Post on 21-Feb-2021
transcript
GY 111: Physical Geology
UNIVERSITY OF SOUTH ALABAMA
Lecture 19: Maps, Bedding and
Attitude
Instructor: Dr. Douglas W. Haywick
GY 111: Lecture test 2 preparation
Word List for Lecture Test 2
Essay Question for Lecture Test 2
Discuss one of the following depositional environments:
Alluvial fans Beaches meandering rivers
In your answer (which must have good illustrations) make sure you discuss the major processes that control sedimentation as well as the sediment and rock types that are deposited in the environment you have selected to discuss.
GY 111: Physical Geology
UNIVERSITY OF SOUTH ALABAMA
Lecture 19: Maps, Bedding and
Attitude
Last Time…
Geological Time
A) How long is long? B) Geological time divisions
Time Eon Time
0 MA (today)
4.6 GA
Phanerozoic 550 MA to 0 MA
Proterozoic 2.5 GA to 550 Ma
Archean 4.2 Ga to 2.5 Ga
Hadean 4.6 Ga to 4.2 Ga
Geological Time
Eons: the largest division of geological time
Time Eon Era Time
0 MA (today)
4.6 GA
Phanerozoic Cenozoic 65 MA to 0 MA Mesozoic 245 MA to 65 MA Paleozoic 550 MA to 245 MA
Proterozoic Neoproterozoic 900 MA to 550 Ma Mesoproterozoic 1.6 GA to 900 MA Paleoproterozoic 2.5 GA to 1.6 GA
Archean 4.2 Ga to 2.5 Ga Hadean 4.6 Ga to 4.2 Ga
Geological Time
Periods: the most useful subdivisions of (mostly) the Phanerozoic eon
Geological Time Era Period
Cenozoic (0 to 65 Ma)
Quaternary (0 to 2 Ma)
Tertiary (2 MA to 65 Ma)
Mesozoic (65 to 251 Ma)
Cretaceous (65 to 144 Ma)
Jurassic (144 to 208 Ma)
Triassic (208 to 251 Ma)
Paleozoic (251 to 542 Ma)
Permian (251 to 286 Ma)
Pennsylvanian (286 to 320 Ma)
Mississippian (320 to 362 Ma)
Devonian (362 to 418 Ma)
Silurian(418 to 441 Ma)
Ordovician (441 to 505 Ma)
Cambrian (505 to 542 Ma)
Proterozoic (2500 Ma to 542 Ma)
Geological Time
http://www.lib.ndsu.nodak.edu/govdocs/text/greatplains/fig05.jpg
Geological Time (It’s still be revised)
http://www.quaternary.stratigraphy.org.uk/images/GeolAug.jpg
Today’s Agenda
Web notes 19 Lab Manual Chapter 5
A) Types of Geological Maps B) Stratigraphic principles C) Beds in 3D space; the problem of orientation D) Strike and Dip E) Geological maps 1: horizontal and inclined bedding
Contour maps Show topographic variations
http://reynolds.asu.edu/topo_gallery/images/hillmap.gif
http://www.3dfmaps.com/h3.gif
Groundwater maps
Show how water flows underground
Assignment 2 is due Thursday
Bathymetry maps A contour maps approach for water bodies (negative contours)
http://geopubs.wr.usgs.gov/open-file/of00-043/bathymetry/map1.jpg
Bathymetry maps Like contour maps, come in numerous scales…
http://maps.grida.no/go/graphic/world-ocean-bathymetric-map
Bathymetry maps …and formats
http://maps.grida.no/go/graphic/world-ocean-bathymetric-map
http://woodshole.er.usgs.gov/project-pages/caribbean/images/seafloor.jpg
Geology maps
Show the geology at the surface of the Earth
http://www.geo.ua.edu/Documentation/jpgs/GeoMap.jpg
Geology maps
Show the geology at the surface of the Earth
1) Age of rocks
2) types of rocks (lithology) 3) Structural features 4) bedding attitude
http://k41.pbase.com/g4/61/689761/2/64774306.3t6va19m.jpg
Geology maps
1) Age of rocks Use single (capital) letters to represent period often followed by subscripts (rock names)
Quaternary
Q
T
K
J
TR
P IP M D S O C PC
http://www.winona.edu/geology/MRW/mrwimages/geological_time.gif
Tertiary
Geology maps
2) Types of rocks Use standardized symbols and/or colors
