HIGH-FLUX VOLCANIC EVENTS OF SOUTHERN CORDILLERAN MAGMATIC ARC RECORDED IN FOREBULGE AND BACK-BULGE DEPOSITS OF THE NORTH MEXICAN FORELAND BASIN (LATE CRETACEOUS), NORTHESTERN MEXICO

Author(s):  
Edgar Juárez-Arriaga ◽  
◽  
Timothy F. Lawton ◽  
Daniel F. Stockli ◽  
Yam Zul E. Ocampo Diaz
2016 ◽  
Vol 3 ◽  
pp. 229-291 ◽  
Author(s):  
Alan L. Titus ◽  
Jeffrey G. Eaton ◽  
Joseph Sertich

The Late Cretaceous succession of southern Utah was deposited in an active foreland basin circa 100 to 70 million years ago. Thick siliciclastic units represent a variety of marine, coastal, and alluvial plain environments, but are dominantly terrestrial, and also highly fossiliferous. Conditions for vertebrate fossil preservation appear to have optimized in alluvial plain settings more distant from the coast, and so in general the locus of good preservation of diverse assemblages shifts eastward through the Late Cretaceous. The Middle and Late Campanian record of the Paunsaugunt and Kaiparowits Plateau regions is especially good, exhibiting common soft tissue preservation, and comparable with that of the contemporaneous Judith River and Belly River Groups to the north. Collectively the Cenomanian through Campanian strata of southern Utah hold one of the most complete single region terrestrial vertebrate fossil records in the world.


2022 ◽  
Author(s):  
Glenn R. Sharman ◽  
Daniel F. Stockli ◽  
Peter Flaig ◽  
Robert G. Raynolds ◽  
Marieke Dechesne ◽  
...  

ABSTRACT Detrital zircon U-Pb and (U-Th)/He ages from latest Cretaceous–Eocene strata of the Denver Basin provide novel insights into evolving sediment sourcing, recycling, and dispersal patterns during deposition in an intracontinental foreland basin. In total, 2464 U-Pb and 78 (U-Th)/He analyses of detrital zircons from 21 sandstone samples are presented from outcrop and drill core in the proximal and distal portions of the Denver Basin. Upper Cretaceous samples that predate uplift of the southern Front Range during the Laramide orogeny (Pierre Shale, Fox Hills Sandstone, and Laramie Formation) contain prominent Late Cretaceous (84–77 Ma), Jurassic (169–163 Ma), and Proterozoic (1.69–1.68 Ga) U-Pb ages, along with less abundant Paleozoic through Archean zircon grain ages. These grain ages are consistent with sources in the western U.S. Cordillera, including the Mesozoic Cordilleran magmatic arc and Yavapai-Mazatzal basement, with lesser contributions of Grenville and Appalachian zircon recycled from older sedimentary sequences. Mesozoic zircon (U-Th)/He ages confirm Cordilleran sources and/or recycling from the Sevier orogenic hinterland. Five of the 11 samples from syn-Laramide basin fill (latest Cretaceous–Paleocene D1 Sequence) and all five samples from the overlying Eocene D2 Sequence are dominated by 1.1–1.05 Ga zircon ages that are interpreted to reflect local derivation from the ca. 1.1 Ga Pikes Peak batholith. Corresponding late Mesoproterozoic to early Neoproterozoic zircon (U-Th)/He ages are consistent with local sourcing from the southern Front Range that underwent limited Mesozoic–Cenozoic unroofing. The other six samples from the D1 Sequence yielded detrital zircon U-Pb ages similar to pre-Laramide units, with major U-Pb age peaks at ca. 1.7 and 1.4 Ga but lacking the 1.1 Ga age peak found in the other syn-Laramide samples. One of these samples yielded abundant Mesozoic and Paleozoic (U-Th)/He ages, including prominent Early and Late Cretaceous peaks. We propose that fill of the Denver Basin represents the interplay between locally derived sediment delivered by transverse drainages that emanated from the southern Front Range and a previously unrecognized, possibly extraregional, axial-fluvial system. Transverse alluvial-fluvial fans, preserved in proximal basin fill, record progressive unroofing of southern Front Range basement during D1 and D2 Sequence deposition. Deposits of the upper and lower D1 Sequence across the basin were derived from these fans that emanated from the southern Front Range. However, the finer-grained, middle portion of the D1 Sequence that spans the Cretaceous-Paleogene boundary was deposited by both transverse (proximal basin fill) and axial (distal basin fill) fluvial systems that exhibit contrasting provenance signatures. Although both tectonic and climatic controls likely influenced the stratigraphic development of the Denver Basin, the migration of locally derived fans toward and then away from the thrust front suggests that uplift of the southern Front Range may have peaked at approximately the Cretaceous-Paleogene boundary.


