What does pelitic mean?
Pelitic is a geological adjective describing clay-rich material, especially fine-grained sedimentary rocks or metamorphic rocks derived from them. The word is used when the presence or proportion of clay minerals is significant to a rock’s classification, origin, or geological history. A deposit might be described as pelitic if it formed from mud or clay, while a metamorphic rock might be called pelitic when its protolith contained abundant clay minerals. In this specialized sense, the term is more precise than general descriptions such as “clayey” or “fine-grained.” It is not normally used in everyday conversation. The related noun pelite denotes clay-rich rock or sediment, while pelitic is the adjective that identifies such material and describes processes or formations involving it.
adjectiveRelating to pelite or to rock derived from clay or mud. In geology, the term describes fine-grained sedimentary or metamorphic material rich in clay minerals.
- Relating to or consisting of pelite, especially fine-grained rock containing abundant clay minerals.
"The geologist identified a band of pelitic slate within the mountain formation."
"The cliff exposes a sequence of pelitic rocks that were deposited in a deep marine basin."
"Heat and pressure converted the pelitic shale into a durable band of schist."
Pelitic is the geological label for Earth’s clay-rich stories, written in layers of mud and transformed by heat and pressure.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does pelitic come from?
The adjective derives from pelite, which in turn comes from Ancient Greek πηλός (pēlos), meaning “clay” or “mud.” The English geological term pelite was formed with the suffix -ite, used for minerals and rocks, and pelitic was then derived from that noun. Pelite and pelitic therefore share a classical Greek origin concerned with clay.
Related word forms
How pelitic is actually used
This is primarily a specialist geological term. It is most often used to characterize sedimentary rocks, metamorphic rocks, or unconsolidated sediment in which clay minerals are abundant.
Easily confused with pelitic
Pelitic refers to clay- or mud-rich rock, whereas pelagic refers to the open ocean or organisms living there.