Hybrid compactive faults formed during burial in micritic limestone (Montpellier area, France)

AbstractDrenov Grič black limestone is considered to be one of the most beautiful Slovenian natural stones due to its black colour interwoven with white veins. Over the centuries, it has been extracted from two major quarries located west of Ljubljana. One of these quarries has been declared a valuable natural feature of national importance and is protected as a natural monument. This well-stratified, Triassic (Carnian) micritic limestone occurs in 10–80 cm thick beds with thin marl interlayers. The limestone occasionally contains abundant fossil bivalves, gastropods and ostracods. It is relatively rich in carbonaceous and bituminous organic matter, which is responsible for the black colour of the stone. The stone has been widely used in Slovenian monuments. Many indoor and outdoor architectural elements have been constructed using this limestone, particularly during the Baroque period, which was known for its extensive use of black limestones in other European countries as well. The most significant use of this limestone has been recorded in sculpted portals and altars. Some important buildings, which were decorated utilizing this stone, have been declared cultural monuments of local or national importance. Use of this limestone was also documented in other European countries (Italy, Austria, Serbia) and worldwide (USA). When exposed to climatic influences, chromatic and salt weathering are recognized as the main deterioration phenomena for this limestone when used in monuments.

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INFLUENCE OF ORGANIC MATTER AND IRON OXIDES ON THE COLOUR PROPERTIES OF A MICRITIC LIMESTONE FROM KEFALONIA

Bulletin of the Geological Society of Greece ◽

10.12681/bgsg.16573 ◽

2004 ◽

Vol 36 (1) ◽

pp. 72 ◽

Cited By ~ 1

Author(s):

G. E. Christidis ◽

N. Sakellariou ◽

E. Repouskou ◽

Th. Markopoulos

Keyword(s):

Organic Matter ◽

Iron Oxides ◽

Carbonate Rocks ◽

Organic Carbon Content ◽

Colour Properties ◽

Ultra High Purity ◽

Proposed Model ◽

Fe Oxyhydroxides ◽

Micritic Limestone ◽

Experimental Values

The influence of organic matter and iron oxides on the colour properties of an ultra-high purity micritic limestone from Kefalonia Island containing 99.7% calcite was studied. Colouring impurities, organic matter and iron-oxide, were added in the form of a xylitic lignite and a hematite-rich Fe-ore respectively. Both impurities decrease lightness (L*) and increase deviation from perfect white diffuser (AE*ab) as well as redness and yellowness of calcite. Organic matter affects colour properties to a greater degree than iron oxides. The results obtained were used in a model, which predicts lightness and AE*ab of white limestones and marbles from their Fe2Ü3 and organic carbon content. The theoretical values of L* and AE*ab of a series of known limestones and calcific marbles obtained from this model are comparable to experimental values determined using a colourimeter. Slight deviations between theoretical and experimental values are attributed to several factors, which include the different nature of iron oxides/oxyhydroxides (goethite or/and lepidocrocite and/or amorphous Fe-oxyhydroxides instead of hematite) and organic matter (kerogene instead of xylitic lignite) present in the carbonate rocks, the different particle size of calcite and impurities in the different carbonates, to the multiphase nature of the colouring impurities used in this study and to the possible existence of other Fe-rich phases such as Fe-carbonates in the limestones. The proposed model can facilitate quality control of limestone resources used as fillers and can be extended to dolomitic rocks.

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An integrated biostratigraphical analysis of the Volkhov–Kunda (Lower Ordovician) succession at Fågelsång, Scania, Sweden

Bulletin of the Geological Society of Denmark ◽

10.37570/bgsd-2003-50-06 ◽

2003 ◽

Vol 50 ◽

pp. 75-94

Author(s):

Svend Stouge ◽

Arne Thorshøj Nielsen

Keyword(s):

Sea Level ◽

East European Platform ◽

Water Environment ◽

Black Shales ◽

Outer Shelf ◽

Cool Water ◽

East European ◽

Lower Ordovician ◽

Upper Level ◽

Micritic Limestone

The Komstad Limestone is composed of dark grey to black micritic limestone deposited in an outer shelf environment on the margin of the East European Platform. It represents an interval of low sea level during the late Volkhov to early Kunda that led to the spread of limestones into the shale-dominated western lithofacies belt. The Baltoniodus norrlandicus, Lenodus antivariabilis, Lenodus variabilis, Yangtzeplacognathus crassus and Lenodus pseudoplanus conodont zones were identified in the upper Volkhov to lower Kunda interval. Based on the most recent taxonomic and biostratigraphical framework, the Megistaspis limbata (with two subzones), Asaphus expansus and Asaphus raniceps trilobite zones were identified. A shale intercalation in the lower part of the Komstad Limestone contains the graptolites Phyllograptus cor in association with Glyptograptus sp. and is referred to Darriwilian 1 (Upper Arenig). In the Baltoscandian zonation this matches the upper part of the Didymograptus hirundo graptolite Zone. The upper level of the Komstad Limestone and the basal part of the overlying Almelund Shale do not contain graptolites, whereas the succeeding black shales of the Almelund Shale belong to the Holmograptus lentus Zone (Llanvirn). The Arenig-Llanvirn boundary is situated at or very near the top of the Komstad Limestone. The conodont assemblage in the lower part of the Komstad Limestone at Fågelsång is associated with forms of Gondwanan affinity, which probably reflects the cool water environment of the outer shelf setting. The higher part of the limestone contains the Whiterockian conodont species Dzikodus sp. and Histiodella tableheadensis. These important Laurentian forms occur together with abundant Gothodus sp. 1 and Cyclopyge umbonata in the base of the Asaphus expansus Zone. The arrival of the Laurentian taxa – as well as Cyclopyge with an ‘Gondwana’ affinity – is related to a transient sea level rise at the base of the A. expansus trilobite Zone.

