This science ClipArt gallery offers 497 illustrations of geology, including structure and composition of land, minerals, and fossilized organisms.

"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…

"Streamlet (b) entering a small lake (a), and depositing a fan of sediment (c)." -Geikie, 1893

Streamlet

"Streamlet (b) entering a small lake (a), and depositing a fan of sediment (c)." -Geikie, 1893

"Streamlet (b) entering a small lake (a), and depositing a fan of sediment (c)." -Geikie, 1893

Streamlet

"Streamlet (b) entering a small lake (a), and depositing a fan of sediment (c)." -Geikie, 1893

"Normal twig-like branching of streamlets&mdash;the type produced in homogenous rock material when uninfluenced by geological structure planes." -Walcott, 1901

Streamlet Branching

"Normal twig-like branching of streamlets—the type produced in homogenous rock material when uninfluenced…

"Streamlet branchings of the abnormal type found in the area in and about the Pomperaug Valley. a and i, streamlets controlled by two sets or airs of fault planes. b and c, streamlets preponderantly controlled by a single series of parallel planes; d, f, and h, by a nearly rectangular system of fault planes. e and g, streamlets indicating that neighboring streamlet branchings have been controlled by the same fault plane. The side streamlets of g indicate control by a second series of faults." -Walcott, 1901

Streamlet Branchings

"Streamlet branchings of the abnormal type found in the area in and about the Pomperaug Valley. a and…

An illustration of the plan of a strike fault. The fault surface is usually near vertical and the footwall moves either left or right or laterally with very little vertical motion. Strike-slip faults with left-lateral motion are also known as sinistral faults. Those with right-lateral motion are also known as dextral faults. A special class of strike-slip faults is the transform faults which are a plate tectonics feature related to spreading centers such as mid-ocean ridges.

Plan of a Strike Fault

An illustration of the plan of a strike fault. The fault surface is usually near vertical and the footwall…

Two of the interlocking prisms or stylolites, showing the striated sides produced by friction during the process of interpenetration.

Stylolites

Two of the interlocking prisms or stylolites, showing the striated sides produced by friction during…

Ancient cedar trees were found buried beneath the Dennisvill swamp in southern New Jersey. It was believed the perculiar action of water and wind kept these trees in the same stage of decay as when they fell. This discovery resulted in the novel business of "mining cedar trees".

Buried Swamp

Ancient cedar trees were found buried beneath the Dennisvill swamp in southern New Jersey. It was believed…

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…

A synclinorium is a large syncline with superimposed smaller folds.

Synclinorium

A synclinorium is a large syncline with superimposed smaller folds.

Section of river terraces.

River Terraces

Section of river terraces.

This illustration shows the calcareous shell Textilaria globulosa. These shells are mostly very small, and yet through their abundance they have been very important in limestone-making.

Textilaria Globulosa

This illustration shows the calcareous shell Textilaria globulosa. These shells are mostly very small,…

Diagram showing passage of thrust fault into fold.

Thrust Fault into Fold

Diagram showing passage of thrust fault into fold.

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…

Natural crystal. 4, topaz.

Topaz

Natural crystal. 4, topaz.

Apparatus for breaking a plate of glass by torsion, with an example of results produced.

Torsion Apparatus

Apparatus for breaking a plate of glass by torsion, with an example of results produced.

Arrangement of fractures in a large plate of glass which was broken by torsion.

Glass Broken by Torsion

Arrangement of fractures in a large plate of glass which was broken by torsion.

Shiny, black, oblong stone.

Tourmaline

Shiny, black, oblong stone.

Plate tracery, Lillington, Northants.

Tracery

Plate tracery, Lillington, Northants.

Trachyte is an igneous, volcanic rock with an aphanitic to porphyritic texture.

Trachyte-phonolite

Trachyte is an igneous, volcanic rock with an aphanitic to porphyritic texture.

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…

The Trenton gravel bluff in New Jersey.

Trenton Bluff

The Trenton gravel bluff in New Jersey.

Section of bluff two miles south of Trenton, New Jersey.

Trenton Bluff

Section of bluff two miles south of Trenton, New Jersey.

"Ideal landscape of the Triassic period." -Taylor, 1904

Triassic Landscape

"Ideal landscape of the Triassic period." -Taylor, 1904

The trilobite was an early animal on earth during the Primordial Period.

Trilobite

The trilobite was an early animal on earth during the Primordial Period.

"Vertical cross-section of a Trilobite (Calymene). i., Intestine; s., shield; L., endopodite; e., exopodite; b., epipodial parts." -Thomson, 1916

Trilobite

"Vertical cross-section of a Trilobite (Calymene). i., Intestine; s., shield; L., endopodite; e., exopodite;…

A trilobite (Paradoxides Bohemicus) of the Cambrian period.

