What is the classification of limestone?
Limestone is a sedimentary stone with 50% by weight calcite or calcium carbonate (CaCO3) content. Limestone is a “clastic” sedimentary stone. …
What are the two main criteria that the Dunham carbonate classification system is based on?
Two carbonate classification systems are in common use today, one by R.L. Folk and the second by R.J. Dunham . The Dunham system is based on depositional texture (that is, the amount of matrix surrounding the grains at the time of deposition).
What type of rock is grainstone?
A grainstone is a carbonate rock in which grains larger than 0.25 mm comprise more than 10 volume% of the rock and have a matrix of sparry calcite. They generally are deposited in moderate- to high-energy environments, but their hydraulic significance can vary.
How could you tell the difference between a Grapestone grainstone and Packstone in carbonate rock?
For example, if the grains of a limestone are touching one another and the sediment contains no mud, then the sediment is called a grainstone. If the carbonate is grain supported but contains a small percentage of mud, then it is known as a packstone.
How are carbonate rocks classified?
The classification divides carbonate rocks into two broad groups, those whose original components were not bound together during deposition and those whose original components formed in place and consist of intergrowths of skeletal material.
How would you describe a carbonate rock?
Carbonate rocks are a class of sedimentary rocks composed primarily of carbonate minerals. When conditions are right for precipitation, calcite forms mineral coatings that cement the existing rock grains together or it can fill fractures.
Which Dunham classification would likely make the best reservoir rock?
Carbonate Rocks Because carbonate minerals in general are soluble in slightly acidic waters, they often have high porosity and permeability, making them ideal reservoirs for petroleum.
Is grainstone a sedimentary rock?
Definition: Carbonate sedimentary rock with recognizable depositional fabric that is grain-supported, and constituent particles are of intrabasinal origin; contains little or no mud matrix.
How do we classify carbonate rocks?
The Dunham classification is based on the concept of grain support. The classification divides carbonate rocks into two broad groups, those whose original components were not bound together during deposition and those whose original components formed in place and consist of intergrowths of skeletal material.
Is Grainstone a sedimentary rock?
What is the classification of granite?
Mineralogical classification of granites includes four rock types: tonalites, granodiorites, granite (monzogranite and syenogranites) and alkali-feldspar granites. Alphabetical classification subdivided granites into: I-type, S-type, A-type and M-type granites.
When did Robert Dunham invent the Dunham Classification system?
The Dunham classification system for carbonate sedimentary rocks was originally devised by Robert J. Dunham in 1962, and subsequently modified by Embry and Klovan in 1971 to include coarse-grained limestones and sediments that had been organically bound at the time of deposition.
When did the classification of carbonates come out?
Two schemes have stood the test of trial and error, in the field and through microscopes; both were compiled in the late 1950s – early 60s, each serves a slightly different purpose, both are still popular. They are the classification schemes of R. Folk (1959, 1962), and R. Dunham (1962).
Can a carbonate be classified as a packstone?
The wide range of percentage of mud matrix that a carbonate may have and still be termed a packstone by Dunham sometimes reduces the utility of this classification. Embry has modified Dunham’s classification and Klovan (1971) to include coarse grained carbonate s (above figure).
When did Embry and Klovan change the Dunham classification?
The most widely adopted of these has been that of Embry and Klovan (1971) who recognized that the Dunham classification scheme lacked detail when it came to the description of organically-bound and coarse-grained limestones.