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Sedimentological and paleontological analysis of the Lower Jurassic part of the Zatrnik Formation on the Pokljuka plateau, Slovenia

Geologija ◽

10.5474/geologija.2021.010 ◽

2021 ◽

Vol 64 (2) ◽

pp. 173-188

Author(s):

Luka GALE ◽

Duje KUKOČ ◽

Boštjan ROŽIČ ◽

Anja VIDERVOL

Keyword(s):

Debris Flows ◽

Carbonate Platform ◽

Clay Content ◽

Lower Jurassic ◽

Foraminiferal Assemblage ◽

Fine Grained ◽

Julian Alps ◽

Mountain Pasture ◽

Lowermost Part ◽

Micritic Limestone

The uppermost Ladinian to Lower Jurassic Zatrnik Formation is the lithostratigraphic unit of the Mesozoic deeper marine Bled Basin. The uppermost part of the Zatrnik Formation and the transition into the overlying Ribnica Breccia was logged at the Zajamniki mountain pasture on the Pokljuka mountain plateau in the Julian Alps. The lowermost part the section belongs to the “classical” Zatrnik Formation and is dominated by beige micritic limestone and fine-grained calcarenite. Foraminifers Siphovalvulina, ?Everticyclammina, ?Mesoendothyra and ?Pseudopfenderina are present, indicating Early Jurassic age. The beige limestone is followed by light pink limestone of the uppermost Zatrnik Formation. Slumps are common in this interval, and crinoids are abundant. Alongside some species already present in beds lower in the succession, Meandrovoluta asiagoensis Fugagnoli & Rettori, Trocholina sp., Valvulinidae, small Textulariidae, Lagenida, and small ?Ophthalmidium alsooccur in this interval. Resedimented limestone predominates through the studied part of the Zatrnik Formation, indicating deposition on the slope or at the foot of the slope of the basin. The switch to crinoid-rich facies within the slumped interval of the Zatrnik Formation may reflect accelerated subsidence of the margins of the Julian Carbonate Platform in the Pliensbachian. The Zatrnik Formation is followed by the formation of the Pliensbachian (?) Ribnica Breccia. Impregnations of ferromanganese oxides, violet colour, and an increase in clay content are characteristic. The foraminiferal assemblage consists of Lenticulina, small elongated Lagenida, and epistominids. Individual beds of the Ribnica Breccia were deposited via debris flows. Enrichments in ferromanganese oxides point to slower sedimentation.

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micritic limestone

Dictionary Geotechnical Engineering/Wörterbuch GeoTechnik ◽

10.1007/978-3-642-41714-6_131567 ◽

2014 ◽

pp. 865-865

Keyword(s):

Micritic Limestone

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Sedimentary record of subsidence pulse at the Triassic/Jurassic boundary interval in the Slovenian Basin (eastern Southern Alps)

Geologica Carpathica ◽

10.1515/geoca-2017-0036 ◽

2017 ◽

Vol 68 (6) ◽

pp. 543-561 ◽

Cited By ~ 2

Author(s):

Boštjan Rožič ◽

Tea Kolar Jurkovšek ◽

Petra Žvab Rožič ◽

Luka Gale

Keyword(s):

