Architecture of coarse-grained gravity flow deposits in a structurally confined submarine canyon (late Eocene Tokaren Conglomerate, Slovakia)

Eocene-Oligocene sedimentation in the external areas of the Moldavide Basin (Marginal Folds Nappe, Eastern Carpathians, Romania): sedimentological, paleontological and petrographic approachesThe Marginal Folds Nappe is one of the most external tectonic units of the Moldavide Nappe System (Eastern Carpathians), formed by Cretaceous to Tertiary flysch and molasse deposits, piled up during the Miocene closure of the East Carpathian Flysch basin, cropping out in several tectonic half-windows, the Bistriţa half-window being one of them. The deposits of this tectonic unit were accumulated in anoxic-oxic-anoxic conditions, in a forebulge depozone (sensuDeCelles & Giles 1996), and consist of a pelitic background sporadically interrupted by coarse-grained events. During the Late Eocene the sedimentation registered a transition from calcareous (Doamna Limestones) to pelitic (Bisericani Beds) grading to Globigerina Marls at the Eocene-Oligocene boundary, and upward during the Oligocene in deposits rich in organic matter (Lower Menilites, Bituminous Marls, Lower and Upper Dysodilic Shales) with coarsegrained interlayers. Seven facies associations were recognized, and interpreted as depositional systems of shallow to deeper water on a ramp-type margin. Two mixed depositional systems of turbidite-like facies association separated by a thick pelitic interval (Bituminous Marls) have been recognized. They were supplied by a "green schists" source area of Central Dobrogea type. The petrography of the sandstone beds shows an excellent compositional uniformity (quartzarenite-like rocks), probably representing a first cycle detritus derived from low rank metamorphic sources, connected with the forebulge relief developed on such a basement. The sedimentation was controlled mainly by different subsidence of blocks created by extensional tectonic affecting the ramp-type margin of the forebulge depozone.

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High frequency of sediment gravity flow events in the Var submarine canyon (Mediterranean Sea)

Marine Geology ◽

10.1016/j.margeo.2009.03.014 ◽

2009 ◽

Vol 263 (1-4) ◽

pp. 1-6 ◽

Cited By ~ 51

Author(s):

Alexis Khripounoff ◽

Annick Vangriesheim ◽

Philippe Crassous ◽

Joel Etoubleau

Keyword(s):

Mediterranean Sea ◽

High Frequency ◽

Submarine Canyon ◽

Gravity Flow ◽

Sediment Gravity Flow

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Gravity-flow dominated sedimentation on the Buda paleoslope (Hungary): Record of Late Eocene continental escape of the Bakony unit

Geologische Rundschau ◽

10.1007/bf01791386 ◽

1992 ◽

Vol 81 (3) ◽

pp. 695-716 ◽

Cited By ~ 30

Author(s):

L. Fodor ◽

A. Magyari ◽

M. Kázmér ◽

A. Fogarasi

Keyword(s):

Late Eocene ◽

Gravity Flow

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Paleogene extension in the Northern Aegean: Colluvial/debris flow deposits of the Early-Middle Eocene in NW Thrace Basin, Turkey

Geologica Carpathica ◽

10.31577/geolcarp.72.3.3 ◽

2021 ◽

Vol 72 (3) ◽

Author(s):

Serdar Akgündüz ◽

Hayrettin Koral

Keyword(s):

Debris Flow ◽

Fault Zone ◽

Middle Eocene ◽

Late Eocene ◽

Coarse Grained ◽

Fine Grained ◽

Metasedimentary Rocks ◽

Early Oligocene ◽

Thrace Basin ◽

Nw Turkey

The Thrace Basin consists of Paleogene–Neogene deposits that lie in the lowland south of the Strandja highlands in NW Turkey, where metagranitic and metasedimentary rocks occur. The Akalan Formation consisting of colluvial fan/debris flow deposits represents the base of the sequence in the northern Thrace basin where it is bounded by a right lateral strike-slip oblique fault called “The Western Strandja Fault Zone”. This formation exhibits a coarse-grained, angular and grain-supported character close to the fault zone which has releasing-bends. Fine-grained, rounded, and matrix-supported sediments occur away from the contact. During this study, the Akalan Formation is described for the first time as having larger benthic foraminifera (LBF) of Coskinolina sp of Ypresian–Lutetian, Nummulites obesus of early Lutetian, Dictyoconus egyptiensis of Lutetian, Orbitolites sp. of Ypresian–Bartonian, Miliola sp of early–middle Eocene, Idalina grelaudae of early Lutetian–Priabonian, Ammobaculites agglutinans, Amphimorphina crassa, Dentalina sp., Nodosaria sp., Operculina sp., Lenticulina sp., Quinqueloculina sp. and Amphistegina sp. of Eocene. This unit passes upward with a conformity into reefal limestones of the middle/late Eocene–early Oligocene Soğucak Formation. At times, the limestone overlies the conformity, there is an indication of a prograding sedimentary sequence. The new stratigraphic, paleontological, sedimentological and structural findings related to the NW Thrace Basin suggest a strong transtensional/extensional tectonic control for the initial Paleogene sedimentary deposition during the Ypresian–Lutetian period as shown by fossil content of the Akalan Formation. Right lateral-slip extensional tectonics appears to have had activity during the middle–late Eocene transgressive deposition of the Soğucak Formation when the basin became deepened and enlarged.

