Sedimentary Rocks (Part 1 - Sediments and Sedimentary Cycle) Flashcards
Pieces of broken down, pre-existing rocks at or near the Earth’s surface.
Sediments
Rocks that are made-up of lithified sediments
Sedimentary Rocks
A sub-branch of Petrology that focuses on the composition, characteristics and origins of sedimentary rocks.
Sedimentary Petrology
A simple model of the processes responsible for the production of sediments and sedimentary rocks.
Sedimentary Cycle
Sedimentary Rocks’ Sequence of Formation
(WETDD)
Weathering
Erosion
Transport
Deposition
Diagenesis
The process that breaks down rocks into sediments.
Weathering
The physical removal of material by mobile agents such as water, wind, ice or gravity.
Erosion
The transfer of rock and soil downslope under the influence of gravity.
Mass Wasting
3 Factors that affect Weathering
(CRD)
Climate - temperature and moisture
Rock characteristics - Chemical traits of rocks
Differential weathering - Unequal weathering
A mixture of minerals, organic matter, water and air.
Soil
The layer of rock fragments produced by weathering.
Regolith
The study of physical and chemical properties soils and its formation.
Pedology
5 Controls of Soil Formation
(PTCOT)
Parent Material - source of weathered mineral matter
Time - length of time that processes have been operating
Climate - Climatic elements
Organisms - Organisms present
Topography - variations in topography
Zones of soil with varying composition, texture and structure found at different depths.
Horizons
A vertical section of all the soil horizons.
Soil Profile
Washing out of fine soil components.
Eluviation
Depletion of soluble materials from upper horizons.
Leaching
Constitutes the O and A horizon
Topsoil
Consists largely of organic material.
O Horizon
The zone beneath the O Horizon that is largely mineral matter, with biological activity is high and humus generally present at up to 30 percent in some instances.
A Horizon
A light colored layer that contains little organic material.
E Horizon
Also known as the Zone of eluvation
E Horizon
The zone of accumulation where much of the material removed from the E Horizon by eluviation is deposited.
B Horizon
Also known as the Subsoil
B Horizon
Also known as the True Soil (what horizons are in it)
Solum (O,A,E and B)
The layer of partially altered parent material
C Horizon
The unweathered parent material
R Horizon
Explain the Soil Profile
kaya mo yan boss ikaw pa
A system of soil classification based on the physical and chemical properties of the soil profile.
Soil Taxonomy
12 Soil Orders and its Characteristics
(AAAEGHIMOSUV) or (HEAVASUMAGOI)
Alfisol - High nutrient
Andisol - Volcanic
Aridosol - Desert
Entisol - New
Gelisol - Permafrost
Histosol - Organic
Inceptisol - Young
Mollisol - Prairie
Oxisol - Tropical forest
Spodosol - Conifer forest
Ultisol - Low-nutrient
Vertisol - Swelling clay
The physical breakdown (me) and the chemical alteration (decomposition) of rocks at or near Earth’s surface.
Weathering
Explain the Difference between Mechanical and Chemical Weathering
Mechanical - physical breakdown
Chemical Weathering - chemical breakdown
5 Types of Physical Weathering
(FISSB)
Frost Wedging
Salt crystal growth
Sheeting or Unloading
Biological actions
Intrusions
The freeze-thaw action of water trapped within fractures of rocks that cause the expansion and contraction which would eventually disintegrate rocks.
Frost wedging
How many % does frost wedging expands when turned into ice?
9%
Frost wedging that expands horizontally
Frost Wedging
Frost Wedging that expands vertically
Frost Heaving
A mode of weathering near coastlines where salt from seawater accumulate and grow through cracks of rocks and fracture them while growing.
Salt crystal growth
Rocks that are originally covered and are then exposed are relieved from pressure, causing an unloading action and expansion.
Sheeting or Unloading
What texture does sheeting produce?
Onion Texture
Organisms, such as plants, can burrow their roots through cracks which breaks down the rocks into
pieces.
Biological Actions
The intrusions from beneath the surface induce pressure from below, fracturing the rock mass on the surface.
Intrusions
3 Types of Chemical Weathering
Solution
Hydrolysis
Oxidation
A solution mixture of reactive components specific to rocks.
Solution
Chemical breakdown of minerals in rocks due to addition of water.
Hydrolysis
Chemical breakdown of minerals in rocks due to exposure to oxygen.
Oxidation
The removal of materials or sediments by mobile agents such as water, wind, ice or humans.
Erosion
4 Transport Media
Air
Water
Ice
Gravity
of the 4 Transport Media’s, which one is the strongest agent?
Ice
of the 4 Transport Media’s, which one is the most effective agent?
Water
2 Modes of Transport
Bedload and Suspended Load
Sediments rolling along the surface of the bed.
Rolling (nagulong)
A series of jumping movement of sediments.
Saltation (natalon)
Sediments suspended in the transporting media.
Suspension (lumilipad)
Glaciers grind against rock as they move, producing
fine particles under them known as what?
Rock Flour
The volume of void space in a sedimentary rock
Porosity
Porosity associated with the original depositional texture of the sediment.
Primary Porosity
Porosity that developed after deposition and burial of
the sediment in the sedimentary basin.
Secondary Porosity
The measure of how much water can move through pore spaces which also describes how water easily flows.
Permeability
A property of curve being tortuous, or twisted, having many turns.
Tortuosity
Occurs when transportation ceases and sediments accumulate on Earth’s surface by collective deposition processes.
Deposition
Encompasses a suite of low temperature processes that affect sediments after their accumulation, typically after burial.
Diagenesis
A process of lithification that results from the expulsion of intergranular fluids caused by increases in
confining pressure during progressively deeper burial.
Compaction
A process of lithification that occurs when subsurface fluids precipitate minerals in the spaces between
grains that bind or cement grains to one another.
Cementation
5 Major Cements in Sedimentary Rocks
Silica Minerals - quartz; occurs chiefly in the form of syntaxial quartz
Carbonate Minerals - sandstones and gravelstones;
Iron oxides and hydroxides - hematite, geothite and limonite
Feldspars - arkosic sandstones and gravelstones
Clay minerals - strongly controlled by temp and pH
Most abundant carbonate mineral cement
Calcite
Early, shallow diagenesis that occurs shortly after burial
Eodiaganesis
Later, deeper diagenesis
Mesodiagenesis
Still later, shallow diagenesis that occurs as sedimentary rocks approach the surface due to erosion.
Telodiagenesis
