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In oil and gas industry, classifying carbonate rocks is a major step in core and thin section description. Two classification systems have been widely used in the industry:  
 
In oil and gas industry, classifying carbonate rocks is a major step in core and thin section description. Two classification systems have been widely used in the industry:  
# Folk (1959<ref name=Flk1959>Folk, R. L., 1959, [https://archives.datapages.com/data/bulletns/1957-60/data/pg/0043/0001/0000/0001.htm Practical petrographic classification of limestones]: AAPG Bulletin, v. 43, p. 1–38.</ref>, 1962) Classification  
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# Folk (1959<ref name=Flk1959>Folk, R. L., 1959, [https://archives.datapages.com/data/bulletns/1957-60/data/pg/0043/0001/0000/0001.htm Practical petrographic classification of limestones]: AAPG Bulletin, v. 43, p. 1–38.</ref>, 1962<ref name=Flk1962>Folk, R. L., 1962, [https://archives.datapages.com/data/specpubs/carbona2/data/a038/a038/0001/0050/0062.htm Spectral subdivision of limestone types], ''in'' W. E. Ham, ed., Classification of carbonate Rocks-A Symposium: [https://archives.datapages.com/data/alt-browse/aapg-special-volumes/m1.htm AAPG Memoir 1], p. 62-84.</ref>) Classification  
# Dunham (1962) Classification  
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# Dunham (1962<ref name=Dnhm>Dunham, R. J., 1962, [https://archives.datapages.com/data/specpubs/carbona2/data/a038/a038/0001/0100/0108.htm Classification of carbonate rocks according to depositional texture], ''in'' W. E. Ham, ed., Classification of Carbonate Rocks: [https://archives.datapages.com/data/alt-browse/aapg-special-volumes/m1.htm AAPG Memoir 1], p. 108–121.</ref>) Classification  
 
Both classifications provide an indication of depositional energy setting and reservoir quality.
 
Both classifications provide an indication of depositional energy setting and reservoir quality.
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* Wentworth (1922){{note|a}} [a]
 
* Wentworth (1922){{note|a}} [a]
 
* Bramkamp & Powers (1958)
 
* Bramkamp & Powers (1958)
* Folk (1959<ref name=Flk1959 />,1962)
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* Folk (1959, 1962)<ref name=Flk1959 /><ref name=Flk1962 />
* Dunham (1962)
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* Dunham (1962)<ref name=Dnhm />
 
* Leignton & Pendexter (1962)
 
* Leignton & Pendexter (1962)
 
* Todd (1966)
 
* Todd (1966)
* Embry & Klovan (1971)
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* Embry & Klovan (1971)<ref name=EmbryKlvn>Embry, A. F., and J. E. Klovan, 1971, A late Devonian reef tract on northeastern Banks Island, N.W.T: Bulletin of Canadian Petroleum Geology, v. 19, no. 4, p. 730–781.</ref>
 
* Wright (1992)
 
* Wright (1992)
 
* Hallsworth & Knox (1999)
 
* Hallsworth & Knox (1999)
Among all of the attempts, Folk (1959<ref name=Flk1959 />, 1962) and Dunham (1962) extended by Embry & Klovan (1971) classifications were widely accepted.  
+
Among all of the attempts, the Folk<ref name=Flk1959 /><ref name=Flk1962 /> and Dunham<ref name=Dnhm />, extended by Embry & Klovan<ref name=EmbryKlvn />, classifications were widely accepted.  
    
==Folk Classification==  
 
==Folk Classification==  
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* Pelmicrite: consists of pellets with microcrystalline matrix (Figure 10).
 
* Pelmicrite: consists of pellets with microcrystalline matrix (Figure 10).
 
<gallery mode=packed heights=300px widths=300px>
 
<gallery mode=packed heights=300px widths=300px>
File:GeoWikiWriteOff2021-Abdulwahab-Figure7.png|{{figure number|7}}Intramicrite
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File:GeoWikiWriteOff2021-Abdulwahab-Figure7.png|{{figure number|7}}Intramicrite<ref>[http://sepmstrata.org/microscopic_gallery_details.aspx?gid=165&pg=1&gcid=9 SEPM Strata Microscopic Gallery]</ref>
File:GeoWikiWriteOff2021-Abdulwahab-Figure8.png|{{figure number|8}}Oomicrite  
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File:GeoWikiWriteOff2021-Abdulwahab-Figure8.png|{{figure number|8}}Oomicrite<ref>[http://www.sepmstrata.org/microscopic_gallery_details.aspx?gid=207&pg=3&gcid=11 SEPM Strata Microscopic Gallery]</ref>
 
