scholarly journals Provenance of Pennsylvanian–Permian sedimentary rocks associated with the Ancestral Rocky Mountains orogeny in southwestern Laurentia: Implications for continental-scale Laurentian sediment transport systems

Lithosphere ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 88-121 ◽  
Author(s):  
Ryan J. Leary ◽  
Paul Umhoefer ◽  
M. Elliot Smith ◽  
Tyson M. Smith ◽  
Joel E. Saylor ◽  
...  
Keyword(s):  
Sediment Transport ◽  
Rocky Mountains ◽  
Detrital Zircon ◽  
Rocky Mountain ◽  
Sedimentary Basins ◽  
The Arctic ◽  
Transport Systems ◽  
Published Data ◽  
Transport Pathways ◽  
Continental Scale

Abstract The Ancestral Rocky Mountains system consists of a series of basement-cored uplifts and associated sedimentary basins that formed in southwestern Laurentia during Early Pennsylvanian–middle Permian time. This system was originally recognized by aprons of coarse, arkosic sandstone and conglomerate within the Paradox, Eagle, and Denver Basins, which surround the Front Range and Uncompahgre basement uplifts. However, substantial portions of Ancestral Rocky Mountain–adjacent basins are filled with carbonate or fine-grained quartzose material that is distinct from proximal arkosic rocks, and detrital zircon data from basins adjacent to the Ancestral Rocky Mountains have been interpreted to indicate that a substantial proportion of their clastic sediment was sourced from the Appalachian and/or Arctic orogenic belts and transported over long distances across Laurentia into Ancestral Rocky Mountain basins. In this study, we present new U-Pb detrital zircon data from 72 samples from strata within the Denver Basin, Eagle Basin, Paradox Basin, northern Arizona shelf, Pedregosa Basin, and Keeler–Lone Pine Basin spanning ∼50 m.y. and compare these to published data from 241 samples from across Laurentia. Traditional visual comparison and inverse modeling methods map sediment transport pathways within the Ancestral Rocky Mountains system and indicate that proximal basins were filled with detritus eroded from nearby basement uplifts, whereas distal portions of these basins were filled with a mix of local sediment and sediment derived from marginal Laurentian sources including the Arctic Ellesmerian orogen and possibly the northern Appalachian orogen. This sediment was transported to southwestern Laurentia via a ca. 2,000-km-long longshore and aeolian system analogous to the modern Namibian coast. Deformation of the Ancestral Rocky Mountains slowed in Permian time, reducing basinal accommodation and allowing marginal clastic sources to overwhelm the system.

scholarly journals Supplemental Material: Detrital zircon geochronology and Hf isotope geochemistry of Mesozoic sedimentary basins in south-central Alaska: Insights into regional sediment transport, basin development, and tectonics along the NW Cordilleran margin

2020 ◽  
Author(s):  
C.R. Fasulo ◽  
et al.
Keyword(s):  
Sediment Transport ◽  
Detrital Zircon ◽  
Isotope Geochemistry ◽  
Sedimentary Basins ◽  
Detrital Zircons ◽  
Zircon Geochronology ◽  
Detrital Zircon Geochronology ◽  
South Central ◽  
Analytical Results ◽  
Cordilleran Margin

<div>Supplemental Data. (A) U-Pb analytical results from detrital zircons from the Nutzotin, Wrangell Mountains, and Wellesly basins. (B) Lu-Hf analytical results from detrital zircons from the Nutzotin and Wellesly basins. <br></div>

Detrital zircon ages from Proterozoic, Paleozoic, and Cretaceous clastic strata in southern New Mexico, U.S.A.

2019 ◽  
Vol 54 (1) ◽  
pp. 19-32
Author(s):  
Jeffrey M. Amato
Keyword(s):  
New Mexico ◽  
Detrital Zircon ◽  
Rocky Mountain ◽  
Published Data ◽  
Data Set ◽  
Basement Rocks ◽  
Dakota Sandstone ◽  
Clastic Sedimentary ◽  
Detrital Zircon Ages ◽  
Combined Data

