GY 402: Sedimentary Petrology - usouthal.edu

UNIVERSITY O

GY 402: Sedime

Lectu
Mature Siliciclast

Ins

OF SOUTH ALABAMA

entary Petrology

ure 11:
tic Environments

structor: Dr. Douglas W. Haywick

Last T

1. Recap major types of sed
2. Recap important grain pa
3. Cement versus matrix
4. Mature sediment/sedimen

Time

diment & sedimentary rock
arameters

ntary rocks

Major Sediment

Siliciclastic
Volcaniclastic
Carbonates (evaporites/ch

tary Rock Types

hemical, non-skeletal, skeletal)

Siliciclastic Sed

Q

F

Source: Blatt, H., Middleton, G and Murray, R., 1980: Origin of

dimentary Rocks

“Mature” rocks

(mineralogically stable)
Enriched in quartz and

clay minerals

R

f Sedimentary Rocks. Prentice Hill, 782 p.

Important P

Grain ro

Immature

Increasing transp

Parameters

ounding

Mature

port distance

Important P

Grain s

Low energy

increasing energy

Parameters

sorting

High energy

y of deposition

Important P

Grain

High energy

Decreasing energy

Parameters

n size

Low energy

y of deposition

Mature Siliciclas

Quartz-rich (quartz arenites)
Generally well rounded grain
Poorly sorted to well sorted
Gravel to clay sized grains

stic Petrography

ns

XN 250 m

Matrix vers

Matrix: fine-grained* materia
larger particles. Generally app
between grains

Cement: a chemical precipitat
pore-water long after depositio

sus Cement

al deposited simultaneously with
pears as darker-coloured detritus

te between grains formed from
on.

Matrix vers

Matrix

 Heterogeneous
 Chemically impure
 Drapes over grains*
 Predates cements
 Generally dark in color*

* Can be c

sus Cement

Cement

 Homogeneous
 Chemically pure

 Lines pores*
 Specific fabrics

 Multiphased
 Zoned

confusing

Hand specimens

Mature siliciclastic sandstones
(quartz arenite)

Quartz and chalcedony cement

Liesengang banding, clay and iron
oxide cement

4 cm Limonite cement

Thin-section Pho

Quartz (overg

ppl
Quartz overgrowth cem

otomicrographs

growth) cement

xn 125 m
ment

Today’s

1. Factors promoting
2. Beach profiles
3. Beach facies & sed

s Agenda

beach development
dimentary sections

Factors controlling

beach development

Factors controlling

Steady supply of sand to the s
longshore drift

beach development

shoreline, by river, delta or

Factors controlling

Steady supply of sand to the s
longshore drift
Wave dominated setting (med
best; low tidal energy necessary

beach development

shoreline, by river, delta or

dium to high wave energy is
y)

Factors controlling

Steady supply of sand to the s
longshore drift
Wave dominated setting (med
best; low tidal energy necessary
Stable, low gradient coastal pl
gradient

beach development

shoreline, by river, delta or

dium to high wave energy is
y)
lan and continental shelf

Factors controlling

Steady supply of sand to the s
longshore drift
Wave dominated setting (med
best; low tidal energy necessary
Stable, low gradient coastal pl
gradient

32,000 km of shoreline meet the
beaches are along the US eastern

beach development

shoreline, by river, delta or

dium to high wave energy is
y)
lan and continental shelf

ese requirements; best studied
n and Gulf coasts

Wave a

Wind
Orbicular m

From Komar, P.D., 1998. Beach Processes and Sedimentatio

action

motion

on. Prentice Hall, New Jersey, 544p.

Wave a

Wave base

From Komar, P.D., 1998. Beach Processes and Se

action

edimentation. Prentice Hall, New Jersey, 544p.

Overall beac

From Walker, R.G. and James, N.P. (1992). Facies Models: Response

ch dynamics

to Sea Level Change. Geological Association of Canada, 409p.

Longsho

From Walker, R.G. and James, N.P. (1992). Facies Models: Re
409p.

ore drift

esponse to Sea Level Change. Geological Association of Canada,

Overall beac

From Blatt, H, Middleton, G. and Murray, R., 1980.

ch dynamics

. Origin of Sedimentary Rocks. Prentice Hill, 782 p.

From Komar, P.D., 1998. Beach Processes and Sedimentation. Prenti

Hydrodynamic
zones

Sedimentary
Facies

ice Hall, New Jersey, 544p.

Beach

From Walker, R.G. and James, N.P. (1992). Facies Mod
Association of Canada, 409p.

Facies

dels: Response to Sea Level Change. Geological