ClipArt ETC

The Structural Geology ClipArt gallery provides 172 illustrations of the study of the stresses and deformations of rock layers. The study of the various folds and deformations of rock strata is an important part of the search for petroleum and mineral resources.

An illustration of a section of anticlinal and synclinal folds on the like CD.

Anticlinal and Synclinal Folds

An illustration of a section of anticlinal and synclinal folds on the like CD.

A symmetrical anticlinal fold, the top of which has been eroded. Near St. Abb's Head, Scotland.

Anticlinal Fold

A symmetrical anticlinal fold, the top of which has been eroded. Near St. Abb's Head, Scotland.

This illustration shows a perspective view and a vertical section of an anticline. It shows the half-cigar-shaped mountains of the hard rocks and the arches formed by the beds.

Anticline

This illustration shows a perspective view and a vertical section of an anticline. It shows the half-cigar-shaped…

A mountain mass composed of a number of anticlines may have these so arranged that they form a part of a larger arch.

Anticlinorium

A mountain mass composed of a number of anticlines may have these so arranged that they form a part…

This illustration shows the Appalachian Mountains, a region of numerous flexures on a grand scale, as well as many faults; some flexures having a span of several miles, and others only a few feet or inches.

Appalachian Mountains

This illustration shows the Appalachian Mountains, a region of numerous flexures on a grand scale, as…

This is a diagram showing the rocks of the successive periods of time. They are shown in order from the Archaean, in Northern New York, southwestward to the Coal-formation of Pennsylvania, showing that they succee one another on the map simply because they come to the surface in succession

Archaean Time

This is a diagram showing the rocks of the successive periods of time. They are shown in order from…

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…

General view, in part schematic, of the "Bassin du Puy" and the "Chaine du Velay" or "Chaine du Deves," Central France.

Bassin du Puy

General view, in part schematic, of the "Bassin du Puy" and the "Chaine du Velay" or "Chaine du Deves,"…

Rapid change in thickness of beds, due to strong folding.

Change in Thickness of Beds

Rapid change in thickness of beds, due to strong folding.

Cross-section of the Black Hills dome, showing the present structure and topography and the former continuation of the beds.

Black Hills Dome

Cross-section of the Black Hills dome, showing the present structure and topography and the former continuation…

Diagram illustrating the development of the block mountain topography of the Basin Ranges.

Development of a Block Mountain

Diagram illustrating the development of the block mountain topography of the Basin Ranges.

Eroded fold, breached asymmetrical anticline, the hard stratum forming two opposing uniclines.

Breached Asymmetrical Anticline

Eroded fold, breached asymmetrical anticline, the hard stratum forming two opposing uniclines.

Cross-section of the Caucasus along the Grusinian military road. Dark beds are lava streams.

Caucasus

Cross-section of the Caucasus along the Grusinian military road. Dark beds are lava streams.

Block diagram of the cuestas and lowlands of Central England.

Lowlands of Central England

Block diagram of the cuestas and lowlands of Central England.

Natural and columnar sections at each end and in the center of a line 100 miles long and extending at right angles to the original shore line.

Clastic Deposits in the Sea

Natural and columnar sections at each end and in the center of a line 100 miles long and extending at…

A homemade clinometer, an instrument used for measuring angles of slope.

Clinometer

A homemade clinometer, an instrument used for measuring angles of slope.

Diagram illustrating gently inclined strata, with the clinometer in proper position to measure the dip at right angles to the strike.

Clinometer Measuring Inclined Strata

Diagram illustrating gently inclined strata, with the clinometer in proper position to measure the dip…

This illustration shows coal-beds with stumps of trees rising out of the coal. The stumps always stand vertically on the bed, however much the latter may be displaced, showing that the bed was horizontal when it was formed, or when the trees were growing.

Coal Beds

This illustration shows coal-beds with stumps of trees rising out of the coal. The stumps always stand…

The costal plain of an overlapping strata after the development of subsequent streams and the formation of an inner lowland. The remnant of the coastal plain now forms a cuesta ending landward in an inface, and transected by the consequent stream valley.

