Studi Mekanisme Sedimentasi Formasi Dolokapa, Gorontalo

2021 ◽  
Vol 3 (2) ◽  
pp. 97-111
Author(s):  
Tedy Harianto Salama ◽  
Sri Maryati ◽  
Intan Noviantari Manyoe
Keyword(s):  
Deep Sea ◽  
Depositional Environment ◽  
Trace Fossils ◽  
Research Area ◽  
Silty Clay ◽  
Marine Sedimentation ◽  
Traction Current ◽  
Layer Stacking ◽  
History Of ◽  
Current Mechanism

The Dolokapa Formation is a sedimentary rock formation formed in a deep-sea depositional environment with a fairly complex level of deformation and tectonic arrangement. Analysis of the sedimentation mechanism is carried out to determine how much tectonic influence on the mechanisms that occur in a depositional environment and the variations in the sedimentation mechanism formed. Research on the sedimentation mechanism needs to be carried out to determine the history of the formation of Gorontalo sedimentary rocks, especially in the Dolokapa Formation which was formed during the Miocene. The purpose of this study is to know the mechanisms of deep-marine sedimentation based on the identification of lithological characteristics, layer stacking patterns, and sedimentary structures. The method used was measuring sections using a range of ropes divided into four measurement paths. After that, a correlation was performed based on the genesis of deep marine formation. Based on the results of processing and analysis of the data, obtained units of lithology that insertion silty-clay, and the sandstone graining insertion of silt. In vertical succession, the layering pattern formed generally thickens upwards which describes the energy of the depositional currents. The sedimentary structure consists of rip up-clast, parallel lamination, graded bedding, convolute, slump, and trace fossils of nereites trace fossils of nereites that characterize the sedimentation of traction currents and turbidite currents in the deep-sea environment. The sedimentation mechanism formed is the traction current mechanism which is a further development of turbidite current and high-low concentration turbidity current mechanism that occurs slowly on a suspension-controlled grain. The stratigraphic relationship of the rock units in the research area is aligned based on the genesis formation that is located in the setting of the deep marine.

scholarly journals New sea spiders from the Jurassic La Voulte-sur-Rhône Lagerstätte

2007 ◽  
Vol 274 (1625) ◽  
pp. 2555-2561 ◽  
Author(s):  
S Charbonnier ◽  
J Vannier ◽  
B Riou
Keyword(s):  
Deep Sea ◽  
Middle Jurassic ◽  
Evolutionary History ◽  
Depositional Environment ◽  
Ecological Stability ◽  
Sea Spiders ◽  
History Of

The diverse and exceptionally well-preserved pycnogonids described herein from the Middle Jurassic La Voulte Lagerstätte fill a 400 Myr gap of knowledge in the evolutionary history of this enigmatic group of marine arthropods. They reveal very close morphological and functional (locomotion, feeding) similarities with present-day pycnogonids and, by contrast, marked differences with all Palaeozoic representatives of the group. This suggests a relatively recent, possibly Mesozoic origin for at least three major extant lineages of pycnogonids (Ammotheidae, Colossendeidae, Endeidae). Combined evidence from depositional environment, faunal associates and recent analogues indicate that the La Voulte pycnogonids probably lived in the upper bathyal zone ( ca 200 m). Our results point to a remarkable morphological and ecological stability of this arthropod group over at least 160 Myr and suggest that the colonization of the deep sea by pycnogonids occurred before the Jurassic.

scholarly journals Glacial-Marine Sedimentation, Canadian Polar Margin, North of Axel Heiberg Island

2007 ◽  
Vol 45 (2) ◽  
pp. 213-227 ◽  
Author(s):  
Frances J. Hein ◽  
Peta J. Mudie
Keyword(s):  
Sediment Cores ◽  
Open Water ◽  
Silty Clay ◽  
Sedimentation Rates ◽  
The Core ◽  
Marine Sedimentation ◽  
Northwestern Shelf ◽  
History Of ◽  
Axel Heiberg Island ◽  
High Sediment

ABSTRACT Sediment cores, taken at depths of 140 to 300 m across the northwestern shelf of Axel Heiberg Island (82° N), record the deposition of sediments under perennial sea ice. Five sedimentary fades are recognized: (A) soft pebbly-sandy-mud with dropstone structures; (B) bioturbated silty muds; (C) wispy-laminated silty clay/clay; (D) laminated sands/silts and mud; (E) firm pebbly-sandy-mud with chaotic pebble fabrics. Other sediments include terrestrial bedrock of Paleogene Eureka Sound Group, and a younger Tertiary deposit, possibly the Beaufort Formation. Ages range from 1530 ± 60 BP (Fades A) to 9950 ± 80 BP (Fades D). Sedimentation rates vary as follows: - 0.8 cm ka-1, Fades B; 4 cm ka"\ Fades A; 90 cm ka-1, Fades C; 134 cm ka~', Fades D. The sedimentation history, as interpreted from the sedimentology, palynology and foraminiferal results, suggests intervals of more continuous ice cover, with a reduced influx of coarse ice-rafted detritus, alternating with more open water conditions, and high sediment input from meltwater and/or floating icebergs. Only marine sediments overlie Neogene bedrock in the cores. The absence of diamictons at the core sites suggests that grounded ice perhaps never occupied this part of the Axel Heiberg Island shelf. The interpreted history of sedimentation generally corresponds to the land-based record from Ellesmere Island, but differs significantly from marine-based studies in more southern latitudes.

