Image credit: Wikipedia commons. Sheep Mountain Anticline Joint pattern Mechanical stratigraphy Plate bending abstract Despite how common folds are as structural features, along-strike fold propagation has proven elusive to document. The Sheep Mountain Anticline is situated between the towns of Lovell and Greybull in the northwest part of Wyoming; its long, narrow, and perfectly straight crest is an easily recognizable sight from many areas around the Big Horn Basin. Methods of Study Field observations for this study were begun in June 1976 and were completed by the end of August that same year. Sheep Mountain Anticline conflict with one another. 0000010929 00000 n Field observations of sheared fractures and bedding planes in various structural locations across Sheep Mountain Anticline, Wyoming, document the role of fracture reactivation and flexural slip in folding related deformation. The field data gathered then form the basis for a paper titled: "Geologic History of the Sheep Mountain Region". The white Muddy sand of the black Thermopolis shale appears at the center of view and bends around the nose of the anticline to extend along strike at the left. x�b```"ѷ� �a�sddZ���z�� Y& � �Xd�c����w�'��.�|`�� 27 0 obj<> endobj Geology of Sheep Canyon Quadrangle: Wyoming is the second such detailed investigation by graduate students at Iowa State University. Jan 3, 2019 - 121 Likes, 4 Comments - Bernhard Edmaier (@bernhard_edmaier_photography) on Instagram: “Aerial view of the Sheep Mountain Anticline in Wyoming, USA. May 1, 2019 - Aerial view of the Sheep Mountain Anticline in Wyoming, USA. Methods of Study Field observations for this study were begun in June 1976 and were completed by the end of August that same year. Modeling studies point to the influence of the elastic stress perturbations induced by slip along the underlying faults on this fracturing. D�i��0�%����������� ����. The fold trends northwest-southeast and is cut by the Bighorn River approximately perpendicular to this trend . An anticline is a geologic formation where the strata slope downward on either side of a crest, and this particular mountain is one of the more famous examples of this kind of formation. 0000011791 00000 n Little Sheep Mountain Anticline - Fracture Analysis Graduate thesis research pertaining to fracture analysis of the Little Sheep Mountain Anticline. Sheep Mountain is a textbook example of an anticline fold. May 20, 2013 - The fascinating, awe inspiring, beer drinking world influenced by the earth's oldest science. The Laramide orogeny was characterized by a NE–SW compression (Engebretson et al., 1985; Bird, 2002). The development of fractures in the sedimentary layers of Sheep Mountain Anticline, a Laramide asymmetric fault-cored fold of the Bighorn Basin, is documented and interpreted to constrain the kinematic evolution of the fold. If you look closely, you may be able to see flat irons, exposed bedding surfaces, dipping away from the center of the fold. 0000000696 00000 n It is a basement-cored thrust-fault related fold of Laramide age. An investigation into the role of fault interaction on fold pattern, Journal of Structural Geology, vol. School has begun, which means that I will have less time to go to the field. Sheep Mountain anticline is located on the eastern flank of the Bighorn Basin (Figure 1a), north central Wyoming, north of the town of Greybull. The Ancestral Bighorn River established a course over the landscape while the anticline was still buried at depth. The surface sedimentary rock formations that are exposed in the fold, range in age from 66-360 million years. This summer two of my sons and I took a hike through the Jurassic time period. Define anticline. By the time the boom was over at least 20 fields had been discovered on the Absaroka thrust plate. Toggle. Wednesday, August 28, 2013. In this paper, we integrate mechanical stratigraphy The eventual goal is complete geologic map coverage of Sheep Mountain Anticline. Name: _____ _ The image above features a slightly off-axis view of the NW-plunging nose of the Sheep Mountain anticline (44.642°N, 1 OB.186°W) in the Bighorn Basin of Wyoming (left side of image). 