7. Sedimentary Environments 4

Sedimentary environments Sedimentary  environments

www.eas.purdue.edu/mesozoic/lab_03/Sedi_Environments.jpg

N. Ramos | Geology 11 Principles of Geology

Lecture Notes: Sedimentary Environments Environments

Transitional  environments

Delta - similar morphology to an alluvial fan but deposition results from sharp reduction in velocity as a stream enters standing water Topset beds - horizontal layers of smaller sediment size that form as the main channel of the river shifts elsewhere and the larger particles of the bed load are no longer deposited

load that the river is moving along which consists of larger sediments that roll along the main channel

upload.wikimedia.org/wikipedia/commons/f/fe/Delta_beds.png

Bottomset beds - created from the suspended sediment that settles out of the water as the river flows into the body of water and loses energy N. Ramos | Geology 11 Principles of Geology

Lecture Notes: Sedimentary Environments

Factors Affectin g Delta Formation and Facies • water and sediment yield of the fluvial system feeding the delta (climate, tectonics), • seasonal changes in water level and sediment yield (climate), • river-mouth processes (differences in river/sea water densities, buoyancy), • coastal configuration, mainly shelf slope and topography (delta gradient), • , , tidal range), • along shore winds and currents, and • geometry and tectonics (subsidence) of the receiving basin

N. Ramos | Geology 11 Principles of Geology

Lecture Notes: Sedimentary Environments

Transitional  environments

Delta - similar morphology to an alluvial fan but deposition results from sharp reduction in velocity as a stream enters standing water

64.19.142.12/www.pnas.org/content/104/ 43/16804/F1.medium.gif 

www.gly.uga.edu/railsback/1121DeltaTypes.jpeg N. Ramos | Geology 11 Principles of Geology

Lecture Notes: Sedimentary Environments

Transitional  environments

Delta lobe switchi ng

oceanworld.tamu.edu/resources/oceanography-book/Images/mississippi-delta.jpg N. Ramos | Geology 11 Principles of Geology

Lecture Notes: Sedimentary Environments

North Antrim coast, Ireland www.irishviews.com/north-antrim-coast2.jpg

Coastal processes

Waves wind waves or wind-generated waves surface waves that occur on the free surface of oceans, seas, lakes, ,

sea waves - directly generated and affected by the local winds, swell w aves - after the wind ceases to blow development of the wave system as it moves away from the source and amount of energy transfer depends on:

(1) wind velocity (2) duration of t he wind (3) distance over whi ch the wind b lows, know n as the fetch 64.19.142.13/upload.wikimedia.org/wikipedia/commons/thumb/4/45/Waves_in_pacifica_1.jpg/800px-Waves_in_pacifica_1.jpg N. Ramos | Geology 11 Principles of Geology

Lecture Notes: Sedimentary Environments

Coastal processes

Waves

Wave height , H vertical distance between wave crest and wave trough

Wavelength, L Wave period, T the time between the passing of two successive crests

horizontal distance between adjacent wave crests or troughs

flowsurfmag.com/wordpress/wp-content/uploads/2010/12/wavegraphcrop_2007523204144.jpg Lecture Notes: Sedimentary Environments

N. Ramos | Geology 11 Principles of Geology

Coastal processes

Wave shoaling the effect by wh ich sur face waves entering shallower water increase in wave height (~twice the amplit ude)

V - wave velocity g - gravity d - water depth

ericbeiers.com/archive/sediment/slide0047_image060.jpg 64.19.142.13/upload.wikimedia.org/wikipedia/commons/2/2d/Propagation_du_tsunami_en_profondeur_variable.gif  N. Ramos | Geology 11 Principles of Geology

Lecture Notes: Sedimentary Environments

Coastal processes

change in direction of a wave (bending) due to a change in i ts s peed

www.cnsm.csulb.edu/departments/geology/people/bperry/geology303/_derived/geol303text.html_txt_142BluffCoveWaveRefractionM ar05S.gif  N. Ramos | Geology 11 Principles of Geology

