ClipArt ETC
"Generalized schematic of the hydrogeology of the study area. 1, unconfined conditions (Hawthorn Formation absent or very thin); 2, semiconfined conditions (Hawthorn Formation less than 100 feet thick); 3, confined conditions (Hawthorn Formation greater than 100 feet thick)." -Hatzell, 1995

Upper Floridan Aquifer

"Generalized schematic of the hydrogeology of the study area. 1, unconfined conditions (Hawthorn Formation…

"Diagram to illustrate the inferred structure in the vicinity of the "Triangle." Arkose conglomerate is represented by lines and ellipses, anterior basalt by the black areas, anterior shale by parallel lines, and main basalt by cross-hachure areas. The finer hachuring (and hence the deeper shade) corresponds to the higher blocks of the basalt." -Walcott, 1901

Basalt Diagram

"Diagram to illustrate the inferred structure in the vicinity of the "Triangle." Arkose conglomerate…

"Basaltic rock interstratified with aqueous rocks; b Basaltic dyke." -Taylor, 1904

Basaltic Rock

"Basaltic rock interstratified with aqueous rocks; b Basaltic dyke." -Taylor, 1904

"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…

"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…

"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…

A geological dip of strata.

Strata Dip

A geological dip of 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.

"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…