Objectives:

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 Distinguish between microquartz (chert) and megaquartz Describe the common appearance of jasper, opal, flint and porcelanite Discuss the origins of bedded and nodular chert List the marine organisms that produce bedded chert Discuss the origin and age of iron-rich rocks Describe the geochemical environment (Eh and pH) that leads to the formation of iron-rich rocks

  

Reading Assignments:

Lecture 10: Evaporite minerals and deposits- Boggs, 5th edition, pp. 168-174 and 189-194.   Lecture 11: Chert and ironstone- Boggs, 5th ed., pp. 175-194   Please fill out a reading log for evaporite deposition, chert, ironstone.  Reading logs are due Wednesday at the start of class.   Reading log

   

Class notes:

Lecture 10 notes Lecture 11 notes

   

Graphics from lectures:

Lecture 10 graphics Lecture 11 graphics

   

Field trip stratigraphic column assignment:

Your stratigraphic column is due the Friday before spring break (March 16).    Choices: You can draw a weathering profile or a grain size profile. You can use computer graphics or hand-draw the stratigraphic column Guidelines for drawing a stratigraphic column:   guidelines   Examples of stratigraphic columns:   examples   Powerpoint template for stratigraphic columns:   template   Reference: Compton, R.R., 1985, Geology in the field, NY, Wiley and Sons, 398 p.

   

Lab this week-   Sedimentary petrography week 1.  This week we will meet in Placer Hall rm. 1002, and will start to look at clastic sediments in thin section.   Your lab write up will be due after spring break.  In today's lab period you will start drawing some common clastic grains.  Next week you will finish drawing the grains, and your lab will be due the following week. Grains this week Where to find them quartz slides S-150, S-1500, Navajo orthoclase fs slide Dove Springs plagioclase fs slide Dove Springs hematite cement slides DD, 5, 205 plutonic rock fragment slides DD, 5, 205 quartz overgrowth slides S-150, S-1500, Navajo     Bring drawing pencils and colored pencils to lab!   I will pass out a copy of the lab.  If you need to print more pages you can get a new copy here:   Grain catalog