A shallow marine volcaniclastic facies model: an example from sedimentary rocks bounding the subaqueously welded Ordovician Garth Tuff, North Wales, U.K.

Fritz, William J.; Howells, M. F.

doi:10.1016/0037-0738(91)90041-b

Cited by 24 publications

(17 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…2; cf. Cas and Wright, 1987, p. 270;Fritz and Howells, 1991;Mueller et al, 2000). The acid agglomerates and associated tuffs have been interpreted as air-fall deposits (Singh, 1998, p. 385).…”

Section: Pyroclastic Faciesmentioning

confidence: 99%

Sedimentation history of the Palaeoproterozoic Dhanjori Formation, Singhbhum, eastern India

Mazumder

Sarkar

2004

Precambrian Research

View full text Add to dashboard Cite

The Palaeoproterozoic Dhanjori Formation, eastern India is a terrestrial (dominantly fluvial) volcano-sedimentary succession. Basal conglomerate, coarse-grained sandstone, and shale rests directly on the granite basement and represents the distal fringe of an alluvial fan complex. Sieve, sheet flood, mass flow and alluvial channel and overbank deposits comprise the fan segment. The rest of the formation is entirely constituted by fining upward fluvial cycles. An event of basin tilting and volcanic eruption intervened and resulted a second phase of Dhanjori sedimentation, although the general fluvial depositional framework remained unaltered. The two members of the Dhanjori Formation display different paleocurrent trends related to fluvial response to basin tilting. In the lower member spatial variability in paleocurrent directions occurs as a consequence of fan development. Unlike the first phase, the second phase of fluvial deposition incorporates profuse volcanics and accompanying volcaniclastic deposits. These volcanic and volcaniclastic rocks might have locally blocked the river courses resulting in short-lived lacustrine deposition. Composition of the volcanics varies upward from ultramafic to mafic. The Dhanjori volcanism took place in an intracontinental rift setting as is evident from the interbedded terrestrial deposits. Interbedded volcanic and volcaniclastic rocks in different stratigraphic levels suggest episodic volcanic eruption. A semiarid paleoclimate is proposed and is consistent with development of an alluvial fan comprised of coarse clastic deposits.

show abstract

Section: Pyroclastic Faciesmentioning

confidence: 99%

Sedimentation history of the Palaeoproterozoic Dhanjori Formation, Singhbhum, eastern India

Mazumder

Sarkar

2004

Precambrian Research

View full text Add to dashboard Cite

show abstract

“…L'observation des structures sédimentaires associées aux faisceaux de marées (tidal bundle) peut indiquer la présence d'un plateau tidal ouvert sur la côte, c'est-à-dire un plateau tidal dominé par les vagues (Yang et al, 2008). Les surfaces de réactivation peuvent représenter un changement de flux sur les côtes ou les deltas dominées par les influences tidales (Fritz et Howells, 1991). La surface de réactivation se met en place sous forme de lits qui se déplacent durant les cycles dominés par les courants tidaux, puis modifiés et érodés durant les phases subordonnées.…”

Section: Ad 051unclassified

“…La stratification planaire au sein des lits de grès tabulaires représente la migration de vagues de sable (dunes 2-d) dans le champ de dunes du régime d'écoulement inférieur (Fritz et Howells, 1991 (Mueller et al, 2000b). Les intervalles de lits planaires se forment sous les conditions de vélocité maximale des flux tidaux alors que les laminations entrecroisées en rides se développent durant les conditions de vannage des flux (Bhattacharya et Bhattacharya, 2006).…”

Section: Ad 051unclassified

“…Les stratifications entrecroisées d'ordre métrique sont interprétées comme des dunes de faible énergie qui se développent durant les conditions de vannage de flux (Mueller et al, 2000b). Ces flux sont communs dans les chenaux tidaux des côtes marines peu profondes (Clifton, 1976in Fritz et Howells, 1991 et se développent à partir d'un transport le long de la ligne de côte (Howard et Reineck, 1981). Les contacts nets et ondulants des lits d'argilites au sommet des grès dans ce faciès pourraient être générés par les processus quotidiens des vagues de beau temps, tôt après la fin des tempêtes comme l'a décrit Wu (1982).…”

Section: Ad 051unclassified

“…Voir figure 2-42 pour la localisation de cette carte. (Fritz et Howells, 1991). Ces dépôts se forment en moyenne côte ou en côte externe à des profondeurs comprises entre 20 et 100 m (Fritz et Howells, 1991).…”

Section: 215-lithofaciès Conglomérats-grèsunclassified

See 2 more Smart Citations

Caractéristiques sédimentologiques, volcanologiques et structurales du bassin de Granada dans la ceinture de roches vertes de l'Abitibi (Québec) /