Lecture Notes: Sedimentary Environments

Coastal processes

change in direction of a wave (bending) due to a change in i ts s peed

elearning.stkc.go.th/lms/html/earth_scienc e/LOcanada6/606/images/6_6_1.jpg

102supercoastswiki.wikispaces.com/file/view/headlands_and_bays7.jpg/232666296/ headlands_and_bays7.jpg www.cnsm.csulb.edu/departments/geology/people/bperry/geology303/_derived/geol30 3text.html_txt_142BluffCoveWaveRefractionMar05S.gif  N. Ramos | Geology 11 Principles of Geology

Lecture Notes: Sedimentary Environments

Coastal processes

www.geol.ucsb.edu/faculty/sylvester/UCSB_Beaches/groins2.jpg N. Ramos | Geology 11 Principles of Geology

Lecture Notes: Sedimentary Environments

Coastal processes

Longshore current an ocean current that fl ows parallel to and close to t he shore

spinner.cofc.edu/CGOInquiry/Graphics/longshore%20drift.gif 

elearning.stkc.go.th/lms/html/earth_science/LOcanada6/ 606/images/6_6_2.jpg www.geol.ucsb.edu/faculty/sylvester/UCSB_Beaches/groins2.jpg N. Ramos | Geology 11 Principles of Geology

Lecture Notes: Sedimentary Environments

Coastal processes

en.wikipedia.org/wiki/Rip_currents Lecture Notes: Sedimentary Environments

N. Ramos | Geology 11 Principles of Geology

Coastal processes

commonly referred to by the misnomer , is a strong channel of water flowing seaward from near the shore, typically t hrough th e surf line typi cal flow is at 0.5 m/s and can be as fast as 2.5 m/s

en.wikipedia.org/wiki/Rip_currents N. Ramos | Geology 11 Principles of Geology

Lecture Notes: Sedimentary Environments

Coastal processes

Tsunami a series of water waves caused by the displ acement of a large volum e of a body o f w ater, usually an ocean, though it can occur in large lakes has distinc tly different characteristic s than w ind-generated waves: (1) enormous w avelength (100 to 200 km) but (2) extremely lo w wave height in deep water (~1 m) (3) long wave period (10 to 30 mins) (4) travels w ith remarkable veloci ty (100~700 km/hr) JR-Maglev (581 km/h)

Bluebird-Proteus CN7 (644.96 km/hr)

en.wikipedia.org/wiki/File:JRen.wikipedia.org/wiki/File:JR -Maglev Maglev--MLX01 MLX01--2.jpg

wwwdelivery.superstock.com/WI/223/1895/Preview Comp/SuperStock_1895-20912.jpg Lecture Notes: Sedimentary Environments

N. Ramos | Geology 11 Principles of Geology

Coastal processes

Storm surge

www.civildefence.govt.nz/memwebsite07.nsf/Files/Photo_library_floods2007/$file/northland%20coastal%20surge.jpg N. Ramos | Geology 11 Principles of Geology

Lecture Notes: Sedimentary Environments

Coastal processes

Storm surge an offshore rise of water associated with a low pressure weather system, typically tropic al cyclones caused primarily by high w inds pushi ng on the ocean's surface, causing the water to pi le up hig her than the ordinary sea level 64.19.142.10/upload.wikimedia.org/wikipedia/commons/thumb/4/42/Storm_surge_graphic.svg/352pxStorm_surge_graphic.svg.png

64.19.142.11/upload.wikimedia.org/wikipedia/commons/thumb/3/32/Surge-en.svg/800px-Surge-en.svg.png www.civildefence.govt.nz/memwebsite07.nsf/Files/Photo_library_floods2007/$file/northland%20coastal%20surge.jpg Lecture Notes: Sedimentary Environments

N. Ramos | Geology 11 Principles of Geology

Shoreline processes

Seiche Swiss French: ‘to sway back and forth’

a standing w ave in an enclos ed or partially encl osed body of water (e.g., lakes, reservoirs, swimmi ng pools , bays, harbors, seas)

en.wikipedia.org/wiki/Standing_wave N. Ramos | Geology 11 Principles of Geology

Lecture Notes: Sedimentary Environments

Coastal processes

Tides rise and fall of sea levels caused by t he combined effects of the gravitational forces exerted by the Moon and the Sun and the rotation o f the Earth semidiurnal - two high tides and two low tides each day diurnal - one high and one low tide each day

