The Company is involved in the exploration and development of mineral properties in Australia and the United States. Because there was no more plate coupling beneath southeastern Arizona after this time, crustal thinning could commence. Together, these two locales indicate the field area has been tilted 90 to the east during Cenozoic extension. With additional work, the nature of shortening, i.e., primarily the geometry, magnitude, and timing of structural features, also could be characterized well in the Laramide porphyry copper belt of Arizona because extension has exposed the Laramide crust at a wide range of crustal depths (Barton et al., 1988; Seedorff et al., 2008). This fault generation is composed of the primarily steeply east-dipping faults of set 5 (Table 3). 5), the Romero Wash fault strikes N25W, dips 2836E, and places older Ruin Granite on younger Apache Group and diabase. This generation includes all faults from set 4 (Table 3). 19) indicates that the Romero Wash fault is a backthrust to the Tecolote fault due to their opposing vergence directions and because the Romero Wash fault has significantly less displacement than the Tecolote fault. We and our partners use cookies to Store and/or access information on a device. These relationships indicate that the western dike contact is the fault plane. Because the presently east-dipping Romero Wash fault projects under cover to the east (Fig. One might not expect two highly contrasting styles of shortening to be only 20 km apart, perhaps even along strike. Because the only other known period of pre-Cenozoic deformation within the region occurred during the early Mesoproterozoic, and the Romero Wash and Tecolote faults cut late Mesoproterozoic diabase, these faults are inferred to be of Laramide age. If you disable this cookie, we will not be able to save your preferences. 18). The porphyry mineralization occurs in and near an intrusion of Laramide San Manuel porphyry in Precambrian Oracle Grani Near Cow Fence Wash (Figs. The amount (and rate) of rock uplift of individual Laramide ranges was less than 2.4-4.8 km (~0.21-0.32 mm/yr) during the early Maastrichtian-Paleocene (stage 1) and increased to more than ~3 km (~0.38-0.60 mm/yr) during the late Paleocene-early Eocene (stage 2). Plots were generated with the program Stereonet 9 (Allmendinger et al., 2012). In all examples documented to date in the Laramide porphyry copper belt of Arizona, porphyry generation and associated hydrothermal alteration postdates reverse faulting at the point of observation. Structural reconstruction along line of section AA moving forward in time from Laramide time (before shortening) to modern. The largest and most prominent fold within the study area is the Tecolote syncline. [4], At most boundaries, Paleozoic through Paleogene units dip steeply into the basins off uplifted blocks cored by Precambrian rocks. 21). One occurrence of exotic copper conglomerate was found near the southern Smith Granodiorite stock. Deformaciones Sevier y Laramide, su presencia en Sonora Sample Ksg-s is a Smith Granodiorite porphyry dike that crosscuts the Romero Wash fault just south of Cow Fence Wash (Fig. Following a period of erosion, rocks of the Proterozoic Apache Group, consisting mostly of fine siliciclastic and lesser carbonate rocks, were deposited on the beveled surface. Laramide's wholly owned subsidiary, Tackle Resources Pty Ltd, owns 100% of . In (B), apparent dip of Tecolote fault in restored cross section is slightly steeper than the true restored dip reported in Table 4 because the strike of the fault rotates during the restoration. In contrast, farther to the south, within a large area centered on the Whetstone Mountains (Fig. (B) Geologic cross section after reverse faulting and intrusion of the Rattle Granodiorite and before Cenozoic extension. The geometry of Laramide foreland magmatism is most unlike an arc. The Jim Thomas syncline, located along Jim Thomas Wash (Fig. Keeping this cookie enabled helps us to improve our website. You can try again. Structural reconstruction along section BB (Fig. Thacker, Jacob O., 2020, Horizontal shortening of the Laramide Zuni arch, west-central New Mexico: A preliminary study: New Mexico Geological Society Special Publication 14, p. 167175. The Tecolote fault places younger Apache Group and diabase on older Ruin Granite. Faults of generation 2 cut and offset faults of generation 1, and faults of generation 2 are cut by faults of generation 3. We are using cookies to give you the best experience on our website. Laramide orogeny - Wikipedia audio files are free to play or download. You can contribute this audio pronunciation of Ceramide to HowToPronounce dictionary. Since you have exceeded your time limit, your recording has been stopped. 