scholarly journals Revised stratigraphy of the Eifelian (Middle Devonian) of southern Belgium: sequence stratigraphy, global events, reef development and basin structuration

2019 ◽  
Vol 22 (3-4) ◽  
pp. 149-173 ◽  
Author(s):  
Julien DENAYER

The Eifelian lithostratigraphic succession of southern Belgium is here revised based on new field investigations and reconsideration of biostratigraphic data. The Couvin Formation is divided into four members: the Villers-la-Tour Member recorded the onset of stromatoporoid biostromes, the Petigny Member is a dark fine-grained limestone that recorded the Choteč event, the Cul d’Efer Member is dominated by stromatoporoid-coral biostromes. These first three members were previously united in the Foulerie Member and correspond to the transgressive and highstand system tracts of the Middle Devonian 3rd-order sequence MD1. The argillaceous and bioclastic successive units of the Abîme Member recorded the sequence MD2. Laterally, this sequence is only composed of siliciclastic deposits of the Vieux Moulin, Station and Cimetière members of the Jemelle Formation. The highstand system tract is the newly introduced carbonate Vierves Member. Large bioherms, newly described as the Wancennes Formation, recorded the first two sequences MD1 and MD2. A major sequence boundary caps the Couvin Formation and is overlaid by the transgressive and diachronous Chavées Member of the Jemelle Formation with a depositional gap increasing eastwards. The highstand system tract of sequence MD3 is recorded in the bioherms of the Tienne Sainte-Anne Member (upper part of the Jemelle Formation), also capped by a sequence boundary. These bioherms probably acted as highs around which the sandy deposits of the Lomme Formation accumulated as lowstand system tract of sequence MD4. The Hanonet Formation and its crinoidal Wellin Member form the transgressive system tracts of sequence MD4 that terminates in the bioclastic and biohermal Trois-Fontaines Formation (Givetian). The Kačák event is identified in the transgressive system tract of this sequence. The geographic distribution of facies and of reefs in particular led to the recognition of at least six sedimentation areas corresponding most probably to synsedimentary faulted blocks here defined as the Eau Blanche, Viroin, Lesse, Ourthe, Condroz and Sambre blocks. These sedimentation areas structured the Namur-Dinant Basin and recorded distinct depositional history and were probably active during the Devonian and Carboniferous interval.

KURVATEK ◽  
2018 ◽  
Vol 3 (1) ◽  
pp. 71-82
Author(s):  
Wahyu Sasongko

Proses diagenesis yang terjadi pada batuan memiliki hubungan yang erat dengan konsep sikuen stratigrafi. Proses diagenesis awal (eogenesis) yang terbentuk pada suatu batuan dipengaruhi oleh posisi stratigrafi batuan tersebut dalam tataan sikuen stratigrafi. Eogenesis tersebut dapat diteliti dengan menggunakan data petrografi batupasir mengenai proses diagenesis yang terdapat pada batuan, dan juga dengan melihat posisi batuan dalam tataan sikuen stratigrafi. Formasi Nanggulan yang tersingkap di Kulon Progo, Yogyakarta merupakan salah satu formasi yang dengan beberapa interval litologi batupasir. Analisis mengenai sikuen stratigrafi Formasi Nanggulan telah diteliti sebelumnya dengan menggunakan analisis batuan inti. Studi lebih lanjut mengenai Formasi Nanggulan bertujuan untuk mengetahui karakteristik batupasir dan proses diagenesisnya, serta mencari hubungan antara proses diagenesis dan sikuen stratigrafi. Penelitian dilakukan dengan menggunakan analisis petrografi dari data batuan inti dan singkapan permukaan dengan tujuan untuk mengetahui hubungan antara diagenesis dan sikuen stratigrafi pada batupasir Formasi Nanggulan.Berdasarkan analisis petrografi terhadap diagenesis pada Formasi Nanggulan, dapat dikonfirmasi bahwa Formasi Nanggulan terdiri dari 3 system tract yaitu lowstand system tract (LST), transgressive system tract (TST), dan highstand system tract (HST). Tahapan proses diagenesis yaitu eogenesis, mesogenesis dan telogenesis telah mempengaruhi Formasi Nanggulan. Karakteristik diagenesis pada Formasi Nanggulan bervariasi sesuai dengan system tract dan marker batas sikuen pada tataan sikuen stratigrafi. Berdasaran penelitian ini dapat diketahui bahwa sikuen stratigrafi Formasi Nanggulan dapat dikonfirmasi dengan data diagenesis.


