Alum shale is a type of sedimentary rock that is rich in organic matter and minerals. This rock is known for its high levels of alumina, which makes it an important source of aluminum and other metals. Alum shale has been used for various purposes throughout history, including as a source of fuel and as a building material. In this article, we will explore the definition, meaning, and associations of alum shale.
Definitions
Alum shale is a fine-grained sedimentary rock that is rich in organic matter, clay minerals, and various metal oxides. The rock is typically black or dark brown in color and has a distinctive odor due to the presence of hydrocarbons. Alum shale is formed from the accumulation of organic matter in marine environments over millions of years.
Origin
Alum shale is found in various parts of the world, including Europe, North America, and Asia. The rock is believed to have formed during the Cambrian and Ordovician periods, which occurred around 500-450 million years ago. During this time, the oceans were rich in organic matter, and the deposition of this material led to the formation of alum shale.
Meaning in different dictionaries
According to the Oxford English Dictionary, alum shale is defined as “a black, fine-grained shale containing alumina, used in the manufacture of alum and as a source of oil.” Merriam-Webster defines it as “a shale containing a high percentage of alumina and used as a source of aluminum and alum.” The Cambridge English Dictionary defines it as “a type of rock that contains a lot of aluminum and is used to make chemicals and as a fuel.”
Associations
Alum shale is associated with various industries, including mining, oil and gas extraction, and chemical manufacturing. The rock is used as a source of aluminum, oil, and other minerals, and is also used as a fuel. Alum shale has been mined for centuries, and its use has been documented as far back as the Roman Empire.
Synonyms
Some synonyms of alum shale include bituminous shale, oil shale, and alum slate. These terms are often used interchangeably with alum shale, although they may refer to slightly different types of sedimentary rock.
Antonyms
There are no specific antonyms for alum shale, as it is a type of rock and not a concept or idea. However, other types of sedimentary rock, such as sandstone or limestone, could be considered antonyms in the sense that they are different types of rock with different properties and uses.
The same root words
The word “alum” in alum shale refers to aluminum, which is one of the main minerals found in the rock. The word “shale” refers to the fine-grained, layered structure of the rock. Other words that share the root word “alum” include alumina, aluminum oxide, and aluminate.
Example Sentences
- The mining company is exploring a new deposit of alum shale in the mountains.
- Alum shale is an important source of aluminum and other metals.
- The odor of the alum shale was overpowering, but the workers were used to it.
- The chemical plant uses alum shale as a raw material for its products.
- The ancient Romans used alum shale to make dyes and medicines.