3 and 22). Most bounding faults show evidence of at least two episodes of Laramide (Late Cretaceous and Eocene) movement, suggesting both thrust and strike-slip types of displacement. The greater areal distribution and earlier timing of northern Laramide deformation provides new constraints on the shape, timing, and path of entry of the flat slab (with or without a . Structural reconstruction along line of section BB. A structural reconstruction of Cenozoic normal faults along a regional line of section AA (Fig. Uncertainties shown in this table are at the 1-sigma level and include only measurement errors. Presently, the Romero Wash fault is an overturned reverse fault that places older Ruin Granite on younger Apache Group but with a down-dip sense of displacement (Fig. Due to relative offsets of diabase and Apache Group just southeast of Bee Wash, the Romero Wash fault is interpreted to continue northward through the Bee Wash area (Figs. Evidence for east-vergent Laramide reverse faults and associated folds in Paleozoic and Mesozoic strata is also observed farther north in the Superior district (Manske and Paul, 2002). The Romero Wash fault system is interpreted to have a strike length of 11 km and may have accommodated the most displacement where it is buried under Cenozoic cover, just east of Smith Wash (Fig. 9A). Average modern dips of each fault generation and modern range of dips for synextensional formations are given. It is a family of waxy lipid molecules that provides moisture to the skin. Oxidized copper minerals such as malachite and chrysocolla have been observed in the Ruin Granite and Pioneer Shale near the Romero Wash fault and in diabase where it is cut by the Smith Granodiorite. In the few examples with geologic constraints, these porphyry systems appear to postdate shortening (Manske and Paul, 2002; Barton et al., 2005; Nickerson et al., 2010). Subscribe to America's largest dictionary and get thousands more definitions and advanced searchad free! 5 and 16). Runyon (2016, personal commun. 16). Here, the Romero Wash fault strikes N25W to N, dips 5560E, and places older Apache Group and diabase on younger Apache Group and diabase. The values presented are based on observed attitudes of Cenozoic strata and normal faults within the map area, coupled with the structural reconstructions, except for generation 2. This study began with a compilation of previous maps of the area by Krieger (1974a, 1974b), Keith (1983), and Dickinson (2002). Synextensional sedimentary rocks with fanning-upward sequences (e.g., Cloudburst Formation and San Manuel Formation) were deposited in the hanging walls of these normal faults. Once restored, major faults within fault set 2a strike roughly S27E and dip 65NNE (Table 4) and appear to be normal faults. Step (H) involves no faulting but demonstrates erosion that produces the modern cross section. 3). Moderate. Because of this, dips are also uncertain, but they are estimated to be 20E because of the attitudes of similar faults only a few km to the north near Ripsey Wash (Nickerson et al., 2010, p. 308309). 1.7 Ga (Meijer, 2014), which subsequently was intruded by various plutons, including the Ruin and Oracle Granites at 1.4 Ga (Conway and Silver, 1989; Dickinson, 1991). (B) Geologic cross section after reverse faulting and intrusion of the Rattle Granodiorite and before Cenozoic extension. The net amount of tilting associated with this fault generation is 20E (Fig. Following an extended period of tectonic quiescence, the subducting slab underneath the North American Cordillera steepened from its previously subhorizontal orientation, allowing for a new influx of magmatism from 3415 Ma (Dickinson, 1991). Beds are highlighted with dashed purple lines. You have earned {{app.voicePoint}} points. Laramide structures that are exposed along much of the Laramide porphyry copper province of southeastern Arizona have been dismembered and tilted by superimposed Cenozoic normal faults, such that the overall style of shortening (e.g., thin-skinned, low-angle thrusts versus basement-cored, moderate-angle reverse faults) is unclear pending a compelling reconstruction of superimposed extension. Structural reconstructions from this study indicate that the Tecolote fault is a reverse fault with associated fault-propagation folds (Fig. Both the Tecolote and Romero Wash faults demonstrate clear