An Introduction to Geological Structures and Maps

1 Horizontal and dipping strata.- Contours, section drawing, vertical exaggeration; Dip, structure contours, construction of structure contours, section drawing; True and apparent dip; Calculation of thickness of a bed, vertical and true thickness; Width of outcrop; Inliers and outliers..- 2 ’Three-point’ problems.- Construction of structure contours; Insertion of outcrops; Depth in boreholes..- 3 Unconformities.- Overstep; Overlap; Sub-unconformity outcrops..- 4 Folding.- Anticlines and synclines; Asymmetrical folds, overfolds and isoclinal folds; Similar and concentric folding; Two possible directions of strike..- 5 Faults.- Normal and reversed faults; The effects of faulting on outcrops; Classification of faults, dip-slip, strike-slip and oblique-slip faults; Dip faults and strike faults; Calculation of the throw of a fault; Wrench or tear faults; Pre- and post-unconformity faulting; Structural inliers and outliers; Posthumous faulting; Isopachytes..- 6 More folds and faulted folds.- Plunging folds, calculation of the amount of plunge; The effect of faulting on fold structures; Displacement of folds by strike-slip (wrench) faults, calculation of strike-slip displacement; Faults parallel to the limbs of a fold; Sub-surface structures; Posthumous folding; Polyphase folding; Bed isopachytes..- 7 Complex structures.- Nappes; Thrust faults; Axial plane cleavage..- 8 Igneous rocks.- Concordant intrusions, sills; Lava flows and tuffs; Discordant intrusions, dykes, ring- dykes, cone-sheets, stocks, bosses and batholiths, volcanic necks..- Description of a geological map; Geological history of Map 28..- Numerical answers.