64.19.142.13/upload.wikimedia.org/wikipedia/en/thumb/0/00/Tide_type.gif/433px-Tide_type.gif  Lecture Notes: Sedimentary Environments

N. Ramos | Geology 11 Principles of Geology

Coastal processes and landforms

Marine deposition - sediment transport and depositi on by wave currents

Marine erosi on - corrosion, corrasion or abrasion, attrition, hydraulic action, and shock pressure of breaking w aves

64.19.142.11/upload.wikimedia.org/wikipedia/commons/thumb/4/48/Accreting_coast_Image6.svg/800px Accreting_coast_Image6.svg.png N. Ramos | Geology 11 Principles of Geology

Lecture Notes: Sedimentary Environments

Marine depositional features

Spit - a type of bar or beach, in whi ch one end connects t o land and the other end extends i nto th e sea - develops by the process of longshore drift  Arab at spit, Ukr aine length: 110 km

www.rower.fan.pl/2007_Stepy/EN/kerchscholkinoleninoarabatspi thenichevsk.jpg

ljplus.ru/img4/m/e/metelik/arabat.jpg Lecture Notes: Sedimentary Environments

N. Ramos | Geology 11 Principles of Geology

Marine depositional features

Tombolo - a narrow piece of land such as a spit or bar that connects an island to the mainland - formed by wave refraction tombolo connecting St Ninian's Isle with the Shetland Mainland, UK

Karystos, Greece

upload.wikimedia.org/wikipedia/commons/thumb/3/33/Tombolo_  St_Ninians_5940.JPG/800px-Tombolo_St_Ninians_5940.JPG

upload.wikimedia.org/wikipedia/commons/thumb/4/4c/Tombolo_  Paximadhi_Eboea.jpg/800px-Tombolo_Paximadhi_Eboea.jpg

N. Ramos | Geology 11 Principles of Geology

Lecture Notes: Sedimentary Environments

Marine depositional features - relatively narrow strip s of sand that parallel the mainland coast - usually occur in chains, consisting of anything from a few islands to more than a do zen - general requirements for formation:

- theories of formation: (1) offshor e bar  (2) spit accretion (3) subm ergence (e.g. Mississi ppi River delta) 64.19.142.12/upload.wikimedia.org/wikipedia/commons/f/f3/Baie_de_Mobile.jpg_hyuncompressed N. Ramos | Geology 11 Principles of Geology

Lecture Notes: Sedimentary Environments

Marine depositional features

Barrier beaches/islands/chains - relatively narrow strip s of sand that parallel the mainland coast - usually occur in chains, consisting of anything from a few islands to more than a do zen

spinner.cofc.edu/CGOInquiry/Graphics/barris.jpg

N. Ramos | Geology 11 Principles of Geology

thewatchers.adorraeli.com/wp-content/uploads/2011/04/barrierisland.jpg

Lecture Notes: Sedimentary Environments

Coastal processes

Marine deposition - sediment transport and depositi on by wave currents

Marine erosi on - corrosion, corrasion or abrasion, attrition, hydraulic action, and shock pressure of breaking w aves

64.19.142.11/upload.wikimedia.org/wikipedia/commons/thumb/4/48/Accreting_coast_Image6.svg/800px Accreting_coast_Image6.svg.png Lecture Notes: Sedimentary Environments

N. Ramos | Geology 11 Principles of Geology

Marine erosional features

Sea cliff s - vertical or near vertical rock exposures formed by w ave erosion and weathering

Kalaupapa, USA (HI) height: 1010 m

www.fodors.com/images/experiences/Molokai-Kalaupapacliffs.jpg

N. Ramos | Geology 11 Principles of Geology

Matengai, Japan height: 257 m

 

64.19.142.12/upload.wikimedia.org/wikipedia/commons/6/64/ Matengai_of_Kuniga_Coast_in_Oki_Island_Shimane_pref600 .jpg