2011 ◽  
Vol 182 (6) ◽  
pp. 479-491 ◽  
Author(s):  
Pierre Maurizot

Abstract New Caledonia lies at the northern tip of the Norfolk ridge, a continental fragment separated from the east Gondwana margin during the Late Cretaceous. Stratigraphic data for constraining the convergence that led to ophiolitic nappes being obducted over Grande Terre during the Eocene are both few and inaccurate. To try and fill this gap and determine the onset of the convergence, we investigated the lithology, sedimentology, biostratigraphy and geodynamic context of the Late Cretaceous – Palaeogene sedimentary cover-rock succession of northern New Caledonia. We were able to establish new stratigraphic correlations between the sedimentary units, which display large southwest-verging overfolds detached along a basal argillite series, and reinterpret their interrelationships. The sediments from the Cretaceous-Paleocene interval were deposited in a post-rift pelagic environment and are mainly biogenic with minimal terrigenous input. From the base up, they comprise black organic-rich sulphide-bearing argillite, black chert (silicified equivalent of the argillite), micritic with chert, and micrite rich in planktonic foraminifera. These passive-margin deposits are found regionally on the Norfolk Ridge down to New Zealand, and on the Lord Howe Rise, and were controlled primarily by regional or global environmental factors. The overlying Eocene deposits mark a change to an active-margin regime with distal calciturbidite and proximal breccia representing the earliest Paleogene flysch-type deposits in New Caledonia. The change from an extensional to a compressive regime marks the beginning of the pre-obduction convergence and can be assigned fairly accurately in the Koumac–Gomen area to the end of the Early Eocene (Late Ypresian, Biozone E7) at c 50 Ma. From this period on, the post-Late Cretaceous cover in northern New Caledonia was caught up and recycled in a southwest-verging accretionary complex ahead of which flysch was deposited in a flexural foreland basin. The system prograded southwards until the Late Eocene collisional stage, when the continental Norfolk ridge entered the convergence zone and blocked it. At this point the autochthonous and parautochthonous sedimentary cover and overlying flysch of northern New Caledonia was thrust over the younger flysch to the south to form a newly defined allochthonous unit, the ‘Montagnes Blanches’ nappe, that is systematically intercalated between the flysch and the obducted ophiolite units throughout Grande Terre.


