94 Questions
Which law of stratigraphy states that beds were deposited nearly horizontal due to gravitational pull?
Law of Original Horizontality
What does the Law of Superposition in stratigraphy state?
Younger strata lies at the top of older strata
What does the branch of geology concerned with the order and relative position of strata and their relationship to the geological time scale refer to?
Stratigraphy
What does the study of facies in stratigraphy help interpret?
Depositional environments from the rocks
What is the difference between bedding and lamination?
Bedding is thicker than 1cm, while lamination is thinner than 1cm
How are massive beds formed?
Through rapid sedimentation
What causes the grain size to range from coarser at the bottom to finer at the top in graded beds?
Sediment-laden current slowing down
How are cross-bedding and cross-lamination primarily formed?
By migration of ripples and dunes
What type of sediment does flaser bedding favor?
Sand deposits
What type of sediment does lenticular bedding favor?
Mud deposits
What causes wavy bedding to occur?
Fluctuating flows
What is hummocky cross stratification a type of?
Bedding formed by sedimentary structures
What are ripple marks?
Undulations of the sediment surface produced by wind or water movement across sand
What is the ripple index a measure of?
The asymmetry of ripple crests
Which type of structure can determine paleocurrent directions?
Sole marks
What are tool marks aligned parallel to?
Current movement
What are rain imprints likely made by?
The impact of rain
What are tafoni?
Small cave-like features in granular rock
What are pot holes created by?
The abrasive action of particles swirling in fast-moving eddies
What do penecontemporaneous structures refer to?
Changes in the fabric and layering of recently deposited sediment
What do erosional structures provide valuable information about?
Past environmental conditions and depositional settings
What do soft sediment deformation processes aid in?
Paleoenvironmental and paleogeographic reconstructions
What are diastems and unconformities examples of?
Erosional structures formed during high shear stress before bed deposition
What are flute casts preserved on?
The bottom surfaces of beds
What are the three principal processes of soft sediment deformation recognized for?
Not specified in the text
What is a characteristic of rain imprints?
Small craterlike pits with slightly raised rims
What is the process of converting granular material from a solid to a fluid-like state?
Fluidization
Which structure forms in rapidly deposited mudstone and sandy mudstone beds due to sediment instabilities?
Slump structures
What do load casts and flame structures relate to?
Loading
What is the result of clastic dikes fluidization?
Formation of vertical clastic dykes
What do dish and pillar structures encompass?
Concave disruptions and vertical water escape channels
What are sand volcanoes formed from?
Extruded liquefied sediment brought to the surface in isolated pipes
What do ball and pillow structures represent?
Masses of clastic sediment taking the form of isolated pillows or protruding ball structures
What is the process of separating particles based on size, shape, and density using a stream of gas or liquid?
Elutriation
What are diapirs formed due to?
Density differences between layers of unconsolidated sediment
What is the characteristic of fluidization structures?
Features formed when fluids escape following deposition
What do slump structures show?
Fold structure with the noses of the anticlines oriented downslope
What do fluidization structures encompass?
Features formed when fluids escape following deposition
How are sinkholes primarily formed?
By the downward dissolution of rock beneath the soil mantle
What is the main process that forms sea mounts?
Submarine volcanism and repeated eruptions
What characterizes a valley as a fluvial landform?
It is bordered by higher land and traversed by a stream or river
What is the distinguishing feature of a cave system?
A group of caves connected to each other
What landform is highly vulnerable to even the slightest change in water level?
Lagoon
What landform is formed by the upward movement of salt layers due to the low density of salt?
Dome
What volcanic landform is formed by the combination of the explosion and collapse of the top of a volcanic cone or group of cones?
Caldera
How are mountains most often formed?
By movement of tectonic plates in the Earth's crust
What erosional landform is generally cut by a river or stream into bedrock?
Canyon
What landform is a shallow body of water separated from a larger body of water by barrier islands or reefs?
Lagoon
What volcanic landform results from differential weathering and erosion between the former feeder tube of a volcano and its surrounding rocks?
Volcanic Neck
What tectonic landform is a round or oval-shaped formation that has risen above the ground around it?
Dome
What tectonic landform is a structural basin where two overlapping faults or a fault bend creates an area of crustal extension undergoing tension, which causes the basin to sink down?
Pull-apart basin
What tectonic landform is a fault-bounded crustal unit or block, generally elongate, that has been depressed relative to the blocks on either side?
Graben
What is the characteristic of a volcanic neck?
Resulting from differential weathering and erosion
What is the distinguishing characteristic of a dome?
Round or oval-shaped formation that has risen above the ground
What is the characteristic of a lagoon?
Separated from a larger body of water by barrier islands or reefs
How are atolls formed?
Coral rim encircling a lagoon due to sinking of volcanic islands
What causes the formation of domes?
Magma pushing up surface rock layers
What defines a pull-apart basin?
An area of crustal extension undergoing tension
How are volcanic necks formed?
When lava hardens within a vent on an active volcano
What forms a crater?
Eruption, explosion, or subsidence
What characterizes a caldera?
A very large, bowl-shaped volcanic depression
How are mountains most often formed?
By movement of tectonic plates in the Earth's crust
What characterizes a canyon?
A deep, steep-walled gorge cut by a river or stream
What is the characteristic of an impact crater?