234 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1916, PART II. The surface sedimentary rock formations that are exposed in the fold, range in age from 66-360 million years. Bergbauer , S. & Pollard , D. D. 2004 . Shown above is a railroad cut that runs through this northwest-southeast trending anticline. The faults and associated fold both trend in a northwest to southeast direction for … @article{osti_6084236, title = {Surface and subsurface analysis of Sheep Mountain anticline, Wyoming}, author = {Abercrombie, S.}, abstractNote = {The Sheep Mountain area, in the southwest Wind River Basin, is the up plunge closure of the Derby Dome-Winkleman Dome producing trend of an echelon folds which comprise the first line of folding down the northeast flank of the Wind River Mountains. 0000001186 00000 n 2004. 0000002914 00000 n The Sheep Mountain Anticline is a fold generated during the Laramide mountain building event from 70 to 50 million years ago. The Ancestral Bighorn River established a course over the landscape while the anticline was still buried at depth. Sheep Mountain Anticline, located on the eastern edge of the Bighorn Basin, Wyoming, is a well known NW–SE trending, asymmetric Laramide fold ().The Laramide orogeny was characterized by a NE–SW compression (Engebretson et al., 1985, Bird, 2002).The Bighorn River cuts the anticline normal to the fold axis, providing exposure of rock strata in the fold core. 0000004414 00000 n Thus, I must pick the areas I will go for fracture analysis wisely. The Bighorn River has carved a canyon through the structure perpendicular to the fold axis. However, if a fold grows laterally along its axis, early-formed fold-related joints may differ significantly in orientation from joints that form later. by impervious shale and within reach of the drill in folds favorable for the accumulation of oil and gas. @article{osti_6084236, title = {Surface and subsurface analysis of Sheep Mountain anticline, Wyoming}, author = {Abercrombie, S.}, abstractNote = {The Sheep Mountain area, in the southwest Wind River Basin, is the up plunge closure of the Derby Dome-Winkleman Dome producing trend of an echelon folds which comprise the first line of folding down the northeast flank of the Wind River Mountains. The fold is cut by the Bighorn River perpendicular to the fold hinge, providing excellent exposure of Upper Paleozoic strata in the core of the fold. 0000005465 00000 n Stanford Libraries' official online search tool for books, media, journals, databases, government documents and more. The Sheep Mountain anticline plunges to the northwest. Sheep Mountain South The Sheep Mountain Anticline is situated between the towns of Lovell and Greybull in the northwest part of Wyoming; its long, narrow, and perfectly straight crest is an easily recognizable sight from many areas around the Big Horn Basin. The Bighorn River cuts the anticline normal to … Shown above is a railroad cut that runs through this northwest-southeast trending anticline. Jeff Hennier, John H. Spang. Journal of Structural Geology 28 , 850 –67. Sheep Mountain Anticline Joint pattern Mechanical stratigraphy Plate bending abstract Despite how common folds are as structural features, along-strike fold propagation has proven elusive to document. As Sheep Mountain is a topographic high and barrier to streamflow, how was the river able to establish itself and eventually erode through the anticline? Savage, Heather M. and Michele L. Cooke. The large fold seen in the sedimentary rocks at Sheep Mountain was created by crystalline basement rock uplifted along faults that parallel the long axis of the structure along the steeper east flank. Map 1: This structure is the Sheep Mountain anticline in Wyoming. Typical anticline. It's where your interests connect you with your people. 0000002679 00000 n Geology Of the Bighorn Basin; 34th Annual Field Conference Guidebook, 1983 Pages 96-111. Joint patterns at Sheep Mountain Anticline, WY, USA, indicate that this structure grew laterally. The Mowry shale crops out in a SE-plunging syncline at the right. 27 20 by impervious shale and within reach of the drill in folds favorable for the accumulation of oil and gas. The Sheep Mountain anticlinal complex between Lovell and Greybull, Wyoming, in the Bighorn basin provides exposure suitable for three-dimensional stratigraphic studies of Mesozoic rocks. Fracture pattern in the hinge. Sheep Mountain Anticline: Backlimb Tightening and Sequential Deformation. The Mowry shale crops out in a SE-plunging syncline at the right. The Sheep Mountain anticline plunges to the northwest. Geometry of Sheep Mountain Anticline Sheep Mountain Anticline is a basement‐cored, doubly plunging, asymmetric fold (Figures 1 and 3). 