Diop¹

2011

View full text Add to dashboard Cite

The Granada Basin, correspond to the stratigraphie unit known as the Granada Formation. This unit lies in the southernmost part of the Southern Volcanic Zone of the greenstone dominated Abitibi Subprovince in Quebec.Faciès analysis in the Granada Basin has identified clastic and volcaniclastic rocks deposited in an environment evolving from relatively deep marine to fluvial. The earliest sediments were mainly turbidites (faciès la and lb) deposited in extensional sub-basins. These sediments were overlain by a regressive sequence that evolved from shallow marine wave base dominated sediments (faciès 2a) to coastal deposits (faciès 2b). These deposits represent the transition between marine and continental depositional environments. The transition zone is marked by deposits of sandstoneargillites-stratified pebble conglomerate (faciès 2b) transported by waves and tides between the subtidal and intertidal zone. Faciès 3a and 3b of the felsic volcaniclastic lithofacies are interbedded with faciès la, lb and 2a.Deposits of the Granada Basin are transitional faciès separated by intra-basin unconformities, which are characteristic of sedimentary basins formed along fault margins. The volcano-sedimentary deposits of the Granada Basin have characteristics of sedimentation influenced by tectonisme such as: i) local and basinwide lateral and vertical faciès variations; ii) alternating fining and coarsening upwards sequences; iii) high rate of accumulation of sediments; iv) some conglomerate boulders are over 1 m in size and the thickness of conglomerate deposits; v) interdigitation of conglomerates and sandstones that denotes a progradation; vi) intra-basin unconformities; vii) the local source of conglomerates; and viii) associated alkaline magmatism. Tectonism would be ongoing throughout the development of the basin which would have induced several phases of source renewal areas for the sediments coupled with intra-basin unconformities. The earliest formed sedimentary deposits of the Granada Basin were affected by uplift and subsequently eroded and recycled into later basin fill along intra-basin unconformities. Gradually as the basin filled the sedimentary deposits became less and less shallower which is a characteristic of piggyback-type basins. The decrease in the depth is a consequence of an increase in topography due to repeated uplift along faults.Sedimentary rocks of the Granada Basin were intruded by alkalic mature volcanic arc-type sills, stocks and porphyritic dikes. These intrusive rocks are similar to Timiskaming-type porphyry intrusions and volcanic rocks found in the Kirkland Lake area of Ontario.The structural style of the Granada Basin, consisting of overturned southward verging tight to isoclinal folds, is characteristic of thrust basins. Two major east-west trending synclinal axial traces are distinguishable and their juxtaposition in a back to back relationship is compatible with there being an unconformity between them. This unconformity is further demonstrated by the presence of sandstone cla...

show abstract

Post‐1.8‐ka Marginal Sedimentation in Lake Taupo, New Zealand: Effects of Wave Energy and Sediment Supply in a Rapidly Rising Lake

Riggs

Ort

White

et al. 2001

Volcaniclastic Sedimentation in Lacustrine Settings

View full text Add to dashboard Cite

The amount and timing of volcaniclastic sediment influx into volcanic lakes is controlled mostly by timing, magnitude and frequency of eruptions. Material is delivered to the lake directly by pyroclastic fall and flow processes, and via fluvial, aeolian and mass-flow remobilization of pyroclastic material. Once in the lake, the final distribution of sediment is influenced by wave-induced currents and density currents.In this paper, we describe young lacustrine sediments in a caldera setting at Lake Taupo, New Zealand. Intracaldera lacustrine sedimentation has not received much study because the record of sedimentation in caldera lakes is often overprinted by post-emplacement erosion or deformation and volcanism ABSTRACTThe eruption of Taupo caldera, New Zealand, c. 1.8 ka, climaxed in the emplacement of the Taupo ignimbrite, which dammed the previous outlet of the caldera lake and allowed rise of the lake behind the dam to c. 34 m above current lake level. After an estimated 20 yrs of lake refilling, the ignimbrite dam was breached, and the lake drained rapidly to a position 2-4 m above current level. From that level, the lake apparently dropped slowly to its present position.Post-1.8-ka lacustrine sediments are exposed at various levels between the highstand and the modern shoreline. The distribution of lacustrine facies at Taupo reflects the location of the mouths of rivers that drained uplands buried and/or denuded of vegetation by the erupted material, together with the position of depositional sites with respect to prevailing winds and energy systems. Four broad facies environments can be recognized, defined by combinations of high or low energy and high or low sediment influx. Sediments deposited in areas of high energy (i.e. strong wave action) and high sediment input are rich in vitric material, but contain abundant lithic material in those deposits interpreted as storm influenced. Deposits in lowenergy areas that had high sediment input are dominantly vitric, with abundant shoreface and pumice-raft deposits. High-energy, low-sediment-input areas are rich in lithic detritus, apparently reworked from ignimbrites along the pre-eruptive lake shore during storms. Deposits that characterize low-energy, lowsediment-input environments are poor in lithic detritus, reflecting the inability of currents to transport material to these sites. Terraces prominent above the modern shoreline of Lake Taupo expose transgressive sequences that range from beach face deposits at the base to below-storm wave-base deposits at the top. Many terraces are capped by deposits of well-rounded, cobble-to boulder-size pumice clasts, which are interpreted as stranded deposits of previously floating clasts, formed during rapid lake-level fall.The Lake Taupo sedimentary record provides insights into sedimentary facies and styles that may be expected during lake filling that immediately follows caldera collapse. The inferred rapid filling rate of the lake, estimated to be 5 -9 m yr -1 for the exposed section, together with the dominantly vi...

show abstract

A shallow marine volcaniclastic facies model: an example from sedimentary rocks bounding the subaqueously welded Ordovician Garth Tuff, North Wales, U.K.

Cited by 24 publications

References 37 publications

Sedimentation history of the Palaeoproterozoic Dhanjori Formation, Singhbhum, eastern India

Sedimentation history of the Palaeoproterozoic Dhanjori Formation, Singhbhum, eastern India

Caractéristiques sédimentologiques, volcanologiques et structurales du bassin de Granada dans la ceinture de roches vertes de l'Abitibi (Québec) /

Post‐1.8‐ka Marginal Sedimentation in Lake Taupo, New Zealand: Effects of Wave Energy and Sediment Supply in a Rapidly Rising Lake

Contact Info

Product

Resources

About