Formed by the impact of a meteor, asteroid, or comet
What is the characteristic of a volcanic neck?
A hill resulting from differential weathering and erosion between the former feeder tube of a volcano and its surrounding rocks
What characterizes a graben?
A fault-bounded crustal unit or block that has been depressed relative to the blocks on either side
What determines the plate tectonic processes and is originally referred to the ocean's depth relative to sea level?
Submarine topography
What landform is characterized by a flat depositional surface on the seafloor at the edge of the ocean margins?
Abyssal plain
What are the transition areas from ocean crust to continental crust that underlie the continental slope characterized by?
Steep angle
What are the deepest parts of the oceans and can reach a depth of approximately 10,000 meters?
Ocean trenches
What is the region of the shelf between the low-tide mark and the depth to which waves normally affect the sea bottom?
Shoreface
What causes exceptionally strong gravitational forces, resulting in very low tides?
Alignment of the sun and moon
What type of tides occur during the full moon and the new moon?
Spring tides
What is the region between mean high water and mean low water marks of the tides and is part of the littoral zone?
Foreshore
What is the cyclic rising and falling of Earth’s ocean surface caused by the tidal forces of the Moon and the Sun acting on the Earth?
Tides
What is the deeper shelf area between the fair weather and storm wave bases?
Offshore-transition zone
What is the bulge of water due to strong gravitational attraction between water and moon?
Tidal bulge
What occurs when the sun and moon are aligned, causing exceptionally strong gravitational forces?
Spring tides
What are the tides that occur when the sun and moon are perpendicular, resulting in cancellation of gravitational forces?
Neap tides
What are the tides that are not as dramatically high and low, occurring during quarter moons?
Neap tides
What is the region below the storm wave base and extends out to the shelf edge break at around 200 meters depth?
Offshore zone
What is the region between the low-tide mark and the depth to which waves normally affect the sea bottom?
Shoreface
What is the depth range of the continental slope?
200 to 2000 meters
What causes exceptionally strong gravitational forces, resulting in very low tides?
Alignment of the sun and moon
What is the characteristic of diurnal tides?
The level of the water rises and falls twice a day
What is the depth range of the abyssal zone?
Below 2000 meters
What is the distinguishing feature of spring tides?
High tides during the full moon and the new moon
What causes neap tides to occur?
Perpendicular alignment of the sun and moon
What is the depth range of the neritic zone?
Up to 200 meters
What characterizes the region of the shelf between the low-tide mark and the depth to which waves normally affect the sea bottom?
Shoreface
What is the characteristic of the region between mean high water and mean low water marks of the tides?
Foreshore
What is the depth range of the hadal zone?
Greater than 5000 meters
What is the depth range of the bathyal zone?
200 to 2000 meters
What is the depth range of the shelf zone?
Up to 200 meters
Study Notes
Geological Erosional and Penecontemporaneous Structures
- Erosional structures are formed during high shear stress before bed deposition, including diastems and unconformities.
- Sole marks, such as flute casts, are preserved on the bottom surfaces of beds and can determine paleocurrent directions.
- Tool marks, like grooves and prod marks, are impressions formed by objects carried in water flow and are aligned parallel to current movement.
- Rain imprints are small craterlike pits with slightly raised rims, likely made by the impact of rain.
- Tafoni are small cave-like features in granular rock with round entrances and smooth, concave walls.
- Pot holes are circular depressions created by the abrasive action of particles swirling in fast-moving eddies.
- Penecontemporaneous structures refer to changes in the fabric and layering of recently deposited sediment.
- Three principal processes of soft sediment deformation are recognized: 1. [not specified in the text].
- The text is sourced from "Correlations 1: Basic Geology / HDAR" and various external sources like "https://www.stephanielarmagnat.com/research" and "http://www.seddepseq.co.uk/SEDIMENTOLOGY/Sedimentology_Features/ToolMarks/ToolMarks.htm".
- Erosional structures are crucial in understanding the geological history and processes of sediment deposition.
- The formation and preservation of these structures provide valuable information about past environmental conditions and depositional settings.
- The study of these structures aids in paleoenvironmental and paleogeographic reconstructions.
Sedimentary Structures in Geology
- Liquefaction occurs when saturated sediment becomes momentarily liquid due to a shock, like an earthquake
- Fluidization is the process of converting granular material from a solid to a fluid-like state
- Elutriation is used to separate particles based on size, shape, and density using a stream of gas or liquid
- Slump structures form in rapidly deposited mudstone and sandy mudstone beds due to sediment instabilities
- Slumped beds show a fold structure with the noses of the anticlines oriented downslope
- Fluidization structures encompass features that form when fluids escape following deposition, commonly found in turbiditic successions
- Dish and pillar structures are concave disruptions and vertical water escape channels formed by the upward movement of fluids
- Clastic dikes fluidization results in the formation of vertical clastic dykes
- Sand volcanoes are formed from extruded liquefied sediment brought to the surface in isolated pipes
- Load casts and flame structures are related to loading, with the latter formed by water-saturated material injection upward into soft sediment
- Ball and pillow structures are masses of clastic sediment taking the form of isolated pillows or protruding ball structures
- Diapirs form due to density differences between layers of unconsolidated sediment, resulting in large-scale movements of material
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