FLUVIAL ARCHITECTURE AND THE TECTONIC CONTROL ON DEPOSITION OF ONSHORE EUMERALLA FORMATION, OTWAY RANGES, VICTORIA: IMPLICATIONS FOR EXPLORATION IN THE EARLY CRETACEOUS OTWAY BASIN

2003 ◽  
Vol 43 (1) ◽  
pp. 99 ◽  
Author(s):  
C.A. Noll ◽  
M. Hall
Keyword(s):  
Hanging Wall ◽  
Normal Faults ◽  
River Channels ◽  
Fluvial System ◽  
Reservoir Properties ◽  
Local Study ◽  
Architectural Analysis ◽  
Drainage Patterns ◽  
Potential Source Rock ◽  
Fluvial Architecture

Spectacular outcrops of the terrestrial Aptian-Albian Eumeralla Formation are exposed in the Skenes Creek– Wongarra region, located on the eastern margin of the Otway Ranges, Victoria. The succession comprises mudstone-dominated floodplain and lacustrine successions and fluvially-derived sandstones. Lithofacies observed in the study area comprise intraformational and exotically derived conglomerate, massive and planar laminated sandstone, trough and tabular cross-bedded sandstone, ripple laminated sandstone, interbedded sandstone and mudstone, massive to laminated mudstone and thin coal seams. Architectural analysis of the fluvial system reveals these lithofacies are arranged into architectural elements that include channel elements, sandy bedforms, downstream and lateral accretion elements, laminated sand sheets and overbank fines elements.The fluvial system is characterised by low-sinuousity, braided river channels with high width to depth ratios. Palaeocurrent data indicates that the generally westward palaeoflow is interpreted to have been diverted into local axial-through drainage patterns by active northeast trending normal faults. One of these, the Skenes Creek Fault, is also likely to have structurally isolated floodplain and lacustrine successions from the main channel belt, leading to the deposition of an anomalously thick coal measure sequence in the hanging wall of the fault. The local study therefore provides insight into regional lithofacies and potential source rock distributions, and the associated tectonostratigraphic evolution of the Eumeralla Formation in the eastern Otway Basin. While the nature of the Eumeralla Formation sandstone does not lend itself to good reservoir properties, the geometry and internal structure of the sands provide an excellent model for other fluvial sandstone reservoir reconstructions.

Discovery of a Jurassic Porphyry Copper Belt, Pangui Area, Southern Ecuador

SEG Discovery ◽  
2000 ◽  
pp. 1-15
Author(s):  
IAN R. GENDALL ◽  
LUIS A. QUEVEDO ◽  
RICHARD H. SILLITOE ◽  
RICHARD M. SPENCER ◽  
CARLOS O. PUENTE ◽  
...  
Keyword(s):  
Porphyry Copper ◽  
Hanging Wall ◽  
Foreland Basin ◽  
Sulfide Mineral ◽  
The Philippines ◽  
Normal Faults ◽  
Geologic Mapping ◽  
Copper Mineralization ◽  
Argillic Alteration ◽  
Infill Drilling