File:GeoWikiWriteOff2021-Abdulwahab-Figure9.png|{{figure number|9}}Biomicrite
 
File:GeoWikiWriteOff2021-Abdulwahab-Figure9.png|{{figure number|9}}Biomicrite
 
File:GeoWikiWriteOff2021-Abdulwahab-Figure10.png|{{figure number|10}}Pelmicrite
 
File:GeoWikiWriteOff2021-Abdulwahab-Figure10.png|{{figure number|10}}Pelmicrite
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==Dunham Classification==  
 
==Dunham Classification==  
 
===Dunham’s Criteria===
 
===Dunham’s Criteria===
Dunham classification system is based on three depositional textural features:
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[[w:Dunham classification|Dunham's classification system]] is based on three depositional textural features:
 
* The presence or absence of lime mud.
 
* The presence or absence of lime mud.
 
* The abundance of grains.[j]  
 
* The abundance of grains.[j]  
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===Extended Dunham Classification (1971)===
 
===Extended Dunham Classification (1971)===
[[File:GeoWikiWriteOff2021-Abdulwahab-Figure18.png|thumbnail|500px|{{Figure number|18}}Extended Dunham classification (1971)]]
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Embry and Klovan<ref name=EmbryKlvn /> expanded the original Dunham classification due to the lack of:
Embry and Klovan expanded the original Dunham classification due to the lack of:
   
* Classifying coarse-grained (>2mm) rocks.  
 
* Classifying coarse-grained (>2mm) rocks.  
 
* Subdividing organically-bound rocks (boundstones).  
 
* Subdividing organically-bound rocks (boundstones).  
 
The extended Dunham Classification is shown in Figure 18.  
 
The extended Dunham Classification is shown in Figure 18.  
 +
[[File:GeoWikiWriteOff2021-Abdulwahab-Figure18.png|center|framed|200px|{{Figure number|18}}Extended Dunham classification (1971)]]
    
====Coarse-Grained Rocks Classification====
 
====Coarse-Grained Rocks Classification====
 
* Floatstone: a matrix-supported rock with > 10% of grains >2mm and original components are not organically bounded together during deposition (Figure 19).   
 
* Floatstone: a matrix-supported rock with > 10% of grains >2mm and original components are not organically bounded together during deposition (Figure 19).   
 
* Rudstone: a grain-supported rock with > 10% of grains >2mm and original components are not organically bounded together during deposition (Figure 20).
 
* Rudstone: a grain-supported rock with > 10% of grains >2mm and original components are not organically bounded together during deposition (Figure 20).
 +
<gallery mode=packed heights=250px widths=250px>
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File:GeoWikiWriteOff2021-Abdulwahab-Figure19.png|{{figure number|19}}Floatstone 
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File:GeoWikiWriteOff2021-Abdulwahab-Figure20.png|{{figure number|20}}Rudstone
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</gallery>
 +
 
====Organically-Bound Rocks Subdivision====
 
====Organically-Bound Rocks Subdivision====
 
* Bafflestone: in situ organically-bound rock in which organisms act as baffles (Figure 21).
 
* Bafflestone: in situ organically-bound rock in which organisms act as baffles (Figure 21).
 
* Bindstone: in situ organically-bound rock in which organisms encrust and bind (Figure 22).
 
* Bindstone: in situ organically-bound rock in which organisms encrust and bind (Figure 22).
 
* Framestone: in situ organically-bound rock in which organisms build a rigid framework (Figure 23).[k]
 
* Framestone: in situ organically-bound rock in which organisms build a rigid framework (Figure 23).[k]
 +
<gallery mode=packed heights=250px widths=250px>
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File:GeoWikiWriteOff2021-Abdulwahab-Figure21.png|{{figure number|21}}Bafflestone
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File:GeoWikiWriteOff2021-Abdulwahab-Figure22.png|{{figure number|22}}Bindstone
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File:GeoWikiWriteOff2021-Abdulwahab-Figure23.png|{{figure number|23}}Framestone
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</gallery>
    
===Depositional Energy Setting and Reservoir Quality Indications===
 
===Depositional Energy Setting and Reservoir Quality Indications===
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Rudstones and framestones are usually formed in high-energy settings (above wave base).  
 
Rudstones and framestones are usually formed in high-energy settings (above wave base).  
 
Organically-bound rocks show good reservoir quality if the skeletal growth is interconnected.
 
