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Different physiografic provinces make up the Basin of Middle Tennessee. Sections from east to west across the basin shows (1) the Lower Silurian strata, (2) the Devonian strata, (3) Carboniferous strata, (4) the Lower Carboniferous strata, (5) Conglomerate (Parma Conglomerae), (6) Coal measures.

Basin of Middle Tennessee

Different physiografic provinces make up the Basin of Middle Tennessee. Sections from east to west across…

Block faulting - region of horizontal strata intersected by vertical fissures.

Block Faulting

Block faulting - region of horizontal strata intersected by vertical fissures.

A coastal plain after elevation and renewed dissection. Two cuestas and two lowlands are now produced from the hard and weak strata, respectively.

Coastal Plain After Elevation

A coastal plain after elevation and renewed dissection. Two cuestas and two lowlands are now produced…

Diagram showing the relationship of the strata in five successive sections, in a compound regressive-transgressive series. The intercalated sandstone xy encloses the hiatus.

Compound Regressive-Transgressive Series

Diagram showing the relationship of the strata in five successive sections, in a compound regressive-transgressive…

Block diagram illustrating the formation of three cuestas and lowlands by normal drainage on the peneplaned strata which surround the old Ontario dome on the south and west.

Cuestas and Lowlands

Block diagram illustrating the formation of three cuestas and lowlands by normal drainage on the peneplaned…

In geology and related fields, a stratum (plural: strata) is a layer of rock or soil with internally consistent characteristics that distinguishes it from contiguous layers. Each layer is generally one of a number of parallel layers that lie one upon another, laid down by natural forces. They may extend over hundreds of thousands of square kilometers of the Earth's surface. Strata are typically seen as bands of different colored or differently structured material. Individual bands may vary in thickness from a few millimeters to a kilometer or more. Each band represents a specific mode of deposition -- river silt, beach sand, coal swamp, sand dune, lava bed, etc. Eozoic strata pertains to rocks or strata older that the Paleozoic, in many of which the eozoön has been found.

Eozoic Strata

In geology and related fields, a stratum (plural: strata) is a layer of rock or soil with internally…

"Plan of strata cut by a dip-fault." — Encyclopedia Britannica, 1893

Fault

"Plan of strata cut by a dip-fault." — Encyclopedia Britannica, 1893

An illustration of a dip fault disrupting the plan of strata.

Dip Fault

An illustration of a dip fault disrupting the plan of strata.

Diagram illustrating drag of strata along a fault plane.

Drag

Diagram illustrating drag of strata along a fault plane.

"Diagram showing a reverse or overthrust fault (b)." -Lee, 1915

Reverse Fault

"Diagram showing a reverse or overthrust fault (b)." -Lee, 1915

"The two faults of larger throw, by which a single sheet of trap is represented in three ridges, are proved by the threefold repetition of series of beds comprising sandstone, conglomerate, and amygdaloidal trap, shale, and heavy trap." -Walcott, 1901

Strike Fault

"The two faults of larger throw, by which a single sheet of trap is represented in three ridges, are…

Diagram illustrating the offset of strata produced by vertical slipping along an inclined plane, when the fault is oblique with reference to the strata. The dotted outline restores the fault scarp and gives the appearance immediately after faulting, before erosion has removed this portion of the block.

Thrust Fault Diagram

Diagram illustrating the offset of strata produced by vertical slipping along an inclined plane, when…

"Diagram showing normal faults (a)." -Lee, 1915

Normal Faults

"Diagram showing normal faults (a)." -Lee, 1915

Machine for producing folded strata.

Machine for Producing Folded Strata

Machine for producing folded strata.

A geologist collecting and studying rocks.

Geologist

A geologist collecting and studying rocks.

"Suppose a to be a gravel hill, and b a strata of clay or rock, impervious to water. The fluid percolating through the gravel would reach the impervious strata, along which it would run until it found an outlet at c at the foot of the hill, where a spring would be formed." — Wells, 1857

Gravel Hill

"Suppose a to be a gravel hill, and b a strata of clay or rock, impervious to water. The fluid percolating…

Hog-backs (RR) changing into cuestas (CC) and these into steps (HH) by progressive flattening of strata; UU, oldland; TT, inner lowland; SS, second lowland; P, plateau between steps; V, nose; Z, outlier.

Hog-back Diagram

Hog-backs (RR) changing into cuestas (CC) and these into steps (HH) by progressive flattening of strata;…

Section of the Horseshoe Falls, Niagara, to show the depth of water below the falls and the arrangement of the strata.

Horseshoe Falls, Niagara

Section of the Horseshoe Falls, Niagara, to show the depth of water below the falls and the arrangement…

An extinct fossil colossal lizard found in the Wealden strata; so called from the resemblance of its teeth to those of the iguana.

