Geology 103 (Sedimentology and Stratigraphy)


California State University, Sacramento


Week 12:

Evaporites and Chert, ironstone, phosphatic rocks and glauconite


Upon completion of this unit students should be able to:

  • Identify common evaporite minerals and their sequence of precipitation
  • Discuss the geochemistry of evaporite deposits
  • Relate hypersaline lake environments to evaporite deposits
  • Describe different modes of formation for nodular chert and bedded chert.
  • Discuss the crystalline or textural forms of chert
  • Identify the geochemical or biological conditions that favor the formation of chert
  • Discuss the evidence that ironstones provide for an early atmosphere.
  • Classify or name ironstones and chert.
  • Distinguish between banded iron formations and ironstones
  • Describe the geochemical conditions that favor different forms of iron
  • Discuss the relationship between ocean upwelling and phosphate deposition.
  • Discuss the formation and occurrence of the mineral glauconite


Reading Assignments:

Lecture 18: Evaporite deposits- Boggs, 5th edition, pp. 168-174


Lecture 19: Chert, ironstone, phosphatic rocks, glauconite- Boggs, 5th edition, pp. 175-194


Please fill out a reading log for this week.  Reading logs are extra credit this week, and are due at the start of class on Wednesday.


Reading log


Class notes:

Lecture 18 notes

Lecture 19 notes


Graphics from lectures:

Lecture 18 graphics

Lecture 19 graphics


Lab this week-


Petrology of evaporites, coal, phosphatic rocks, glauconite and ironstones:


I will pass out a copy of the lab.  If you need another copy you can click here:


Evaporite and coal lab


Due date:  start of lab, next week. 



Field trip:

Weekend field trip: Coastal processes, sedimentary environments

(Friday April 26th through Sunday April 28th)


We will have two lectures on our weekend field trip.  Click here for field trip notes and graphics:


Beach and barrier island deposits:

Beach notes

Beach graphics


Eolian deposits:

Eolian notes

Eolian graphics


Field trip handout:

Coastal field trip handout