ABSTRACT Grassroots exploration has led to discovery of 10 porphyry copper prospects in the previously unexplored Jurassic arc of southeastern Ecuador. The prospects are located in steep, wet, jungle-covered terrain in the Pangui area, part of the Cordillera del Cóndor. The exploration program, initially mounted in search of gold in the Oriente foreland basin, employed panned-concentrate drainage sampling. Follow-up of the resulting anomalies utilized soil sampling combined with rock-chip sampling and geologic mapping of the restricted creek outcrops. Scout and infill drilling of two of the prospects, San Carlos and Panantza, has shown hypogene mineralization averaging 0.5 to 0.7 percent Cu overlain by thin (averaging <30 m) zones of chalcocite enrichment or oxidized copper mineralization. The prospects are centered on small, composite granocliorite to monzogranite porphyry stocks that cut the Zamora batholith or, in one case, a satellite pluton. The batholith is emplaced into Jurassic volcanosedimentary formations, which concealed Triassic extensional half-grabens before being incorporated into the Subandean fold-thrust belt along the western margin of the Oriente basin. North- and northwest-striking normal faults in the hanging wall of a major north-striking fault zone controlled the locations of most of the porphyry centers. K silicate and variably overprinted intermediate argillic alteration, containing chalcopyrite as the principal sulfide mineral, characterize the central parts of most of the porphyry prospects and grade outward to pyrite-dominated propylitic halos. Overprinted sericitic alteration is generally less widely developed, although apparently shallower erosion at the Warintza and Wawame prospects resulted in preservation of extensive pyrite-rich sericitic zones. All the prospects contain appreciable (60–250 ppm) molybdenum, but gold tenors are low except at Panantza and Wawame (~0.15 and 0.2 g/t, respectively). Supergene oxidation and chalcocite enrichment zones are immature because of inhibition by the rapid erosion prevalent in the Pangui area. Supergene profiles attain their maximum development on ridge crests but are essentially absent along major creeks. Discovery of the Pangui belt, along with other recently defined porphyry copper systems in northern Perú, Indonesia, and the Philippines, underscores yet again the efficacy of drainage geochemistry as an exploration technique in tropical and subtropical arc terranes as well as the outstanding potential for additional exposed deposits in poorly explored parts of the circum-Pacific region.

scholarly journals Recent changes in sediment redistribution in the upper parts of the fluvial system of European Russia: regional aspects

2015 ◽  
Vol 367 ◽  
pp. 333-339 ◽  
Author(s):  
O. P. Yermolaev ◽  
V. N. Golosov ◽  
M. V. Kumani ◽  
L. F. Litvin ◽  
I. I. Rysin ◽  
...  
Keyword(s):  
Arable Land ◽  
Russian Plain ◽  
Cultivated Land ◽  
River Channels ◽  
Fluvial System ◽  
Sediment Redistribution ◽  
Erosion Models ◽  
Gully Head ◽  
Major Reduction ◽  
Quantitative Assessments

Abstract. Quantitative assessments of soil loss from cultivated land and sediment redistribution along pathways from cultivated fields to river channels have been undertaken using a range of different methods and techniques, including erosion models, detailed studies of sediment redistribution in representative catchments, monitoring of gully head retreat and evaluation of sediment deposition in ponds and small reservoirs. Most of the sediment eroded from arable land is deposited between the lower portions of the cultivated slopes and the river channels. Less than 15% of the eroded sediment is delivered to the river channels. Sediment redistribution rates in the upper parts of the fluvial system have declined during the last 25 years in both the western and eastern parts of the Russian Plain, because of a major reduction of surface runoff during snowmelt and a reduction of the area of arable land in some parts of the study area.

Quantification of fluvial-peat interactions in the Pikeville formation Central Appalachian Basin, USA.

2021 ◽  
Author(s):  
Peter Wooldridge ◽  
Robert Duller ◽  
Rhodri Jerrett ◽  
Kyle Straub
Keyword(s):  
Accumulation Rate ◽  
Appalachian Basin ◽  
River Channels ◽  
Channel Depth ◽  
Peat Accumulation ◽  
Floodplain River ◽  
Basin Scale ◽  
Well Data ◽  
Fluvial Architecture ◽  
Sand Bodies

