The *_lith.dbf file is a database file that can be added as a table within your map document or project, 
and linked to the attribute table of the corresponding water wells theme via the WELLID common field.  
This creates a one-to-many link relationtionship with the *_lith.dbf table as the source table, and the theme 
attribute table as the destination table.

All information is exactly as was entered on the well log by the water well drilling contractor.  The 
following is a definition of the Lithology fields:

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Field Definitions:

• SEQ_NUM : Sequential numbering of all the strata associated with a well, ordered from 
surface to bottom of well.

• COLOR : Color descriptor of the stratum.

• PRIM_LITH : Primary lithology/material of the stratum.

• LITH_MOD : Lithology modifier- a secondary descriptor of the primary lithology.

• DEPTH : Measurement from surface to bottom of the stratum, in feet.

• THICKNESS : Measurement from top of stratum to bottom of stratum, in feet. 

• AQTYPE : Aquifer type- Characterization of the primary lithology into one of 3 types:  
	D = drift
	R = rock
	U = unknown  

• CLASS : Further characterization of the primary lithology into one of 4 classes:
	AQ  = aquifer material
	MAQ = marginal aquifer material
	CM  = confining material
	PCM = partially confining material

• EFFECT : Numerical representation of the LITHMOD field.  This is an intermediate value used in deriving the final field 
MAQTYPE, it is not applicable as a separate attribute.

• MAQTYPE : Modified aquifer type- The final characterization of the strata.  Derived by expression by 
combining the PRIMLITH & LITHMOD fields, there are 4 choices for this field:
	AQ  = aquifer material
	MAQ = marginal aquifer material
	CM  = confining material
	PCM = partially confining material



For questions, contact:

Anita Ladouceur, Department of Environmental Quality
phone: (517) 284-6533
email: ladouceura@michigan.gov

or

Andrew LeBaron, Department of Environmental Quality
phone: (517) 284-5563
email: lebarona@michigan.gov