The pacific northwest has been the site of ongoing orogenies since north america rifted from the rest of pangaea approximately 200 million years ago. Nevadan orogeny mid to late jurassic sevier orogeny mid. Cenerian orogeny is a newly suggested term for these early paleozoic events, which culminate in the ordovician. Chapter 2 geologic history of west texas kevin urbanczyk1, david rohr1, and john c. An overview article pdf available in geological society london special publications 1211. Segmentation of the laramide slabevidence from the. The laramide orogeny refers to a phase of mountain building that affected parts of montana, wyoming, colorado, and lesser areas of nearby states see the shaded area in the figure below. Evaluation of the different geodynamic models requires analysis of the timing, rates, and patterns of rock uplift sensuenglandandmolnar, 1990 over the long duration of laramide deformation during the late cretaceousearly eocene. Sep 27, 2019 orogeny, that is, the creation of the southern rocky mountains between something like 75 and 45 million years ago.
An orogeny is a major cycle of mountain building that affects an entire region of a continent. Black hills granite, igneous intrusion that poped up through a sedimentary cap during the laramide orogeny 70. The event is commonly defined in a temporal context to encompass a basementinvolved style of deformation that took place from about 75 to 40 ma coney, 1976. Age constraints from reos geochronology in molybdenite fernando barra, joaquin ruiz, victor a. In the part of the southern tuscarora mountains currently under study, the roberts mountains thrust crops out only in the general area of the dee mine and bootstrap hill fig.
A late jurassic 150 ma consolidation of the subduction boundary and the nevadan orogeny. Generalized geology of the northern part of the carlin trend showing location of santa renia fields and beaver peak 712 mi nute quadrangles, nev. Tectonic evolution of the sevier and laramide belts within. Kinematics of the uinta fault system southern wyoming and.
The episode started with the earliest paleozoic rifting, extending from ellesmere island to melville island see also. The mescal quadrangle straddles the divide between the tucson basin to the west and the san pedro basin to the east. In the alps, relicts of prevariscan basement are composed of metagreywackes and metapelites partly migmatic with intercalated amphibolites and sheets of cambroordovician peraluminous metagranitoids. The laramide province is characterized by foreland basin partitioning through the growth of basement arches. They consist mainly of monzogranite and kfeldspar granite. White1 introduction the region embraced within the transpecos region of texas encompasses many snapshots of north american geologic history. We present the results of field mapping, structural and metamorphic analysis in an area at the. Jurassic and continued into the cenozoic was the cordilleran orogeny or the mountain building activity. Most of the orogenys are related to the continued westward movement of the n.
Since the sevier and laramide orogenies occurred at similar times and places, they are sometimes confused. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Laramide uplifts are topographically high areas that were created during this period. Given that the laramide orogeny occurred from roughly 70 to 40 ma ago e. Orogeny pdf tional of mice and men pdf full book sliding as a possible oded schwartz preserving pdf mechanism of orogenic deformation. A new perspective on the relationship between orogenic gold mineralization and crustal shearing is presented in this case study on the gold deposits along ailaoshan.
Early yanshanian magmatic suites predominate absolutely in the nanling granite belt. Tethyan margin and th start of orogenesis in the western and central alps. Open buy once, receive and download all available ebook formats, including pdf, epub, and mobi for kindle. Steepwalled canyons, broad exhumed basins, and dissected subsummit erosion surfaces all record the history of deep incision mostly by rivers that began sometime after the end of the laramide orogeny ca. The largely amagmatic laramide style of deformation can be ascribed to the dynamic effects of an overlapped plate scraping beneath the cordillera. Relationship between orogenic gold mineralization and.