ABSTRACT U-Pb ages were obtained from detrital zircon grains from Proterozoic, Ordovician, Devonian, Pennsylvanian, and Cretaceous clastic sedimentary rocks in southern New Mexico and are compared to previously published data from Proterozoic, Cambrian, Permian, and other Cretaceous strata. This provides the first combined data set from most of the known pre-Cenozoic clastic formations in southern New Mexico, albeit in a reconnaissance fashion. Proterozoic quartzite, conglomerate, and lithic sandstone yield mostly 1.65-Ga zircon ages that were derived from the Mazatzal province, with minor 1.8–1.7-Ga zircon ages from the Yavapai province. The Cambrian–Ordovician Bliss Sandstone is dominated by Grenville-age grains and Cambrian grains inferred to be locally derived. Newly acquired ages from the Ordovician Cable Canyon Sandstone are dominated by 1.7–1.6-Ga Mazatzal province zircon grains, whereas new data from the Devonian Percha Shale indicate subequal contributions from 1.7–1.6-Ga and ~1.4-Ga sources, along with 1.8–1.7-Ga zircon ages. Both of these formations likely had mainly distal sources as the Precambrian basement in the region was largely buried by older Paleozoic strata. New data from a sandstone in the Pennsylvanian La Tuna Formation show mostly Yavapai grains and minor Paleozoic zircon grains, including Cambrian zircon grains sourced from the nearby Florida Mountains landmass postulated to have been exposed during Pennsylvanian time. The Permian ‘Abo tongue’/Robledo Mountains Formation of the Hueco Group has mostly Neoproterozoic and Grenville-age zircon grains and was derived from Ancestral Rocky Mountain uplifts that did not have a large ~1.4-Ga component. The Aptian Hell-to-Finish Formation of the Bisbee Group has mostly Yavapai-aged zircon grains in the pre-1000-Ma age group, but younger Albian- and Campanian-age sandstones have mostly Grenville-age zircon grains. New data from the Albian Beartooth Quartzite indicate syndepositional volcanic grains at 102 Ma and support correlations with the Mojado Formation rather than the younger Dakota Sandstone. Archean zircon ages are rare overall in all of the strata in southern New Mexico, but zircon grains with ages of ~2.74 Ga are most abundant. These grains could have been derived from basement rocks in the Wyoming or Superior provinces, or recycled from sediment originally derived from those sources.

scholarly journals Linking sediment supply variations and tectonic evolution in deep time, source-to-sink systems—The Triassic Greater Barents Sea Basin

2021 ◽  
Author(s):  
Albina Gilmullina ◽  
Tore Grane Klausen ◽  
Anthony George Doré ◽  
Valentina Marzia Rossi ◽  
Anna Suslova ◽  
...  
Keyword(s):  
Sediment Transport ◽  
Sediment Load ◽  
Barents Sea ◽  
Lower Triassic ◽  
Sediment Supply ◽  
The Arctic ◽  
Ural Mountains ◽  
Triassic Boundary ◽  
Volcanic Event ◽  
Continental Scale

Triassic strata in the Greater Barents Sea Basin are important records of geodynamic activity in the surrounding catchments and sediment transport in the Arctic basins. This study is the first attempt to investigate the evolution of these source areas through time. Our analysis of sediment budgets from subsurface data in the Greater Barents Sea Basin and application of the BQART approach to estimate catchment properties shows that (1) during the Lower Triassic, sediment supply was at its peak in the basin and comparable to that of the biggest modern-day river systems, which are supplied by tectonically active orogens; (2) the Middle Triassic sediment load was significantly lower but still comparable to that of the top 10 largest modern rivers; (3) during the Upper Triassic, sediment load increased again in the Carnian; and (4) there is a large mismatch (70%) between the modeled and estimated sediment load of the Carnian. These results are consistent with the Triassic Greater Barents Sea Basin succession being deposited under the influence of the largest volcanic event ever at the Permian-Triassic boundary (Siberian Traps) and concurrent with the climatic changes of the Carnian Pluvial Event and the final stages of the Northern Ural orogeny. They also provide a better understanding of geodynamic impacts on sedimentary systems and improve our knowledge of continental-scale sediment transport. Finally, the study demonstrates bypass of sediment from the Ural Mountains and West Siberia into the adjacent Arctic Sverdrup, Chukotka, and Alaska Basins in Late Carnian and Late Norian time.

scholarly journals Supplemental Material: Detrital zircon geochronology and Hf isotope geochemistry of Mesozoic sedimentary basins in south-central Alaska: Insights into regional sediment transport, basin development, and tectonics along the NW Cordilleran margin