0000000927 00000 n xref Please report any quality issues you encounter to digital@library.tamu.edu, referencing the URI of the item. An anticline … <]>> Heather I. Stanton and Eric A. Erslev. Many of the ranges that form the Rocky Mountains also took shape at this time. Observations of shearing also constrain spatial and temporal variations of the stress state across the anticline during folding. The Sheep Mountain anticline, in the Bighorn Basin of Wyoming, formed during the Laramide orogeny. Stitcher Notes Toggle Minimize. Categories: The %%EOF As Sheep Mountain is a topographic high and barrier to streamflow, how was the river able to establish itself and eventually erode through the anticline? School has begun, which means that I will have less time to go to the field. In the case of sheep mountain imagine that the area around the center of this image is eroded leaving a peak where the folded rocks are bent up. Photo taken on May 28, 2013. 16. google_ad_client = "pub-1182166660032404"; Fold geometry at Sheep Mountain anticline, Wyoming, constructed using airborne laser swath mapping data, outcrop-scale geologic mapping, and numerical interpolation JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH Lovely, P., Zahasky, C., Pollard, D. D. 2010; 115 google_ad_slot = "7812802037"; Introduction Sheep Mountain Anticline is located on the northwest flank of the Bighorn Basin, west of the Bighorn Mountains (Figure 1). 1). Sheep Mountain Anticline, located on the eastern edge of the Bighorn Basin, Wyoming, is a well known NW–SE trending, asymmetric Laramide fold (Fig. School Begins! //-->, Earth Science Picture of the Day is a service of, Earth Science World Image Bank: Sheep Mountain Anticline, A Virtual Field Trip to the Virgin Anticline, North Antelope Rochelle Coal Mine, Wyoming. basement-cored, fault-related fold: Sheep Mountain Anticline, Wyoming, United States Nicolas Beaudoin, Nicolas Bellahsen, Olivier Lacombe, Laurent Emmanuel To cite this version: Nicolas Beaudoin, Nicolas Bellahsen, Olivier Lacombe, Laurent Emmanuel. However, if a fold grows laterally along its axis, early-formed fold-related joints may differ significantly in orientation from joints that form later. 0000002261 00000 n It's where your interests connect you with your people. The fracture pattern is interpreted to identify five main fracture sets. the chronology of the main fracturing events defined using the standard tool of structural geology. Spence Cave is an inactive, dry cave located 390 feet above the Bighorn River in the Upper Madison Formation. Many studies have investigated the large scale structure of this anticline, including the fold shape and the underlying There were two productive trends, the western trend aligned with the fault cutoff of the Paleozoic section and the second at the fault cutoff of the Jurassic Twin Creek. Wednesday, August 28, 2013. the backlimb of the anticline. Field mapping of Sheep Mountain and … trailer Many of the ranges that form the Rocky Mountains also took shape at this time. google_ad_height = 200; Sheep Mountain is a textbook example of an anticline fold. Mechanisms for Deformation of Sedimentary Strata at Sheep Mountain Anticline, Bighorn Basin, Wyoming . In order to unravel the history of strain during folding, we carried out combined anisotropy of magnetic susceptibility (AMS), anisotropy of P ‐wave velocity (APWV) and Fry strain analyses. The trend of the anticline … The Ancestral Bighorn River established a course over the landscape while the anticline was still buried at depth. Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Little Sheep Mountain Anticline - Fracture Analysis Graduate thesis research pertaining to fracture analysis of the Little Sheep Mountain Anticline. /* Archives 200x200 */ Sheep Mountain Anticline, Wyoming Coordinates. Mesozoic strata at the Sheep Mountain Anticline, Bighorn Basin, Wyoming Different ways to divide up the geologic record: Lithostratigraphy: by physical attributes of rock Biostratigraphy: by index fossils It is 15 miles long and the involved rock formations, which were originally horizontal, have been bent and uplifted over 1000 feet. (a) Field photograph of bedding surface showing the abutting relationships between Sets II (0458) and III (1358) at hinge site 39 in a sandstone of the Amsden Fm. Fold geometry at