Coastal Plain

The costal plain of an overlapping strata after the development of subsequent streams and the formation…

Diagrammatic section of coastal plain strata formed in a retreating sea (off-lapping series).

Coastal Plain Strata

Diagrammatic section of coastal plain strata formed in a retreating sea (off-lapping series).

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…

Development of concentric ridges in anticlinal structures. A) An anticlinal or cigar-shaped mountain results from the position of the hard rock. B) The anticlinal mountain A is replaced by an anticlinal valley because of the position of the strata.

Concentric Ridges in Anticlinal Structures

Development of concentric ridges in anticlinal structures. A) An anticlinal or cigar-shaped mountain…

Development of concentric ridges in synclines. A) a region with synclinal or canoe-shaped folds. B) The synclinal valley shown in A is replaced by a mountain because of the occurrence of a hard stratum in the center.

Concentric Ridges in Synclines

Development of concentric ridges in synclines. A) a region with synclinal or canoe-shaped folds. B)…

"Curved and contorted rocks, near Old Head of Kinsale." — Encyclopedia Britannica, 1893

Contorted Rocks

"Curved and contorted rocks, near Old Head of Kinsale." — Encyclopedia Britannica, 1893

"Hall's Experiment illustrating contortion" of rocks." -Geikie, 1893

Contortion of Rocks

"Hall's Experiment illustrating contortion" of rocks." -Geikie, 1893

Section of Corndon Hill, in Shropshire, England; the type of the phacolith.

Corndon Hill

Section of Corndon Hill, in Shropshire, England; the type of the phacolith.

Crag and tail, a term used to designate a peculiar hill conformation. a, crag; b, tail (boulder clay, drift, etc.); c, hollow in front of crag.

Crag and Tail

Crag and tail, a term used to designate a peculiar hill conformation. a, crag; b, tail (boulder clay,…

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…

"Deformation of shale by porphyry, Burlington Railroad, east of Whitetail Gulch." -Walcott, 1901

Shale Deformation

"Deformation of shale by porphyry, Burlington Railroad, east of Whitetail Gulch." -Walcott, 1901

"Dip, in geology, the name given to the angle of slope of inclined rock strata, as dip in the diagram...The horizontal direction at right angles to the line of dip is called the strike, shown by st in the diagram." -Foster, 1921

Dip

"Dip, in geology, the name given to the angle of slope of inclined rock strata, as dip in the diagram...The…

"Section showing displacement of strata by a fault. a and a were once a continuous mass of rock." -Whitney, 1911

Displacement of Strata

"Section showing displacement of strata by a fault. a and a were once a continuous mass of rock." -Whitney,…

Transverse section of the great ore chamber in the Emma mine, Utah.

Emma Mine, Utah

Transverse section of the great ore chamber in the Emma mine, Utah.

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…

Eroded anticlines with horizontal and with pitching axes. In the first case the strata crop out in parallel series, the oldest at the center; in the second case they converge in the direction of pitch.

Eroded Anticlines

Eroded anticlines with horizontal and with pitching axes. In the first case the strata crop out in parallel…

This illustration shows a cliff, having its lower layers near the level of low tide, extending out as a platform a hundred yards wide.

Erosion

This illustration shows a cliff, having its lower layers near the level of low tide, extending out as…

"Diagram illustrating development of erosion profiles on laccolith domes." -Walcott, 1901

Erosion Development

"Diagram illustrating development of erosion profiles on laccolith domes." -Walcott, 1901

Diagram illustrating change in facies of marine clastics, from sands and muds near the shore to calcareous beds near coral reefs, etc. Note also the overlap of the successive formations.

Change in Facies

Diagram illustrating change in facies of marine clastics, from sands and muds near the shore to calcareous…

Section across the Livingston and Lewis ranges, with the Flattop Mountain, a synclinal mountain, and Chief Mountain, a remnant of an overthrust fault block. The strata are more complexly folded than is here shown.