2004 ◽  
Vol 141 (5) ◽  
pp. 583-603 ◽  
Author(s):  
OSMAN PARLAK ◽  
VOLKER HÖCK ◽  
HÜSEYİN KOZLU ◽  
MICHEL DELALOYE

A number of Late Cretaceous ophiolitic bodies are located between the metamorphic massifs of the southeast Anatolian orogenic system. One of them, the Göksun ophiolite (northern Kahramanmaraş), which crops out in a tectonic window bounded by the Malatya metamorphic units on both the north and south, is located in the EW-trending nappe zone of the southeast Anatolian orogenic belt between Göksun and Afşin (northern Kahramanmaraş). It consists of ultramafic–mafic cumulates, isotropic gabbro, a sheeted dyke complex, plagiogranite, volcanic rocks and associated volcanosedimentary units. The ophiolitic rocks and the tectonically overlying Malatya–Keban metamorphic units were intruded by syn-collisional granitoids (∼ 85 Ma). The volcanic units are characterized by a wide spectrum of rocks ranging in composition from basalt to rhyolite. The sheeted dykes consist of diabase and microdiorite, whereas the isotropic gabbros consist of gabbro, diorite and quartzdiorite. The magmatic rocks in the Göksun ophiolite are part of a co-magmatic differentiated series of subalkaline tholeiites. Selective enrichment of some LIL elements (Rb, Ba, K, Sr and Th) and depletion of the HFS elements (Nb, Ta, Ti, Zr) relative to N-MORB are the main features of the upper crustal rocks. The presence of negative anomalies for Ta, Nb, Ti, the ratios of selected trace elements (Nb/Th, Th/Yb, Ta/Yb) and normalized REE patterns all are indicative of a subduction-related environment. All the geochemical evidence both from the volcanic rocks and the deeper levels (sheeted dykes and isotropic gabbro) show that the Göksun ophiolite formed during the mature stage of a suprasubduction zone (SSZ) tectonic setting in the southern branch of the Neotethyan ocean between the Malatya–Keban platform to the north and the Arabian platform to the south during Late Cretaceous times. Geological, geochronological and petrological data on the Göksun ophiolite and the Baskil magmatic arc suggest that there were two subduction zones, the first one dipping beneath the Malatya–Keban platform, generating the Baskil magmatic arc and the second one further south within the ocean basin, generating the Göksun ophiolite in a suprasubduction zone environment.


2014 ◽  
Vol 2 (4) ◽  
pp. SJ75-SJ102 ◽  
Author(s):  
Matías G. Sánchez ◽  
Murray M. Allan ◽  
Craig J. R. Hart ◽  
James K. Mortensen

Aeromagnetic lineaments interpreted from reduced-to-pole (RTP) magnetic grids were compared with gravity, topography, and field-based geologic maps to infer regional structural controls on hydrothermal mineral occurrences in a poorly exposed portion of the North American Cordillera in western Yukon and eastern Alaska. High-frequency and variable-intensity aeromagnetic lineaments corresponding to discontinuities with an aeromagnetic domain change were interpreted as steep-dipping and either magnetite-destructive or magnetite-additive faults. These structures were interpreted to be predominantly Cretaceous in age and to have formed after the collision of the Intermontane terranes with the ancient Pacific margin of North America. To demonstrate the reliability of the aeromagnetic interpretation, we developed a multidata set stacking methodology that assigns numeric values to individual lineaments depending on whether they can be traced in residuals and first vertical derivative of RTP aeromagnetic grids, isostatic residual gravity grids, digital topography, and regional geologic maps. The sum of all numeric values was used to estimate the likelihood of the aeromagnetic lineament as a true geologic fault. Fault systems were interpreted from zones of lineaments with high spatial density. Using this procedure, 10 major northwest-trending fault systems were recognized. These were oriented subparallel to the regional Cordilleran deformation fabric, the mid-Cretaceous Dawson Range magmatic arc, and well-established crustal-scale dextral strike-slip fault systems in the area. These orogen-parallel fault systems were interpreted to play a structural role in the emplacement of known porphyry Cu-Au and epithermal Au systems of mid-Cretaceous (115–98 Ma) and Late Cretaceous (79–72 Ma) age. The procedure also identified seven northeast-trending, orogen-perpendicular fault-fracture systems that are prominent in eastern Alaska and exhibit sinistral-to-oblique extensional kinematics. These structures were interpreted to govern the emplacement of Late Cretaceous (72–67 Ma) porphyry Mo- and Ag-rich polymetallic vein and carbonate replacement systems in the region.


Geosphere ◽  
2019 ◽  
Vol 15 (6) ◽  
pp. 1774-1808 ◽  
Author(s):  
Stephen E. Box ◽  
Susan M. Karl ◽  
James V. Jones ◽  
Dwight C. Bradley ◽  
Peter J. Haeussler ◽  
...  