2020 ◽  
Author(s):  
C.R. Fasulo ◽  
et al.
Keyword(s):  
Sediment Transport ◽  
Detrital Zircon ◽  
Isotope Geochemistry ◽  
Sedimentary Basins ◽  
Detrital Zircons ◽  
Zircon Geochronology ◽  
Detrital Zircon Geochronology ◽  
South Central ◽  
Analytical Results ◽  
Cordilleran Margin

<div>Supplemental Data. (A) U-Pb analytical results from detrital zircons from the Nutzotin, Wrangell Mountains, and Wellesly basins. (B) Lu-Hf analytical results from detrital zircons from the Nutzotin and Wellesly basins. <br></div>

scholarly journals Detrital zircon geochronology and Hf isotope geochemistry of Mesozoic sedimentary basins in south-central Alaska: Insights into regional sediment transport, basin development, and tectonics along the NW Cordilleran margin

Geosphere ◽  
2020 ◽  
Vol 16 (5) ◽  
pp. 1125-1152 ◽  
Author(s):  
Cooper R. Fasulo ◽  
Kenneth D. Ridgway ◽  
Jeffrey M. Trop
Keyword(s):  
Detrital Zircon ◽  
Lower Cretaceous ◽  
Sedimentary Basins ◽  
Upper Jurassic ◽  
Detrital Zircons ◽  
Hf Isotope ◽  
Published Data ◽  
Convergent Margin ◽  
South Central ◽  
Detrital Zircon Ages

Abstract The Jurassic–Cretaceous Nutzotin, Wrangell Mountains, and Wellesly basins provide an archive of subduction and collisional processes along the southern Alaska convergent margin. This study presents U-Pb ages from each of the three basins, and Hf isotope compositions of detrital zircons from the Nutzotin and Wellesly basins. U-Pb detrital zircon ages from the Upper Jurassic–Lower Cretaceous Nutzotin Mountains sequence in the Nutzotin basin have unimodal populations between 155 and 133 Ma and primarily juvenile Hf isotope compositions. Detrital zircon ages from the Wrangell Mountains basin document unimodal peak ages between 159 and 152 Ma in Upper Jurassic–Lower Cretaceous strata and multimodal peak ages between 196 and 76 Ma for Upper Cretaceous strata. Detrital zircon ages from the Wellesly basin display multimodal peak ages between 216 and 124 Ma and juvenile to evolved Hf compositions. Detrital zircon data from the Wellesly basin are inconsistent with a previous interpretation that suggested the Wellesly and Nutzotin basins are proximal-to-distal equivalents. Our results suggest that Wellesly basin strata are more akin to the Kahiltna basin, which requires that these basins may have been offset ∼380 km along the Denali fault. Our findings from the Wrangell Mountains and Nutzotin basins are consistent with previous stratigraphic interpretations that suggest the two basins formed as a connected retroarc basin system. Integration of our data with previously published data documents a strong provenance and temporal link between depocenters along the southern Alaska convergent margin. Results of our study also have implications for the ongoing discussion concerning the polarity of subduction along the Mesozoic margin of western North America.

Mitbringsel aus den Ferien

Praxis ◽  
2005 ◽  
Vol 94 (47) ◽  
pp. 1869-1870
Author(s):  
Balestra ◽  
Nüesch
Keyword(s):  
Rocky Mountains ◽  
Spotted Fever ◽  
Rocky Mountain ◽  
Rickettsia Conorii ◽  
Rocky Mountain Spotted Fever ◽  
Klinische Diagnose ◽  
Rickettsia Rickettsii

Eine 37-jährige Patientin stellt sich nach der Rückkehr von einer Rundreise durch Nordamerika mit einem Status febrilis seit zehn Tagen und einem makulösem extremitätenbetontem Exanthem seit einem Tag vor. Bei suggestiver Klinik und Besuch der Rocky Mountains wird ein Rocky Mountain spotted fever diagnostiziert. Die Serologie für Rickettsia conorii, die mit Rickettsia rickettsii kreuzreagiert, war positiv und bestätigte die klinische Diagnose. Allerdings konnte der beweisende vierfache Titeranstieg, möglicherweise wegen spät abgenommener ersten Serologie, nicht nachgewiesen werden. Nach zweiwöchiger antibiotischer Therapie mit Doxycycline waren Status febrilis und Exanthem regredient.

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