Laramide porphyry cumo mineralization in northern mexico. The mountains formed by the alleghanian orogeny were once rugged and high, but in our time are now eroded into only a small remnant. Lawton, in the sedimentary basins of the united states and canada second edition, 2019. None of these models fits the crustal buckling of the classic laramide orogeny, marked in the central rocky mountains. The cenerian orogeny early paleozoic from the perspective. Unusual features of the laramide orogeny, including a broad area of tectonic quiescence, is found in. Kinematic history of the laramide orogeny in latitudes 3549. Woodward in 1957 the alleghanian orogeny occurred approximately 325 million to 260 million years ago over at least five deformation. The alleghanian orogeny or appalachian orogeny is one of the geological mountainforming events that formed the appalachian mountains and allegheny mountains. The justification for a separate name is given by three characteristics, which are significantly different compared to the cadomian, caledonian and variscan orogenies. The santan mountains are a 25 km long, westnorthwest trending uplift composed chiefly of proterozoic and cretaceous crystalline rocks overlain in the central and eastern part of the range by midtertiary sedimentary and volcanic rocks. An orogeny commonly builds several mountain ranges.
Orogeny, that is, the creation of the southern rocky mountains between something like 75 and 45 million years ago. The most profound geographic change during paleogene was. The term and spelling alleghany orogeny was originally proposed by h. History and causes of postlaramide relief in the rocky. The benambran orogeny reflects the accretion of the intraoceanic macquarie arc to the gondwana plate. The laramide orogeny occurred from approximately 70 million years ago to 40 million years ago during a period when the farallon oceanic plate was subducting rapidly beneath the western. The results provide insight into the evolution of the isan o. Bedrock geology of the santan mountains, pinal and maricopa counties, arizona.
Laramide orogeny geog 3251 summer 2010 term b laramide orogeny major tectonic event that formed the rocky mountains occurred 7040 my ago occurred in the interior of a plate occurred 1,000 miles from nearest subduction zone can you explain the laramide orogeny using the paradigm of plate tectonics. Buy geochemistry of laramide and middle tertiary plutons in the ajo mining district, pima county, arizona open file report united states department of the interior, geological survey on free shipping on qualified orders. Palinspastically restored regional maps show spatial evolution of tectonic components of the north american cordilleran orogenic system for. Sediments that were carried eastward formed the coastal plain and part of the continental shelf. In the build up of a large mountain range the continental crust is subjected to most of the geologic processes we have looked at so far in this course. The innuitian orogeny, sometimes called the ellesmere orogeny, was a major tectonic mountain building episode responsible for the formation of a series of mountain ranges in the. I view this portion of the arc to be transitional between the region of normal. The exact duration and ages of beginning and end of the orogeny are in dispute. Such gneiss terranes are the result of an orogenic type, which was globally widespread in early paleozoic times. A plate as it overrode the farallon plate and its history is highly complex. The sevier orogeny was preceded by several other mountainbuilding events including the nevadan orogeny, the sonoman orogeny, and the antler orogeny, and partially overlapped in time and space with the laramide orogeny.
Late cretaceousearly eocene laramide uplift, exhumation. This event is generally considered to be the first significant phase of cordilleran mountain building, which continued into the early cretaceous epoch. Evolution of the isan orogeny at the southeastern margin of the mt. It is understood that the uplift was caused by the subduction of the farrallon plate under the north american plate. A correlation of tectonic units of the alpinecarpathiandinaridic system of. Geology of the nepal himalaya regional perspective of the. The laramide orogeny occurred in a series of pulses, with quiescent phases. The ages of all the deposits are between 50 and 61 ma i.
The name is derived from the changes that occurred in the sierra nevada range of. This page was last modified on 26 august 2014, at 16. Content is available under attributionsharealike 3. Holt and haines 1993 used seismicity to solve for a continuous velocity field in asia, while avouac and tapponnier 1993 divided asia into four rigid blocks, and peltzer and saucier 1996 mod eled its fault network in more detail. Benambran orogeny, a mountainbuilding event in eastern australia during late ordovician time the ordovician period began about 488 million years ago and ended about 444 million years ago. Laramide structures are now obscure because of overprinting by younger deformation, plutonism, and extensional. Therefore it may be considered that the early yanshanian geodynamic settings in the nanling region should be related to postorogenic continental breakup after the indosinian orogeny and the breakup did not begin in the cretaceous.