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Revised Timing of Cenozoic Atlantic Incursions and Changing Hinterland Sediment Sources during Southern Patagonian Orogenesis

Lithosphere ◽

10.2113/2020/8883099 ◽

2020 ◽

Vol 2020 (1) ◽

pp. 1-18 ◽

Cited By ~ 2

Author(s):

Julie C. Fosdick ◽

R. A. VanderLeest ◽

J. E. Bostelmann ◽

J. S. Leonard ◽

R. Ugalde ◽

...

Keyword(s):

Detrital Zircon ◽

Atlantic Coast ◽

Foreland Basin ◽

Late Eocene ◽

Coarse Grained ◽

Plate Convergence ◽

Metasedimentary Rocks ◽

Sediment Routing ◽

Thrust Sheets ◽

Major Shift

Abstract New detrital zircon U-Pb geochronology data from the Cenozoic Magallanes-Austral Basin in Argentina and Chile ~51° S establish a revised chronostratigraphy of Paleocene-Miocene foreland synorogenic strata and document the rise and subsequent isolation of hinterland sources in the Patagonian Andes from the continental margin. The upsection loss of zircons derived from the hinterland Paleozoic and Late Jurassic sources between ca. 60 and 44 Ma documents a major shift in sediment routing due to Paleogene orogenesis in the greater Patagonian-Fuegian Andes. Changes in the proportion of grains from hinterland thrust sheets, comprised of Jurassic volcanics and Paleozoic metasedimentary rocks, provide a trackable signal of long-term shifts in orogenic drainage divide and topographic isolation due to widening of the retroarc fold-thrust belt. The youngest detrital zircon U-Pb ages confirm timing of Maastrichtian-Eocene strata but require substantial age revisions for part of the overlying Cenozoic basinfill during the late Eocene and Oligocene. The upper Río Turbio Formation, previously mapped as middle to late Eocene in the published literature, records a newly recognized latest Eocene-Oligocene (37-27 Ma) marine incursion along the basin margin. We suggest that these deposits could be genetically linked to the distally placed units along the Atlantic coast, including the El Huemul Formation and the younger San Julián Formation, via an eastward deepening within the foreland basin system that culminated in a basin-wide Oligocene marine incursion in the Southern Andes. The overlying Río Guillermo Formation records onset of tectonically generated coarse-grained detritus ca. 24.3 Ma and a transition to the first fully nonmarine conditions on the proximal Patagonian platform since Late Cretaceous time, perhaps signaling a Cordilleran-scale upper plate response to increased plate convergence and tectonic plate reorganization.

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Sedimentology, architecture, and depositional evolution of a coarse-grained submarine canyon fill from the Gelasian (early Pleistocene) of the Peri-Adriatic basin, Offida, central Italy

Sedimentary Geology ◽

10.1016/j.sedgeo.2011.05.003 ◽

2011 ◽

Vol 238 (3-4) ◽

pp. 233-253 ◽

Cited By ~ 27

Author(s):

Claudio Di Celma

Keyword(s):

Central Italy ◽

Submarine Canyon ◽

Coarse Grained ◽

Early Pleistocene ◽

Depositional Evolution ◽

Adriatic Basin

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Eocene exhumation and extensional basin formation in the Copper Mountains, Nevada, USA

Geosphere ◽

10.1130/ges02101.1 ◽

2019 ◽

Vol 15 (5) ◽

pp. 1577-1597

Author(s):

Andrew S. Canada ◽

Elizabeth J. Cassel ◽

Allen J. McGrew ◽

M. Elliot Smith ◽

Daniel F. Stockli ◽

...

Keyword(s):

