Sedimentary Rock Flashcards
(64 cards)
<p>Sedimentary Rock</p>
<p>Product of chemical/mechanical weathering</p>
<p>Continental Environment</p>
dominated by stream erosion and deposition
<p>Mechanical Weathering</p>
<p>broken down into smaller pieces,
| Increases surface area for chemical weathering attack</p>
<p>Frost Wedging</p>
<p>Water Freezes in Cracks</p>
<p>Root Wedging</p>
<p>plants grow into fractures</p>
<p>Burrowing animals</p>
<p>move fresh materials to surface</p>
<p>Rock Blasting</p>
<p>Human inmpact</p>
<p>Salt Crystal Growth</p>
<p>sea spray/salty groundwater penetrates crevices and pore spaces, evaporating to form salt crystals enlarging crevices</p>
<p>Sheeting Unloading</p>
<p>•Large masses of igneous rock are exposed by erosion and concentric slabs break loose due to release of confining pressure</p>
<p>Exfoliation Dome</p>
<p>formed after continued weathering causes slabs to separate and fall off</p>
<p>Detrital Rocks</p>
<p>Transported Sediment as Solid Particles</p>
<p>Detrital Cheif Consitituents (4)</p>
<p>clay, quartz, feldspar, micas</p>
<p>Evaporites</p>
<p>triggers deposition of chemical precipitates </p>
<p>Chemical Rocks</p>
<p>consist of precipitated material once in solution</p>
<p>Evaporite Examples</p>
<p>rock salt, rock gypsum</p>
<p>Natural Cements</p>
<p>Calcite, silica, iron oxide</p>
<p>Lithification</p>
<p>Sediments transformed into solid rock by compaction and cemenation</p>
<p>Diagenesis</p>
<p>Chemical. physical biological changes after seediment deposit
</p>
<p>Bowen's Reaction Series</p>
<p>Silicate minerals weather in the same order as crystallization</p>
<p>Speroidal Weathering</p>
<p></p>
<p>Oxidation</p>
(2)
<p>Rusting of iron rich materials for iron oxide
| -slow in dry environments, faster reaction in water</p>
<p>Hydrolysis</p>
<p>Oxidation can only occur after; iron freed from silicate structure</p>
<p>Dissolution</p>
<p>Certain Minerals (halite) dissolve in water</p>
<p>Chemical Weathering</p>
<p>small amount of acid in water increases corrosive force of water, causing dissolution. </p>
sediment
fragmented material
Climate Effect on Weathering (Temperature + Precipitation) 3
Frequency of freeze-thaw Moisture available for dissolution Conditions favoring vegetation growth
Detrital Identification
Particle Size
Chemical Identification
Texture
Stages of Coal Formation
1. Plant material 2. Peat 3. Lignite 4. Bituminous 5. Anthracite
Coal
composed of organic materials unlike other rocks
Geographic Setting
Determines sediments that accumulate (grain size/shape)