<p>Basin-scale fluvial architecture is, to a large extent, determined by the ability of river systems to migrate and avulse across their own floodplain. River avulsion takes place when a river aggrades by one channel depth to achieve super-elevation above the surrounding floodplain. However, peat enhancement of floodplain aggradation is likely to affect this fluvial behaviour and has received little attention. The interaction between river channels and peat-dominated floodplains is likely to have the effect of inhibiting or prolonging the conditions required for river avulsion, and so will impact on basin scale architecture during prolonged peat accumulation on floodplains. To elucidate and quantify the nature of this channel-floodplain interaction we investigate the coal-bearing clastic interval of the Carboniferous Pikeville Formation, Central Appalachian Basin, USA. Using a combination of well data and outcrop data, two coal horizons and intervening sand bodies, were mapped across an area of 5700 km<sup>2</sup> to ascertain overall basin-scale architecture. Comparison of the accumulation rate of the coal units (corrected for decompaction) with the synchronously deposited sand bodies suggests that extensive and rapid peat accumulation can increase avulsion timescales by 3 orders of magnitude and dramatically alter basin-scale fluvial architecture.</p>

The Late Miocene-Early Pliocene out-of-sequence thrusting event: new insights into the tectonic evolution of the southern Apennines (Italy)

2021 ◽  
Author(s):  
Vitale Stefano ◽  
Prinzi Ernesto Paolo ◽  
Francesco D'Assisi Tramparulo ◽  
Sabatino Ciarcia
Keyword(s):  
Late Miocene ◽  
Hanging Wall ◽  
Early Pleistocene ◽  
Normal Faults ◽  
Southern Apennines ◽  
Campania Region ◽  
Early Pliocene ◽  
Upper Miocene ◽  
Thrust System ◽  
Tectonic Windows

<p>We present a structural study on late Miocene-early Pliocene out-of-sequence thrusts affecting the southern Apennine chain. The analyzed structures are exposed in the Campania region (southern Italy). Here, leading thrusts bound the N-NE side of the carbonate ridges that form the regional mountain backbone. In several outcrops, the Mesozoic carbonates are superposed onto the unconformable wedge-top basin deposits of the upper Miocene Castelvetere Group, providing constraints to the age of the activity of this thrusting event. We further analyzed the tectonic windows of Giffoni and Campagna, located on the rear of the leading thrust. We reconstructed the orogenic evolution of this part of the orogen. The first was related to the in-sequence thrusting with minor thrusts and folds, widespread both in the footwall and in the hanging wall. A subsequent extension has formed normal faults crosscutting the early thrusts and folds. All structures were subsequently affected by two shortening stages, which also deformed the upper Miocene wedge top basin deposits of the Castelvetere Group. We interpreted these late structures as related to an out-of-sequence thrust system defined by a main frontal E-verging thrust and lateral ramps characterized by N and S vergences. Associated with these thrusting events, LANFs were formed in the hanging wall of the major thrusts. Such out-of-sequence thrusts are observed in the whole southern Apennines and record a thrusting event that occurred in the late Messinian-early Pliocene. We related this tectonic episode to the positive inversion of inherited normal faults located in the Paleozoic basement. These envelopments thrust upward crosscut the allochthonous wedge, including, in the western zone of the chain, the upper Miocene wedge-top basin deposits. Finally, we suggest that the two tectonic windows are the result of the formation of an E-W trending regional antiform, associated with a late S-verging back-thrust, that has been eroded and crosscut by Early Pleistocene normal faults.</p>

Basement-involved inversion at the Appalachian structural front, western Newfoundland: an interpretation of seismic reflection data with implications for petroleum prospectivity

2004 ◽  
Vol 52 (3) ◽  
pp. 215-233 ◽  
Author(s):  
Glen S. Stockmal ◽  
Art Slingsby ◽  
John W.F. Waldron
Keyword(s):  
Seismic Reflection ◽  
Hanging Wall ◽  
Normal Fault ◽  
Hydrocarbon Exploration ◽  
Normal Faults ◽  
Apparent Magnitude ◽  
Seismic Reflection Data ◽  
The Public ◽  
Reflection Data ◽  
New Interpretation

