When sedimentologists interpret rock units, they do so using a genetic approach based on characteristics of depositional environments, as opposed to simple descriptions of rocks. The typical watercourse in an arid climate has a large, funnelshaped basin at the top, leading to a narrow defile, which opens out into an alluvial fan at the bottom. The trollheim alluvial fan and facies model revisited article pdf available in geological society of america bulletin 1046. This paper presents the first detailed account of the sedimentary structures, textures, and composition of sediments of the hinuera formation in the hamilton basin in order to relate the various lithologies in the formation to particular depositional facies within the alluvial environment.
Sedimentology and climatic environment of alluvial fans in. At the waters edge the processes would switch from subaerial to subaqueous processes, involving a change in depositional slope and in sedimentary style. The trollheim alluvial fan and facies model revisited. Sedimentary structures and environments this old earth. Exploration potential of the mature southern north sea. Burrowing boring encrustation compaction cementation. Sedimentary facies analysis ias special publication, no. We address these issues through a detailed stratigraphic analysis, crater countderived ages, quantitative. The sedimentary facies is broadly divided into sandy or sandstone facies, shaly facies, and. Evolution of the quaternary alluvial fan system in the himalayan foreland basin. Palaeoenvironmental reconstruction of a middle miocene alluvial. Implications for tectonic and climatic decoupling rohtash kumar, n.
Sarah garceau, melissa harris, ryan mcdaniel, kimberly pettit and brian ragan ems2012ca0011. Sedimentary structures and environments sean tvelia introduction not all sedimentary rocks form under the same conditions. Placzek abstract dbcp 1,2dibromo3chloropropane contamination in the sole source aquifer near fresno, california, has significantly affected drinkingwater supplies. Kendall andrew miall is a productive writer and this book is another magnum opus, consisting of. Each of those could also be considered a facies, and the overall alluvial fan deposit could be assigned to an alluvial fan facies. Palaeoenvironmental reconstruction of a middle miocene. If an alluvial fan toes out in water, a lake, a fjord or an arm of the sea, it would be termed a fan delta fig. When a stream comes out of the mountains onto the flat plain, it drops its sediment load. Pdf the trollheim alluvial fan and facies model revisited.
Contrary to common contemporary usage, alluvial fans are a naturally unique phenomenon readily distinguishable from other sedimentary environments, including gravelbed rivers, on the basis of morphology, hydraulic processes, sedimentologic processes, and facies assemblages. Pdf facies architecture and depositional evolution of. Facies and depositional model of alluvial fan dominated by. As seen in the previous lab, the specific rock that forms depends on the source material. In nonmarine environments, facies architecture in pullapart basins is controlled by tectonics and climate. Each of list items above could be described as a subfacies of the alluvial fan facies, with its own grain sizes, characteristics, sedimentary structures, etc. For this reason, it is essential that any investigation of alluvial fan flooding include careful examination of the specific fan for. Hydrogeologic facies characterization of an alluvial fan near fresno, california, using geophysical techniques by k. The paleoenvironments documented in the sedimentary record are. Geology and geomorphology of alluvial and fluvial fans. Alluvial fans alluvial fan sediments are deposits of. Pdf facies analysis of tertiary alluvial fan deposits in. Alluvial fans are aggradational sedimentary deposits.
Big wood, lower boise, payette, teton and upper spokane watersheds 102120 alphabetical listing of contributing authors. Whether an arkose, greywacke, sandstone, or limestone, forms depends purely on the material that is being deposited, the. Proximal and medial alluvial fan facies table 1 the alluvial fan facies, characterized by successions of red siliciclastic deposits more than 100 m. Contemporaneous volcanism, indicated schematically, occured in the. This problem is compounded because the accumulated. The sedimentary facies is of most interest with respect to fluid flow. The fluvial facies consist of coarse to mediumgrained arkose with pebbly admixtures, which predominates over finegrained sandstone. Sedimentology of the narmada alluvial fan, western india. Facies models and alluvial fan facies lecture facies. Alluvial facies architecture and the role of climate and tectonics in basin fan systems, death valley, california abstract pullapart basins are common structural features in strikeslip regimes that have significant petroleum potential. This paper provides the first general account of the facies associations that fill a miocene fault bounded basin located in the central part of the isparta angle turkey, in order to define processcontrolled sedimentary units reflecting. Holocene alluvialfan development in the macgillycuddys. Facies analysis of the middle and late pleistocene sediment infill of.
Conversely, better reservoir quality and greater extent, together with thinning and lower ng towards distal areas is expected in the upper unit. Point counting for this or the next lab assignment immature siliciclastic sediment and sedimentary rocks. The detailed descriptions and interpretations of these lithofacies are given in tables, and a summary is presented in the following paragraphs. Depositional processes in the distal part of a large. Purchase of an open document does not constitute license for republication in any form, nor does it allow web posting without prior written permission. Borehole and surface geophysical data were integrated with borehole textural data to characterize the kings river alluvial fan sediments and to provide a framework for computer modeling of pesticide transport in ground water. The sedimentary characteristics of nearsource gravel fan.