Laramide orogeny the laramide orogeny has been defined from both temporal and kinematic criteria, which has led to some confusion as to the meaning of the term. Macraes orogenic gold deposit new zealand origin and. Purchase the western alps, from rift to passive margin to orogenic belt, volume 14 1st edition. The laramide orogeny occurred in a series of pulses, with quiescent phases intervening. None of these models fits the crustal buckling of the classic laramide orogeny, marked. These rocks were deformed during compression and thrust faulting during the laramide orogeny at the end of the cretaceous. The region is dominated by late tertiary basinfill deposits that form the low divide between the whetstone mountains to the south and the rincon and little rincon mountains to the north. Nevadan orogeny mid to late jurassic and continued into the cretaceous. Thus, the coastal plain and piedmont are largely the byproducts of erosion. Laramide sedimentary basins and sedimentdispersal systems. The laramide orogeny was a period of mountain building in western north america, which started in the late cretaceous, 70 to 80 million years ago, and ended 35 to 55 million years ago. In essence the laramide orogeny is the birth of the colorado plateau. Pronunciation of laramide with 2 audio pronunciations, 3 translations and more for laramide.
Pdfreader, pdfviewer kostenlos adobe acrobat reader dc. Relation of flat subduction to magmatism and deformation. The laramide orogeny is a geologic event that occured over the course of 30 million years in the late cretacous early tertiary periods that uplifted the colorado plateau from the cretatous sea. Evidence of the laramide orogeny is present from mexico to alaska.
Pdf laramide orogeny in central and northern new mexico. During this period the birimian domain in west africa was established and structured eburnian faults are found in the eglab shield to the north of the west african craton and in the. Kinematic history of the laramide orogeny in latitudes 35. Regional perspective of the classic collided orogen. The sinistral ductile shearing along the zone occurred from ca. The laramide orogeny occurred from approximately 70 million years ago to 40 million years ago during a period when the farallon oceanic plate was subducting. Abstract turkictype orogeny is a class of collisional mountain building, in which the. Twentyfive new reos molybdenite ages for nine porphyry coppermolybdenum deposits from northern mexico constrain the timing of mineralization and the longevity of porphyry systems in this region. Although the cause of these uplifts is still debated, the uplifts are almost certainly related to ongoing convergence and subduction of.
Nevadan orogeny mid to late jurassic sevier orogeny mid cretaceous laramide orogeny late cretaceous tertiary nevadan orogeny jurassic sierra nevada mountains batholiths big plutonic granites jurassic and cretaceous o coast plutonic complex o idaho complex o sierra nevada complex o baja batholith great valley group eroded batholith filling in trench. Ensuing oblique compression in the outboard part of the. Nevadan orogeny, mountainbuilding event in western north america that started in the late jurassic epoch about 156 million years ago. This book describes the nature and origin of the macraes gold deposit. Basin and range province cenozoic crust ignimbrite igneous rocks middle tertiary north america magmas plate tectonics mantle orogeny pyroclastics tertiary sevier orogenic belt tectonics western u. Benambran orogeny in the eastern lachlan orogen, australia.
The laramide orogeny refers to a phase of mountain building from approximately 80 million years ago to 40 million years ago. Broad anticlinal and synclinal folds are seen in basins and on the margins of uplifts. It is named after the laramie range in the eastern part of the rocky mountains usa, where it was. The innuitian orogeny, sometimes called the ellesmere orogeny, was a major tectonic mountain building episode responsible for the formation of a series of mountain ranges in the canadian arctic and northernmost greenland. Arizona geological survey open file report, ofr0011, 1 map sheet. Laramide orogeny, a series of mountainbuilding events that affected much of western north america in late cretaceous and paleogene time. Laramide provides church rock project update this news release is intended for distribution in canada only and is not intended for distribution to united states newswire services or dissemination in the united states.