Abstract Recent hydrocarbon exploration in western Newfoundland has resulted in six new wells in the Port au Port Peninsula area. Port au Port No.1, drilled in 1994/95, penetrated the Cambro-Ordovician platform and underlying Grenville basement in the hanging wall of the southeast-dipping Round Head Thrust, terminated in the platform succession in the footwall of this basement-involved inversion structure, and discovered the Garden Hill petroleum pool. The most recent well, Shoal Point K-39, was drilled in 1999 to test a model in which the Round Head Thrust loses reverse displacement to the northeast, eventually becoming a normal fault. This model hinged on an interpretation of a seismic reflection survey acquired in 1996 in Port au Port Bay. This survey is now in the public domain. In our interpretation of these data, the Round Head Thrust is associated with another basement-involved feature, the northwest-dipping Piccadilly Bay Fault, which is mapped on Port au Port Peninsula. Active as normal faults in the Taconian foreland, both these faults were later inverted during Acadian orogenesis. The present reverse offset on the Piccadilly Bay Fault was previously interpreted as normal offset on the southeast-dipping Round Head Thrust. Our new interpretation is consistent with mapping on Port au Port Peninsula and north of Stephenville, where all basement-involved faults are inverted and display reverse senses of motion. It also explains spatially restricted, enigmatic reflections adjacent to the faults as carbonate conglomerates of the Cape Cormorant Formation or Daniel’s Harbour Member, units associated with inverted thick-skinned faults. The K-39 well, which targeted the footwall of the Round Head Thrust, actually penetrated the hanging wall of the Piccadilly Bay Fault. This distinction is important because the reservoir model invoked for this play involved preferential karstification and subsequent dolomitization in the footwalls of inverted thick-skinned faults. The apparent magnitude of structural inversion across the Piccadilly Bay Fault suggests other possible structural plays to the northeast of K-39.

Submerged drainage patterns in Barrow Strait, Canadian Arctic

1976 ◽  
Vol 13 (2) ◽  
pp. 305-311 ◽  
Author(s):  
Brian D. Bornhold ◽  
Nancy M. Finlayson ◽  
David Monahan
Keyword(s):  
Canadian Arctic ◽  
Original Model ◽  
Normal Faults ◽  
Canadian Arctic Archipelago ◽  
Drainage Basins ◽  
Fluvial Erosion ◽  
Devon Island ◽  
Drainage Patterns ◽  
Somerset Island ◽  
East West

Recent detailed bathymetric maps of Barrow Strait enabled a reconsideration of the Tertiary fluvial erosion model used to account for the physiography of the Canadian Arctic Archipelago. Five distinct drainage basins were distinguished within Barrow Strait, including both dendritic and rectangular drainage patterns. The latter were controlled by normal faults along the Precambrian–Paleozoic contact in Peel Sound and Barrow Strait.Several changes in the original model are proposed, including the placement of the main east–west drainage divide through Somerset Island and across Barrow Strait and southern Wellington Channel to Devon Island.

scholarly journals The Timing of Metamorphism, Magmatism, and Cooling in the Zanskar, Garhwal, and Nepal Himalaya

1995 ◽  
Vol 11 ◽  
Author(s):  
M. P. Searle
Keyword(s):  
Hanging Wall ◽  
Crustal Thickening ◽  
Indian Plate ◽  
Eastern Himalaya ◽  
Normal Faults ◽  
The Tibetan Plateau ◽  
Main Central Thrust ◽  
Southern Tibet ◽  
Peak Metamorphism ◽  
Exhumation Rates

