range Alaska written by Margarete Ann Jadamec and published by . This book was released on 2003 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: "A new surveying technique was developed to document the geometry of eight km size thrust-related folds in the eastern Brooks Range, Alaska. This method combines data from a theodolite and reflectorless laser rangefinder to construct cross sections that are more precise than those based on field map data. In the study area, weakly to non-metamorphosed Carboniferous carbonates typically form northeast-trending, northwest-vergent, asymmetric thrust-truncated folds. The geometry of most of the folds is consistent with a detachment fold model that allows local thickness changes. The anticlines typically display interlimb angles of less than 90,̊ structurally thickened hinge zones, and overturned forelimbs that dip steeply to moderately, suggesting the folds are over-tightened. Furthermore, structural disruption of bedding in the anticlinal forelimbs suggests that strain was localized in this region of the fold and is interpreted to be a record of the transition from folding to thrust faulting within each fold"--Leaf iii.

Download or read book Detachment Folds Above a Passive roof Duplex an Example from the Northeastern Brooks Range Alaska written by Wesley Kent Wallace and published by . This book was released on 1992 with total page 41 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Detachment Folds of the Northeastern Brooks Range Alaska written by Thomas X. Homza and published by . This book was released on 1995 with total page 670 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Geometry and Kinematics of Thrust truncated And or Flattened Asymmetrical Folds in the Eastern Brooks Range Alaska written by Rebecca D. Bailey and published by . This book was released on 2007 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Exceptional exposures of thrust-related folds within carbonate rocks of the Lisburne Group of the Brooks Range of northern Alaska are classified into four groups: unbroken/parallel folds, thrust-truncated/parallel folds, unbroken/flattened folds and thrust-truncated/flattened folds. The geometry of these folds varies greatly along strike, suggesting that serial sections do not represent successive stages in fold evolution. Geometric and kinematic modeling of individual folds reveals that no single fault-related fold model can reproduce the geometry of a given fold. Instead, successful forward modeling of the folds requires some combination of detachment folding with fault-bend folding or fault-propagation folding. All folds followed one of two kinematic paths: the initially parallel folds either broke through without flattening or flattened first and then broke through. Preferred hypothesis for why folds would deform by one path verses the other include: I) Original asymmetry will promote breakthrough over flattening, so that originally asymmetric folds will break through without flattening while initially symmetric folds will flatten before breaking through; and 2) A thin detachment unit may limit fold growth resulting in breakthrough without flattening, while a thick detachment units will not limit fold growth, allowing folds to shorten via flattening before breaking through"--Leaf iii.

Download or read book Architecture of the Central Brooks Range Fold and Thrust Belt Arctic Alaska written by and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Character and Controls of Fold and thrust Deformation from Pre orogenic to Foreland Basin Deposits written by Garrett G. Speeter and published by . This book was released on 2010 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The character of structures in the Gilead Creek region is influenced by the mechanical stratigraphy in the area. Shortening is distributed throughout the mechanical stratigraphy along detachments in the incompetent Kayak, Kavik, Kingak, and Hue Shales. Detachment intervals separate competent Lisburne Group, Echooka Formation, Ledge Sandstone/Shublik Formation, Gilead sandstone, and moderately competent Seabee Formation from each other and allow the competent units to fold at distinct wavelengths according to their mechanical properties. Thick, competent units tend to form long-wavelength folds. Thin, competent units form relatively short-wavelength folds. Thin, competent units that are structurally bound to a thicker, structurally more dominant unit, adhere to the structural style of the dominant unit unless there is some detachment between them. Strain is distributed through shale intervals in the moderately competent units, allowing short-wavelength folds in the thin competent beds. The dominant trend of structures in the area is northeast overprinted on east. East-trending structures formed during the ~60 Ma event that formed the main axis of the Brooks Range and its foothills. Northeast-trending structures formed during the formation of the northeastern Brooks Range dated at ~45 Ma, ~35 Ma, and ~27 Ma, manifest locally by the compressional uplift of the Echooka anticlinorium southeast of Gilead Creek"--Leaf iii.

Download or read book Subsurface Stratigraphic Structural and Economic Geology Northern Alaska written by Florence Rucker Collins and published by . This book was released on 1967 with total page 325 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Thrust breakthrough of Folds Southwest of Galbraith Lake Central Brooks Range Alaska written by Elizabeth A. Grischkowsky and published by . This book was released on 2002 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Detailed mapping of a 32 square-kilometer area in the fold-and-thrust belt of the north-central Brooks Range indicates that fault-related folds in the Lisburne Limestone formed as detachment folds and were subsequently cut by thrust faults. Thrust faulting resulted in a duplex structure with a floor thrust in the Kayak Shale and a roof thrust in the Siksikpuk Formation. The linking thrusts of the duplex dip toward the hinterland while the floor and roof thrusts dip toward the foreland indicating that the duplex has been tilted by underlying structures. I constructed models for the sub-lisburne structure to account for the structural geometry observed in the study area. Duplexing of the Kanayut Conglomerate is the most likely cause of the forward tilt, but thickening of the Kayak Shale or deformation beneath the basal thrust of the Endicott Mountains allochthon may also contribute"--Leaf iii.

Download or read book Structural Geometry and Sequence in the Eastern Sadlerochit Mountains Northeastern Brooks Range Alaska written by Andrew Jacobsen Meigs and published by . This book was released on 1989 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt: