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.

Volcanic sills - Salisbury Crag in Edinburgh, Scotland.

Salisbury Crag

Volcanic sills - Salisbury Crag in Edinburgh, Scotland.

"Vertical section through a Gulf Coast salt dome." -Johnson, 1916

Salt Dome

"Vertical section through a Gulf Coast salt dome." -Johnson, 1916

An illustration of a section of a sand-filter bed.

Sand-Filter Bed

An illustration of a section of a sand-filter bed.

Section of a sandbank in the bed of the Arve at its confluence with the Rhone, showing the stratification of deposits where currents meet.

Sandbank Deposits

Section of a sandbank in the bed of the Arve at its confluence with the Rhone, showing the stratification…

Along the south shore of Lake Superior is a sandstone once regarded as belonging to the Potsdam, but probably, in part , of the age of the Calciferous, in which we search in vain for any of those fossil remains so common in Minnesota. Whaterver its geological age, the Lake Superior sandstone is a formation of remarkable interest. This section across Lake Superior shows (a) water level. (b) trap outburst north of the lake, (c) trap outburst forming Isle Royale, (d) trap outburst forming Kewenaw Point, (e) Lake Superior sandstone and conglomerate. Eözoic and other rocks underlying the sandstone (f).

Sandstone

Along the south shore of Lake Superior is a sandstone once regarded as belonging to the Potsdam, but…

Cross-bedding in Sylvania sandstone.

Sandstone with Cross-bedding

Cross-bedding in Sylvania sandstone.

"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…

"In sedimentary deposits, however, some variation from horizontality may be produced by the slope of the sea-bottom in certain cases." -Dana, 1880

Sedimentary Deposits

"In sedimentary deposits, however, some variation from horizontality may be produced by the slope of…

The floor of the sea was first formed or rocks that had cooled from a state of fusion. The few islands that existed were but exposed portions on the floor. The debris scattered over this foundation would be arranged in layers, as water always arranges its sediments. The coarser materials would be transported by the more powerful action and deposited in one place. The finer materials would be carried beyond and deposited in a remoter region. Here we see (a) the primordial igneous crust, (b) a sea-side cliff gnawed by the waves, (c) the ordinary sea-level, (d) the ruins of the cliff with the coarser deposited near the shore, and the finer floated to greater depths.

Shore Erosion and Distribution of Sediments

The floor of the sea was first formed or rocks that had cooled from a state of fusion. The few islands…

Cross-sections of shallow basins, separated a) by a simple anticline, b) by two anticlines and a syncline.

Shallow Basins

Cross-sections of shallow basins, separated a) by a simple anticline, b) by two anticlines and a syncline.

Unconformity at Siccar Point, Berwick, Scotland. Folded and truncated Siluro-Ordovician beds and Old Red Sandstone beds.

Siccar Point, Berwick, Scotland

Unconformity at Siccar Point, Berwick, Scotland. Folded and truncated Siluro-Ordovician beds and Old…

Section through the Simplon massif, along the axis of the Great Simplon tunnel from the Rhone Valley, Switzerland to the Val Diveria, Italy.

Simplon Massif

Section through the Simplon massif, along the axis of the Great Simplon tunnel from the Rhone Valley,…

A piece of rock in which slaty cleavage has been developed, as shown by the fine lines; the coarser bands represent the original bedding planes, now compressed and contorted.

Slaty Cleavage

A piece of rock in which slaty cleavage has been developed, as shown by the fine lines; the coarser…

North-south cross-section of the St. Gothard Massif, Switzerland, showing the fan-folds.

St. Gothard Massif, Switzerland

North-south cross-section of the St. Gothard Massif, Switzerland, showing the fan-folds.

"Sterogram of Jura Mountains...The Jura Mountains in France and Switzerland consist of a series of parallel ridges and valleys in which each ridge is an anticline and each valley is a syncline." -Dryer, 1901

Mountain Sterogram

"Sterogram of Jura Mountains...The Jura Mountains in France and Switzerland consist of a series of parallel…

A geological dip of strata.

Strata Dip

A geological dip of strata.

"Diagram suggesting the type of structure possessed by the simple folding of strata. The diagram shows the folded surface was worn down." -Salisbury, 1919

Strata Folding

"Diagram suggesting the type of structure possessed by the simple folding of strata. The diagram shows…

Strata folding after erosion. "No further folding is shown, and erosion has isolated the hard layers as mountain ridges." -Salisbury, 1919

Strata Folding

Strata folding after erosion. "No further folding is shown, and erosion has isolated the hard layers…

This image shows the foldings in strata.

Strata Folding

This image shows the foldings in strata.

"Generalized columnar section, northern Black Hills." -Walcott, 1901

Strata Thickness

"Generalized columnar section, northern Black Hills." -Walcott, 1901

Anticlinal strata is a geological fold upwards with the oldest layer at the core.

Anticlinal Strata

Anticlinal strata is a geological fold upwards with the oldest layer at the core.

Synclinal strata is a geological fold downwards.

Synclinal Strata

Synclinal strata is a geological fold downwards.

"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…

These diagrams show the unconformity of strata. "In some places a series of strata A, having a certain dip, rest directly upon the eroded surface of another series, having either the same dip (B), or an entirely different one (C)." -Hinman, 1888

Unconformable Strata

These diagrams show the unconformity of strata. "In some places a series of strata A, having a certain…

"Unconformability between horizontal and inclined strata. Inferior Oolite (a b) resting on Carboniferous Limestone (c); Frome, Somerset." -Geikie, 1893

Unconformable Strata

"Unconformability between horizontal and inclined strata. Inferior Oolite (a b) resting on Carboniferous…

(1) sandstone, (2) Gray Band, (3) greenish shale, (4) compact limestone, (5) greenish shale, (6) limestone, (7) shale, (8) limestone.