Lecture Notes: Sedimentary Environments

Marine erosional features

Wave-cut/shore platfo rm - a narrow, flat area often found at the base of a sea cliff or along the shoreline of a lake, bay, or sea that was created by th e acti on of w aves

64.19.142.11/upload.wikimedia.org/wikiped ia/commons/a/a1/Wave_cut_platform.png

www.stacey.peak-media.co.uk/purbeck/Kimmeridge/800wavevcut2.jpg

Lecture Notes: Sedimentary Environments

N. Ramos | Geology 11 Principles of Geology

Marine erosional features

Coves/bays/bights - area of water mostly surro unded by land often formed by differential erosion McWay Cove, USA (CA)

Bay of Bengal area: 2,172,000 km²

upload.wikimedia.org/wikipedia/commons/thumb/8/89/McWay_cov e_1.jpg/800px-McWay_cove_1.jpg

upload.wikimedia.org/wikipedia/commons/thumb/0/0e/Bay_of_  Bengal_map.png/588px-Bay_of_Bengal_map.png N. Ramos | Geology 11 Principles of Geology

Lecture Notes: Sedimentary Environments

Marine erosional features

Headland/promontory/cape - a point of land, usually high and often wit h a sheer drop, that extends out into a body of w ater 

Koko Head, USA (HI)

Cape Engaño, Philip pines

upload.wikimedia.org/wikipedia/commons/thumb/0/00/Oahu_fro m_air2.jpg/800px-Oahu_from_air2.jpg

N. Ramos | Geology 11 Principles of Geology

farm4.static.flickr.com/3013/2552847162_ddddcb28f2.jpg

Lecture Notes: Sedimentary Environments

Marine erosional features

Headland/promontory/cape - a point of land, usually high and often wit h a sheer drop, that extends out into a body of w ater 

cgz.e2bn.net/e2bn/leas/c99/schools/cgz/accounts/staff/rchambers/GeoBytes%20GCSE%20Blog%20Resources/Images/Coasts/Hea dland_Erosion.gif  N. Ramos | Geology 11 Principles of Geology

Lecture Notes: Sedimentary Environments

Marine erosional features

Headland/promontory/cape - a point of land, usually high and often wit h a sheer drop, that extends out into a body of w ater   Arc h of Cabo San Lucas, Mexico

sea cave

upload.wikimedia.org/wikipedia/commons/c/cd/CaboSanLucasLa ndsEnd.JPG

upload.wikimedia.org/wikipedia/en/thumb/e/e4/Seacave_fault.jp g/512px-Seacave_fault.jpg Lecture Notes: Sedimentary Environments

N. Ramos | Geology 11 Principles of Geology

Marine erosional features: Headlands

stacks/stumps at Torre Sant'Andrea, Italy

upload.wikimedia.org/wikipedia/commons/thumb/8/85/Torre_San t%27Andrea.jpg/800px-Torre_Sant%27Andrea.jpg

Old Man of Hoy, Scotland

upload.wikimedia.org/wikipedia/commons/6/63/Old_man_of_ho y2.jpg

skerries which are part of the Åland Islands, Finland

upload.wikimedia.org/wikipedia/commons/thumb/0/03/Archipelago062009.jpg/800px-Archipelago062009.jpg N. Ramos | Geology 11 Principles of Geology

Lecture Notes: Sedimentary Environments

Coastal features

Coral reefs Great Barrier reef

Moorea, French Polynesia

4.bp.blogspot.com/_EH8GsUqg6-U/R1OFFQJ5SI/AAAAAAAAAKE/tyAwfy-xwPY/s1600-R/fringe+reef+2.bmp

Tokelau, New Zealand

www.bayactionplan.com/wordpress/wpcontent/uploads/2011/02/great-barrier-reef.jpg

upload.wikimedia.org/wikipedia/commons/6/6b/At afutrim.jpg Lecture Notes: Sedimentary Environments