Hanging Wall ◽

Normal Fault ◽

High Elevation ◽

Late Eocene ◽

Closure Temperature ◽

Coarse Grained ◽

Normal Faults ◽

Extensional Deformation ◽

Early Oligocene ◽

Basin Formation

Abstract Within extended orogens, records that reflect the driving processes and dynamics of early extension are often overprinted by subsequent orogenic collapse. The Copper Mountains of northeastern Nevada preserve an exceptional record of hinterland extensional deformation and high-elevation basin formation, but current geochronology and thermochronology are insufficient to relate this to broader structural trends in the region. This extension occurred concurrent with volcanism commonly attributed to Farallon slab removal. We combine thermochronology of both synextensional hanging-wall strata and footwall rocks to comprehensively evaluate the precise timing and style of this deformation. Specifically, we apply (U-Th)/(He-Pb) double dating of minerals extracted from Eocene–Oligocene Copper Basin strata with multi-mineral (U-Th)/He and 40Ar/39Ar thermochronology of rocks sampled across an ∼20 km transect of the Copper Mountains. We integrate basement and detrital thermochronology records to comprehensively evaluate the timing and rates of hinterland extension and basin sedimentation. Cooling and U-Pb crystallization ages show the Coffeepot Stock, which spans the width of the Copper Mountains, was emplaced at ca. 109–108 Ma, and then cooled through the 40Ar/39Ar muscovite and biotite closure temperatures by ca. 90 Ma, the zircon (U-Th)/He closure temperature between ca. 90 and 70 Ma, and the apatite (U-Th)/He closure temperature between 43 and 40 Ma. Detrital apatite and zircon (U-Th)/(He-Pb) double dating of late Eocene fluvial and lacustrine strata of the Dead Horse Formation and early Oligocene fluvial strata of the Meadow Fork Formation, both deposited in Copper Basin, shows that Early Cretaceous age detrital grains have a cooling history that is analogous to proximal intrusive rocks of the Coffeepot Stock. At ca. 38 Ma, cooling and depositional ages for Copper Basin strata reveal rapid exhumation of proximal source terranes (cooling rate of ∼37 °C/m.y.); in these terranes, 8–12 km of slip along the low-angle Copper Creek normal fault exhumed the Coffeepot Stock in the footwall. Late Eocene–early Oligocene slip along this fault and an upper fault splay, the Meadow Fork fault, created a half graben that accommodated ∼1.4 km of volcaniclastic strata, including ∼20 m of lacustrine strata that preserve the renowned Copper Basin flora. Single-crystal sanidine 40Ar/39Ar geochronology of interbedded tuffs in Copper Basin constrains the onset of rapid exhumation to 38.0 ± 0.9 Ma, indicating that surface-breaching extensional deformation was coincident with intense proximal volcanism. Coarse-grained syndeformational sediments of the Oligocene Meadow Fork Formation were deposited just prior to formation of an extensive regional Oligocene–Miocene unconformity and represent one of the most complete hinterland stratigraphic records of this time. We interpret this history of rapid late Eocene exhumation across the Copper Mountains, coeval volcanism, and subsequent unconformity formation to reflect dynamic and thermal effects associated with Farallon slab removal. The final phase of extension is recorded by late, high-angle normal faults that cut and rotate the early middle Miocene Jarbidge Rhyolite sequence, deposited unconformably in the hanging wall. These results provide an independent record of episodic Paleogene to Miocene exhumation documented in Cordilleran metamorphic core complexes and establish that substantial extension occurred locally in the hinterland prior to province-wide Miocene extensional break-up.

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Morphology, architecture, and evolutionary processes of the Zhongjian Canyon between two carbonate platforms, South China Sea

Interpretation ◽

10.1190/int-2017-0222.1 ◽

2018 ◽

Vol 6 (4) ◽

pp. SO1-SO15 ◽

Cited By ~ 1

Author(s):

Yintao Lu ◽

Wei Li ◽

Shiguo Wu ◽

Bryan T. Cronin ◽

Fuliang Lyu ◽

...

Keyword(s):

Seismic Data ◽

Large Scale ◽

Middle Miocene ◽

Sedimentary Environment ◽

Submarine Canyon ◽

High Amplitude ◽

Seismic Facies ◽

Coarse Grained ◽

Carbonate Platforms ◽

Depositional Processes

Two isolated Neogene carbonate platforms (Xisha and Guangle carbonate platforms) have developed in the rifted uplifts since the Early Miocene. A large-scale submarine canyon system, the Zhongjian Canyon (ZJC), has developed in the tectonic depression between the two platforms since the Middle Miocene. High-resolution bathymetry data and 2D and 3D seismic data reveal the existence of the ZJC on the present seafloor, as well as in Neogene intervals. It exhibits typical characteristics of deepwater canyons that cut the surrounding rocks and indicate strong erosional features. The ZJC resulted from northwest–southeast strike-slip fault activities during synrift and postrift stages, and it periodically grew during the development of carbonate platforms since the Middle Miocene. We identified four cycles of parallel to subparallel high amplitude and dim reflectors in seismic data, which we interpreted as alternating canyon fill, based on the interpretation of seismic facies. Thus, the sedimentary evolution of the ZJC can be divided into four typical stages, which were in the Middle Miocene, Late Miocene, Early Pliocene, and Pleistocene. Considering the tectonic background of the carbonate platforms, as well as the on-going igneous activities, the sediment filling the canyon could be derived from a mixture of carbonate clasts, igneous clasts, mud, and silt. The laminar high-amplitude reflectors and dim-reflector package represented a fining-upward sedimentary cycle. The coarse-grained sediment in canyon fillings could be turbidites, carbonate debrites, and even igneous clasts. In contrast, the fine-grained sediment is likely to be dominated by pelagic to hemipelagic mud, and silt. This case study describes a deepwater canyon under a carbonate-dominated sedimentary environment and has significant implications for improving our knowledge of periplatform slope depositional processes. Furthermore, the insight gained into periplatform slope depositional processes can be applied globally.

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