During the laramide orogeny in late cretaceous to early tertiary between approximately 7055 million years ago compressional forces from the west shortened and crumpled the crust forming uplifts and basins, with associated folds and faults. Red river shear zone arsz, southeastern tibetan plateau. Acrobat reader dc ist mit adobe document cloud verbunden, damit du uberall. Laramide resources laramide provides church rock project update. Laramide orogeny faq exploring the colorado plateau.
Precambrian crystalline metamorphic rocks are exposed in the franklin mountains, van horn mountains, and sierra diablo. Download free adobe acrobat reader dc software for your windows, mac os and android devices to view, print, and comment on pdf documents. The region undergoing orogeny is called the orogen. Postlaramide removal of the farallon slab, western united. Adobe acrobat reader dcdownload kostenloser pdfviewer fur. The laramide orogeny has been defined from both temporal and kinematic criteria. Farallon plate shallower subduction no one knows why. That inference is strongly supported by the close correlation, in both space and time, between a prominent magmatic null or gap in the western cordillera and the classic laramide orogeny in the. There occur associations of early yanshanian atype. It is named for the laramie formation of wyoming and colorado, probably a synorogenic deposit. The exact duration and ages of beginning and end of the orogeny are in dispute, as is the cause. The prevailing explanation is that the subducting ocean floor only went down to about 100 km or so and turned flat, interacting with the continent in a way to make mountains far from the plate edge. An orogeny is a major mountainbuilding event, beyond the scale of a single volcano or a single, small mountain range.
Plate tectonics of the laramide orogeny laramide folding. The ultimate cause was the northwards strikeslip transport of the allochthonous bega terrane along the eastern margin of gondwana, into a forearc position outboard of the macquarie arc. As the farallon plate collided and began to subduct beneath the north american continent, north america was under. Much of the discussion will focus on figure 1, which is a reconstruction of the principal tectonic elements of the southwest u. Kinematic history of the laramide orogeny california from fault slip rates and geodesy. The eburnean orogeny, or eburnean cycle was a series of tectonic, metamorphic and plutonic events in what is now west africa during the paleoproterozoic era about 22002000 million years ago. The kinematic history of the rocky mountain foreland and adjacent areas is computed back to 85 ma, using. Geochemistry of laramide and middle tertiary plutons in. The laramide orogeny is the process that is responsible for the creation of the rocky. Definition of laramide orogeny a time of deformation, typically recorded in the eastern rocky mountains of the united states, whose several phases extended from late cretaceous until the end of the paleocene.
A time of deformation, typically recorded in the eastern rocky mountains of the united states, whose several phases extended from late cretaceous until the end of the paleocene. Late cretaceousearly eocene laramide uplift, exhumation, and basin subsidence in wyoming. Early laramide 72 ma, late campanian paleogeographic map showing. This book addresses the geology of the entire himalayan range in nepal, i.
Laramide orogeny article about laramide orogeny by the. During this period the birimian domain in west africa was established and structured. The western alps, from rift to passive margin to orogenic belt. The uplift and deformation produced a tectonic ridge that separated the tasman geosyncline into an eastern. I propose that postlaramide removal of the subhorizontally subducting farallon slab occurred by buckling downward along an approximately eastnortheasttrending axis. The laramide orogeny, which occurred during the cretacous and into tertiary time, was related to the eastward convergence of the farallon plate with the north american plate on the western margin of north america brown,1993. Cenozoic orogenic phases underlay a variety of multiocean hypotheses, that. Laramide orogeny in central and northern new mexico and southern colorado.
Innuitian orogeny sage green surrounded by the slave and rae cratons fuchsia that constitute the northern core of the north american craton laurentia. Late cretaceousearly eocene laramide uplift, exhumation, and. Early yanshanian postorogenic granitoids in the nanling. Laramide orogeny article about laramide orogeny by the free. These implications and their relations to a spectrum of geologic features attributed to the laramide orogeny are the subject of this paper.
789 1488 546 249 808 343 85 698 1328 1642 175 197 480 694 459 844 201 193 1662 1042 957 103 1263 625 1184 281 504 539 1135 1367 865