Trilobite

A trilobite (Paradoxides Bohemicus) of the Cambrian period.

"Trilobite from the Silurian rocks. Pultowa, Russia (Illaenus crassicauda)." -Taylor, 1904

Trilobite

"Trilobite from the Silurian rocks. Pultowa, Russia (Illaenus crassicauda)." -Taylor, 1904

A track of the early life form, the trilobite.

Trilobite Track

A track of the early life form, the trilobite.

Asaphus is a genus containing at least 35 species of Ordovician trilobites found primarily in Europe. All were benthic predators or detritivores. The typical individual was about 2&ndash;7.5 cm in length. The cephalon was smooth, and the glabellum tends not to be distinct from the cephalon. The segments of the pygidium are fused together, though some hint of segmentation may be apparent.

Asaphus Gigas a Trilobite

Asaphus is a genus containing at least 35 species of Ordovician trilobites found primarily in Europe.…

Trilobites ("three-lobes") are extinct marine arthropods that form the class Trilobita. Why the trilobites became extinct is not clear. Their numbers began to decrease with the appearance of the first sharks and other early gnathostomes (jawed vertebrates) in the Silurian and their subsequent rise in diversity during the Devonian period. Trilobites may have provided a rich source of food for these new animals.

Dicellocephalus Minnesotenis a Trilobite

Trilobites ("three-lobes") are extinct marine arthropods that form the class Trilobita. Why the trilobites…

Trilobites ("three-lobes") are extinct marine arthropods that form the class Trilobita. Why the trilobites became extinct is not clear. Their numbers began to decrease with the appearance of the first sharks and other early gnathostomes (jawed vertebrates) in the Silurian and their subsequent rise in diversity during the Devonian period. Trilobites may have provided a rich source of food for these new animals. Fossilised trilobites are often found enrolled (curled up) like modern woodlice for protection; evidence suggests enrollment helped protect against exploitation of arthropod cuticle weakness by Anomalocarid predator attacks.

Dicellocephalus Minnesotenis a Trilobite

Trilobites ("three-lobes") are extinct marine arthropods that form the class Trilobita. Why the trilobites…

Trilobites ("three-lobes") are extinct marine arthropods that form the class Trilobita.The earliest trilobites had complex, compound eyes with lenses made of calcite, a unique characteristic of all trilobite eyes. The trilobite eyes were typically compound, with each lens being an elongated prism. The number of lenses in such an eye varied: some trilobites had only one, while some had thousands of lenses in a single eye. In these compound eyes, the lenses were typically arranged hexagonall (b).

Dicellocephalus Minnesotenis a Trilobite

Trilobites ("three-lobes") are extinct marine arthropods that form the class Trilobita.The earliest…

"Spiny trilobite (Acidaspid Dufrenogi). Silurian rocks of Bohemia." -Taylor, 1904

Spiny Trilobite

"Spiny trilobite (Acidaspid Dufrenogi). Silurian rocks of Bohemia." -Taylor, 1904

This illustration shows the calcareous shell Triloculina Josephina. These shells are mostly very small, and yet through their abundance they have been very important in limestone-making.

Triloculina Josephina

This illustration shows the calcareous shell Triloculina Josephina. These shells are mostly very small,…

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…

View of a part of the Val-del-Bove with parasitic cones and steep lava streams.

Val-del-Bove

View of a part of the Val-del-Bove with parasitic cones and steep lava streams.

This illustration shows veins that have formed within rocks.

Vein-form Condition

This illustration shows veins that have formed within rocks.

This illustration shows a network of thin veins that have formed with a rock.

Vein-form Condition

This illustration shows a network of thin veins that have formed with a rock.

This illustration shows two very irregular veins. a represents regular veins, whereas b shows an intersecting irregular vein.

Vein-form Condition

This illustration shows two very irregular veins. a represents regular veins, whereas b shows an intersecting…

This illustration shows two large veins, of irregular character that cross one another.

Vein-form Condition

This illustration shows two large veins, of irregular character that cross one another.

This illustration shows a large band of veins within rock.

Vein-form Condition

This illustration shows a large band of veins within rock.

This illustration shows a large band of veins within rock.

Vein-form Condition

This illustration shows a large band of veins within rock.

An experimental illustration of the mode of formation of volcanic blister cones composed of viscid lavas.

Volcanic Blister Cone

An experimental illustration of the mode of formation of volcanic blister cones composed of viscid lavas.

The sides of volcanic cones are often rent during the eruption, and the fissures filled with lava, which hardens and forms rocky ribs called <em>dykes</em>. Sometimes the central cone becomes choked, and secondary or parasitic cones are formed.

Volcanic Dykes and Parasitic Cones

The sides of volcanic cones are often rent during the eruption, and the fissures filled with lava, which…