evidence for fault-propagation folds (Figs. doi: https://doi.org/10.1130/GES01381.1. Register 3). Late Cretaceous-early Eocene Laramide uplift, exhumation, and basin The center of the study area is 80 km north of Tucson and 120 km east-southeast of Phoenix. In New Mexico, the work has important implications for the states natural resources, such as oil and gas and metals, as well as groundwater. [4], According to paleontologist Thomas M. Lehman, the Laramide orogeny triggered "the most dramatic event that affected Late Cretaceous dinosaur communities in North America prior to their extinction. [2] Geologists call such a lack of volcanic activity near a subduction zone a magmatic gap. The reconstruction presented here closely resembles Proffetts (1977) reconstruction of the Yerington district, Nevada, where rocks had been rotated steeply westward by multiple sets of crosscutting normal faults. We appreciate the constructive comments of Jon Spencer and Tim Lawton, and especially the useful, detailed comments of Associate Editor Terry Pavlis. Log in or It was chosen for dating to place an upper age limit on the Romero Wash fault. The Walnut Canyon thrust is located just northwest of this study area, where we have interpreted basement-cored uplifts to be the shortening style. 80 Ma to ca. Tilting history of the San Manuel-Kalamazoo porphyry system Many of the iconic mountains and major oil and gas producing intermontane basins of the Rocky Mountains and Colorado Plateau, such as the Wind River range in Wyoming and the San Juan Basin here in New Mexico, formed during this time as Earths crust was compressed. Primary copper mineralization has only been observed in a small number of locations. Assuming a bedding-to-fault angle of 60 (i.e., possibly the expected angle of an initially steeply west-dipping fault) with beds at the base of the upper Cloudburst Formation that currently dip 50E, then the present-day attitude of second-generation faults might be expected to be 10W, as discussed further in the reconstruction below. The Romero WashTecolote Ranch area is located within a highly extended portion of the southeastern Basin and Range province where mid- to late Cenozoic extension resulted in dismemberment of the Laramide magmatic arc (Dickinson, 1991). 3 and 6). The Swim Hole fault has also been projected from north of the line of section (Fig. Onset of Laramide arch development is estimated from cooling recorded in representative thermochronologic samples in a three-step process of initial forward models, secondary HeFTy . The total thickness of pre-Cenozoic strata is 1 km in the study area, and a complete section is only observed west of Jim Thomas Wash (Fig. You can contribute this audio pronunciation of Laramide orogeny to HowToPronounce dictionary. There are few examples where time-space relationships between shortening and porphyry copper generation can be demonstrated, with the scarcity of examples in part due to a lack of detailed observations. Important Laramide intrusions include diorite, Smith Granodiorite, and Rattler Granodiorite (Fig. Laramide y, de Ia misma manera que para el sureste En una una hipOtesisdiferente para explicar de Arizona, se han propuesto dos diferentes estas estructuras se considera que la provincia hipatesis para el mecanisrno de su deformacion. The normal faults that crop out in the field area can be grouped into four separate generations using crosscutting relationships, and an additional generation is interpreted to be present based on relationships exposed north of the field area (Table 3). The Laramide San Manuel-Kalamazoo porphyry system of Arizona has been pivotal in concepts of both extensional tectonics and alteration-mineralization zoning. Similar features in the Sierras Pampeanas in Argentina are forming above a zone of shallow-angle subduction, suggesting a similar process may have occurred beneath western North America during the Late Cretaceous. The Laramide orogeny is sometimes confused with the Sevier orogeny, which partially overlapped in time and space.[1]. Faults belonging to sets 2b, 3, 4, and 5 are Cenozoic normal faults because they cut all Laramide features (Fig. Pronunciation of Laramide orogeny with 2 audio pronunciations 0 rating 0 rating Record the pronunciation of this word in your own voice and play it to listen to how you have pronounced it. The overturned limb is inconsistent with normal fault-drape folding, and map patterns of bedding attitudes suggest that the Jim Thomas syncline is not coaxial with the Tecolote syncline. Unfortunately, this device does not support voice recording, Click the record button again to finish recording. Magmatism associated with subduction occurred not near the plate edges (as in the volcanic arc of the Andes, for example), but far to the east, along the Colorado Mineral Belt. Active New Mexico Bureau of Geology mapping and research focuses on studying Laramide features in the state. The style of Laramide shortening in southeastern Arizona appears to be variable (Fig. Browse nearby or related words . 