Abstract The Kahiltna assemblage in the western Alaska Range consists of deformed Upper Jurassic and Cretaceous clastic strata that lie between the Alexander-Wrangellia-Peninsular terrane to the south and the Farewell and other pericratonic terranes to the north. Differences in detrital zircon populations and sandstone petrography allow geographic separation of the strata into two different successions, each consisting of multiple units, or petrofacies, with distinct provenance and lithologic characteristics. The northwestern succession was largely derived from older, inboard pericratonic terranes and correlates along strike to the southwest with the Kuskokwim Group. The southeastern succession is characterized by volcanic and plutonic rock detritus derived from Late Jurassic igneous rocks of the Alexander-Wrangellia-Peninsular terrane and mid- to Late Cretaceous arc-related igneous rocks and is part of a longer belt to the southwest and northeast, here named the Koksetna-Clearwater belt. The two successions remained separate depositional systems until the Late Cretaceous, when the northwestern succession overlapped the southeastern succession at ca. 81 Ma. They were deformed together ca. 80 Ma by southeast-verging fold-and-thrust–style deformation interpreted to represent final accretion of the Alexander-Wrangellia-Peninsular terrane along the southern Alaska margin. We interpret the tectonic evolution of the Kahiltna successions as a progression from forearc sedimentation and accretion in a south-facing continental magmatic arc to arrival and partial underthrusting of the back-arc flank of an active, south-facing island-arc system (Alexander-Wrangellia-Peninsular terrane). A modern analogue is the ongoing collision and partial underthrusting of the Izu-Bonin-Marianas island arc beneath the Japan Trench–Nankai Trough on the east side of central Japan.


2016 ◽  
Vol 3 ◽  
pp. 229-291
Author(s):  
Alan Titus ◽  
Jeffrey Eaton ◽  
Joseph Sertich

The Late Cretaceous succession of southern Utah was deposited in an active foreland basin circa 100 to 70 million years ago. Thick siliciclastic units represent a variety of marine, coastal, and alluvial plain environments, but are dominantly terrestrial, and also highly fossiliferous. Conditions for vertebrate fossil preservation appear to have optimized in alluvial plain settings more distant from the coast, and so in general the locus of good preservation of diverse assemblages shifts eastward through the Late Cretaceous. The Middle and Late Campanian record of the Paunsaugunt and Kaiparowits Plateau regions is especially good, exhibiting common soft tissue preservation, and comparable with that of the contemporaneous Judith River and Belly River Groups to the north. Collectively the Cenomanian through Campanian strata of southern Utah hold one of the most complete single region terrestrial vertebrate fossil records in the world.


1993 ◽  
Vol 33 (1) ◽  
pp. 215 ◽  
Author(s):  
L.G. Elliott

Analysis of seismic data from the Bowen and Surat Basins has yielded valuable information on the Permian and Triassic evolution of eastern Australia. When combined with seismic data from the Clarence-Moreton and Maryborough Basins, a new understanding of the post-Triassic evolution of the region can be gained, with widespread implications for other eastern Australian basins.The Early Permian-Middle Triassic Bowen-Sydney Basin is a foreland basin system extending 2000 km in preserved section from Nowra in the south to Collinsville in the north. Permian outcrops as far north as Cape York were probably part of the same system prior to deformation and erosion. The basins in the Bowen-Sydney system were linked by similar structural and stratigraphic patterns controlled by a magmatic arc to the east. The Esk Trough and associated remnant basins east of the Taroom Trough were part of the Middle Triassic foreland sequence. The structural style in the system is dominated by thrusting from the east. An Early Triassic deformation is shown to be the most important, rather than the previously believed Middle Triassic event.The overlying Jurassic-Cretaceous foreland system, which included the Surat, Maryborough and Clarence-Moreton Basins, were once joined behind another magmatic arc, east of the Triassic arc position. A major mid-Cretaceous deformation is documented which fragmented the Jurassic-Cretaceous foreland basin into a number of remnant basins prior to the opening of the Tasman Sea in the Cenomanian. The dominant structural style is again thrusting from the east. Given the severity of the deformation, its effects are expected to be present in continental margin basins around Australia.


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