in the Bighorn Basin, Wyoming . 234 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1916, PART II. The trend of the anticline … The #1 Sheep Newton discovery well ignited the oil boom mid-1970s-1980s throughout the Rocky Mountain thrust belt. Geology of Sheep Canyon Quadrangle: Wyoming is the second such detailed investigation by graduate students at Iowa State University. 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. The Wednesday, August 28, 2013. Modeling studies point to the influence of the elastic stress perturbations induced by slip along the underlying faults on this fracturing. The Bighorn River has carved a canyon through the structure perpendicular to the fold axis. Mechanisms for Deformation of Sedimentary Strata at Sheep Mountain Anticline, Bighorn Basin, Wyoming . google_ad_slot = "7812802037"; 0000000927 00000 n Jan 3, 2019 - 121 Likes, 4 Comments - Bernhard Edmaier (@bernhard_edmaier_photography) on Instagram: “Aerial view of the Sheep Mountain Anticline in Wyoming, USA. Observations of shearing also constrain spatial and temporal variations of the stress state across the anticline during folding. Many of the ranges that form the Rocky Mountains also took shape at this time. The eventual goal is complete geologic map coverage of Sheep Mountain Anticline. 0000001292 00000 n Shown above is a railroad cut that runs through this northwest-southeast trending anticline. 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. Sheep Mountain is a Laramide asymmetric, faulted anticline located just north of Greybull, Wyoming. The Sheep Mountain anticline plunges to the northwest. 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 Bighorns Geology Adventure. This summer two of my sons and I took a hike through the Jurassic time period. It is 15 miles long and the involved rock formations, which were originally horizontal, have been bent and uplifted over 1000 feet. Typical anticline. The surface sedimentary rock formations that are exposed in the fold, range in age from 66-360 million years. 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). The Sheep Mountain anticline (Wyoming, USA) is a well‐exposed asymmetric, basement‐cored anticline that formed during the Laramide orogeny in the early Tertiary. - "The role of fractures in the structural interpretation of Sheep Mountain Anticline, Wyoming" Fig. 0000009897 00000 n Sheep Mountain is a textbook example of an anticline fold. Photo by Bernhard Edmaier #patterns #geology We plan to reprocess ten 1980s vintage 2D seismic reflection profiles in the hopes of imaging the fault geometry beneath the anticline, focusing specifically on the abutting relationship between two oppositely dipping thrust faults. 0000000016 00000 n Joint patterns at Sheep Mountain Anticline, WY, USA, indicate that this structure grew laterally. Introduction Sheep Mountain Anticline is located on the northwest flank of the Bighorn Basin, west of the Bighorn Mountains (Figure 1). Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. 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. by impervious shale and within reach of the drill in folds favorable for the accumulation of oil and gas. 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. 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. x�b```"ѷ� �a�sddZ���z�� Y& � �Xd�c����w�'��.�|`�� An example of an anticline is shown in the map below. School Begins! Many of the ranges that form the Rocky Mountains also took shape at this time. The Sheep Mountain anticline, in the Bighorn Basin of Wyoming, formed during the Laramide orogeny. The Ancestral Bighorn River established a course over the landscape while the anticline was still buried at depth. 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. 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. The Laramide orogeny was characterized by a NE–SW compression (Engebretson et al., 1985; Bird, 2002). Where in the World is this GigaPan? Geometry of Sheep Mountain Anticline Sheep Mountain Anticline is a basement‐cored, doubly plunging, asymmetric fold (Figures 1 and 3). 16. Dec 4, 2013 - Tumblr is a place to express yourself, discover yourself, and bond over the stuff you love. startxref Stitcher Notes Toggle Minimize. In this paper, we integrate mechanical stratigraphy 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? by impervious shale and within reach of the drill in folds favorable for the accumulation of oil and gas. Sheep Mountain Anticline, located on the eastern edge of the Bighorn Basin, Wyoming, is a well known NW–SE trending, asymmetric Laramide fold (Fig. 0000001759 00000 n 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. GEOL 102 Historical Geology. the backlimb of the anticline. The San Rafael Swell, Uinta Mountains, and the Rocky Mountains are examples of other geologic features that were formed during Laramide time. " School Begins! D�i��0�%����������� ����. Sheep Mountain anticline is located on the northeast flank of the Bighorn Basin, just west of the Bighorn Mountains. 0000008787 00000 n 0000001007 00000 n Sheep Mountain is a textbook example of an anticline fold. 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. the chronology of the main fracturing events defined using the standard tool of structural geology. The field data gathered then form the basis for a paper titled: "Geologic History of the Sheep Mountain Region". The stream at left is the Bighorn River. Gigapan Comments (0) Toggle Minimize gigapan_comment. 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. anticline n. Geology A fold with strata sloping downward on both sides from a common crest. 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. 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. Field mapping of Sheep Mountain and … The Sheep Mountain anticline, in the Bighorn Basin of Wyoming, formed during the Laramide orogeny. 0000002679 00000 n Shown above is a railroad cut that runs through this northwest-southeast trending anticline. Interaction among faults and influence on folding . This analysis demonstrates that the growth of Sheep Mountain anticline induces a brutal release of 15Mpa of overpressure accumulated before folding during layer parallel shortening. google_ad_client = "pub-1182166660032404"; _GeologyLinks | Geography | Geology | Landforms |, Interact: var addthis_pub="usra";Share | Discuss on Facebook | Subscribe,