Flattop Mountain, a Synclinal Mountain

Section across the Livingston and Lewis ranges, with the Flattop Mountain, a synclinal mountain, and…

This illustration shows a rock formation with folds or flexures in strata. a x represents the axis or axial plane of the fold.

Flexures

This illustration shows a rock formation with folds or flexures in strata. a x represents the axis or…

Eroded anticline

Eroded Anticline

Eroded anticline

Eroded syncline.

Eroded Syncline

Eroded syncline.

Machine for producing folded strata.

Machine for Producing Folded Strata

Machine for producing folded strata.

Cross section of an eroded anticline.

Eroded Anticline

Cross section of an eroded anticline.

Cross section of an eroded syncline.

Eroded Syncline

Cross section of an eroded syncline.

An overthrust anticline of a strata fold.

Overthrust Anticline Folds

An overthrust anticline of a strata fold.

An overthrust anticline of a strata fold.

Overthrust Anticline Folds

An overthrust anticline of a strata fold.

"A syncline is a downfolding of the strata in the form of a trough, as at a...An anticline is an upfolding of the strata in the form of an arch, as at b." -Dryer, 1901

Strata Folds

"A syncline is a downfolding of the strata in the form of a trough, as at a...An anticline is an upfolding…

Diagrammatic section through the Freiburg region showing the former and present topography and the extensive erosion.

Freiburg Region

Diagrammatic section through the Freiburg region showing the former and present topography and the extensive…

Section of the lower Genesee River from Lake Ontario to Rochester, N.Y.

Genesee River

Section of the lower Genesee River from Lake Ontario to Rochester, N.Y.

"Section showing Granite nucleus, with strata lying on its flanks, the overlapping and continuous portions of which have been denuded off." -Taylor, 1904

Granite Section

"Section showing Granite nucleus, with strata lying on its flanks, the overlapping and continuous portions…

"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…

The diagram shows the source of groundwater: water falls into porous ground (a), flows underground to be brought to the surface in another location.

Groundwater Source

The diagram shows the source of groundwater: water falls into porous ground (a), flows underground to…

Hesperus Mountain, showing wedges and sheets of trachyte intruded into the shales, from the laccolith of Mt. Moss.

Hesperus Mountain

Hesperus Mountain, showing wedges and sheets of trachyte intruded into the shales, from the laccolith…

Diagrammatic sections representing the development of hog-backs. I, a simple anticlinal ridge consisting of hard and soft sediments overlying crystallinew rocks; II, the same after erosion and development of hog-backs (uniclines) on opposite sides; III, the same region after peneplanation and further arching; IV, development of the hog-backs in the second cycle of erosion.

Development of Hog-backs

Diagrammatic sections representing the development of hog-backs. I, a simple anticlinal ridge consisting…

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;…

This illustration shows exceptions to horizontal rock formations. When a river empties ino a lake or sea, the bottom of which, near its mouth, is more or less inclined, the deposits of detritus made by the river will for a while conform to the slope of the bottom.

Horizontal Rock

This illustration shows exceptions to horizontal rock formations. When a river empties ino a lake or…

When a single large mass of rock is caught between two faults it is spoken of as a "horse."

Horse

When a single large mass of rock is caught between two faults it is spoken of as a "horse."

Diagram to illustrate the underground extension of inclined strata which crop out on the surface, and the former relationship of the two inclined beds.

Inclined Strata

Diagram to illustrate the underground extension of inclined strata which crop out on the surface, and…

Diagram illustrating the relationships of dip and strike of the inclined strata of an outcropping series of ledges. The strike is represented by the horizontal line; the dip by the line at right angles to the strike.

Inclined Strata Dip and Strike

Diagram illustrating the relationships of dip and strike of the inclined strata of an outcropping series…

Diagram illustrating the deflection of outcrop of an inclined stratum, from the true strike on a horizontal surface to false strike on an inclined surface.

Deflection of Outcrop of an Inclined Stratum

Diagram illustrating the deflection of outcrop of an inclined stratum, from the true strike on a horizontal…