Back in 1959, Wilson was trying to make a mine off that ridge top (Rosemont-area) mineralization; they were trying to make a mine out it. They were looking, too, at the Helvetia deposit, which lies on the west side and occurs in carbonate rock. All Limestone eats up acid (for leaching) voraciously, you can’t leach the minerals in a conventional way (acid leaching). Something we don’t appreciate, and I try and get my students to think about, is that geologists in exploration are held hostage to metallurgists. If the metallurgists can’t treat it, your work is not worth the time spent. You might as well have stayed home and watched the ballgame.
[Ed. note: The conversation turned towards Dr. Titley’s long career at the University of Arizona and his many experiences with students.]
When I graduated from Arizona I went back to industry for 3 years. I worked in New Mexico and here in Arizona in exploration. I became concerned with working and raising a family when I was gone 28 days a month and back two days. A job opened here (University of Arizona) and I took it. When I first moved in here everyone had rocks in their office. You walk down these halls (UA Geosciences Dept. in Gould-Simpson Building) and this is the only room with rocks in it. My office is the only office with rocks in it; when I first moved in here everyone had rocks in there office. The rocks have gradually disappeared and we have got computer screens in their place.
The students are good. I teach a course with three or four students. The course is called “Conversation with Rocks”; what is the rock trying to tell you? We go at it from that point of view, but most students have not always had much experience with minerals and rocks.
When I first came here there were about 160 units in the degree program for Geological Engineers (whose degree was in my department and consisted of students in my classes). That dropped to 145 units and then to 135 units. Now it’s 120 (units). And what we lost were many of the” how- to- do “courses, all the hands-on and all the professional courses. The sacrifice of units was all on the professional side. I think we paid for it - in my judgment. Another 20 units sitting in here with the rocks and discussing them (would benefit the students). The six of eight students who sat across this table in the last year are employed.
Do you think the model we have now of porphyry copper ore bodies is right?
The popular model was built at San Manuel, Arizona is for which it is probably mostly correct. It was built on drill holes. There is no alteration map of San Manuel and all we see is the drill hole data from Kalamazoo.
Much of my field work has been in deposits of the southwestern Pacific Islands. Most of it has been “follow-up” geology on prospects discovered by other groups. In that work I have used maps that were developed by other geologists and have found that field evidence for what is shown is incorrect and much of the incorrect information appears “squeezed” to, “apparently” fit a model. The “model” issue was large in the 1970s and perhaps in the early 1980s, when very numerous symposia and special conferences were held to talk about and create new models of one ore deposit type or another. And especially the porphyries where different models were created for different rock types and places; an example of which is some of the modeling proposed for different kinds of Western Canadian Porphyries.
I teach students that the first order of business is developing an accurate geological map of the mine or prospect of interest. Then worry about the model- not the reverse -- and don’t be surprised if it doesn’t match anything in the detail you expected. I hope we are out of the model business as the first choice in further exploration activity. Regions, rocks with age and tectonics, should be the first priority. I have worked in a variety of porphyry systems, including San Manuel, Arizona, and have to say that in my experience, every system exposed to our view is different; there seems not to be a unique solution. My best exploration guide is that published in the first porphyry copper deposit book (Titley and Hicks 1966) outlined by S.E.Jerome. It is almost faultless and shows many characteristics relevant to interpretation of kinds of data that may be acquired in ore search. Hopefully we have learned through experience and misinterpretation that the use of models must be constrained and used under experienced guidance. This is what (Harrison) Schmidt taught me and this is what Courtright and Richard taught me. You can’t just look at the rocks, you’ve got to see them.
Reminiscing about Walter Heinrichs and Willard Lacy
I’ve played my tape. Walt Heinrichs died in October 2013. Walt was a wonderful man. I met him the first day I was working in copper exploration in Tucson. It was 1958. I walked into the office that he and Jean, his wife, had on Grant Rd. And we had been friends ever since. I completely missed his passing and had no idea he was gone until I read it in a newspaper; it was some two weeks later.
I also record here, at a time of editing this review, my sadness at the passing of Bill Lacy in December 2013. He was my graduate study professor, and I his first doctoral graduate in 1958. We walked into the Geology Department in the old Engineering Building at the same time in August 1955 and I followed Bill into the office of Frtiz Galbraith, Department Head. Bill had come from La Oroya, Peru, I had come from Gilman, Colorado. At this first meeting, Bill’s first question was “have you had a course in Physical Chemistry? I answered yes.) Bill taught me about my first porphyry, took me on our first field trip to Bisbee, and after a year of mapping, we wrote a joint article on the Pima (Sierrita) Mining district, discussing the issue of the transport of the Pima ore body. Bill also taught me that I could do more and accomplish more than I realized that I could do. I have never forgotten that lesson and his continued encouragement through my career.