scholarly journals Zircon (U-Th)/(He-Pb) double-dating constraints on the interplay between thrust deformation and foreland basin architecture, Sevier foreland basin, Utah

Geosphere ◽  
2021 ◽  
Author(s):  
E.J. Pujols ◽  
D.F. Stockli
Keyword(s):  
Foreland Basin ◽  
Sediment Supply ◽  
Sediment Provenance ◽  
Thrust Belt ◽  
Lower Paleozoic ◽  
Magmatic Arc ◽  
Book Cliffs ◽  
Time Estimates ◽  
Stratal Architecture ◽  
Cordilleran Foreland

The Cretaceous Cordilleran foreland basin strata exposed in the Book Cliffs of eastern Utah and western Colorado have motivated important concepts linking thrust belt deformation and foreland basin evolution largely on the basis of sequence stratigraphy, stratal architecture, and sediment provenance evolution. However, these methods and approaches generally cannot provide critical insights into the temporal or causal linkages between foreland basin architecture and thrust belt deformation. This is in part due to discrepancies in age resolution and lack of evidence with which to directly couple sediment supply and basin-fill evolution to thrust belt unroofing. New detrital zircon (DZ) geothermochronometric data from Upper Cretaceous proximal to distal foreland basin strata in the Book Cliffs provide new quantitative insights into sediment origin and dispersal in relation to thrust belt deformation and exhu­mation. Detailed DZ U-Pb and (U-Th)/He double dating reveals that the Book Cliffs foredeep detritus was mainly delivered by transverse routing systems from two major sources: (1) Neoproterozoic and Lower Paleozoic strata from the central Utah Sevier thrust belt, and (2) Permian–Jurassic and synorogenic Cretaceous strata recycled from the frontal part of the thrust belt. A dramatic increase in Sierran magmatic arc and Yavapai-Mazatzal DZ U-Pb ages, as well as Paleozoic DZ He ages, in the deeper marine portions of the foreland basin points to axial fluvial and littoral sediment input from the Sierran magmatic arc and Mogollon highland sources. Both transverse and axial transport sys­tems acted contemporaneously during eastward propagation of the Late Cretaceous thrust belt. DZ He depositional lag time estimates reveal three distinct exhumation pulses in the Sevier thrust belt in the Cenomanian and Campanian. The exhumation pulses correlate with shifts in sediment prove­nance, dispersal style, and progradation rates in the foreland basin. These new data support conceptual models that temporally and causally link accelerated exhumation and unroofing in the thrust belt to increases in sediment supply and rapid clastic progradation in the foreland basin.

Sediment provenance in contractional orogens: The detrital zircon record from modern rivers in the Andean fold-thrust belt and foreland basin of western Argentina

2017 ◽  
Vol 479 ◽  
pp. 83-97 ◽  
Author(s):  
Tomas N. Capaldi ◽  
Brian K. Horton ◽  
N. Ryan McKenzie ◽  
Daniel F. Stockli ◽  
Margaret L. Odlum
Keyword(s):  
Detrital Zircon ◽  
Foreland Basin ◽  
Sediment Provenance ◽  
Thrust Belt

scholarly journals A magnetostratigraphic age constraint for the proximal synorogenic conglomerates of the Late Cretaceous Cordilleran foreland basin, northeast Utah, USA

2020 ◽  
Author(s):  
Ziaul Haque ◽  
John W. Geissman ◽  
Peter G. DeCelles ◽  
Barbara Carrapa
Keyword(s):  
Late Cretaceous ◽  
Foreland Basin ◽  
Magnetic Polarity ◽  
Coarse Grained ◽  
Sediment Provenance ◽  
Fine Grained ◽  
Magnetic Carriers ◽  
Normal Polarity ◽  
Cordilleran Foreland ◽  
Geomagnetic Polarity