N. Ramos | Geology 11 Principles of Geology

TERRESTRIAL SEDIMENTARY ENVIRONMENTS

 ALLUVIAL FAN Rock Type

FLUVIAL

Breccia, conglomerate, arkose,

Conglomerate sandstone siltstone, shale

Compositi on

Terrigenous

Terrigenous

Color

Brown or red

Brown or red

Grain Size

Clay to gravel

Clay to gravel (Fining upward)

Grain Shape

Angular

Rounded to angular

Sorting

Poor

Inorganic Sedimentary

Variable

LACUSTRINE

DESERT (DUNES)

Siltstone, Quartz arenite (sandstone) shale, limestone, or gypsum or evaporites (gypsum) Terrigenous, carbonate, or evaporite

Terrigenous or evaporite

Black, gray,

Clay to silt or sand (Coarsening upward)

Sand

Clay to silt

---

Variable

graded bedding

cross-bedding, lamination, cross-bedding, graded bedding, graded bedding, tool marks mudcracks, raindrop prints Tracks, trails, bu rr ow s

Fossils

---

Rare freshwater shells, shells, bones, bones,

Terrigenous

Yellow, red,

Asymmetrical ripples,

---

Peat, coal, black shale, siltstone

Black, brown,

Cross-bedding

Organic or Bi ogen ic Sedimentary Structures

PALUDAL

Symmetrical ripples,

Tracks, trails, burrows, r ar e s tr om ato li tes

Freshwater shells, fish, bones, plant fragments

Rounded

Good

---

Variable

Cross-bedding

Laminated to massive

Tracks, trails

---

Root marks, b ur ro ws

Plant fossils, rare freshwater  plant fragments

TRANSITIONAL SEDIMENTARY ENVIRONMENTS

DELTA

BARRIER BEACH

Rock Type

Sandstone, siltstone, shale, coal

Quartz arenite, coquina

Compositi on

Terrigenous

Terrigenous or carbonate

Color

Brown, black, gray, green, re

Grain Size

Clay to sand (Coarsening upward)

Grain Shape

Sorting

---

Poor

LAGOON

TIDAL FLAT

Siltstone, shale, limestone, oolitic limestone or gypsum

Terrigenous, carbonate, or evaporite

Siltstone, shale, calcilutite, dolostone or gypsum Terrigenous, carbonate, or evaporite

White to tan

Dark gray to black

Sand

Clay to silt

Clay to silt

---

---

Rounded to angular

Good

Gray, brown, tan

Poor

Variable

Inor a nic i Sedimentary Structures

Cross-beddin i , graded bedding

Cross-beddin i , symmetrical ripples

Lamination i i ,rii les l , cross-bedding

Lamination i i ,mudcracks , ripples, cross-bedding

Organic or Biogenic Sedimentary Structures

Trails, burrows

Tracks, trails, burrows

Trails, burrows

Stromatolites, trails, tracks, burrows

Fossils

Plant fragments, shells

Marine shells

Marine shells

Marine shells

MARINE SEDIMENTARY ENVIRONMENTS

REEF

CONTINENTAL SHEL F

CONTINENTAL SL OPE & RISE AB YSSAL PL AIN

Rock Type

Fossiliferous limestone

Sandstone, shale, siltstone, fossiliferous limestone, oolitic limestone

Litharenite, siltstone, and shale (or limestone)

Shale, chert, micrite, chalk, diatomite

Composition

Carbonate

Terrigenous or carbonate

Terrigenous or carbonate

Terrigenous or carbonate

Color

Gray to white

Gray to brown

Grain Size

Variable, frameworks, few to no grains

Clay to sand

Gray, green, brown

Clay

Grain Shape

---

Sorting

---

Poor to good

Inorganic Sedimentary

---

Lamination, cross-bedding

Graded bedding, cross-bedding, lamination, flute marks, tool marks i i

Organic or Biogenic Sedimentary Structures

---

Trails, burrows

Trails, burrows

Fossils

Corals, marine shells

---

Marine shells

Black, white red

---

Poor

Marine shells, rare plant fragments

---

Good Lamination

Trails, burrows

Marine shells (mostly microscopic)