Geos 435, Intro to Sed/Strat 1

Sedimentary Geology

An Introduction To Sedimentology And

Stratigraphy

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Sedimentary Geology

• Sedimentology: – Processes that erode, transport, and deposit

sediments – Surface environments of sediment

accumulation– Genesis of sedimentary strata

• Sedimentary Petrology:– Physical and mineralogical properties and

origin of sediments and sedimentary rocks (SEDS)

• Stratigraphy: – Distribution, origin, and description of

sedimentary strata in space and time

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Relevance of Sedimentary Geology

• ~ 75% of the Earth's Surface materials consists of SEDS (sedimentary earth materials)

• SEDS contain the majority of Earth Resources– Oil, Natural gas, fossils fuels – minerals – water – building materials– Subsurface fluid storage

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Earth History

Largely based on the SED Record

• Climate/atmospheric dynamics through time

• Paleoceanography

• Plate tectonics and crustal dynamics

• History of Life

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Environmental/Natural Hazards

An understanding of Earth Surface Processes and Materials is fundamental to:

• Slope Stability: Landslide and catastrophic slope failure

• Fluvial processes: river basin flood hazards

• Coastal Change: erosion/flooding hazards; coastal land loss

• Ground water resources: contamination/remediation

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Sedimentary Geology is Fun!

• We see SEDS and sedimentary environments all around us

• We observe and hear about exciting surface processes almost every day,

• We are all interested in the past and future evolution of the Earth, especially the Earth’s Surface Environments (‘cuz we are Geoscientists!)

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Social Relevance of Sedimentary Geology

• Chat with one or 2 other students and list five important issues of our time

• Let’s see how sedimentary geology might address these issues

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History of Sedimentary Geology

Nick Steno: 17th century Original horizontality/Superposition

Jimmy Hutton: 18th century The geological cycle: including surface erosion and deposition/Uniformitarianism

Billy Smith: 17th/18th century Faunal Succession

d'Orbigney/Oppel: 18th/19th century

Stages, Zones, Biozones

Hank Sorby: 19th century Sedimentary Petrology/Petrography

Lot’s o Folks: 1960's - 70's Plate Tectonics

Al Scott, Bill Galloway (UT Austin);Harold Reading (Oxford Un); and many others: 1970's - 80's

Depositional Systems Analysis/ Facies Oriented Sedimentology

Exxon Research, Peter Vail: 1970's - 80's

Seismic/Sequence Stratigraphy

Jan VanHinte, and many others: 1970’s-80’s

Quantitative Basin Modeling: 1980's - 90's

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Sedimentary Geology is a "synthesis course"

It depends on other geology courses and other science disciplines:

• Physics: fluid dynamics, petrophysics, plate tectonics

• Chemistry: weathering, chemical sediments, diagenesis, sedimentary petrology

• Biology: paleoecology, sedimentary environments, the fossil record

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Sedimentary Geology provides the framework for most

other Geosciences disciplines• Structural Analysis Studies: requires an

understanding of initial sedimentary and stratigraphic context prior to deformation, etc.

• Geochemical Studies: require a stratigraphic and petrological context

• Hydrogeological Studies: depend on an understanding of the “hydrogeological matrix" both macro- and micro-scale

• Geophysical Studies: built on a stratigraphic context and requires "ground truth" based on a reasonable sedimentologic and stratigraphic framework.

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Sedimentary Geology is the Study of

Sedimentary Processes and Stratigraphic Products

(Process - Response Models) • Sedimentary Facies

– A sedimentary facies--> descriptive aspect of a rock stratigraphic unit including

• lithology, sedimentary structures, geometry, fossils, etc• Sedimentary-Depositional Environments

– Limited areas of the Earth’s surface where sediment accumulates, from mountain top to deep sea, with distinctive physical, chemical, and biological processes.

• Paleogeography– Determined from the stratigraphic record of

sedimentary facies and the time/space distribution of sedimentary-depositional environments

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Paleogeography and Earth History

The time and space mosaic of sedimentary-depositional environments reflecting the evolution of:

• Tectonic, • Climatic, • Biologic, and • Eustatic (sea level)

Dynamics through time,• either on a relative (geological) or • absolute (radiometric) time frame

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Sedimentary GeologyProvides methodology and a theoretical basis to

understand:• Stratigraphic relationships

– relative age, geometry, physical/spatial relationship of strata• Provenance

– sediment source, location, type, etc• Depositional setting, sediment dispersal patterns, and

transport mechanisms – sedimentary processes

• Paleogeography – physical geography during deposition

• Tectonic setting – Plate tectonic setting during deposition

• Diagenesis – modifications to sediment during burial and the conditions

(temperature, timing, fluid flow regime) responsible for those changes

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Using the Principles of Sedimentary Geology

We can make useful interpretations and predictions about:

• Relationships that are not available for observation (hidden from view)– Spatial distribution, properties, and geometry of

stratigraphic units and resources that are not exposed/have not been sampled

• Relationships that are not preserved in the geological record– Geological terranes eroded or tectonically removed

• Earth processes that have not yet occurred– Environmental hazards such as coastal change, flood

hazards, landslides, etc

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Class Attendance and Engagement

The emphasis in this class is on application, analysis, synthesis, and evaluation of our topic material (higher order thinking skills)

• active learning strategies (in the class room)• move beyond passive participation in the

learning experience (sitting and listening to me)• aggressively think about what you are learning• hard, time consuming work

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Class Attendance and Engagement

Active learning strategy in the class room requires some prior knowledge and comprehension of topic material in preparation for class discussions

• mastery of basic facts and vocabulary – Book and Power Point Presentations

• use class time efficiently and effectively for the development of higher level intellectual skills

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Class Attendance and Engagement

Inquiry-based portion of class meetings • a collaborative learning format • Small groups (2-3) of students working together

to process knowledge and reach conclusions to questions through thinking and discussion amongst the collaborative group

• In class group accountability

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Class Attendance and Engagement

In-class group accountability. • Each group member is accountable for the

information/conclusions reached by the group in class.

• A group member will be selected by me to present group consensus conclusions in class.

• The evaluation of the group is dependant on the individuals presentation which will assess the effectiveness of group comprehension

Geos 435, Intro to Sed/Strat 19