Organically-bound rocks show good reservoir quality if the skeletal growth is interconnected.
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==Gallery==
  −
  −
 
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[[File:GeoWikiWriteOff2021-Abdulwahab-Figure19.png|thumbnail|Fig. 19 Floatstone [19]]] 
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[[File:GeoWikiWriteOff2021-Abdulwahab-Figure20.png|thumbnail|Fig. 20 Rudstone [20]]]
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[[File:GeoWikiWriteOff2021-Abdulwahab-Figure21.png|thumbnail|Fig. 21 Bafflestone [21]]]
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[[File:GeoWikiWriteOff2021-Abdulwahab-Figure22.png|thumbnail|Fig. 22 Bindstone [22]]]
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[[File:GeoWikiWriteOff2021-Abdulwahab-Figure23.png|thumbnail|Fig. 23 Framestone [23]]]
      
==Notes==  
 
==Notes==  
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==References==
 
==References==
{{reflist}}  
+
{{reflist}}
21. ^ [6] Gregg, Jay. (December 18). Limestone Petrology. Missouri S&T. https://web.mst.edu/~greggjay/carbonate_page/lsgallery/pages/c-ACS190_10.htm
  −
 
  −
22. ^ [7] (2021, March 29). Microscopic Gallery. SEPM Strata. http://sepmstrata.org/microscopic_gallery_details.aspx?gid=165&pg=1&gcid=9
  −
 
  −
23. ^ [8] (2021, March 29). Microscopic Gallery. SEPM Strata. http://www.sepmstrata.org/microscopic_gallery_details.aspx?gid=207&pg=3&gcid=11
  −
 
  −
24. ^ [10] Sahraeyan, Mohammad. (2013, June). Sedimentary Basin Analysis of Sachun Formation in Southwestern Iran: Implication for Sedimentary Environments and Tectonic Setting. ResearchGate. https://www.researchgate.net/figure/Photomicrographs-showing-micrite-and-pelmicrite-in-the-argillaceous-limestone-facies-of_fig8_262337097
  −
 
  −
25. ^ [12] [18] K. Bjørlykke (ed). Petroleum Geoscience: From Sedimentary Environments to Rock Physics, DOI 10.1007/978-3-642-34132-8_5, Ⓒ Springer-Verlag Berlin Heidelberg 2015.
  −
 
  −
26. ^ [13] Mudstone. Wikipedia. https://en.wikipedia.org/wiki/Mudstone
  −
 
  −
27. ^ [14] Carbonate Rock Classification. Carbonateworld. https://carbonateworld.com/carbonate-atlas/carbonate-rock-classification/images/wackstone/
  −
 
  −
28. ^ [15] [16] F. Jerry Lucia. Estimating Permeability in Carbonates Using the Rock-Fabric Method. Bureau of Economic Geology. https://www.beg.utexas.edu/lmod/_IOL-CM07/cm07-step02a.htm
  −
 
  −
29. ^ [17] Ardakani, Omid H. (2013, June). Diagenetic evolution and associated mineralization of Middle Devonian carbonates, southwestern Ontario, Canada. ResearchGate. https://www.researchgate.net/figure/Thin-section-photomicrographs-of-Middle-Devonian-rocks-A-Syntaxial-and-equant-calcite_fig3_235413575
  −
 
  −
30. ^ [19] [20] Al-Awwad, Saad F. & pomar, Luis. (2015, May 21). Origin of the rudstone–floatstone beds in the Upper Jurassic Arab-D reservoir, Khurais Complex, Saudi Arabia. ScienceDirect. https://www.sciencedirect.com/science/article/pii/S0264817215001634
  −
 
  −
31. ^ [21] Khanaqa, Polla. (2018, December). Stratigraphy and Facies Analysis of the Govanda Formation from Western Zagros, Kurdistan Region, Northeastern Iraq. ResearchGate. https://www.researchgate.net/figure/a-Photo-of-the-Coral-
  −
Bafflestone-of-Barda-Balaka-Outcrop-Between-the-stems-Fine_fig12_330094098
  −
 
  −
32. ^ [22] Bindstone. Bureau of Economic Geology. https://www.beg.utexas.edu/lmod/_IOL-CM02/st21-ancbindstone.htm
  −
 
  −
33. ^ [23] Camuera, Jon. (2014, July). Origin and palaeo-environmental significance of the Berrazales carbonate spring deposit, North of Gran Canaria Island, Spain. ResearchGate. https://www.researchgate.net/figure/A-Framestone-facies-composed-of-parallel-plant-moulds-coated-with-calcite-B-Plant_fig4_283498781
  −
 
