10,372
edits
Changes
Jump to navigation
Jump to search
Line 72:
Line 72: − + − + + − + − + Line 87:
Line 88: − + + − + − + − + − Organically-Bound Rocks Subdivision+ − Depositional Energy Setting and Reservoir Quality Indications+ + Line 107:
Line 110: − Gallery − + − + − + − + − + − + − + − + − + − + − + − + + + + + + + + − + − Fig. 9 Biomicrite [9]+ − − Fig. 10 Pelmicrite [10] − − Fig. 13 Mudstone [13] − − Fig. 14 Wackestone [14] − − Fig. 15 [15] − − Fig. 16 [16] + + − + − Fig. 17 Crystalline rock [17] − − Fig. 19 Floatstone [19] − − Fig. 20 Rudstone [20] − − Fig. 21 Bafflestone [21] − + − Fig. 22 Bindstone [22] − − Fig. 23 Framestone [23] − + − Notes − 1. ^[a] Early carbonate classification is grain-size based system: Calcilutite (grains < 63 μm), calcarenite (63 μm < grains < 2mm), calcirudite (grains > 2mm). − 2. ^[b] This family has restricted limits because cement by itself cannot form a rock and the supported framework component (allochems) has limited packing. − 3. ^[c] If the microcrystalline limestone had been disturbed either by bioturbation or soft-sediment deformation, the term “disturbed microcrystalline limestone” or “dismicrite” could be assigned. − 4. ^[d] Examples of biolithites are: algal biolithite and coral biolithite. − 5. ^[e] Naming of a subdivision is a composite of two parts. The first part refers to the name of the allochem. The second part refers to the family type. For Example, intrasparite: intra- refers to intraclasts, and –sparite refers to family I. − 6. ^[f] Oosparites are more common than Oomicrites because the need of strong current to form these rocks. + + + + − References + + + + + + + + + + + + + − + + + + + + + − 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 + + + +
Carbonate sedimentary rocks classification (view source)
Revision as of 16:07, 21 April 2022
, 16:07, 21 April 2022no edit summary
==Dunham Classification==
==Dunham Classification==
Dunham’s Criteria
===Dunham’s Criteria===
Dunham classification system is based on three depositional textural features:
Dunham 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]
• the presence of in situ organic binding
• the presence of in situ organic binding
Dunham (1962) Classification
===Dunham (1962) Classification===
The original Dunham classification system composes of six classes summarized in Figure 12:
The original Dunham classification system composes of six classes summarized in Figure 12:
[[File:GeoWikiWriteOff2021-Abdulwahab-Figure12.png|thumbnail|Fig. 12 Dunham classification system for carbonate rock (1962) [12]]]
Fig. 12 Dunham classification system for carbonate rock (1962) [12]
• Mudstone: a mud-supported rock with < 10% grains, and original components are not organically bounded together during deposition (Figure 13).
• Mudstone: a mud-supported rock with < 10% grains, and original components are not organically bounded together during deposition (Figure 13).
• Wackestone: a mud-supported rock with > 10% grains, and original components are not organically bounded together during deposition (Figure 14).
• Wackestone: a mud-supported rock with > 10% grains, and original components are not organically bounded together during deposition (Figure 14).
• Boundstone: a rock with the presence of organic components bounded together during deposition.
• Boundstone: a rock with the presence of organic components bounded together during deposition.
• Crystalline: a rock with unrecognizable depositional texture (Figure 17).
• Crystalline: a rock with unrecognizable depositional texture (Figure 17).
Extended Dunham Classification (1971)
===Extended Dunham Classification (1971)===
Embry and Klovan 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|thumbnail|Fig. 18 Extended Dunham classification (1971) [18]]]
Fig. 18 Extended Dunham classification (1971) [18]
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).
====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]
===Depositional Energy Setting and Reservoir Quality Indications===
Generally, mud-supported rocks: mudstones and wackestones are formed in low-energy settings and show poor reservoir quality.
Generally, mud-supported rocks: mudstones and wackestones are formed in low-energy settings and show poor reservoir quality.
Grain-supported rocks: packstones and grainstones are formed in high-energy settings and show good reservoir quality. Grainstones is considered to be the best reservoir quality rock, especially if it is partially cemented. It is usually characterized by good porosity & permeability, and good sorting.
Grain-supported rocks: packstones and grainstones are formed in high-energy settings and show good reservoir quality. Grainstones is considered to be the best reservoir quality rock, especially if it is partially cemented. It is usually characterized by good porosity & permeability, and good sorting.
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.
