[Prize-winning Quiz on Oil Production Geology] 3

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11. An unconformity indicates that intense crustal movements occurred after the formation of the older strata; these older strata were () and subjected to erosion, resulting in the creation of an erosional surface. Subsequently, the crust sank, and deposition took place on this erosional surface, giving rise to the newer strata. (A) Folded uplift (B) Uneven surface (C) Horizontal tilt (D) Above water level. 12. When the orientations of the new and old strata differ, and when there are changes in the rock properties and in the evolution of paleontological species, as well as interruptions in sedimentation processes, there are extensive erosion surfaces between the new and old strata. Conglomerates often accumulate on these erosion surfaces; these erosion surfaces are parallel to the overlying strata, but the contact relationship in which they cover different underlying strata is called a ( ) contact. (A) Integration (B) Paragenesis (C) Angular unconformity (D) Parallel unconformity. 13. The main characteristics of an intrusive contact are the presence of contact () phenomena at the boundary between the intrusion and its surrounding rock; xenoliths are often found at the edges of the intrusion, and the boundary between the intrusion and the surrounding rock is usually irregular. (A) Metamorphism (B) Quantitative change (C) Gradual change (D) Erosion. 14. The depositional contact relationship of an intrusion indicates that the age of the intrusion is ( ) older than that of the rock layers directly above it, and that intense crustal movements occurred during the formation of the intrusion. (A) Less than or equal to (B) Equal to (C) Less than (D) Greater than. 15. The ancient submarine hill itself is in ( ) contact with its overlying cover layer. (A) Unconformity (B) Conformity (C) Continuity (D) Intrusion Last edited by No.18 on 2009-4-18 08:33]