Limestone Classification Flashcards

Questions and Answers

What is Oolitic Limestone composed of?

Ooids (correct)

Fossils

Granules

Sand

What is Skeletal-oolitic Limestone?

A rock composed of ooids that also contains a minor element such as skeletal fragments.

The 8 basic kinds of limestone include Intrasparite, Intramicrite, Oosparite, Oomicrite, Biosparite, Biomicrite, Pelsparite, and ______.

Pelmicrite

What are the 2 Limestone Classification Schemes?

Dunham System and Folk System Signup and view all the answers

What distinguishes the Dunham System?

It distinguishes two kinds of limestones based on whether the original components were bound together during deposition. Signup and view all the answers

Match the terms with their corresponding definitions in the Folk System:

Particles = Sand-sized or larger components Micrite = Fine-grained carbonate Cement = Material binding the particles Allochems = All particles in the limestone Signup and view all the answers

What are the 4 kinds of particles classified in the Folk System?

Intraclasts, Ooids, Whole skeletons or fragments of fossils, and Pellets. Signup and view all the answers

Allochems refer to the cement known as sparry calcite.

True Signup and view all the answers

What is the definition of Micrite?

A limestone composed of micrite lacking sand-sized particles. Signup and view all the answers

What are Boundstones?

Limestones showing evidence of binding during deposition. Signup and view all the answers

What are Rudites?

Carbonate rocks with particles of granule size, like shells or large pellets. Signup and view all the answers

What are the Limestone Prefixes?

Intra for intraclasts, oo for ooids, bio for fossils, and pel for pellets. Signup and view all the answers

What is a Biolithite?

A limestone composed of a reef framework. Signup and view all the answers

What is Sparite?

A limestone having cement consisting of sparry calcite. Signup and view all the answers

What is Pelmicrudite?

A limestone composed of unusually large pellets accumulated in a micrite. Signup and view all the answers

What characterizes Pelsparrudite and Intrasparrudite?

Limestones where sparry cement occurs between pebble-sized particles. Signup and view all the answers

What are Stromatolites?

Laminated carbonate rocks formed by sticky blue-green algae mats that trap carbonate sediments. Signup and view all the answers

Study Notes

Oolitic and Skeletal-Oolitic Limestone

Oolitic limestone consists of spherical grains known as ooids.
Skeletal-oolitic limestone contains ooids along with skeletal fragments, indicating biological influence in its composition.

Basic Kinds of Limestone

Eight primary classifications include:
- Intrasparite
- Intramicrite
- Oosparite
- Oomicrite
- Biosparite
- Biomicrite
- Pelsparite
- Pelmicrite

Limestone Classification Schemes

Two main systems used to classify limestone are:
- Dunham System
- Folk System

Dunham System Details

Differentiates based on whether limestone components were bound during deposition.
Focuses on rock fabric and texture, reflecting the depositional energy of the environment.

Folk System Details

Subdivides limestone constituents into three categories:
- Particles (sand-sized or larger)
- Micrite
- Cement
All particles are termed allochems, while micrite is known as orthochemical constituents (orthochems).

Types of Particles in Folk System

Particle classifications include:
- Intraclasts, which can be organic or inorganic fragments
- Ooids, spherical grains formed by precipitation
- Fossil fragments, either whole or broken
- Pellets, small carbonate grains.

Definition of Allochems

Allochems refer to the cement found in limestones, specifically identified as sparky calcite.

Understanding Orthochems

Orthochems synonymously describe micrite, indicating a fine-grained limestone.

Boundstones Characteristics

Boundstones display evidence of biological binding during deposition.
Common forms include reefs, stromatolites, and travertine, which preserve ecological processes.

Rudites Description

Rudites are carbonate rocks characterized by granule-sized particles, such as shells or large pellets, and identified as carbonate conglomerates.

Limestone Prefixes

Specific prefixes indicate limestone properties:
- Intrasparite for intraclasts
- Oomicrite for ooids
- Biomicrite for fossils
- Pelmicrite for pellets.

Biolithite Definition

Biolithite refers to a limestone built predominantly from reef frameworks and biological structures.

Characteristics of Micrite

Micrite type limestone is noted for lacking sand-sized particles and primarily composed of fine calcite.

Sparite Features

Sparite is characterized by having a cement texture consisting of calcite with a sparkling appearance.

Pelmicrudite Overview

Pelmicrudite is formed from large, distinct pellets embedded within a micrite matrix.

Intramicrudite Definition

Intramicrudite is identified by the presence of flat pebbles situated within a micrite composition.

Pelsparrudite & Intrasparrudite

These types of limestone contain pebble-sized particles bound by sparry cement, contributing to their structural integrity.

Stromatolites Explanation

Stromatolites are layered carbonate structures formed by the activity of blue-green algae, representing some of the earliest evidence of life on Earth.
They develop through the trapping of sediment between successive growth layers and can appear as sheets, domes, or oncolites (rolling balls).

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Description

Test your knowledge on limestone types with these flashcards. Learn about oolitic limestone and its variations, as well as the eight basic kinds of limestone. This quiz is perfect for geology students looking to reinforce their understanding of sedimentary rocks.