Environmental Changes ◽

Carbonate Platform ◽

Southern Alps ◽

Upper Triassic ◽

Early Jurassic ◽

Platform Margin ◽

Basin Floor ◽

Micritic Limestone ◽

Slovenian Basin ◽

Basin Area

AbstractIn the Alpine Realm the Early Jurassic is characterized by the disintegration and partial drowning of vast platform areas. In the eastern part of the Southern Alps (present-day NW Slovenia), the Julian Carbonate Platform and the adjacent, E-W extending Slovenian Basin underwent partial disintegration, drowning and deepening from the Pliensbachian on, whereas only nominal environmental changes developed on the large Dinaric (Friuli, Adriatic) Carbonate Platform to the south (structurally part of the Dinarides). These events, however, were preceded by an earlier - and as yet undocumented extensional event - that took place near the Triassic/Jurassic boundary. This paper provides evidence of an accelerated subsidence from four selected areas within the Slovenian Basin, which show a trend of eastwardly-decreasing deformation. In the westernmost (Mrzli vrh) section - the Upper Triassic platform-margin - massive dolomite is overlain by the earliest Jurassic toe-of-slope carbonate resediments and further, by basin-plain micritic limestone. Further east (Perbla and Liščak sections) the Triassic-Jurassic transition interval is marked by an increase in resedimented carbonates. We relate this to the increasing inclination and segmentation of the slope and adjacent basin floor. The easternmost (Mt. Porezen) area shows a rather monotonous, latest Triassic-Early Jurassic basinal sedimentation. However, changes in the thickness of the Hettangian-Pliensbachian Krikov Formation point to a tilting of tectonic blocks within the basin area. Lateral facies changes at the base of the formation indicate that the tilting occurred at and/or shortly after the Triassic/Jurassic boundary

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An Upper Ordovician sponge-bearing micritic limestone and implication for early Palaeozoic carbonate successions

Sedimentary Geology ◽

10.1016/j.sedgeo.2015.02.002 ◽

2015 ◽

Vol 319 ◽

pp. 124-133 ◽

Cited By ~ 8

Author(s):

Jino Park ◽

Jeong-Hyun Lee ◽

Jongsun Hong ◽

Suk-Joo Choh ◽

Dong-Chan Lee ◽

...

Keyword(s):

Upper Ordovician ◽

Early Palaeozoic ◽

Micritic Limestone

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Different triggers for the two pulses of mass extinction across the Permian and Triassic boundary

Scientific Reports ◽

10.1038/s41598-021-86111-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Guoshan Li ◽

Wei Liao ◽

Sheng Li ◽

Yongbiao Wang ◽

Zhongping Lai

Keyword(s):

Mass Extinction ◽

Temporal Dynamics ◽

Oxygen Deficiency ◽

Marine Ecosystem ◽

Volcanic Eruptions ◽

Ecosystem Change ◽

Triassic Boundary ◽

Low Diversity ◽

Micritic Limestone ◽

Fossil Records

AbstractWidespread ocean anoxia has been proposed to cause biotic mass extinction across the Permian–Triassic (P–Tr) boundary. However, its temporal dynamics during this crisis period are unclear. The Liangfengya section in the South China Block contains continuous marine sedimentary and fossil records. Two pulses of biotic extinction and two mass extinction horizons (MEH 1 & 2) near the P–Tr boundary were identified and defined based on lithology and fossils from the section. The data showed that the two pulses of extinction have different environmental triggers. The first pulse occurred during the latest Permian, characterized by disappearance of algae, large foraminifers, and fusulinids. Approaching the MEH 1, multiple layers of volcanic clay and yellowish micritic limestone occurred, suggesting intense volcanic eruptions and terrigenous influx. The second pulse occurred in the earliest Triassic, characterized by opportunist-dominated communities of low diversity and high abundance, and resulted in a structural marine ecosystem change. The oxygen deficiency inferred by pyrite framboid data is associated with biotic declines above the MEH 2, suggesting that the anoxia plays an important role.

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Cambrian ooids, their genesis and relationship to sea-level rise and fall: A case study of the Qingshuihe section, Inner Mongolia, China

Stratigraphy ◽

10.29041/strat.18.2.04 ◽

2021 ◽

Vol 18 (2) ◽

pp. 139-151

Author(s):

Muhammad Riaz ◽

Tehseen Zafar ◽

Khalid Latif ◽

Enzhao Xiao ◽

Shahid Ghazi

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

Extracellular Polymeric Substances ◽

Microbial Mats ◽

Middle Part ◽

Relative Sea Level ◽

Sulfate Reducing ◽

The North ◽

Northwestern Margin ◽

Micritic Limestone

ABSTRACT: TheCambrian strata at the northwestern margin of the North China Platform in InnerMongolia hold thick oolitic-grain bank deposits.Generally, the strata are dominated by calcareous mudstone of shelf facies in the lower part, micritic limestone consisting of deep to middle ramp facies in the middle part, and oolitic limestone encompassing shallow ramp to grain bank facies in the upper part of each formation. The shelf and deep ramp facies are the result of relative sea-level rise, while oolitic limestones developed in response to relative sea-level fall. Microscopically, the studied ooids are represented by radial crystal structures and concentric laminations with or without cores, single crystal or neomorphosed ooids, and highly bored ooids. The size andmorphology of the ooids indicate a two-fold mechanical influence of microbes; constructive in the Miaolingian and destructive in the Furongian ooids. Based on these observations, it can be inferred that microbes (predominantly composed of filamentous fossils of cyanobacteria) excreted extracellular polymeric substances (EPS) to develop multiple bacterial biofilms microbial mats. The subsequent decay of the EPS through sulfate reducing bacteria most likely caused precipitation around these ooids. The depositional style of ooids occupying the upper parts of the formations, and their possible genesis from microbes provide clue for regional correlation, as well as affirm biological control in the formation of ooids.

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