3 and 9D). 19B). Log in or Oops! Unfortunately, this device does not support voice recording, Click the record button again to finish recording. Scientists have long debated the uplift of the Colorado Plateau region (CP), including the modern Colorado River (CR) drainage from the Rocky Mountains to where it exits the modern plateau southwest of Grand Canyon (GC; Figure 1).This region was a tectonically stable sedimentary basin near sea-level until the Laramide orogeny initiated in the Late Cretaceous (Hunt, 1956; Nations . 5), an unaltered Smith Granodiorite porphyry dike, with a U-Pb zircon age of 65.87 0.69 Ma, crosscuts the Romero Wash fault; therefore, the Romero Wash fault must be Laramide or older. Calcite-siderite veins occur throughout the study area, primarily near faults, and may be a more distal expression of propylitic alteration. The cut-off angle (red) between the oldest synextensional strata and the modern fault dip is the inferred angle of initiation for a given fault generation. Until there are more examples of these relationships, the dominant patterns remain elusive. 20) and CC (Fig. Likewise, faults of set 3 in the study area likely bounded the half-grabens in which the sediments of the San Manuel Formation accumulated (see generation 3 below). Twelve kilometers of structural relief between basins and adjacent uplifts is not uncommon. Laramide | AZGS Smith Granodiorite porphyry also cuts the Tecolote fault, but the Tecolote fault cuts a dacite porphyry within the fault-bounded footwall Tecolote syncline (Tables 3 and 4). The orogeny is commonly attributed to events off the west coast of North America, where the Kula and Farallon Plates were sliding under the North American plate. How to pronounce lampyridae | HowToPronounce.com Finally, two-mica granites were emplaced from the late Laramide to the mid-Cenozoic (e.g., Gehrels and Smith, 1991; Fornash et al., 2013). 130 King Street West, Suite 3680 Difficult. The Crownpoint-Churchrock Uranium Project consists of two discrete ISR-amenable uranium deposits, Crownpoint and Church Rock, covered by a single NRC licence. Topographically, the basin floors resemble the surface of the western Great Plains, except for vistas of surrounding mountains. You can find out more about which cookies we are using or switch them off in settings. Supplemental File 2 (see footnote 3) is a 3D model of the structures after they have been rotated 90W, restoring them to their original orientations. Laramide mountain ranges and Yellowstone Park - geology.wisc.edu The Laramide orogeny was a mountain building event that affected the US western interior during the Late Cretaceous to Paleogene (approximately 90-45 million years ago). In rare exposures of the fault within this area, there is a zone of fault breccia and gouge roughly 1 m wide. Faults that have been involved in structural reconstructions have qualitative uncertainty values for both the amount of offset and amount of tilting. 3). 17). Subscribe to learn and pronounce a new word each day! In several cases, displacements are estimated from fault exposures north of the line of section where the same faults cut rocks with reliable markers, such as near Hackberry Wash and the Tea CupGrayback pluton (e.g., Seedorff and Maher, 2003; Barton et al., 2007; Nickerson et al., 2010). Fault set 2b consists of the Dirt and Sand faults (Table 1), which occur west of Jim Thomas Wash. This erosion would result in a maximum of 250-300 m of rock uplift, assuming Airy isostasy. 