  −
==Sources==
  −
1. Lokier, Stephen W.; Al Junaibi, Mariam (2016). "The petrographic description of carbonate facies: are we all speaking the same language?". Sedimentology. 63 (7): 1843–1885. doi:10.1111/sed.12293
  −
 
  −
2. Folk, R. L., 1959, Practical petrographic classification of limestones: AAPG Bulletin, v. 43, p. 1–38.
  −
 
  −
3. Folk, R.L., 1962, Spectral subdivision of limestone types, in Ham, W.E., ed., Classification of carbonate Rocks-A Symposium: American Association of Petroleum Geologists Memoir 1, p. 62-84.
  −
 
  −
4. Dunham, R. J., 1962, Classification of carbonate rocks according to depositional texture, in Ham, W. E., ed., Classification of Carbonate Rocks: AAPG Memoir 1, p. 108–121.
  −
 
  −
5. Embry, Ashton F.; Klovan, J. Edward (1971-12-01). "A late Devonian reef tract on northeastern Banks Island, N.W.T". Bulletin of Canadian Petroleum Geology. 19 (4): 730–781.
     −
6. K. Bjørlykke (ed). Petroleum Geoscience: From Sedimentary Environments to Rock Physics, DOI 10.1007/978-3-642-34132-8_5, Ⓒ Springer-Verlag Berlin Heidelberg 2015.
+
==Other Sources==
 +
* Gregg, Jay. (December 18). Limestone Petrology. Missouri S&T. https://web.mst.edu/~greggjay/carbonate_page/lsgallery/pages/c-ACS190_10.htm
 +
* Sahraeyan, Mohammad. (2013, June). Sedimentary Basin Analysis of Sachun Formation in Southwestern Iran: Implication for Sedimentary Environments and Tectonic Setting. ResearchGate. https://www.researchgate.net/figure/Photomicrographs-showing-micrite-and-pelmicrite-in-the-argillaceous-limestone-facies-of_fig8_262337097
 +
* K. Bjørlykke (ed). Petroleum Geoscience: From Sedimentary Environments to Rock Physics, DOI 10.1007/978-3-642-34132-8_5, Ⓒ Springer-Verlag Berlin Heidelberg 2015.
 +
* Carbonate Rock Classification. Carbonateworld. https://carbonateworld.com/carbonate-atlas/carbonate-rock-classification/images/wackstone/
 +
* F. Jerry Lucia. Estimating Permeability in Carbonates Using the Rock-Fabric Method. Bureau of Economic Geology. https://www.beg.utexas.edu/lmod/_IOL-CM07/cm07-step02a.htm
 +
* Ardakani, Omid H. (2013, June). Diagenetic evolution and associated mineralization of Middle Devonian carbonates, southwestern Ontario, Canada. ResearchGate. https://www.researchgate.net/figure/Thin-section-photomicrographs-of-Middle-Devonian-rocks-A-Syntaxial-and-equant-calcite_fig3_235413575
 +
* Al-Awwad, Saad F. & pomar, Luis. (2015, May 21). Origin of the rudstone–floatstone beds in the Upper Jurassic Arab-D reservoir, Khurais Complex, Saudi Arabia. ScienceDirect. https://www.sciencedirect.com/science/article/pii/S0264817215001634
 +
* Khanaqa, Polla. (2018, December). Stratigraphy and Facies Analysis of the Govanda Formation from Western Zagros, Kurdistan Region, Northeastern Iraq. ResearchGate. https://www.researchgate.net/figure/a-Photo-of-the-Coral-Bafflestone-of-Barda-Balaka-Outcrop-Between-the-stems-Fine_fig12_330094098
 +
* Bindstone. Bureau of Economic Geology. https://www.beg.utexas.edu/lmod/_IOL-CM02/st21-ancbindstone.htm
 +
* Camuera, Jon. (2014, July). Origin and palaeo-environmental significance of the Berrazales carbonate spring deposit, North of Gran Canaria Island, Spain. ResearchGate. https://www.researchgate.net/figure/A-Framestone-facies-composed-of-parallel-plant-moulds-coated-with-calcite-B-Plant_fig4_283498781
 +
* Lokier, Stephen W.; Al Junaibi, Mariam (2016). "The petrographic description of carbonate facies: are we all speaking the same language?". Sedimentology. 63 (7): 1843–1885. doi:10.1111/sed.12293

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