Stratigraphy and Sedimentology
Expert-defined terms from the Professional Certificate in Archaeological Site Documentation: Recording Techniques course at London School of Business and Administration. Free to read, free to share, paired with a globally recognised certification pathway.
**Absolute dating** #
**Absolute dating**
: Also known as numerical dating, it is a method of determining the exact age of… #
: Also known as numerical dating, it is a method of determining the exact age of a artifact or archaeological site using various techniques such as radiocarbon dating, dendrochronology, and thermoluminescence.
**Alluvium** #
**Alluvium**
: A deposit of clay, silt, sand, and gravel that has been carried by running wat… #
: A deposit of clay, silt, sand, and gravel that has been carried by running water and deposited in a river valley, floodplain, or delta.
**Anthropogenic** #
**Anthropogenic**
: Relating to or resulting from the influence of human beings on the natural wor… #
: Relating to or resulting from the influence of human beings on the natural world.
**Bedding** #
**Bedding**
: The arrangement of sedimentary particles into layers or strata in a sedimentar… #
: The arrangement of sedimentary particles into layers or strata in a sedimentary rock.
**Bioturbation** #
**Bioturbation**
: The disturbance of sediment by the burrowing or feeding activities of living o… #
: The disturbance of sediment by the burrowing or feeding activities of living organisms.
**Carbonate** #
**Carbonate**
: A mineral that is composed primarily of carbonate ions, such as calcite and do… #
: A mineral that is composed primarily of carbonate ions, such as calcite and dolomite.
**Chert** #
**Chert**
: A hard, fine-grained sedimentary rock that is composed of microcrystalline qua… #
: A hard, fine-grained sedimentary rock that is composed of microcrystalline quartz.
**Clast** #
**Clast**
: A particle of sediment, such as a sand grain or pebble #
: A particle of sediment, such as a sand grain or pebble.
**Cross #
bedding**
: A sedimentary structure that forms when sediment is deposited at an angle to t… #
: A sedimentary structure that forms when sediment is deposited at an angle to the horizontal, creating a series of inclined layers.
**Diagenesis** #
**Diagenesis**
: The chemical and physical changes that occur in sedimentary rocks after deposi… #
: The chemical and physical changes that occur in sedimentary rocks after deposition, including compaction, cementation, and recrystallization.
**Eolian** #
**Eolian**
: Relating to or produced by the wind, such as eolian sand dunes #
: Relating to or produced by the wind, such as eolian sand dunes.
**Facies** #
**Facies**
: A body of rock that has a distinctive set of characteristics that distinguish… #
: A body of rock that has a distinctive set of characteristics that distinguish it from other rocks in the area, such as a particular set of fossils or sedimentary structures.
**Fluvial** #
**Fluvial**
: Relating to or produced by a river or stream, such as fluvial sediments #
: Relating to or produced by a river or stream, such as fluvial sediments.
**Foraminifera** #
**Foraminifera**
: A type of single-celled plankton that has a shell made of calcium carbonate, c… #
: A type of single-celled plankton that has a shell made of calcium carbonate, commonly found in marine sediments.
**Grain size** #
**Grain size**
: The size of individual sediment particles, typically measured in millimeters o… #
: The size of individual sediment particles, typically measured in millimeters or micrometers.
**Horizon** #
**Horizon**
: A layer of soil or sediment that has a distinct set of characteristics and can… #
: A layer of soil or sediment that has a distinct set of characteristics and can be traced laterally over a large area.
**Lithology** #
**Lithology**
: The physical characteristics of a rock, including its color, texture, and comp… #
: The physical characteristics of a rock, including its color, texture, and composition.
**Lithostratigraphy** #
**Lithostratigraphy**
: The study of rock layers and their arrangement, including the identification o… #
: The study of rock layers and their arrangement, including the identification of individual strata and their boundaries.
**Loose sediment** #
**Loose sediment**
: Sediment that has not been cemented or compacted into a solid rock, such as sa… #
: Sediment that has not been cemented or compacted into a solid rock, such as sand or gravel.
**Mineral** #
**Mineral**
: A naturally occurring inorganic solid that has a crystal structure and a defin… #
: A naturally occurring inorganic solid that has a crystal structure and a defined chemical composition.
**Paleocurrent** #
**Paleocurrent**
: The direction of ancient water flow, inferred from the alignment of sedimentar… #
: The direction of ancient water flow, inferred from the alignment of sedimentary structures such as cross-bedding.
**Paleosol** #
**Paleosol**
: A fossil soil horizon that has been buried and preserved in the geologic recor… #
: A fossil soil horizon that has been buried and preserved in the geologic record.
**Pedogenesis** #
**Pedogenesis**
: The process of soil formation, including the chemical and physical changes tha… #
: The process of soil formation, including the chemical and physical changes that occur in the soil over time.
**Regolith** #
**Regolith**
: The loose, unconsolidated material that covers the bedrock, including soil, se… #
: The loose, unconsolidated material that covers the bedrock, including soil, sediment, and rock fragments.
**Sedimentary structures** #
**Sedimentary structures**
: The physical features of sedimentary rocks that provide information about the… #
: The physical features of sedimentary rocks that provide information about the conditions of deposition, such as bedding, cross-bedding, and ripple marks.
**Sedimentology** #
**Sedimentology**
: The study of sedimentary rocks, including their formation, composition, and te… #
: The study of sedimentary rocks, including their formation, composition, and texture.
**Strata** #
**Strata**
: Layers of sedimentary rock that have been deposited over time, often containin… #
: Layers of sedimentary rock that have been deposited over time, often containing different types of sediment and fossils.
**Stratigraphy** #
**Stratigraphy**
: The study of rock layers and their arrangement, including the identification o… #
: The study of rock layers and their arrangement, including the identification of individual strata and their boundaries.
**Tephra** #
**Tephra**
: Volcanic ash and other pyroclastic material that has been deposited from the a… #
: Volcanic ash and other pyroclastic material that has been deposited from the air.
**Till** #
**Till**
: Sediment that has been deposited by a glacier, typically unsorted and poorly s… #
: Sediment that has been deposited by a glacier, typically unsorted and poorly stratified.
**Unconformity** #
**Unconformity**
: A boundary between two rock layers that represents a gap in the geologic recor… #
: A boundary between two rock layers that represents a gap in the geologic record, caused by erosion, non-deposition, or other processes.
**Varve** #
**Varve**
: A pair of thin layers of sediment that are deposited in a lake or ocean during… #
: A pair of thin layers of sediment that are deposited in a lake or ocean during one year, typically consisting of a light-colored layer of silt or clay and a dark-colored layer of organic material.
**Weathering** #
**Weathering**
: The physical and chemical breakdown of rocks and minerals at the Earth's surfa… #
: The physical and chemical breakdown of rocks and minerals at the Earth's surface, including processes such as freeze-thaw, chemical dissolution, and abrasion.
**X #
ray fluorescence (XRF)**
: A technique for analyzing the chemical composition of rocks and minerals using… #
: A technique for analyzing the chemical composition of rocks and minerals using X-rays, often used in archaeological dating and provenance studies.
**Zircon** #
**Zircon**
: A mineral that is commonly found in igneous rocks and is resistant to weatheri… #
: A mineral that is commonly found in igneous rocks and is resistant to weathering and alteration, making it useful for geochronology and provenance studies.