Iguanodon

An extinct fossil colossal lizard found in the Wealden strata; so called from the resemblance of its…

"Conduit of Tilford laccolith, showing porphyry (P) breaking across limestone (L)." -Walcott, 1901

Laccolith

"Conduit of Tilford laccolith, showing porphyry (P) breaking across limestone (L)." -Walcott, 1901

This illustration represents a section of the rocks along the river below Niagara Falls. It gives some idea of the alterations which occur in the strata.

Niagara Falls

This illustration represents a section of the rocks along the river below Niagara Falls. It gives some…

Section through North Hill, Kingston, N.Y. showing the overthrust which led to a repetition of the strata.

North Hill Overthrust

Section through North Hill, Kingston, N.Y. showing the overthrust which led to a repetition of the strata.

Strata (plural of stratum), is the geological formation of an area of land. A sequence of discrete rock layers used for age dating and identification of concurrent regional or worldwide events in the geologic record. Section from East to West across the peninsula of Michigan. The Several groups of strata from the Coal measures to the Lower Silurian.

Michigan Peninsula

Strata (plural of stratum), is the geological formation of an area of land. A sequence of discrete rock…

Parallel vertical or columnar sections on the face of Pulpit Rock, near Colorado Springs, through identical strata, and only 20 feet apart; illustrating rapid lateral changes in the character of the strata.

Pulpit Rock Sections

Parallel vertical or columnar sections on the face of Pulpit Rock, near Colorado Springs, through identical…

"Diagrammatic structure section of the Wasatch Range in Ogden Canyon." -Lee, 1915

Rock Layers Showing Geological Periods

"Diagrammatic structure section of the Wasatch Range in Ogden Canyon." -Lee, 1915

"Cross section of Marsh Creek valley at McCammon, Idaho." -Lee, 1915

Rock Layers Showing Types of Rock

"Cross section of Marsh Creek valley at McCammon, Idaho." -Lee, 1915

"A sandy stratum, a a, acting as a filter, occupies an inclined position between two other strata impervious to water, such as clay, the water being absorbed by the superficial parts of the strata, as at a a (which may be of very great extent), will penetrate through its whole depth, and, finding no egress below on account of the basin-like form of the stratum, or from its resting at the lower termination upon a compact rock, will accumulate." — Wells, 1857

Sandy Stratum

"A sandy stratum, a a, acting as a filter, occupies an inclined position between two other strata impervious…

An illustration of undulating strata cut by a fault with alternate throw in opposite directions.

Diagram of Undulating Strata Cut by a Fault

An illustration of undulating strata cut by a fault with alternate throw in opposite directions.

An illustration of a plan of strata transversed by a diminishing strike fault.

Strata Transversed by a Diminshing Strike Fault

An illustration of a plan of strata transversed by a diminishing strike fault.

An illustration of strata bent at a line of fault. In geology and related fields, a stratum (plural: strata) is a layer of rock or soil with internally consistent characteristics that distinguishes it from contiguous layers. Each layer is generally one of a number of parallel layers that lie one upon another, laid down by natural forces.

Strata with Fault Line

An illustration of strata bent at a line of fault. In geology and related fields, a stratum (plural:…

"In some places a series of strata A, having a certain dip, rest directly upon the eroded surface of another series, having the same dip." — Hinman, 1888

Uncomformable strata

"In some places a series of strata A, having a certain dip, rest directly upon the eroded surface of…

Subsequent streams are streams whose course has been determined by selective headward erosion along weak strata. Pictured here is an overdeepened subsequent stream.

Overdeepened Subsequent Stream

Subsequent streams are streams whose course has been determined by selective headward erosion along…

This illustration represents the effects of erosion of a synclinal region consisting of alternations of hard and soft strata.

Synclinal Region

This illustration represents the effects of erosion of a synclinal region consisting of alternations…

This illustration represents the effects of erosion of a synclinal region consisting of alternations of hard and soft strata.

Synclinal Region

This illustration represents the effects of erosion of a synclinal region consisting of alternations…

This illustration represents the effects of erosion of a synclinal region consisting of alternations of hard and soft strata.

Synclinal Region

This illustration represents the effects of erosion of a synclinal region consisting of alternations…

This illustration represents the effects of erosion of a synclinal region consisting of alternations of hard and soft strata.

Synclinal Region

This illustration represents the effects of erosion of a synclinal region consisting of alternations…

This illustration represents the effects of erosion of a synclinal region consisting of alternations of hard and soft strata.

Synclinal Region

This illustration represents the effects of erosion of a synclinal region consisting of alternations…

This illustration represents the effects of erosion of a synclinal region consisting of alternations of hard and soft strata.

Synclinal Region

This illustration represents the effects of erosion of a synclinal region consisting of alternations…