Monday, February 22, 2010

What is Continuity?

I am a geologist, and these are going to be notes that I write in little journal books I carry around. ...a whole lot of them are going to lack any structure at all, but if you know a geologist, you know that that is the way he expresses things. Notes: there is no continuity in a geologist’s life, not in an active, busy one, anyway.”

Rick Bass, Oil Notes

This blog post, a submission for the March Scientiae Carnival, will explore the topic of continuity. Scientiae is facing a problem in continuity — will it continue or not — which is one reason why the topic is so appropriate. Bear with me: I'm a geologist, I may meander a bit.

For the hell of it, I'm currently searching "My Documents" for files that have the word "continuity" in them. I'm doing this for a specific reason: I think I've written about this subject before; but also for a more general reason: to see how often I've used the word. Found: ten files.

"Perhaps the process of individuation is not the same for everyone. Perhaps some people individuate through becoming something different from their parents, more so than I am from mine. Perhaps not, though — maybe I underestimate our differences sometimes and overestimate our similarities other times. Right now, I like the sense of stability and continuity I find by seeing myself in my parents, even though I have spent much of my life — and even much of the past four years — trying to be different." (1995)
"...a life buttressed by the strength and continuity of the granite of the Sierran batholith, which looked down on the valley from the east, forming the backbone of my early life." (2000)
"And maybe there is more continuity in my life than [Rick Bass] is referring to above. Maybe." (2004)
"I think that some of the continuity in a geological career or in a geologist’s life comes through seeing old places again and through watching/seeing/knowing where former colleagues are working.... This knowledge can be obtained by following the movement and careers of other geologists (engineers, techs, miners, et cetera) and by following the evolution and history of certain properties, projects, and mines. One can also follow the status and changes in mining and exploration companies in general. So, I think there is continuity after all, despite what Rick Bass said in that one book of his...." (2007)
"Further work is recommended to test for continuity and thickness of this deep zone, and to see if it shallows to the east or south." (date withheld)

So, is there no continuity in a geologist's life, especially if the geologist is an exploration geologist of some sort? It's true that one rambles and roams from place to place, town to town, prospect to project, company to company — but is there a larger, greater sense of continuity somewhere? Sometimes, I'm really not sure. When I first read the words by Rick Bass, quoted at the beginning of this meander blog post, I felt that despite certain breaks, disruptions — fault lines in my life — that there had been a certain continuity, which I described earlier as the remembering or revisiting of continuous life aspects, for example people. I think I was referring to something larger than that, though, but am not sure I can describe what I really meant.

When I think about continuity, I first have to say that my parents have been a constant in my life: they have provided a backdrop to what I've done with my life through all these many years. And yet I know that they will not always be here sharing my life with me, even if from afar by phone, through visits, and through email. And when I think about that, I feel sad. But as I write that, I also realize that the constancy in this one aspect of my life is larger than it seems: despite an anticipated future in which they are no longer here, they will still, in some way, provide a backdrop or internal place of permanency inside me for what I will do in the future. They will always be part of me; they will always be here. That is one sense of continuity, although that sense is also combined with a similarly large sense of discontinuity.

Geologists of the exploration persuasion (and many geologists of other persuasions) are always looking for (and sometimes finding) continuity between this outcrop here and that one over there, a correlation that will provide an understanding between two spatially distant areas. Once a correlation is found between these two outcrops — no matter how distant they are — a certain geological understanding might come about. For example, one might then realize that these distant outcrops represent the same moment in geologic time. This type of continuity can easily arise when the rock type and rock formation at the two distant outcrops are the same (for example the Ely Limestone of Pennsylvanian age). You might see identical and very specific fossil assemblages in the two outcrops, an indication that the two outcrops are from the same bed or geologic horizon; you might see other geologic indicators hinting at correlation, such as specific types of chert nodules; and you might notice that the particular bed is overlain by another diagnostic bed and underlain by even another diagnostic bed, if you are very lucky. You might then realize that you are seeing the same bed at both exposures, and you will therefore come to realize that you are looking at practically the same time in geologic history in both places. You've just found continuity in time across spatial distance by correlating two outcrops of one specific cherty limestone bed containing a particular key fossil or set of fossils. [This may be a rather meandering way of explaining part of the stratigraphic principle of lateral continuity.]

Another way in which you might, as a geologist, recognize continuity in geologic time across outcrops separated by spatial distance, is to find a correlation in key fossils from a particular geologic time interval, even though the two outcrops in question are of different rock types. Here we have a concept that's slightly more complex, but one might find the same trilobite in a Cambrian shale in this area over here and find the same trilobite in a Cambrian limestone some tens of miles (or more) away.

Another example of this second type of geologic continuity would be what happens with correlation of tephra beds: a resultant volcanic ash layer or bed that is deposited after one particular volcano erupts ash during one single volcanic event. An example would be the eruption of Mt. St. Helens on a particular day in 1980: on May 18th, 1980, Mt. St. Helens ash was spread far and wide across the northwestern U.S., and where it is preserved as a layer, one can identify that particular day in geologic time. Another example would be the eruption of the Mazama Ash from Mt. Mazama (now Crater Lake) on an unknown day about 7000 years ago. That ash was blown even farther and wider across the western U.S., and it was deposited in a recognizable layer and preserved in more than one kind of geologic environment. One can correlate that particular moment in geologic time from clayey lake sediments in southeast Oregon to rocky talus deposits in central Nevada. The geologic formations are different, they are separated by a distance of hundreds of miles, but those different geologic formations — a lake bed in Oregon and a talus slope in Nevada — were forming at exactly the same time. That's demonstrable geologic continuity between dissimilar geologic formations. These particular geologic beds — lake clay and talus — may not survive to become parts of future rock formations, but maybe they will.