Facies and architectural analysis of fluvial deposits of. Several alluvial fans are developed at the foot of the escarpment, and they terminate in playa and sabkha sediments towards kadhmah bay. Definition facies is a body of rock characterized by a particular combination of lithology, physical and biological structures that bestow an aspect that different from the bodies of rock above, below and laterally adjacent the facies concept refers to the sum of characteristics of a sedimentary. Sedimentary facies the deposits comprise five lithofacies. Forming a buffer zone between the source and sink of the ganga foreland basins gola alluvial fan, the ranibag valley is filled with coarse gravels comprising five distinct facies. Sedimentary architecture and facies analysis from chronologically constrained. This distinction is crucial for prediction of reservoir quality, which in the case of a sheetflooddominated alluvial fan, can be several orders of magnitude better higher lateral connectivity and vertical permeability than a debrisflow dominated alluvial fan. Alluvial fans are often found in desert areas often subjected to periodic flash floods from nearby thunderstorms in local hills. The sedimentary facies and the facies model the quaternary alluvial fan stratigraphy, as presented in table 2, can be further subdivided into three facies, each characterized by its bulk geometry, lithology, stratification, and sedimen tary structures. From those informations, we can construct the facies model thats a general summary of the characteristics of certain depositional system.
The depositional facies include alluvial fans, fluvial, lacustrine and playa environments. Scientific publications on desert alluvial fans pre. July, pages 450489 alluvial fans and their natural distinction from rivers based on morphology, hydraulic processes, sedimentary processes, and facies assemblages. Evolution of the quaternary alluvial fan system in the. Morphology and facies of alluvial fans in kadhmah bay. Coomloughra glen alluvialfan and debriscone complex geomorphology and stratigraphy the alluvialfan complex within coomloughra glen consists of two distinct fans, referred to here as fan a and fan b, and a series of inset bars and channel lags along the length of the main catchment stream fig.
A semicircular to conical accumulation of coarsegrained sediments. Facies and depositional model of alluvial fan dominated by episodic flood events in arid conditions. This viewpoint allows us to predict what types of sediments and stratigraphic sequences would be formed in a given depositional setting. Chapter 1 subsurface macro structure rice university. A mialls 1978 schematic vertical sedimentary sequence for the trollheim fan. The sedimentary characteristics of near source gravel fan delta controlled by traction flowa case international organization of scientific research 29 p a g e fig. Geomorphic and depositional expressions of alluvial fans. Alluvial fan, unconsolidated sedimentary deposit that accumulates at the mouth of a mountain canyon because of a diminution or cessation of sediment transport by the issuing stream.
Detailed facies analysis and morphotectonic investigations of the malin rivers alluvial fan in the western ganga plain, india, reveal that the morphology of the fan is largely tectonically controlled whereas the sedimentary processes are mainly climatically controlled. Sedimentary facies, physical, chemical, and biological aspects of a sedimentary bed and the lateral change within sequences of beds of the same geologic age. Sedimentary rocks are formed by 5 processes, there are erosion, weathering. Alluvial sedimentology of the upper pleistocene f ormation. The quaternary sediments of the alluvial fans are divided into three facies.
Sedimentary facies and processes sediment gravity flows are very common sedimentary processes in the alpine region and are often characterized by. Sedimentary rocks can be formed only where sediments are deposited long enough to become. Alluvial facies architecture and the role of climate and. Characteristics of sedimentary facies and reservoir properties of some tertiary sandstones in sabah and sarawak, east malaysia by teoh ying jia thesis submitted in fulfillment of the requirements for the degree of. Facies models and alluvial fan facies lecture facies a. Descriptions of common sedimentary environments river systems. The deposits, which are generally fan shaped in plan view, can develop under a wide range of climatic conditions and.
Underwater alluvial fan comprises of 5 kinds sedimentary facies. Clarke2 1faculty of geosciences, utrecht university, 3584cb utrecht, the netherlands 2school of natural and social sciences, university of gloucestershire, cheltenham gl50 4az, uk correspondence. Sedimentary processes on alluvial fans are controlled primarily by the nature of. Terrestrial sedimentary environments i alluvial fans. What is the facies model like for the overbank deposits. Alluvial fans and alluvial fan floods show great variability in climate, fan history, rates and styles of tectonism, source area lithology, vegetation, and land use. Guy plint this book celebrates the professional career of harold reading, who has played a leading role in the development of the ias, and has been at the roots of the development of facies sedimentology as an art in itself and as a major tool in the broader field of geology. A combined study of radar facies, lithofacies and three. Alluvial fan mapping and risk assessment project report. Schematic sedimentary logs through debrisflow, sheetflood and streamchannel alluvial fan deposits.
To identify sedimentary characteristics of underwater alluvial fan and determine its oil bearing property so as to develop this type of reservoir reasonably and effectively. They are formed where neighbouring alluvial fans feed into a closedsystem valley. Dbcp 1,2dibromo3chloropropane contamination in the sole source aquifer near fresno, california, has significantly affected drinkingwater supplies. Alluvial fans and their natural distinction from rivers.
Sedimentary facies, basin analysis, and petroleum geology by a. The facies coding scheme modified after miall, 1985 used in this study is shown in table 1. Hydrogeologic facies characterization of an alluvial fan. Indicators for characterizing alluvial fans and alluvial.
370 1351 261 1411 1580 1504 1406 585 1595 1382 321 780 1234 1284 9 1177 1003 212 614 1523 512 150 770 329 1438 1116 806 476 697 694