Unconformity
What happens in unrecorded time?
Absence
I’ve been absent from these pages for a year. Geologically speaking, it is less than an instant in Earth’s history. But for us humans, a year can seem like a long time. Although this newsletter doesn’t document what I was up to this year, plenty went on.
Absent Rocks
In spring of 2024, I visited my home farm – the first time since 1975. I expected changes but could not have guess what changed and what didn’t. I expected a barn with empty metal cow stachions. I didn’t expect a barn falling over. There were changes to the house and yard but the smokehouse was much the same as it was 50 and even 150 years ago.
The oak trees in the yard were gone but the sycamore by the creek still stood (see photo above). The sycamore tree at a creek has its roots in the rocks of the flat bottom land which are 505-438 million years old Ordovician rocks. This land wasn't land at all but a vast ocean full of corals, brachiopods. Sediment covered these organisms and over the millenia, they were buried under piles of new sediment. The rocks up the hill to the right are Mississippian in age, i.e. 360-320 million years ago.
So in this place, there is absent over 100 million years of Earth’s history. Earth scientists call this an unconformity – and I don’t know whether the sediments of that 100 million years were never deposited here or whether they were deposited and then eroded. I’ll look for more information from geologists who study the history of the earth, but I don’t really care. It is enough for me to know that someone looked at the rocks and recorded the types of fossils and their age.
Absent Data
In November, 2023 I visited the library of the United States Geological Survey in Denver, Colorado, on a mission to find the field notes of the geologist who had mapped my home county in Kentucky, specifically the farm where I grew up. The field notebooks should have been filed with the survey according to an agreement and joint project with the Kentucky Geological Survey.
Alas, the notebooks are missing. I found several from the fieldwork in counties rich in coal – both eastern and western Kentucky, but none in boring ‘ole’ Lincoln County. I imagine the geologists just took them home or stuck them in a desk drawer to be discarded upon their retirement. Anyway, no carefully recorded observations of the geology.
The process of looking for Kentucky-related maps and field notes was instructive in itself – notebooks referring to folders and portfolios in boxes with no index. Thank goodness for good librarians who know how their system works.
I learned that the Denver library was closing in 2024 (which hasn’t happened yet) and all materials would be sent to the archive outside Washington, D.C. In this digital age, many people think the entire record of everything has been digitized to be retrieved at the push of a button. Alas, that is not the case.
As I walked out of the library, I became quite nostalgic over the hundreds of file cabinets and cardboard boxes with uncataloged, unrecorded information The minute handwriting in pencil and rapidograph (anyone who used one of those knows how painstaking it is to keep that ink flowing) correlated with numbers on paper maps is now archaic – and much information will be lost in the dark hold of an archive.
Life goes on with new technologies updating maps daily with new data gleaned from satellites.
Absence of Order
In late February, 2024 I visited Turin, Italy to participate in a calligraphy class at the studio of Massimo Polello, an internationally known artist.
Being a student and lover of symmetry in minerals, I was drawn to his study of order and disorder. We took three letters from an unfamiliar alphabet and first made a pattern and then turned them into artistic disorder. I’m currently working on doing similar work with geologic symbols for my own artwork. Stay tuned.
Why I Like This Rock
2024 is my Jubilee Year - if the Queen of England had one, why can’t I? The culminating activity for my actual 75th December birthday is a hike on New Zealand’s Routeburn Track. My last big hike was the Milford Sound Trek in 2017.
There is a rock on the Milford Trek which I didn’t bring home, and I’ve regretted that decision ever since. It is “The Rock That Got Away”. For the sake of getting this newsletter out in a timely manner (ahem), I’ll describe it for I don’t even have a photograph. It was the third day of the trek, and I was exhausted, wet ,and cold - and late, for I am a slow hiker. There was a rock - longish oval in shape - half was black and half was white - right down the middle. We were in the New Zealand alps where continents had smashed into one another, so it was most likely a metamorphic rock with one half amphibolite - black with 100% amphibole. The other part was quartz or, perhaps, feldspar. I was too preoccupied with putting one foot in front of the other to to look closely.
However, it was beautiful. And it still sits close to its origin - happily being tossed down the river in the frequent floods from westerly storms and melting snow.
What will I see this December?
More about Earth to Susan
I’ve taken a break from my book over the last year to do some research on specific topics and to just write without the objective of finishing a book. But I’m back at it which means I plan to post more regular topics here.
For those of you new to Earth to Susan, I am writing a book about how people see the Earth in different ways. I bring science, poetry, music, theology, literature, philosophy, history, geography, politics, and economics to these pages – all in relationship to Earth.
Most importantly, I believe that helping people understand that we all see the Earth in different ways will open conversations to help find solutions for the many issues facing the planet we call home.
I will continue one newsletter per month, and I hope you will read Earth to Susan and please share it with your friends! It’s free.
Until next month,
Susan
Hi Susan! Enjoyed your post, and your 'The Rock That Got Away' phrase made me laugh, too relatable! Looking forward to new posts.
Susan, this is a lovely accounting of your year!