Types of Igneous Intrusions Quiz

Pahoehoe Flow

Mid-Atlantic Ridge and Juan de Fuca Ridge

Impact Crater

<p>Optically recognizable microscopic features</p> Signup and view all the answers

<p>Distinctive cone or fan-shaped features in rocks</p> Signup and view all the answers

<p>Distinctive cone or fan-shaped features in rocks</p> Signup and view all the answers

<p>A surface contact where a sediment layer is deposited over any preexisting rock, the contact is parallel and continuous, representing a continuous time gap.</p> Signup and view all the answers

<p>Represents a gap or missing information in the geologic record, caused by external processes such as tectonic or erosional processes.</p> Signup and view all the answers

<p>It is the contact between inclined beds and horizontal beds where relatively flat younger strata overlay steeply dipping older strata.</p> Signup and view all the answers

<p>It is the contact between sedimentary or volcanic rocks overlying older igneous or metamorphic rock, which may represent a time gap of over one billion years.</p> Signup and view all the answers

<p>A disconformity is the contact between two sedimentary rocks that have undergone erosion, and the separated layers are horizontal to each other.</p> Signup and view all the answers

<p>A nonconformity involves the contact between younger sedimentary/volcanic rocks and older igneous/metamorphic rocks, while an angular unconformity involves inclined beds over horizontal beds.</p> Signup and view all the answers

<p>Bulbous nose that flares out toward the other end</p> Signup and view all the answers

<p>Current scour around small obstacles like pebbles or shells</p> Signup and view all the answers

<p>Load Casts lack the regular form and orientation of Flute Casts</p> Signup and view all the answers

<p>Mudcracks form due to changes in weather patterns and are commonly seen in palayan (rice fields)</p> Signup and view all the answers

<p>Syneresis cracks tend to be discontinuous and vary in shape from polygonal to spindleshaped or sinuous</p> Signup and view all the answers

<p>Narrow semicircular or horseshoe-shaped troughs around small obstacles</p> Signup and view all the answers

<p>Orientation of two nonparallel lines in a plane</p> Signup and view all the answers

<p>Azimuth of the horizontal line in a dipping plane or the intersection between a given plane and the horizontal surface</p> Signup and view all the answers

<p>A dip angle at 90° to the strike</p> Signup and view all the answers

<p>Any angle between the plane and the horizontal that is not measured perpendicular to the strike</p> Signup and view all the answers

<p>Azimuth of the horizontal line in a dipping plane or the intersection between a given plane and the horizontal surface</p> Signup and view all the answers

<p>Imagine grasping a strike/dip map symbol with the right hand, palm down, and fingers pointing in the direction of the dip. The thumb then indicates the strike direction to be recorded.</p> Signup and view all the answers

<p>Stock has a surface exposure of less than 100 square kilometers, while a batholith has a surface exposure larger than 100 square kilometers.</p> Signup and view all the answers

<p>A laccolith has a domelike structure, formed by splitting apart two strata.</p> Signup and view all the answers

<p>Lopolith is lenticular in shape with a depressed central region, concordant with the intruded strata.</p> Signup and view all the answers

<p>A phacolith typically occurs at the crest of an anticline or the trough of a syncline, and it is lens-shaped.</p> Signup and view all the answers

<p>An aa flow is characterized by a rough or rubbly surface composed of broken lava blocks called clinker.</p> Signup and view all the answers

<p>Lobate lava flows resemble pahoehoe flows but are more inflated-looking, and they are common on fast-spreading mid-ocean ridges like the East Pacific Rise.</p> Signup and view all the answers