The Interaction of Small and Medium Scale Heterogeneities from a Shallow Marine Depositional Environment with Various Two Phase Displacements

Author(s):  
Svein Tore Opdal ◽  
Charles A. Kossack ◽  
Jonathan J.M. Lewis
2012 ◽  
Vol 150 (3) ◽  
pp. 519-535 ◽  
Author(s):  
JACK E. TREAGUS ◽  
SUSAN H. TREAGUS ◽  
NIGEL H. WOODCOCK

AbstractThe boundary between the Rhoscolyn and New Harbour formations on Holy Island, Anglesey, has been described as a high strain zone or as a thrust. The boundary is here described at four localities, with reference to the contrasting sedimentary and deformational character of the two formations. At one of these localities, Borth Wen, sandstones and conglomerates at the top of the Rhoscolyn Formation are followed, without any break, by tuffs and then mudstones of the New Harbour Formation. It is concluded that there is clear evidence of depositional continuity across the boundary here, and that both formations subsequently shared a common two-phase deformation. The first (D1) was manifestly different in intensity and scale in the two formations, whereas the second (D2) produced very similar structures in both. The other three localities provide continuity of sedimentary and tectonic features at this boundary in a traverse along the length of Holy Island, leading us to identify two previously unrecognized major D1 folds in addition to the Rhoscolyn Anticline. At one of these localities (Holyhead), we confirm the presence of Skolithos just below the boundary, supporting radiometric evidence for a lower Cambrian or later age for the Rhoscolyn Formation. A turbidite interpretation for both the Rhoscolyn and New Harbour formations best fits the available evidence. A deep-water depositional environment is still compatible with the sporadic presence of Skolithos burrows, but less so with reported observations of hummocky and swaley cross-stratification lower down the South Stack Group.


2019 ◽  
Vol 8 (2) ◽  
pp. 65-80
Author(s):  
Unggul Prasetyo Wibowo ◽  
Anton Ferdianto ◽  
Nurul Laili ◽  
Dida Yurnaldi ◽  
Ruli Setiawan

Cisaar Valley is located on the east part of Sumedang Regency, West Jawa Province. It’s close to the boundary of Sumedang-Majalengka Regency. In this location the sandy and clay dominated sedimentary rocks are well exposed along the outcrops in the Cisaar Valley. These sedimentary rocks is inferred from Pliocene-Pleistocene deposits from Kaliwangu and Citalang Formation. Foraminifera microfossil that commonly used for interpretation of depositional environment is rarely found, whereas freshwater mollusk and vertebrate fossils often found in the sediment rocks of this area.  This condition raises a question, what is the environment of this valley in the past? Data obtained from measured stratigraphic sections along Cisaar river and its tributary rivers in Cibengkung and Cirendang hamlets, Jembarwangi village. There are at least three depositional paleoenvironments which from old to young are: shallow marine, estuarine and fluviatil braided channel depositional paleoenvironment.  Characteristics of the lower, middle and upper of the estuarine environment were found in this Cisaar Valley as the evidences of the oceanic regression processes was happened in the past in this area. 


2009 ◽  
Vol 60 (2) ◽  
pp. 139-149 ◽  
Author(s):  
Katrin Ruckwied ◽  
Annette Götz

Climate change at the Triassic/Jurassic boundary: palynological evidence from the Furkaska section (Tatra Mountains, Slovakia)The palynology of the Triassic/Jurassic boundary interval of the Furkaska section (Tatra Mts, Slovakia) was studied with respect to a major climatic change during that period. The palynofacies is dominated by terrestrial particles, indicating a shallow marine depositional environment. The palynomorphs are fairly well-preserved and the assemblage shows characteristic changes within the Triassic/Jurassic boundary interval: the lower part of the section is characterized by high abundance ofRicciisporites tuberculatus.The sudden increase in abundance of trilete spores, the decrease in the abundance ofOvalipollisspp., the last appearance ofAlisporites minimusandCorollinaspp., and the first appearance ofConcavisporites rhaetoliassicus, Cyatidites australis, Callialasporites dampieri, Pinuspollenites minimus, Platysaccusspp. andZebrasporites fimbriatusare striking features for a subdivision of two palynomorph assemblages. The detected spore shift is interpreted to display a sudden increase in humidity most probably caused by the volcanic activity of the Central Atlantic Magmatic Province (CAMP) associated with the onset of rifting of Pangaea during early Mesozoic times.