Following India-Asia collision, which is estimated at ca. 54-50 Ma in the Ladakh-southern Tibet area, crustal thickening and timing of peak metamorphism may have been diachronous both along the Himalaya (pre-40 Ma north Pakistan; pre-31 Ma Zanskar; pre-20 Ma east Kashmir, west Garhwal; 11-4 Ma Nanga Parbat) and cross the strike of the High Himalaya, propagating S (in Zanskar SW) with time. Thrusting along the base of the High Himalayan slab (Main Central Thrust active 21-19 Ma) was synchronous with N-S (in Zanskar NE-SW) extension along the top of the slab (South Tibet Detachment Zone). Kyanite and sillimanite gneisses in the footwall formed at pressure of 8-10 kbars and depths of burial of 28-35 km, 30- 21 Ma ago, whereas anchimetamorphic sediments along the hanging wall have never been buried below ca. 5-6 km. Peak temperatures may have reached 750 on the prograde part of the P-T path. Thermobarometers can be used to constrain depths of burial assuming a continental geothermal gradient of 28-30 °C/km and a lithostatic gradient of around 3.5-3.7 km/kbar (or 0.285 kbars/km). Timing of peak metamorphism cannot yet be constrained accurately. However, we can infer cooling histories derived from thermochronometers using radiogenic isotopic systems, and thereby exhumation rates. This paper reviews all the reliable geochronological data and infers cooling histories for the Himalayan zone in Zanskar, Garhwal, and Nepal. Exhumation rates have been far greater in the High Himalayan Zone (1.4-2.1 mm/year) and southern Karakoram (1.2-1.6 mm/year) than along the zone of collision (Indus suture) or along the north Indian plate margin. The High Himalayan leucogranites span 26-14 Ma in the central Himalaya, and anatexis occurred at 21-19 Ma in Zanskar, approximately 30 Ma after the collision. The cooling histories show that significant crustal thickening, widespread metamorphism, erosion and exhumation (and therefore, possibly significant topographic elevation) occurred during the early Miocene along the central and eastern Himalaya, before the strengthening of the Indian monsoon at ca. 8 Ma, before the major change in climate and vegetation, and before the onset of E-W extension on the Tibetan plateau. Exhumation, therefore, was primarily controlled by active thrusts and normal faults, not by external factors such as climate change.

scholarly journals Stratigraphic Architecture of the Karoo River Channels at the End-Capitanian

2021 ◽  
Vol 8 ◽  
Author(s):  
Emese M. Bordy ◽  
Francisco Paiva
Keyword(s):  
Environmental Drivers ◽  
River Channels ◽  
Fold Belt ◽  
Karoo Basin ◽  
Architectural Elements ◽  
Stratigraphic Architecture ◽  
Cape Fold Belt ◽  
Biotic Change ◽  
Extinction Events ◽  
Fluvial Architecture

The main Karoo Basin of southern Africa contains the continental record of the end-Triassic, end-Permian, and end-Capitanian mass extinction events. Of these, the environmental drivers of the end-Capitanian are least known. Integrating quantitative stratigraphic architecture analysis from abundant outcrop profiles, paleocurrent measurements, and petrography, this study investigates the stratigraphic interval that records the end-Capitanian extinction event in the southwestern and southern main Karoo Basin and demonstrates that this biotic change coincided with a subtle variation in the stratigraphic architectural style ∼260 Ma ago. Our multi-proxy sedimentological work not only defines the depositional setting of the succession as a megafan system that drained the foothills of the Cape Fold Belt, but also attempts to differentiate the tectonic and climatic controls on the fluvial architecture of this paleontologically important Permian succession. Our results reveal limited changes in sediment sources, paleocurrents, sandstone body geometries, and possibly a constant hot, semi-arid paleoclimate during the deposition of the studied interval; however, the stratigraphic trends show upward increase in 1) laterally accreted, sandy architectural elements and 2) architectural elements that build a portion of the floodplain deposits. We consider this to reflect a long-term retrogradational stacking pattern of facies composition that can be linked to changes on the medial parts of southward draining megafans, where channel sinuosity increased, and depositional energy decreased at the end-Capitanian. The shift in the fluvial architecture was likely triggered by basin-wide allogenic controls rather than local autogenic processes because this trend is observed in the coeval stratigraphic intervals from geographically disparate areas in the southwestern and southern main Karoo Basin. Consequently, we propose that this regional backstepping most likely resulted from tectonic events in the adjacent Cape Fold Belt.