Reliable ages of proximal conglomerates in the Cordilleran foreland basin that are associated with emplacement and erosion of major thrust sheets are essential for reconstructing the kinematic history of the Sevier fold-thrust belt. Although these conglomerates have been dated by palynology, their absolute ages have been difficult to determine because of their coarse-grained texture and a lack of marine interbeds and tuffaceous deposits. We collected sets of oriented samples from outcrops in northeastern Utah, USA, to construct an overall magnetic polarity stratigraphy that can be correlated to the geomagnetic polarity time scale (GPTS). We sampled fine-grained, hematitic interbeds in the Upper Cretaceous Echo Canyon Conglomerate and Weber Canyon Conglomerate. Common paleomagnetic and rock magnetic analyses were conducted, and several rock magnetic results indicated that the dominant magnetic carriers in these weakly magnetized rocks are hematite and very subordinate magnetite/titanomagnetite/maghemite and goethite. Demagnetization results show that hematitic, fine-grained sandstone to siltstone intervals carry a geologically stable magnetization with directions and polarity consistent with the Late Cretaceous geomagnetic field. A small percentage of samples carry a low laboratory unblocking temperature secondary overprint residing primarily in goethite. Magnetic polarity results indicate that the Echo Canyon Conglomerate is exclusively of normal polarity and that the younger Weber Canyon Conglomerate is of normal polarity in its lowermost part, reverse polarity in the middle, and normal polarity in the upper part of the sequence. The new data indicate that these coarse-grained strata were most likely deposited over the time span of the magnetic polarity Chron (C) 34n to C33r interval and the younger C33r to C33n interval; the former interval includes the Santonian-Campanian stage boundary (ca. 83.4 Ma/83.1 Ma). Palynological data suggest that these rocks span Coniacian-Santonian time (ca. 89−84 Ma); thus, the most parsimonious correlation of the normal polarity magnetozone of the Echo Canyon Conglomerate is with the youngest part of C34n Superchron, which is of ca. 30 Ma duration (ca. 115 Ma to 83.4 Ma/83.1 Ma). The normal polarity magnetozone of the lower part of the younger Weber Canyon Conglomerate likely correlates to the youngest part of C34n, whereas the reverse and normal magnetozone from the middle and upper parts of the Weber Canyon Conglomerate likely correlate to C33r and C33n, respectively. We infer that the Santonian-Campanian boundary resides in the lower Weber Canyon Conglomerate, which implies that deposition of the unit started prior to the C34n/C33r boundary age (ca. 83.4 Ma/83.1 Ma) and continued through the C33r and C33n chrons. Sediment provenance data and growth structures tie the Echo Canyon and Weber Canyon Conglomerates to emplacement of the Crawford thrust sheet. Based on the magnetic polarity data, as constrained by the biostratigraphic age estimates from these synorogenic deposits, we hypothesize that the principal displacement along the Crawford thrust started during the Coniacian (>C34n/C33r boundary age) and continued into the middle Campanian (<C33r/C33n boundary age), from ca. 90−75 Ma, which is nearly 10 Ma longer than previously thought. The new age constraints demonstrate complete temporal overlap between proximal and distal coarse-grained deposits in this part of the Cordilleran foreland basin, coeval with active thrust displacement and rapid hinterland exhumation.

scholarly journals Faulty foundations: Early breakup of the southern Utah Cordilleran foreland basin

2021 ◽  
Author(s):  
Gabriela A. Enriquez St. Pierre ◽  
Cari L. Johnson
Keyword(s):  
Early Stage ◽  
Foreland Basin ◽  
River System ◽  
Thrust Belt ◽  
Marine Strata ◽  
Straight Cliffs Formation ◽  
Average Grain Size ◽  
Straight Cliffs ◽  
Cordilleran Foreland ◽  
Thickness Variations

Anomalous features of Upper Cretaceous strata in southern Utah challenge existing tectonic and depositional models of the Cordilleran foreland basin. Extreme thickness variations, net to gross changes, and facies distributions of nonmarine to marginal marine strata of the Turonian−early Campanian Straight Cliffs Formation are documented across the Southwestern High Plateaus. Contrary to most traditional models of foreland basin architecture, regional correlations demonstrate abrupt stepwise thickening, with a punctuated increase in average grain size of key intervals from west to east, i.e., proximal to distal relative to the fold-thrust belt. Except in the most proximal sections, fluvial drainage systems were oriented predominantly subparallel to the fold-thrust belt. Combined, these results suggest that modern plateau-bounding faults may have had topographic expressions as early as Cenomanian time, and influenced the position of the main axial river system by creating northeast-trending paleotopography and sub-basins. Laramide-style tectonism (e.g., basement-involved faults) is already cited as a driver for sub-basin development in latest Cretaceous−Cenozoic time, but new data presented here suggest that this part of the foredeep was “broken” into distinct sub-basins from its earliest stages. We suggest that flexural foundering of the lithosphere may have caused early stage normal faulting in the foredeep. Regional implications of these new data indicate that both detachment-style and basement-involved structures were simultaneously active in southern Utah earlier than previously recognized. These structures were likely influenced by inherited Proterozoic basement heterogeneities along the edge of the Colorado Plateau. This interpretation suggests that tectonic models for the region should be reevaluated and has broader implications for understanding variability and geodynamics of foreland basin evolution.

scholarly journals Detrital zircon U-Pb geochronology of modern Andean rivers in Ecuador: Fingerprinting tectonic provinces and assessing downstream propagation of provenance signals

Geosphere ◽  
2019 ◽  
Vol 15 (6) ◽  
pp. 1943-1957 ◽  
Author(s):  
Lily J. Jackson ◽  
Brian K. Horton ◽  
Cristian Vallejo
Keyword(s):  
Detrital Zircon ◽  
Foreland Basin ◽  
High Elevation ◽  
Tectonic Deformation ◽  
Thrust Belt ◽  
Environmental Signals ◽  
Magmatic Arc ◽  
Metasedimentary Rocks ◽  
Unconsolidated Sands ◽  
Source Regions