Another way that geologists find continuity in the field, is to walk out contacts between particular rock formations from outcrop to outcrop, mapping them on paper and with GPS. Geologists map the correlation between rock formations, fault exposures, and mineralized zones this way: by mapping them in the field, by following them on the ground from outcrop to outcrop. The continuity an exploration geologist looks for will often be a speculative one during this mapping phase, one that will be later proven — or disproven — through drilling. The mineralized area might be continuous for hundreds of feet or even miles; this is a kind of spatial continuity that is required for mining. It's good, also, to find continuity in assay grade and in other economic parameters such as metallurgy. I look for these kinds of continuity while prospecting, I try to predict and project these kinds of continuities when mapping, I sometimes prove these kinds of continuities by drilling.

When I once again think about continuity in my life, I really have to go back to basics. I know that in some ways I am the same (or at least similar) to ways I was in the past. Certain characteristics will, perhaps, be found within me throughout my life. I have an experience of continuous (or mostly continuous) memory from one point in my life to another — a seeming persistence of myself through time — but I also know that I have changed through that time, sometimes profoundly. I wonder then — when I think of my life, my character, myself as containing a certain kind of continuity — am I deceiving myself?

So I go even farther back, back to basic basics. And I think that geology itself is something continuous in my life: it goes back to an early time in my life, if one considers geology to include my early childhood interest in rocks.
I am a geologist. I was a geologist. I will be a geologist. I will always be a geologist.

I have been other things, I have done other things, but there is something basic about being a geologist that will stay with me no matter what I might do in the future. For one thing, I will probably always have rocks in the house. If I clean them out, I just make space for new rocks to come in. It happens every time I remove various rock piles scattered from truck to garden to living room to garage. It doesn't seem to matter what I'm doing with my life at the time — geology, art, travel, school — a new and interesting rock will somehow work its way into my house, often when there isn't really room, and sometimes when I'm not really looking.

I often, however, have a hard time seeing the day-to-day, year-to-year continuity in my life. My outward activities change, my jobs change, the places I go for work change, the people I work with change. Perhaps it's easier to see continuity when one is younger. Perhaps continuity is really an illusion, something I create in my mind in order to feel something solid, something dependable, something constant, something rocklike in myself and in my life.

I am a geologist. The rocks, the earth — they are always the same. See how they don't move (except during those occasional events like earthquakes, volcanic eruptions, and landslides). See how the landforms and topography of even geologically active areas remain solid enough and constant enough that we can use topographic maps made in the 1970's and earlier — at least for most of the basics. But because I am a geologist, I know that all those statements are exactly and precisely incorrect. The rocks and the earth, the landforms and the topography do not stay the same, no matter how much I think they do, no matter how much I wish they would. The topographic maps of the 1970's and before show identity of topography until you come down to the details that are changing day to day and year to year. The stream beds have moved. The talus slopes have creeped. Lava flows have massively changed the topography in Hawaii, and they do so on a daily and yearly basis. Shorelines and barrier islands have moved. Deltas have changed their shapes. Rapids in canyons like the Jarbidge and the Grand have changed: they move, they increase, they diminish. New rapids form. Old ones disappear. Nothing is the same; the only constant is change.

Mountains like the Sierra Nevada, rock solid and made of granite, always give me a feeling of continuity. The Sierra Nevada in particular has provided some sense of structure and constancy in my life since I can remember. I was not born near them, but grew up with them looming above me. I have lived more than 3000 miles away from them, and they have even then been part of my life. They are there; they provide a sense of where I am, a sense of location, even when I can't see them across the many mountains of the Great Basin. When I am in Alaska, there they are, miles and miles to the southeast. When I am on the East Coast, there they are, miles and miles to the west. They are always there. Through my life, they have always been there. It is, thus, easy for me to extrapolate back in time to think that they have always been there — and they have been there for a very, very long time, but not forever. It is also easy for me to extrapolate into the future and find no future in which they don't exist. In my lifetime, they will always be there. In the geologic history of the far future, they will be there as mountains for a very long time. Even after they are no longer mountains, but are plains with an occasional granite knob sticking out through future sediments that have long since buried them, they will be there as a geologic province for a very, very long time (look at the ancient Appalachian Mountains, no longer the same as they were when first a mountain range akin to the Sierra Nevada, yet still, hence these many geologic eras, well-recognizable as a geologic province). Someday, however, every trace of the Sierra Nevada will have been subducted into the mantle by some future, yet-to-form subduction zone. They will not be there forever. They have not been there forever, no matter how much I'd like to think so, no matter how much I wish they were and will be. Even this one rock-hard, granite-solid seeming constant in my life isn't. When I think about continuity, at least today, I find little, maybe none. I find that sad, and yet, there it is.

Continuity: I get up in the morning at about the same time every day, I make the bed and turn on the computer, while the computer is turning itself on I make coffee. I heat my cold cup with hot water, I take the coffee to the room and start up my internet connection. I sign in to Blogger and open up my main blog page, I check the weather on one to three websites using two to ten weather subpages, I turn on or sign in to one or more social network sites and check them, or not. ... No matter what my current state of life is, I find or set up some kind of routine. The routine provides me a sort of comfort, but it doesn't provide any real continuity.

Photos from Wikimedia:

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