2000 ◽  
Vol 137 (4) ◽  
pp. 381-394 ◽  
Author(s):  
S. LOUWYE ◽  
J. DE CONINCK ◽  
J. VERNIERS

Detailed dinoflagellate cyst analysis of the Lower–Middle Miocene Berchem Formation at the southernmost margin of the North Sea Basin (northern Belgium) allowed a precise biostratigraphical positioning and a reconstruction of the depositional history. The two lower members of the formation (Edegem Sands and decalcified Kiel Sands) are biostratigraphically regarded as one unit since no significant break within the dinocyst assemblages is observed. The base of this late (or latest) Aquitanian–Burdigalian unit coincides with sequence boundary Aq3/Bur1 as defined by Hardenbol and others, in work published in 1998. A hiatus at the Lower–Middle Miocene transition separates the upper member (the Antwerpen Sands) from the underlying member. The greater part of the Antwerpen Sands were deposited in a Langhian (latest Burdigalian?)–middle Serravallian interval. The base of this unit coincides with sequence boundary Bur5/Lan1. Biostratigraphical correlation points to a diachronous post-depositional decalcification within the formation since parts of the decalcified Kiel Sands can be correlated with parts of the calcareous fossil-bearing section, up to now interpreted as Antwerpen Sands. The dinoflagellate cyst assemblages are dominated by species with a inner neritic preference, although higher numbers of oceanic taxa in the upper part of the formation indicate incursions of oceanic watermasses into the confined depositional environment of the southern North Sea Basin.


2016 ◽  
Vol 53 (1) ◽  
pp. 34-40
Author(s):  
Robin L. Sissons ◽  
Michael W. Caldwell ◽  
Carol A. Evenchick ◽  
Donald B. Brinkman ◽  
Matthew J. Vavrek

Although the Jurassic was a period of high diversity in ichthyosaurs, only a small number of specimens have been recorded from Canada to date. We describe here a new occurrence of an ophthalmosaurid ichthyosaur from a shallow marine depositional environment within the Bowser Basin of northern British Columbia. Based on vertebral diameters and the size of the humerus, the ichthyosaur was relatively large compared to other contemporaneous forms, yet possessed teeth that were small for its body size. As well, the height to length ratio of the preserved vertebrae suggests it may have had a more elongate, less regionalized body shape. Although indeterminate at a generic level, the presence of Late Jurassic ichthyosaurs in nearshore waters of northwestern North America further demonstrates their cosmopolitan distribution.


Author(s):  
Luhut Pardamean Siringoringo ◽  
Dardji Noeradi

Northern part of Masalima Trench Basin is located in the southern part of the Strait of Makassar, which includes Masalima Trough and Massalima High. The area of research is an extension of the South Makassar Basin which extends from South Makassar Basin to the Northeast part of Java Sea. Subsurface data are used such as 2D seismic sections (21 lines) and data drilling wells (2 wells) to understand the tectonic structure in the basin formation and understand the stratigraphic order of basin. Based on well data can be known that Northern part Masalima Trench Basin is aborted rift because marked by post rift phase. Northern part Masalima Trench Basin was formed by normal faults which have trend northeast-southwest with  pre rift, early syn rift, late syn rift, and post rift sediment geometry. Early syn rift sediment was Middle Eocene, late syn rift sediment was Middle Eocene till Early Oligocene and post rift sediment was Early Oligocene till Early Miocene. The Depositional environment of early syn rift phase such as beach, shallow marine, and land. The Depositional environment of late syn rift phase such as beach till deep marine, and the depositional environment of post rift is deep marine.


2017 ◽  
Vol 50 (1) ◽  
pp. 478 ◽  
Author(s):  
M.V. Triantaphyllou ◽  
K.P. Pavlopoulos ◽  
K. Kouli ◽  
O. Koukousioura ◽  
M.D. Dimiza ◽  
...  