Sheep Mountain anticline, Wyoming, constructed using airborne laser swath mapping data, outcrop-scale geologic mapping, and numerical interpolation JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH Lovely, P., Zahasky, C., Pollard, D. D. 2010; 115 By. Mechanical model of two interacting faults. Stanford Libraries' official online search tool for books, media, journals, databases, government documents and more. Typical anticline. The white Muddy sand of the black Thermopolis shale appears at the center of view and bends around the nose of the anticline to extend along strike at the left. Sheep Mountain is a Laramide asymmetric, faulted anticline located just north of Greybull, Wyoming. Dec 4, 2013 - Tumblr is a place to express yourself, discover yourself, and bond over the stuff you love. 0000003215 00000 n The trend of the anticline parallels that of the Bighorn Mountain uplift located 20 miles to the east. This summer two of my sons and I took a hike through the Jurassic time period. Thus, I must pick the areas I will go for fracture analysis wisely. Day 2: Sheep Mountain June 29, 2009 6/23/09 “And be on guard, I saw five or six rattlesnakes last time I was here.” Chris and Eric at the anticline. anticline n. Geology A fold with strata sloping downward on both sides from a common crest. Comb Ridge is the abrupt eastern flank of the Monument Upwarp. Bighorns Geology Adventure. Near Greybull, Wyoming is a long ridge called Sheep Mountain. %PDF-1.4 %���� The role of fractures in the structural interpretation of Sheep Mountain Anticline, Wyoming. 26, pp 905-917. 29 0 obj<>stream The blue line down the center of the fold represents the axial trace, or the line that separates the two dipping limbs of the fold. 0000001007 00000 n 0000007620 00000 n 0000009897 00000 n Sheep Mountain Anticline is a basement cored, doubly-plunging, asymmetric fold on the east limb of the Bighorn structural basin. The Sheep Mountain anticline (Wyoming, USA) is a well-exposed asymmetric, basement-cored anticline that formed during the Laramide orogeny in the early Tertiary. 0000001292 00000 n As Sheep Mountain is a topographic high and barrier to streamflow, how was the river able to establish itself and eventually erode through the anticline? An anticline is an upward, curved fold in the layers of rock in the earth's surface. The #1 Sheep Newton discovery well ignited the oil boom mid-1970s-1980s throughout the Rocky Mountain thrust belt. Name: _____ _ The image above features a slightly off-axis view of the NW-plunging nose of the Sheep Mountain anticline (44.642°N, 1 OB.186°W) in the Bighorn Basin of Wyoming (left side of image). It is a basement-cored thrust fault–related fold that formed in response to Laramide tectonics. The Sheep Mountain anticline, in the Bighorn Basin of Wyoming, formed during the Laramide orogeny. Sheep Mountain Anticline, located on the eastern edge of the Bighorn Basin, Wyoming, is a well known NW–SE trending, asymmetric Laramide fold ().The Laramide orogeny was characterized by a NE–SW compression (Engebretson et al., 1985, Bird, 2002).The Bighorn River cuts the anticline normal to the fold axis, providing exposure of rock strata in the fold core. In the case of sheep mountain imagine that the area around the center of this image is eroded leaving a peak where the folded rocks are bent up. In addition to simply making geologic maps, stratigraphic sections and structural cross-sections, the students have to put the local geology into the broader contexts of the Big Horn Basin and sequences of western orogenies. Fracture controlled pale-ohydrogeology in a basement-cored, fault-related fold: Sheep Mountain Anticline, Wyoming, United States. " Compressional forces during the Laramide mountain-building event (40–70 million years ago) uplifted an area of southeast Utah known as the Monument Upwarp. startxref 0000003139 00000 n 0000008787 00000 n Spring Semester 2020 Lithostratigraphy. It is 15 miles long and the involved rock formations, which were originally horizontal, have been bent and uplifted over 1000 feet. 0000006560 00000 n Recent field studies at Sheep Mountain Anticline, a Laramide fold on the eastern flank of the Bighorn Basin in Wyoming, constrain the fold kinematics using the fracture pattern mapped across the fold. _GeologyLinks | Geography | Geology | Landforms |, Interact: var addthis_pub="usra";Share | Discuss on Facebook | Subscribe,