==Gallery==
Fig. 3 Intrasparite [3]
[[File:GeoWikiWriteOff2021-Abdulwahab-Figure3.png|thumbnail|Fig. 3 Intrasparite [3]]]
[[File:GeoWikiWriteOff2021-Abdulwahab-Figure4.png|thumbnail|Fig. 4 Oosparite [4]]]
Fig. 4 Oosparite [4]
[[File:GeoWikiWriteOff2021-Abdulwahab-Figure5.png|thumbnail|Fig. 5 Biosparite [5]]]
[[File:GeoWikiWriteOff2021-Abdulwahab-Figure6.png|thumbnail|Fig. 6 Pelsparite [6]]]
Fig. 5 Biosparite [5]
[[File:GeoWikiWriteOff2021-Abdulwahab-Figure7.png|thumbnail|Fig. 7 Intramicrite [7]]]
[[File:GeoWikiWriteOff2021-Abdulwahab-Figure8.png|thumbnail|Fig. 8 Oomicrite [8]]]
Fig. 6 Pelsparite [6]
[[File:GeoWikiWriteOff2021-Abdulwahab-Figure9.png|thumbnail|Fig. 9 Biomicrite [9]]]
[[File:GeoWikiWriteOff2021-Abdulwahab-Figure10.png|thumbnail|Fig. 10 Pelmicrite [10]]]
Fig. 7 Intramicrite [7]
[[File:GeoWikiWriteOff2021-Abdulwahab-Figure13.png|thumbnailFig. 13 Mudstone [13]]]
[[File:GeoWikiWriteOff2021-Abdulwahab-Figure14.png|thumbnail|Fig. 14 Wackestone [14]]]
Fig. 8 Oomicrite [8]
[[File:GeoWikiWriteOff2021-Abdulwahab-Figure15.png|thumbnail|Fig. 15 [15]]]
[[File:GeoWikiWriteOff2021-Abdulwahab-Figure16.png|thumbnail|Fig. 16 [16]]]
[[File:GeoWikiWriteOff2021-Abdulwahab-Figure17.png|thumbnail|Fig. 17 Crystalline rock [17] ]]
[[File:GeoWikiWriteOff2021-Abdulwahab-Figure19.png|thumbnail|Fig. 19 Floatstone [19]]]
[[File:GeoWikiWriteOff2021-Abdulwahab-Figure20.png|thumbnail|Fig. 20 Rudstone [20]]]
[[File:GeoWikiWriteOff2021-Abdulwahab-Figure21.png|thumbnail|Fig. 21 Bafflestone [21]]]
[[File:GeoWikiWriteOff2021-Abdulwahab-Figure22.png|thumbnail|Fig. 22 Bindstone [22]]]
[[File:GeoWikiWriteOff2021-Abdulwahab-Figure23.png|thumbnail|Fig. 23 Framestone [23]]]
==Notes==
1. ^[a] Early carbonate classification is grain-size based system: Calcilutite (grains < 63 μm), calcarenite (63 μm < grains < 2mm), calcirudite (grains > 2mm).
2. ^[b] This family has restricted limits because cement by itself cannot form a rock and the supported framework component (allochems) has limited packing.
3. ^[c] If the microcrystalline limestone had been disturbed either by bioturbation or soft-sediment deformation, the term “disturbed microcrystalline limestone” or “dismicrite” could be assigned.
4. ^[d] Examples of biolithites are: algal biolithite and coral biolithite.
5. ^[e] Naming of a subdivision is a composite of two parts. The first part refers to the name of the allochem. The second part refers to the family type. For Example, intrasparite: intra- refers to intraclasts, and –sparite refers to family I.
6. ^[f] Oosparites are more common than Oomicrites because the need of strong current to form these rocks.
7. ^[g] Intrasparites are more common than intramicrites because the need of strong current to transfer course rock fragments.
7. ^[g] Intrasparites are more common than intramicrites because the need of strong current to transfer course rock fragments.
8. ^[h] Both biosparites and biomicrites are common. However, biosparites are usually more rounded and abraded because of the strong current.
8. ^[h] Both biosparites and biomicrites are common. However, biosparites are usually more rounded and abraded because of the strong current.
9. ^[i] The subdivisions could be applied considering other types of allochems: intraclasts, oolites, and pellets.
9. ^[i] The subdivisions could be applied considering other types of allochems: intraclasts, oolites, and pellets.
10. ^[j] The abundance of grains defines the nature of the framework. In other words, whether it is mud-supported or grain-supported.
10. ^[j] The abundance of grains defines the nature of the framework. In other words, whether it is mud-supported or grain-supported.
11. ^[k] The term “boundstone” is retained if the organic bounding type is not recognized.
11. ^[k] The term “boundstone” is retained if the organic bounding type is not recognized.
==References==
19. ^ [1] [2] [11] Folk, R. L., 1959, Practical petrographic classification of limestones: AAPG Bulletin, v. 43, p. 1–38.
19. ^ [1] [2] [11] Folk, R. L., 1959, Practical petrographic classification of limestones: AAPG Bulletin, v. 43, p. 1–38.
20. ^ [3] [4] [5] [9] Folk Classification. Wikipedia. https://en.wikipedia.org/wiki/Folk_classification#cite_ref-2
20. ^ [3] [4] [5] [9] Folk Classification. Wikipedia. https://en.wikipedia.org/wiki/Folk_classification#cite_ref-2
21. ^ [6] Gregg, Jay. (December 18). Limestone Petrology. Missouri S&T. https://web.mst.edu/~greggjay/carbonate_page/lsgallery/pages/c-ACS190_10.htm
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
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
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
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.
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
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/
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
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
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
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
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
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
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.
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.
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.
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.
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.
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.