The joint application of benthic foraminifera, pollen and non-pollen palynomorphs (NPPs), molluscs and magnetic susceptibility analyses in Piraeus coastal plain deposits resulted in the detailed study of palaeoenvironmental evolution of the area during almost the last 9000 years and the distinction of five lithostratigraphicalpaleoenvironmental units and subunits. Combined results of our analyses features the occurrence of an inner lagoon (unit Aa) followed by  open lagoon (Unit Ab) depositional environment that was transformed to a shallow marine paleoenvironment with lagoonal features (Unit B) after 7800 BP. Since about 4800 BP a closed oligohaline lagoon (Unit C) used for grazing, occurred in the area, while after 2800 BP a marshy oligohaline depositional environment (Unit D) and signs of intensive agricultural activities are evidenced. The very good correlation of benthic foraminiferal, palynological, molluscan and magnetic susceptibility data and resulted indices is indicative of the potential of the applied methodologies as a paleoenvironmental tool box.


2018 ◽  
Vol 66 ◽  
pp. 47-60
Author(s):  
Gilles Cuny ◽  
Lars Stemmerik

The Moscovian of eastern North Greenland has yielded an assemblage dominated by teeth and dermal denticles of chondrichthyans with rarer teeth of actinopterygians. The rather poor preservation of the material precludes precise identification but the following taxa have been recorded: Adamantina foliacea, Bransonella spp., Denaea sp., “Stemmatias” simplex, Lagarodus specularis, Actinopterygii indet., as well as teeth probably belonging to new genera of Heslerodidae, ?Protacrodontidae and Hybodontiformes. This fauna appears therefore quite endemic. The abundance of Bransonella and durophagous chondrichthyans is in accordance with the shallow marine depositional environment. The record of a ?protacrodontid is possibly the youngest one for this taxon.


2021 ◽  
Vol 50 (2) ◽  
pp. 301-313
Author(s):  
Hafzan Eva Mansor ◽  
Meor Hakif Amir Hassan ◽  
Junaidi Asis

There have been many disagreements regarding the depositional environment of the Oligocene Tajau Sandstone Member of the Kudat Formation, Northern Sabah. We present here, the first detailed sedimentary facies analysis for the Tajau Sandstone Member, exposed on the Kudat Peninsula. The identified facies are interpreted as the deposits of subaqueous sediment density flows, which are common processes in deep marine depositional settings. These include debrites, hyperconcentrated density flow deposits, and turbidites. Several of the turbidite facies display evidence for hydraulic jumps, which are also common processes in deepwater settings and probably indicate changes in slope topography or loss of flow confinement. Trace fossils characteristic of the Nereites ichnofacies are also diagnostic of a deep marine depositional environment. Facies previously identified by previous workers as hummocky cross-stratification in the Tajau Sandstone Member, which was used to support a shallow marine interpretation, is better interpreted as supercritical antidunes developed in high density turbidites, based on the coarse-grained texture, spaced layering and association with other subaqeuoues density flow deposits.


2015 ◽  
Vol 1 (2) ◽  
Author(s):  
Sugeng Sapto Surjono ◽  
Mohd Shafeea Leman ◽  
Kamal Roslan Mohamed ◽  
Che Aziz Ali

Conglomeratic rocks in East Johor are found in the separately three formations that are the Murau, Tanjung Leman and Linggiu Formations. The Murau Formation is characterized by cobble to boulder grained breccia with very angular to angular and disorganized clasts. It was deposited by fan-delta system in the sub-aerial to shallow marine environment. The Tanjung Leman Formation consists of pebble to cobble grained conglomerate with rounded to subrounded and organized clasts. It was deposited by braided river system in the sub-aerial environment. Both formations outcropped in eastern coastal of Johor. The rudaceous rocks of the Linggiu Formation consist of pebble to cobble-sized clasts with sub angular and disorganized texture. It present as subordinate rocks within sandstone dominant in the central part of East Johor and was deposited by debris flows in the shallow marine environment. All these rudaceous rocks were interpreted as Palaeozoic in age ranging from Late Carboniferous to Late Permian. Those rudaceous rocks indicated that since Late Carboniferous, palaeogeography of East Johor was a continent with subaerial to shallow marine depositional environment. Keywords: Conglomerate, Palaeozoic, East Johor, subaerial, shallow marine.


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