scholarly journals Hurricane Fault

Geosites ◽  
2019 ◽  
Vol 1 ◽  
pp. 1-12
Author(s):  
Robert Biek
Keyword(s):  
East Coast ◽  
Hanging Wall ◽  
Grand Canyon ◽  
Normal Fault ◽  
Local Area ◽  
Fault Scarp ◽  
Normal Faults ◽  
Slip Rates ◽  
The Town

The Hurricane fault is the big earthquake fault in southwestern Utah. It stretches at least 155 miles (250 km) from south of the Grand Canyon northward to Cedar City and is capable of producing damaging earthquakes of about magnitude 7.0. The Hurricane fault is a “normal” fault, a type of fault that forms during extension of the earth’s crust, where one side of the fault moves down relative to the other side. In this case, the down-dropped side (the hanging wall) is west of the fault; the upthrown side (the footwall) lies to the east. Like most long normal faults, the Hurricane fault is composed of discrete segments that tend to rupture independently (figure 1). The fault lies at or near the base of the Hurricane Cliffs, which form an impressive, little-eroded fault scarp several hundred feet high. Conspicuous, west-tilted, faulted slivers of mostly Triassic and Jurassic red beds are locally exposed at the base of the cliffs, and contrast strongly with gray Permian carbonates exposed in the cliffs themselves. Several Pleistocene basaltic lava flows flowed across and are now offset by the fault zone, dramatically recording long-term slip rates. Should you make the mistake of pronouncing the name “Hurricane” as one would when describing a mighty storm on the East Coast, you should stand to be corrected, for locals pronounce it as “Hurricun” even though pioneers named the town after ferocious winds common to the local area.

scholarly journals Descriptive text to the Geological map of Greenland, 1:100 000, Kilen 81 Ø.1 Syd

2018 ◽  
pp. 1-29
Author(s):  
Kristian Svennevig ◽  
Peter Alsen ◽  
Pierpaolo Guarnieri ◽  
Jussi Hovikoski ◽  
Bodil Wesenberg Lauridsen ◽  
...  
Keyword(s):  
Hanging Wall ◽  
Field Work ◽  
Normal Faults ◽  
The South ◽  
Thrust Sheet ◽  
Basin Inversion ◽  
North East ◽  
The North ◽  
Geological Map ◽  
Surrounding Areas

The geological map sheet of Kilen in 1:100 000 scale covers the south-eastern part of the Carboniferous– Palaeogene Wandel Sea Basin in eastern North Greenland. The map area is dominated by the Flade Isblink ice cap, which separates several minor isolated landmasses. On the semi-nunatak of Kilen, the map is mainly based on oblique photogrammetry and stratigraphical field work while in Erik S. Henius Land, Nordostrundingen and northern Amdrup Land the map is based on field data collected during previous, 1:500 000 scale regional mapping. Twenty-one Palaeozoic–Mesozoic mappable units were identified on Kilen, while the surrounding areas comprise the Late Cretaceous Nakkehoved Formation to the north-east and the Late Carboniferous Foldedal Formation to the south-west. On Kilen, the description of Jurassic–Cretaceous units follows a recently published lithostratigraphy. The Upper Palaeozoic–lowermost Cretaceous strata comprise seven formations and an informal mélange unit. The overlying Lower–Upper Cretaceous succession comprises the Galadriel Fjeld and Sølverbæk Formations, which are subdivided into six and five units, respectively. In addition, the Quaternary Ymer Formation was mapped on south-east Kilen. The Upper Palaeozoic to Mesozoic strata of Kilen are faulted and folded. Several post-Coniacian NNW–SSE-trending normal faults are identified and found to be passively folded by a later N–S compressional event. A prominent subhorizontal fault, the Central Detachment, separates two thrust sheets, the Kilen Thrust Sheet in the footwall and the Hondal Elv Thrust Sheet in the hanging wall. The style of deformation and the structures found on Kilen are caused by compressional tectonics resulting in post-extensional, presumably Early Eocene, folding and thrusting and basin inversion. The structural history of the surrounding areas and their relation to Kilen await further studies.

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