2002 ◽  
Vol 67 (1) ◽  
pp. 5-36 ◽  
Author(s):  
David J. Meltzer ◽  
Lawrence C. Todd ◽  
Vance T. Holliday

Research on the Folsom Paleoindian type site, involving renewed field investigations and an analysis of extant collections from the 1920s excavations, was undertaken between 1997 and 2000. The preliminary results of that research show that all excavations to date have been in the kill area, which took place in a small and relatively shallow tributary to the Pleistocene paleovalley of Wild Horse Arroyo as well as in the paleovalley itself. Preliminary butchering of ∼32 Bison antiquus took place near where the animals were dropped. The kill area is dominated by low-utility bone elements and broken projectile points; high-utility bones and tools for processing meat and hides are rare or absent, and either occur in another, as-yet undiscovered area of the site, or altogether off-site. Faunal remains are generally in excellent condition. Those in the tributary are mostly in primary context, and underwent rapid burial beneath fine-grained (dominantly aeolian) sediments, which in turn were subsequently armored by a shingle shale; those in the paleovalley experienced postdepositional transport and redeposition. The small lithic assemblage is dominated by projectile points and comprised of material mostly from two sources in the Texas panhandle, several hundred kilometers southeast of the site. It also includes stone obtained from sources at comparable distances north and northwest of the site. A series of radiocarbon ages is available for the stratigraphic units, nearly all from charcoal of non-cultural origins; radiocarbon dates on bison bone put the age of the kill at 10,500 B.P.


1991 ◽  
Vol 28 (7) ◽  
pp. 1009-1018 ◽  
Author(s):  
S. Feinstein ◽  
G. K. Williams ◽  
L. R. Snowdon ◽  
F. Goodarzi ◽  
T. Gentzis

The Fort Norman area is marked by a complex structural and depositional history with temporally and spatially variable temperature and maturity gradients. Maturity of the Middle Devonian Canol – Hare Indian unit indicates two terrains of markedly different paleotemperatures and thermal gradients, roughly coinciding with the Palaeozoic Keele Arch (north) and Root Basin (south), with a sharp transition (lateral discontinuity) between them. Maturity of the unconformably overlying Cretaceous to early tertiary section is lower and laterally continuous across the entire study area, showing no relation to the sub-Cretaceous structures. The vertical maturity profile in the southern terrain is unique in that two discontinuous segments record markedly different thermal histories, neither of which is related to present burial conditions. Maturity of the Devonian formations was established some time prior to the sub-Cretaceous erosion, whereas that in the Cretaceous to Tertiary section postdates Palaeocene but predates a major part of the later Tertiary deformation and erosion. In contrast, the continuous maturity profile recorded in the northern terrain reflects a significant effect of the Tertiary thermal conditions, indicating much lower thermal gradients in the Keele Arch than in the Root Basin during the early phase of maturation. Along with the structural pattern and sedimentary history, the striking differences indicated in the thermal gradients between the Root Basin and the Keele Arch suggest a strike-slip-related pull-apart or another stretching mechanism for the Root Basin in contrast to the compression in the Keele Arch. In addition to the characterization of the regional thermal history and its variation with time, the maturity pattern obtained allows some estimate to be made of the thickness of the eroded section and timing of the major erosional phases.


Lithosphere ◽  
2021 ◽  
Vol 2021 (Special 1) ◽  
Author(s):  
Guanping Wang ◽  
Zhijun Jin ◽  
Zongquan Hu ◽  
Guangxiang Liu ◽  
Tong Zhu ◽  
...  

Abstract The deposition and evolution of fine-grained sediments is a hot topic in fine-grained sedimentary rock studies and is important for accurately evaluating shale gas sweet spots. In this paper, the fine-grained deposition and evolution characteristics of the Wufeng-Longmaxi shales, major targets for Chinese shale gas exploration, were studied by using core observations, thin section analyses, scanning electron microscopy, geochemical analysis, and fossil identification. This work accurately identified six typical lithofacies; among them, the organic matter-rich siliceous shale facies (OMRSSF), the high-organic matter siliceous argillaceous shale facies (HOMSASF), and the medium-high organic matter low calcareous siliceous shale facies (M-HOMLCSASF) are favorable facies for shale gas exploration. The high-resolution isochronous unit in the shelf fine-grained sedimentary system was established, and the differential evolution of lithofacies in the system tract was discussed. The lithofacies deposition and differentiation in the transgressive system tract were controlled by the transgressive scale and tectonics under increasingly shallow water conditions. The lithofacies deposition and differentiation in the regressive system tract were controlled by tectonics and the preexisting lithofacies. The lithofacies in the regressive system tract had more frequent facies transitions and greater differentiation than those in the transgressive system tract, and they exhibited significant spatiotemporal inheritance. Sequential differential sedimentary sequences and symmetric differential sedimentary sequences were distinguished in the continental shelf sedimentary system. The lithofacies depocenters and subsidence centers were consistent in the transgressive system tract, while the tectonically active paleocontinent was important in the regression system tract. This study is of great significance for further high-resolution exploration of marine shale and improvement of the theory of shelf fine-grained sedimentary systems.


