Demonstration Kit

HUB 8 A R OTM , scientific

Prepared by: James V. Pacilio, Science Education Specialist Ediloraial Consultants: W.H. Johnson, DepartmentofG80logy, University of IHinois; WiUard F. Reese, University ofAlberta INTROOUCTION

The Geology Demonstration Kitpermits students at all levels to visualize the causes and forces that shape the earth's surface. Construetionallandform-building actions ofvotcanoes, folding, and faulting can be demonstrated. Hard-to-define basic geologic tenns, such as , , , , lava flow, can be defined by demonstration, Also, an erupting nonflammable volcano, the action offolding and faulting, and other phenomena can be observed. Numerous projects provide a basic geologic understanding for the elementary student, or solidify concepts and introduce the advanced student to more complex subjects, such as isostatic movement and dip and strike.

The actual kit consists ofa watertight demonstration tray. 20 inches x 4.25 inches, three pieces ofdifferent colored flexible foam, three simulated rock formations of rugged varnished cardboard construction for demonstrations, an erupting volcano, 7 inch x 7 inch, plus miscellaneous materials needed for the many demonstrations.

THE FORMATION OF : FOLDING Some mountains are formed by folding. The To illustrate a SYNCLINE-a trough ("down­ earth's crust can become extremely hot because of ward arch") formed by rock layers that have been heat deep within the earth. This factor can cause bent downward: the rocks of the crust to become plastic and pliable. Folded mountains are for m e d when the earthl s crust is subjected to h 0 r iz a n ta I compressional pressure. Layers of rock are forced upward, forming"wrinkles" or folds on the earth's surface. lllustration 3 You can 'illustrate some features of the folding process using the three pieces of flexible foam. Duplicate the positioning of the flexible foam pieces as shown in the above illustration. To illustrate an ANTICLINE-an arch formed by rock layers that have been bent upward: To illustrate both an ANTICLINE and SYN­ CLINE:

Illustration 1

Duplicate the positioning of the flexible foam pieces illustration 4 as sbown in the above illustration. Duplicate the positioning of the three flexible foam To illustrate an OVERTURNED ANTICLlNE­ pieces as shown in the above illustration. an anticline in which one side or limb of the has been overturned: To illustrate a -a fold charac­ terized by a slight downward bend or flexture in the rock layers:

TIlustration 5

lliustration 2 Duplicate the positioning of the flexible foam pieces as shown above. Duplicate thepositioning of the flexible foam pieces as shown in the above illustration. 2 Copyright 0 2003 Hubbard Scientific, Inc. To illustrate ISOCLINAL FOLDS-a ! 0 I din To illustrate a STRIKE-SLIP FAULT-a fault which the sides or limbs are virtually parallel: in which the movement has been horizontal:

illustration 6

To illustrate a RECUMBENT FOLD-a fold in lliustration 9 which the sides or limbs are practically horizontal: 1. Set up the two larger simulated rock formations as shown.

illustration 7 Duplicate the positioning of the two pieces of flexi­ ble foam as shown above. lllustration 10

FORMATION OF A HOGBACK 2. Move the simulatedrock formation on the right in the direction indicated. A hogback forms on the fiank of a fold after the crest of an anticline has been breached by ero­ To illustrate a NORMAL FAULT (also called a sion. It is a ridge in which both the dip slope and gravity fault) •.. a fault where the hanging wall'" scarp Slop~ are relatively steep. A hogback can has moved down relative to the footwall"': be illustrated as follows:

I

nlustration 8 Duplicate positioning of the flexible foam pieces as shown above. illustration 1 1. Set up the two larger simulated rock formations FAULTING (FAULT BLOCK MOUNTAINS) as shown.

A fault is a ! r actu r e or oreak in the earth's .. The terms hanging wall and footwall are used to crust along which movement has taken place. describe the two blocks that are involved in fault­ Therefore the rock strata (layers) on the two sides ing. The hanging wallis the block above the fault of the fault do not match. Mountains resulting from plane and the footwall is the block below the fault. faulting are called fault block mountains. The terms were devised by miners when they found themselves in a b.mne~ running along a fault. They You can illus t rate the formation of several naturally called the block above the fault the hang­ basic types of faults uSing the three simulated ing wall and the block below the footwall. rock formations contained in the kit. 3 FOOTWALL

illustration 15 lllustration·12

2. Remove blocks from the right side as shown. 1. Position the three simulated rock formations as shown.

To illustrate a REVERSE FAULT-a fault where the hanging wall has moved up relative to the footwall:

lliustration 16

2. Place two blocks under the center rock forma­ tion.

To illustrate the formation of a GRABEN-a depression formed by the subsidence or dropping of land between two parallel faults: illustration 13

1. Set up the two larger simulated rock formations as shown.

HANGING WALL

illustration 17

1. Set up the three simulated rock formations as shown.

Illustration 14

2. Add two blocks to right side as shown. lliustration 18 To illustrate the formation of a HORST-a 2. Place two blocks under each of the larger raised block of land between parallel faults: formations as shown. 4