http://www.rockware.com/rockworks/revisions/litho_plan_02.png
Geology maps
2) Types of rocks
Use standardized symbols and/or colors
http://dept.kent.edu/geology/edlab/structure/GeoMapSymbols.gif
Geology maps
3) Structural Features 4) Bedding Attitude
Use standardized symbols…
http://dept.kent.edu/geology/edlab/structure/GeoMapSymbols.gif
Notable Geology maps
http://go-passport.grolier.com/map?id=mtlr082&pid=go
World Geology (simple)
Notable Geology maps
USA Geology (simple)
Lunar Geology Near Side Far Side
Notable Geology maps
There is some truly spectacular topography on Mars (at least 25 km vertical relief)
Martian Topography
Notable Geology maps
Martian Paleogeography •geography some time is the past
Northern Mars with postulated shorelines to ancient oceans (c 2.0+ GA). Source: Perron et al. (2007)
http
://an
twrp
.gsf
c.na
sa.g
ov/a
pod/
imag
e/02
06/m
arsl
akes
_top
omap
_big
.jpg
Ma'adim Vallis, one of the largest canyons on Mars may have been carved by running water. (c 3.5+ GA).
Notable Geology maps
Stratigraphy
Stratigraphy: the study, classification and correlation of rock layers and layering
1) The principle of superposition that states in any sedimentary succession that has not been overturned, the oldest strata occur on the bottom.
Stratigraphic Principles
1) The principle of superposition that states in any sedimentary succession that has not been overturned, the oldest strata occur on the bottom.
2) The principle of original horizontality that states sedimentary layers are
originally deposited as horizontal sheets
Stratigraphic Principles
Beds in 3D Space
All sedimentary beds are initially deposited in horizontal sheets (strata). But you may not initially appreciate this with my 2D cartoons.
Beds in 3D Space
All sedimentary beds are initially deposited in horizontal sheets (strata). But you may not initially appreciate this with my 2D cartoons.
Beds in 3D Space
Horizontal bedding is easy to describe…. …. But what if the bedding is inclined
Beds in 3D Space
Horizontal bedding is easy to describe…. …. But what if the bedding is inclined
Beds in 3D Space
Inclined bedding can be oriented any amount in any direction,
And this is a problem to describe
Chalk board
Beds in 3D Space
Strike: The orientation of the inclined bed (0 to 360º) Dip: The inclination of the inclined bed (0 to 90º)
Geological Mapping Symbols
Chalk board
Geological Maps 1
Horizontal bedding leads to fairly simple geological maps.
Geological Maps 1
Horizontal bedding leads to fairly simple geological maps.
Geological Maps 1
Horizontal bedding leads to fairly simple geological maps (unless you have a lot of erosion (e.g., the Grand Canyon)
Geological Maps 1
Horizontal bedding leads to fairly simple geological maps (unless you have a lot of erosion (e.g., the Grand Canyon)
Geological Maps 1
Inclined bedding leads to more complex geological maps (but they are still interpretable if you know the rules… which you will get in GY 111L exercises)
Today’s Homework 1. Study! (lecture test 2 one week Today)
2. Assignment Three (due Thursday) 3. Mac and Cheese bonus opportunity
Next Time Quiz (fill-in-the-blank picture)
Rock Deformation
GY 111: Physical Geology
Lecture 19: Bedding/Strike and Dip
Instructor: Dr. Doug Haywick
dhaywick@southalabama.edu
This is a free open access lecture, but not for commercial purposes. For personal use only.