Eart 120 - Spring 08Sedimentology & Stratigraphy

1. Course Logistics• Lectures• Labs• Field trips/ Project Reports

2. Lect 1 - Introduction• Course objectives• Applications

3. Lect 2 - Weathering

Course Logistics• Lectures; 3:30-5:15 Monday, Wednesday• Weekly Reading Assignments:

1. Sedimentary Geology, Prothero & Schwab2. Research Articles (PDF files on the website)

• Website http://ic.ucsc.edu/~jzachos/eart120/

• Basis for Your Evaluation– Mid-term 25%– Final 30%– Field Trip Reports/Abstracts 40%– Problem Sets/Quizzes 5%

Course LogisticsLabs• Labs meet weekly in D236.• EART 120L-01: Tu 8:30 – 11:00 A.M.• EART 120L-02: Th 12:30 – 3:30 P.M.

Week of Main Topic31 – Mar Introduction7 – Apr Grain Size Analysis14– Apr Clastic Sed Rocks21 – Apr Paleocurrent Analysis28 – April Carbonate Sed Rocks5 – May Clastic Petrography12 – May Carbonate Petrography19 – May Correlation & Facies Analysis26 – May Field Site Presentations

*Lab attendance is required

Course LogisticsSaturday Field Trips

Date Location#1 April 5 TRIP: Main Beach: Self Guided

#2 April 19 TRIP: San Benito County

#3 May 3 TRIP: Pebble Beach State Beach

#4 May 17 TRIP: Montara State Beach

*Depart from campus transportation center (near TAPS) PROMPTLY at 8am. In most cases we will return by 5:30 pm

Items required:• Hand lens, grain size card, field note bookhttp://www.forestry-suppliers.com/product_pages/View_Catalog_Page.asp?mi=5740

Why Study Sediments andSedimentary Processes?

Applications:1. Earth History2. Economic Resources3. Environmental Engineering

Drill Ship “Resolution”

Drill sites

Archive - Ocean & Earth HistorySediment composition (lithology, fossils, chemistry) - detailed

information (evidence) about Earth’s past– climate ~ temperature, circulation– ocean chemistry– ecology and evolution

Insight into the dynamics of environmental processes

~90 Mya “Black” shales

Applications

1. Reconstructing Earth History– Paleogeography -configuration of land

masses– Paleoclimatology (greenhouse /ice-house)– Paleoceanography, Paleoecology,

Paleobiology - Oceanic/terrestrialenvironments, evolution, and ecosystems -

– Tectonic processes (mountain building)

Natural Resources:Lime (Cement)

trestle

Limestone Kilns

UCSC 1853

The Village Quarry

Natural resources - fossil fuels• Oil and gas - marine sediments deposited millions of years ago

– continental margins• basins• river deltas

• Coal - continental sediments– Swamps, bogs– Coastal wetlands

Seismic Section - Reef (Papua-New Guinea)• Depositional facies, 3-d geometry, ages, etc.

– Litho-, seismic-, chronostratigraphy

Applications2. Recovery of Economic Resources

– Limestone, phosphorites, gypsum, salt– Oil, gas, & coal– Uranium and other ores– Ground water

• Aquifers

Poorly indurated marineshale, siltstone, sandstone

• Monterey Formation• Pico Formation

Applications• Geologic Hazards

La Conchita

19952005

Applications

3. Environmental/Civil Engineering– Coastal Erosion– Groundwater Contamination– Geologic Hazards

Sediments/ Sedimentary Rocks

“Result from the accumulation and consolidation of sediment”• Sediments/sedimentary rocks have a history

– Chemical, Physical, Fossil characteristics provideinformation about the history

1. Depositional environment– Marine vs. Terrestrial

2. Climate3. Sediment Source &Transport4. Time (when the sediments were deposited)5. Tectonics

Description and Interpretation

Sediments/ Sedimentary Rocks

• angular unconformity in New York

Hutton’s Unconformity

unconformity at Siccar Point (www.albion.edu/geology/ gif/uk/uk_25.gif).

Principle of Uniformitarism

- processes that shaped Earth throughgeologic time were the same as those

shaping it today

James Hutton (1726 -1797)

Present is the key to the past

Sediments/SedimentaryRocks/Stratigraphy

Description1. Color

• Primary, secondary2. Composition

• Minerals (%, size)3. Texture

• Clastic vs. crystalline• Grain size, shape, orientation

4. Sedimentary structures5. Fossil Content6. Geometry

• sedimentary bed in relation to over andunderlying beds

Sediments/SedimentaryRocks/StratigraphyInterpretation

1. Stratigraphy• When was the rock deposited

2. Provenance• What was the source of the sediments

3. Dispersal• How were those sediments delivered

4. Transporting agent• River, wind, ice, etc.

5. Paleogeography• Where was the rock deposited

6. Diagenesis• How was the rock altered after deposition?

Sediments/SedimentaryRocks/StratigraphyCategories (4)

1. Detrital (lithogeneous)• Weathered rock fragments (clasts)• Siliciclastic

2. Biogenic• Biogenic precipitates (& settling)• Fossil shells, organic matter

3. Chemical• Abiogenic precipitates• evaporites

4. Others• Pyroclastics (Volcanic ash)• tektites

Geologic Time

Source: paleo.cortland.edu/.../Timescale/Timescale3.GI

Date Lecture Topic Reading *

T

3--Apr Introduction -Development and Applications

Weathering, Sedimentary textures.

Chap.1

Chap 2

Th 5-Apr Fluid Flow, Mechanics of Sediment Transport and

Deposition

Chap 3

Sat 7-Apr FIELD TRIP - Main Beach

T 10-Apr Sedimentary Structures Chap. 4

Th 12-Apr Composition, Classification, of Sedimentary Rocks Chap 5, 6

T 17-Apr Terrestrial Sedimentary Environments

Siliciclastic – Fluvial Systems

Chap. 8

Th 19Apr Siliciclastic - Coastal Depositional Environments Chap. 9.

Sat 21-Apr FIELD TRIP – San Benito

T 24-Apr Siliciclastic - Deep Sea Depositional Environments Chap 10

Th 26-Apr Carbonate Rocks Chap. 11

T 1-May Carbonate Environments Chap. 12

Th 3-May Other Biogenic Sedimentary Rocks Chap.13

Sat 5-May FIELD TRIP - Pigeon Poin t

T 9-May MID-TERM

T 9-May MID-TERM

Th 11-May Chemical Sedimentary Rocks Chap 14

T 15-May Chronostratigraphy, Lithostratigraphy & Facies Analysis Chap 15

Th 17-May Biostratigraphy Chap.16

Sat 19-May FIELD TRIP - Montara State Beach

T 22-May Logging, Physical, Chemical Properties Chap 17

Th 24-May Chemostratigraphy (O, C, Sr isotopes) Handouts

T 29-May Chemostratigraphy (cont.) Handouts

Th 31-May Radiometric Dating & Magneto stratigraphy Chap.18

T 5-June Seismic & Sequence Stratigraphy-Rocks in Space & Time Chap. 19

Th 7-June Sediments and the Environment

Tue 13-June

8-11 AM

FINAL EXAM 8-11 AM

D236

nannofossil ooze

dusky-red clay

nannofossil ooze

Walvis Ridge, South Atlantic