Implications for the age of South African Devonian rocks in which Tropidoleptus (Brachiopoda) has been found

1983 ◽  
Vol 120 (1) ◽  
pp. 51-58 ◽  
Author(s):  
A. J. Boucot ◽  
C. H. C. Brunton ◽  
J. N. Theron
Keyword(s):  
South Africa ◽  
North America ◽  
South African ◽  
Early Carboniferous ◽  
Fossil Plants ◽  
Geological Time ◽  
Marine Sedimentation ◽  
History Of ◽  
Near Shore ◽  
First Time

SummaryThe Devonian brachiopod Tropidoleptus is recognized for the first time in South Africa. It is present in the lower part of the Witteberg Group at four widely separated localities. Data regarding the stratigraphical range of the genus elsewhere, combined with information on recently described fossil plants and vertebrates from underlying strata of the upper Bokkeveld Group, suggest that a Frasnian or even Givetian age is reasonable for the lower part of the Witteberg Group. The recognition of Tropidoleptus in a shallow water, near-shore, molluscan association, at the top of the South African marine Devonian sequence, is similar to its occurrence in Bolivia, and suggests a common Malvinokaffric Realm history of shallowing, prior to later Devonian or early Carboniferous non-marine sedimentation. It is noteworthy that Tropidoleptus is now known to occur in ecologically suitable environments around the Atlantic, but is absent from these same environments in Asia and Australia. Tropidoleptus is an excellent example of dispersal in geological time — first appearing in northern Europe and Nova Scotia, then elsewhere in eastern North America and North Africa, followed by South America and South Africa, while continuing in North America.

THE FORMATION OF THE HISTORICAL AND LITURGICAL RESEARCH AREA IN RUSSIAN ACADEMIC SCHOLARSHIP IN THE LATE 19TH – EARLY 20TH CENTURY. A COMPARATIVE ANALYSIS OF METHODOLOGICAL APPROACHES OF N.V. POKROVSKY AND I.A. KARABINOV

2021 ◽  
pp. 30-49
Author(s):  
Zoya M. Dashevskaya ◽  
Keyword(s):  
Research Methodology ◽  
Research Area ◽  
Academic Science ◽  
Scientific School ◽  
Academic Scholarship ◽  
Academic Courses ◽  
History Of ◽  
Christian Worship ◽  
The Subject ◽  
The 19Th Century

n the second half of the 19th century – especially in the period following the introduction of the Academic Constitution of 1869, and in the 1880s and continuing until the forced closure of Theological Academies after the Revolutionary coup – the historical and liturgical research area in Russian academic science experienced a period of its formation and flourishing. The subject of the article is a comparison of approaches to the study of the worship service history and analysis of the formation of the research methodology for teaching Liturgics by professors N.V. Pokrovsky and I.A. Karabinov of the St. Petersburg Theological Academy, where they taught the history of Christian worship from the 1880’s until its forced closure in 1918. Analysis and juxtapos- ing of academic courses in Liturgics allows defining the boundaries and content of the discipline in the period of its formation as well as considering the evolu- tion in research methodology and, more broadly, the formation of the Russian historical and liturgical scientific school. A comparison of the courses reveals the authors attitudes towards histori- cal sources material and its studies. Their own ideas about the provenance of various rites used in church worship characterize their views on the develop- ment of the liturgical tradition, expressing their approaches to its study and thereby form our picture of the establishment of historical Liturgics as a field of researchable knowledge.

scholarly journals Erratum: Palaeoenvironmental trends in the history of trace fossils

Nature ◽  
1988 ◽  
Vol 333 (6175) ◽  
pp. 786-786
Author(s):  
D. J. Bottjer ◽  
M. L. Droser ◽  
D. Jablonski
Keyword(s):  
Trace Fossils ◽  
History Of

The significance of the boundary between the Rhoscolyn and New Harbour formations on Holy Island, North Wales, to the deformation history of Anglesey

2012 ◽  
Vol 150 (3) ◽  
pp. 519-535 ◽  
Author(s):  
JACK E. TREAGUS ◽  
SUSAN H. TREAGUS ◽  
NIGEL H. WOODCOCK
Keyword(s):  
Lower Cambrian ◽  
Depositional Environment ◽  
High Strain ◽  
The Other ◽  
Deformation History ◽  
Two Phase ◽  
Phase Deformation ◽  
North Wales ◽  
History Of ◽  
Tectonic Features

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.

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