Objectives:  Use the data in the Copper Kettle Grid rock chip log to plot the lithology, alteration and mineralization on the grid map, and select the best drill targets.

Coyote Hills Soil Sampling Project

The Coyote Hills district is on a regional trend of porphyry copper deposits.  Unfortunately, the exposure is poor since the area is covered with sagebrush.  The property owner leased the ground to Penny Lane Mining Inc. (PLMI), which conducted a power-auger soil sampling program to test the mineral potential of the property.  The program gathered quality soil samples from the B-horizon which were sent to the lab for analysis.  After the soil sample was collected, the auger was used again to drill down to the “C-Horizon”, just above bedrock, where the geologist collected some rock chips in a bag labeled with a sample number. 

After returning from the field, the geologist washed the rock chips and examined them with a petrographic microscope.  The geologist identified the lithology (rock type), and the type of alteration and mineralization, and rated the intensity of alteration and mineralization by using a scale of 1 = weak, 2 = moderate, and 3 = strong.  Alteration minerals which were logged include chlorite, quartz, sericite, biotite, magnetite, pyrite and chalcopyrite. 

Procedure:

2. Outline the monzonite plutonic rocks on the alteration map.  Put a green dot on each location consisting of monzonite rock chips (lithology).  Then draw a line/curve which circles around each set of contiguous (beside each other) green dots.  Color the inside of this (these) area(s) green to illustrate the location(s) of the pluton(s).  Label the plutons from north to south with the letters A, B, etc...  Place a yellow dot on each location consisting of sandstone rock chips.  Color yellow all areas with contiguous yellow dots to illustrate the location of sandstone.

     Alteration:

            Show the relative intensity by shading the colors (1 = light, 3 = dark).

• Use a red hatch pattern for phyllic alteration (sericite + pyrite). 
• Use an orange crosshatch pattern for zones of potassic alteration (biotite). 
• Use a purple horizontal hatch pattern to designate areas of propylitic alteration. 

     Mineralization:

• Use a blue cross hatch for areas of chalcopyrite mineralization.
• Use a stipple pattern to show the areas of pyrite mineralization.
• Use small black circles to show areas with molybdenite mineralization.
• Use small black crosses (plus signs) to show areas with magnetite mineralization.

(from Guilbert & Park).

PLMI has decided to fund a RVC drilling program.  The budget for the first phase drilling program is $51,000.  The company’s priority for the first phase of drilling is to prove up the existence and aerial extent of porphyry copper mineralization.  The cost of the drilling is $15 per foot, and the maximum drill depth is 200 feet.  Without busting the budget, select the best sample sites to use as drill sites, which will have the best potential for discovery of new copper resources. 

Study the summaries and graphic images on the internet pertaining to hydrothermal alteration and hydrothermal vein deposits.

Hydrothermal Alteration:

            http://www.oresystems.com/pics/method1.html

            Cross section of alteration and mineralization associated with a VMS deposit.

            http://www.uct.ac.za/depts/geolsci/dlr/econ.html

            Read the abstract and observe the slides on the Haib porphyry copper deposit, Namibia

            http://www.candente.com/s/Projects.asp?PropertyInfoID=654&View=4

            Pamel epithermal Au deposit, Peru

            http://virtualgeology.com/pages/teaching/364/lectures/alteration/default.asp

            http://www.petrascience.com/courses/mapping.htm

            Study the split drill core photos of the different types of veining of a porphyry copper deposit.

Hydrothermal Vein Deposits:

            http://geology.cr.usgs.gov/pub/open-file-reports/ofr-95-0831/CHAP15.PDF

            Alteration in a Au-Te epithermal deposit.

            http://geology.cr.usgs.gov/pub/open-file-reports/ofr-95-0831/CHAP18.PDF

            Epithermal deposit alteration and mineralization zoning.

            http://www.earthsci.org/esa/mindep/depfile/vei_dep.htm

            Overview of hydrothermal vein deposits.

            http://geology.csupomona.edu/drjessey/class/GSC433/Vein.htm

            Summary of vein type deposits with associated metal zoning.