Stratification

(1) sandstone, (2) Gray Band, (3) greenish shale, (4) compact limestone, (5) greenish shale, (6) limestone,…

"Ideal section of part of the earth's crust, with landscape above. Granite and other crystalline rocks appear with irregular outlines at the bottom of the section; over them are stratified rocks, partly bent and partly flat. The forms of the landscape are related to the arrangement of the rocks." -Gilbert, 1910

Stratified Layers

"Ideal section of part of the earth's crust, with landscape above. Granite and other crystalline rocks…

The different layers or strata are shown by the shadling's. Stratified rocks are the most common of rock's found near the earth's surface. Stratified rocks are largely composed of fragments of older rocks; for this reason they are sometimes called <em>fragmental</em> rocks.

Stratified Rock

The different layers or strata are shown by the shadling's. Stratified rocks are the most common of…

Eroded fold, symmetrical anticline, from the axis of which the higher beds have been eroded down to a harder stratum.

Symmetrical Anticline

Eroded fold, symmetrical anticline, from the axis of which the higher beds have been eroded down to…

Synclinal fold near Banff, Scotland.

Synclinal Fold

Synclinal fold near Banff, Scotland.

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…

This illustration shows a perspective view and a vertical section of a syncline. It shows the spoon-shaped ridges of hard rock and the troughs formed by the beds.

Syncline

This illustration shows a perspective view and a vertical section of a syncline. It shows the spoon-shaped…

A synclinorium is a large syncline with superimposed smaller folds.

Synclinorium

A synclinorium is a large syncline with superimposed smaller folds.

A series of diagrams showing the development of the Chief Mountain thrust. The older rocks from which the mountains are cut are represented by cross-lines, the younger rocks of the plains in white.

The Chief Mountain Thrust of Montana

A series of diagrams showing the development of the Chief Mountain thrust. The older rocks from which…

Section in the Northwest Highlands of Scotland showing the overthrust of the Archaean onto the older Palaeozoics.

Thrusts in the Northwest Highlands of Scotland

Section in the Northwest Highlands of Scotland showing the overthrust of the Archaean onto the older…

Block diagram and section illustrating overthrust in the Alps.

The Alpine Overthrusts

Block diagram and section illustrating overthrust in the Alps.

This illustration shows a rock formation that has a tilted strata. d p is the direction of the dip. Both the angle of slope and the direction are noted by the geologist: thus, it may be said of beds, the dip is 50 degrees to the south, or 45 degrees to the northwest, etc.

Tilted Strata

This illustration shows a rock formation that has a tilted strata. d p is the direction of the dip.…

This illustration shows a rock formation that has a tilted strata. a b c d represents a square block of wood, having a graduated arc b c and a plummet hung below a. Placed on the sloping surface A B, the position of the plummet gives the angle of dip.

Tilted Strata

This illustration shows a rock formation that has a tilted strata. a b c d represents a square block…

Diagram showing the relationships of a transgressive-regressive-transgressive series. A hiatus is found at the base of the transgressive series and between the regressive and upper transgressive series. Owing to the vertical exaggeration of the scale the essential parallelism of the strata is not expressed.

Transgressive-Regressive-Transgressive Series

Diagram showing the relationships of a transgressive-regressive-transgressive series. A hiatus is found…

"Map and section of trap ridges near Woodbury. The topography is indicated by sketched contours, with hachures for trap bluffs. The lower sandstone slopes are all covered, and the northern bluff of the western group of ridges is quite buried in drift. The crystalline rocks appear on the east. The section suggests an interpretation of the surface forms." -Walcott, 1901

Trap Ridges

"Map and section of trap ridges near Woodbury. The topography is indicated by sketched contours, with…

Block diagram of the uniclinal ridges of the Appalachian type; the original anticline from which the uniclines are cut was asymmetric, with the steeper limb on the west.

Uniclinal Ridges

Block diagram of the uniclinal ridges of the Appalachian type; the original anticline from which the…

"If the walls of the valley contain strata of unequal hardness, the form is modified by the projection of hard layers and the retreat of the softer ones." -Dryer, 1901

Unequal Valley Development

"If the walls of the valley contain strata of unequal hardness, the form is modified by the projection…

"If the strata are not horizontal, various unsymmetrical forms are produced." -Dryer, 1901

Usymmetrical Valley Development

"If the strata are not horizontal, various unsymmetrical forms are produced." -Dryer, 1901

Diagram illustrating several stages in the development of the Wasatch Mountains from the original fault block through rugged mountain topography to subdued mature topography, and final obliteration and formation of a peneplane.

Wasatch Mountains

Diagram illustrating several stages in the development of the Wasatch Mountains from the original fault…

"Geologic units penetrated by water wells in Seminole County." -Barraclough, 1962

Water Wells

"Geologic units penetrated by water wells in Seminole County." -Barraclough, 1962

Cross-section of a part of the West Alps, south of Lake Geneva, mainly in France.

West Alps, South of Lake Geneva

Cross-section of a part of the West Alps, south of Lake Geneva, mainly in France.

Volcanic sills - Whin Sill, North England.

Whin Sill, North England

Volcanic sills - Whin Sill, North England.