Secondary Types of Evidence

Secondary Types of EvidencePrepared By: Shienna Marie M. BaugbogRock Structurethenatureofthemakeupofrocksfrommineralsandmineralaggregates.Textureisdeterminedbytedimensions,shape,andinterrelationshipsoftheminerals;structuredependsonthegeneral featuresandspatialarrangementofthelargercomponentsoftherock(mineralaggregates).Sedimentary BedsOriginally laid with parallel strata are found buckled into folds.Anticlines

are folds in which each half of the fold dips away from the crest.An A shape.Synclinesare folds in which each half of the fold dips toward the trough of the fold.An Sshape.

Anticlines and Synclines The YoungestRocks are in the centre of the fold.

TheOldestRocks are in the centre of the fold.

Geosynclinesa term still occasionally used for a subsiding linear trough that was caused by the accumulation ofsedimentary rockstratadeposited in abasinand subsequently compressed, deformed, and uplifted into amountain range, with attendantvolcanismandplutonism.

Jointsfracture in rocks along which no appreciable movement has occurred (seefault). Nearly vertical, or sheet, joints that result from shrinkage during cooling are commonly found in igneous rocks.