2012 ◽  
Vol 616-618 ◽  
pp. 56-59 ◽  
Author(s):  
Zhe Wang ◽  
Zhen Kui Jin ◽  
Gui Zai Li

In the light of the principle and method of sequence stratigraphy, the sequence stratigraphic framework of Badaowan formation in the Dishuiquan area was established. The results show that the sequence of Badaowan formation is one and half, including 5 system tracts. The whole experiences the process of retrogradation, progradation and then retrogradation again. There develop three types of sedimentary facies such as braided river, braided river delta and lakes, five types of sedimentary subfacies and 10 types of sedimentary microfacies. Most of JSQ1 sequence lowstand system tract is braided rivers, the lacustrine transgressive system tract mainly develops shore-shallow lacustrine sediment and most of highstand system tract is braided river delta; lowstand systems tract of JSQ2 sequence mainly develops braided river delta, most of the lacustrine transgressive system tract is shore-shallow lacustrine sediments.


2021 ◽  
pp. 014459872110189
Author(s):  
Yongping Ma ◽  
Xianwen Zhang ◽  
Linjun Huang ◽  
Guodong Wang ◽  
Han Zhang ◽  
...  

The glutenite reservoir rock of the fan delta facies is associated with a complex sedimentary environment and high heterogeneity, and by far the characteristics and controlling factors of the reservoir rock quality have not been well understood. By comprehensively investigating the lithofacies, petrology, physical properties and diagenesis of the Upper Wuerhe Formation of the Mahu Sag, the Junggar Basin, it is concluded that the Upper Wuerhe Formation develops three major groups of lithofacies, totally consisting of 11 sub-types, and reservoir rock properties of different lithofacies are greatly varied. This research shows that the lithofacies attributed to the tractive current and density current have well-sorted rock particles, low mud content, well-developed secondary dissolved pores, and thus high overall reservoir rock quality. On the contrary, the lithofacies based on debris flow and sheet flow, are observed with high mud content, suppressed development of intergranular and dissolved pores, and thus poor reservoir rock quality. The system tract controls the macro variation of the reservoir rock quality. The best quality is found in the highstand system tract, followed by those of the lake transgression and at last lowstand system tracts. The micro variation of the reservoir rock quality is determined by the mud content, rock particle size and dissolution. The muddy matrix mainly damages the pore connectivity, and presents the strongest correlation with permeability. The reservoir rock with concentrated particle sizes and well-sorted particles has quality better than those of reservoir rocks composed of excessively large or small particles. Dissolution effectively improves the storage capability of the reservoir rock, resulting in an average porosity increment by 4.2%.


Author(s):  
G. C. Yulitha

The Baong Formation is one of the formations that has hydrocarbon potential in the Aru Sub Basin, North Sumatra Basin (Figure 1). However, geological information in that area is still far less than is available in others. Analysis of sequence stratigraphy needs to be done to enrich geological information of the study area, maximize the results of exploration before exploitation, and make it easier to find the distribution of potential layers of oil and gas. Methods that are used in this research are electrofacies analysis to show the appearance of rock grain size and geological processes that affect its formation, Well Seismic Tie and interpretation of the horizon along with structures to produce a Time Structure Map, and correlate the sequences in log wells and 2D seismic cross section to know the same area of each sequence. Based on third-order sequence, the Baong Formation was divided into two types of system tract, such as Lowstand System Tract (LST) and Transgressive System Tract (TST). Maximum Flooding Surface (MFS) as the lower boundary of LST, Transgressive Surface (TS) as the boundary between LST and TST, and Maximum Flooding Surface as the upper boundary of TST. Based on fourth-order sequence, each of the system tracts was divided into seven parasequences with Flooding Surface as the boundary. The research area can also be interpreted into a conceptual model of a hydrocarbon system.


Sign in / Sign up

Export Citation Format

Share Document