Abstract Recognizing detrital contributions from sediment source regions is fundamental to provenance studies of active and ancient orogenic settings. Detrital zircon U-Pb geochronology of unconsolidated sands from modern rivers that have source catchments with contrasting bedrock signatures provides insight into the fidelity of U-Pb age signatures in discriminating tectonic provenance and downstream propagation of environmental signals. We present 1705 new detrital zircon U-Pb ages for 15 samples of unconsolidated river sands from 12 modern rivers over a large spatial extent of Ecuador (∼1°N–5°S and ∼79°–77°W). Results show distinctive U-Pb age distributions with characteristic zircon age populations for various tectonic provinces along the Andean convergent margin, including the forearc, magmatic arc, and internal (hinterland) and external (foreland) segments of the fold-thrust belt. (1) Forearc and magmatic arc (Western Cordillera) river sands are characterized by Neogene–Quaternary age populations from magmatic sources. (2) Rivers in the hinterland (Eastern Cordillera) segment of the Andean fold-thrust belt have substantial populations of Proterozoic and Paleozoic ages, representing upper Paleozoic–Mesozoic sedimentary and metasedimentary rocks of ultimate cratonic origin. (3) River sands in the frontal fold-thrust belt (Subandean Zone to Oriente Basin) show distinctive bimodal Jurassic age populations, a secondary Triassic population, and subordinate Early Cretaceous ages representative of Mesozoic plutonic and metamorphic bedrock. Detrital zircon U-Pb results from a single regional watershed (Rio Pastaza) spanning the magmatic arc to foreland basin show drastic downstream variations, including the downstream loss of magmatic arc and hinterland signatures and abrupt introduction and dominance of selected sources within the fold-thrust belt. Disproportionate contributions from Mesozoic crystalline metamorphic rocks, which form high-elevation, high-relief areas subject to focused precipitation and active tectonic deformation, are likely the product of focused erosion and high volumes of local sediment input from the frontal fold-thrust belt, leading to dilution of upstream signatures from the hinterland and magmatic arc.

scholarly journals Supplemental Material: Zircon (U-Th)/(He-Pb) double-dating constraints on the interplay between thrust deformation and foreland basin architecture, Sevier foreland basin, Utah

2021 ◽  
Author(s):  
E.J. Pujols ◽  
D.F. Stockli
Keyword(s):  
Foreland Basin ◽  
Thrust Belt ◽  
Isotopic Data ◽  
Book Cliffs ◽  
Fold And Thrust Belt ◽  
Before And After ◽  
D Values

<div>Table S1 contains sample locations and formation names. Tables S2 and S3 contain the isotopic data for all samples DZ U-Pb (Table S2) and DZHe ages (Table S3). Table S4a-b shows the K‐S test p and D values between all Book Cliffs DZ U‐Pb samples before and after excluding volcanic grains. Table S4c shows K‐S test p and D values between all the DZ U‐Pb age populations from the Book Cliffs (this study), Sevier fold-and-thrust belt, and proximal strata (Pujols et al., 2020).<br></div>

scholarly journals Supplemental Material: Zircon (U-Th)/(He-Pb) double-dating constraints on the interplay between thrust deformation and foreland basin architecture, Sevier foreland basin, Utah

2021 ◽  
Author(s):  
E.J. Pujols ◽  
D.F. Stockli
Keyword(s):  
Foreland Basin ◽  
Thrust Belt ◽  
Isotopic Data ◽  
Book Cliffs ◽  
Fold And Thrust Belt ◽  
Before And After ◽  
D Values

<div>Table S1 contains sample locations and formation names. Tables S2 and S3 contain the isotopic data for all samples DZ U-Pb (Table S2) and DZHe ages (Table S3). Table S4a-b shows the K‐S test p and D values between all Book Cliffs DZ U‐Pb samples before and after excluding volcanic grains. Table S4c shows K‐S test p and D values between all the DZ U‐Pb age populations from the Book Cliffs (this study), Sevier fold-and-thrust belt, and proximal strata (Pujols et al., 2020).<br></div>

SEDIMENT PROVENANCE AND DISPERSAL DURING FORELAND BASIN UPLIFT: LOWER CRETACEOUS MANNVILLE GROUP, ALBERTA BASIN, CANADA

2017 ◽  
Author(s):  
Benjamin G. Daniels ◽  
◽  
Stephen M. Hubbard ◽  
William A. Matthews ◽  
Garrett M. Quinn ◽  
...  
Keyword(s):  
Lower Cretaceous ◽  
Foreland Basin ◽  
Sediment Provenance ◽  
Alberta Basin
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