5). Other significant reverse faults are located within the Little Rincon Mountains, Santa Rita Mountains, Chiricahua Mountains, and the Christmas and Superior mining districts (Fig. Both features strike northeast, dip steeply to the southeast or northwest, and affect Ruin Granite and related aplite dikes. Crosscutting relationships indicate that sample Krd cannot be Proterozoic in age. The fault strikes N40E to N10E and dips 41W. This suggests these faults may be related to the deposition of the lower Cloudburst Formation (i.e., fault set 2b). "laramide" pronunciation, "laramide disturbance" pronunciation, "laramide sands" pronunciation, laram (line addressable ram) laram (line addressable ram) laram (line addressable ram) laram (line addressable ram) sound 3, 5, and 6) and includes the Romero Wash fault and Bee Wash fault (Table 1). Location for this figure is shown in Figure 3. Our Mineral Museum Consequently, a structure contour map was made for the fault based on the intersection of topography with the trace of the fault for a length of 1 km, which yields a dip of 28W (Fig. How to pronounce Laramide orogeny | HowToPronounce.com Reverse faulting appears to have predated porphyry generation and related hydrothermal alteration at Kelvin-Riverside (Nickerson et al., 2010), Resolution (Manske and Paul, 2002), and Ray (Barton et al., 2005; Maher, 2008). A pervasive east-northeasttrending quartz biotite fabric in Ruin Granite has been mapped northwest of the study area in the Kelvin-Riverside area (Schmidt, 1971). Nearby towns include Dudleyville and Winkelman, both located 7 km to the west. Once restored to its original orientation (Fig. The first generation of Cenozoic normal faults consists of faults from set 2b (Table 3), because faults of sets 1 and 2a are Laramide faults (see above). This change in bedding orientation occurs locally around the Romero Wash and Bee Wash faults, as shown in roughly E-W cross sections (Figs. (A) Restored geologic cross section along line of section BB during Laramide time, before reverse faulting. Magmas were emplaced throughout the Laramide time interval in southeastern Arizona (e.g., Reynolds et al., 1986). U-Pb ages were obtained from microanalysis of zircons by the laser ablationinductively coupled plasmamass spectrometry (LA-ICP-MS) method at the University of Arizona. This is where Cenozoic extension and associated sedimentation have resulted in dismemberment, tilting, burial, and local erosion of earlier products of Laramide deformation (Dickinson, 1991). pronouncekiwi Listen to the pronunciation of Laramide Orogeny and learn how to pronounce Laramide Orogeny correctly. Investor Centre - Laramide Resources Ltd. Within the main area of alteration, the Diorite and Southern Ridge faults crosscut altered rocks. Geologic map of the Romero Wash area. (8 votes) Very easy. Associated veins include carbonate, epidote, and chlorite veins. Fault propagation to slip ratio for Tecolote fault = 2.0. 3) was primarily mapped using the Anaconda paper- and mylar-based mapping method (Brimhall et al., 2006) at scales ranging from 1:5000 to 1:10,000. Another proposed cause was subduction of thickened oceanic crust. Restoration of offset along this younger fault indicates that the Dirt fault and Sand fault are likely separate, parallel faults, with the Dirt fault being structurally higher. In addition, the relatively large interlimb angle of the Jim Thomas syncline supports this claim. Crosscutting Smith Granodiorite Porphyry (Fig. This parallelism suggests that some kind of shear-parallel mechanism for melt generation is more likely than a typical slab dewatering mechanism, which . [4], During the Laramide orogeny, basin floors and mountain summits were much closer to sea level than today. The estimated uncertainty in the amount of tilting for Cenozoic fault generations is fair for generations 2 and 3 (20%) and good for generations 1 and 4 (10%). : of or relating to the mountain-making movements near the opening of the Cenozoic era Word History Etymology irregular from Laramie mountains, southeastern Wyoming and northern Colorado Love words? You've got the pronunciation of lampyridae right. Keep up. In line with Laramides strategy, the Projects provide the potential for low cost, low technical risk uranium mining operations. Oops! After the seas retreated from the Rocky Mountain region, floodplains, swamps, and vast lakes developed in the basins. The amount (and rate) of rock uplift of individual Laramide ranges was less than 2.4-4.8 km (~0.21-0.32 mm/yr) during the early Maastrichtian-Paleocene and increased to more than ~3 km (~0.38-0.60 mm/yr) during the late Paleocene-early Eocene. However, the larger width and along-strike extent of the Laramide belt remains difficult to explain. Geologic evidence indicates that alteration appears to postdate reverse faulting within the study area even though there is no indication of Laramide faults or folds near the two centers of alteration. The Hackberry fault displays similar relationships. The amount of Laramide shortening (e = l/li) in the study area was 1.8 km or 20%, followed by a small amount of late Laramide extension.
