The river itself was flat, bone-dry, and in some places was obscured by windblown sand. I could see where the annual torrential water had woven around and over large, smooth rocks in its path. Now it looked, at maximum, twenty feet wide and was interspersed with grooved channels dotted by spindly brush and nests of interwoven sticks and weeds left behind by swift-moving water.
Most significantly, the water, like a diligent housecleaner, had scoured the underlying rock with the swirling particles of quartz sand it carried. This yearly “sanding” wore away any outer layers of weathered rock and left it free of blemishes.
No matter how many times I looked at the river rocks, their remarkably clear detail always fascinated me. My metabasites were beautiful.
As I walked the river, I stopped and took measurements with my Brunton compass of the strike and dip—the direction rocks were orientated from north (strike) and their angle from the horizontal (dip), respectively—of selected specimens that remained in situ since they had been formed. This data—hundreds of measurements—could determine the direction of the last pressure or squeezing deformational event. If such an event occurred, it would have taken place deep within the earth in response to internal movement processes. Following uplift to the earth’s surface due to erosion of the overburden, I was now able to observe the deformed rocks.
Often there were several deformational events imposed on one another over the billion-year period since the Precambrian rocks were born. Remnants of the earlier events could coexist with the latest, perhaps stronger, event. Each may have a different measurable strike and dip. I had to look closely for evidence. I recorded this data and the kinds of rocks I saw on a map, which, in the end, would be a geological map of the whole fifty miles of my field area. Basically, it was a question of figuring out what came first and what followed.
I also collected softball- to basketball-size samples from each interesting outcrop of rock by hitting them with the sledgehammer I carried on my shoulder. I took photographs of these samples and included a ruler-scale in the picture, the specimen number, and an arrow pointing to north. I numbered each piece and then recorded it on an aerial photograph to show where it came from. Lastly, I put the samples in respectively numbered plastic bags and carried them to the Land Rover in my backpack. The work had to be slow, careful, and orderly, with no room for error. Once back at the university, I would look at them under a microscope and analyze them.
Rock sampling of this nature could become very rhythmic, seductive to the point it absorbed all concentration. But this was Africa, so it was never good to forget that danger could find you when you least expected it. Once, I had to abandon my backpack full of preciously selected rocks when a leopard followed my every move. Another time, lulled by silence and the hot sun, I tripped over a python. Then there was the cobra that reared up . . . luckily several yards away, but still too close.
Returning toward evening to the Land Rover, I made a flavorsome mulligan stew and scooped out a place to lay my blanket and sleep. The wind made a frail whistling sound as it nudged the small, hard leaves of an acacia tree close to me—the quintessential African tree with its skeletal outline, locally called an umbrella tree. Early moonbeams against a dark sky peeked through the drought-resistant, thorny, dry branches. It fascinated me that the trees’ meager foliage was concentrated along the flat-topped crown, while their starved-looking supporting limbs were elbowed and bent, resembling the bony framework of an upturned bird’s foot. They looked as if the sky was almost too heavy for them to grow under. Without them the flat open land would appear disrobed. It would not say, “Africa.”
Morning came quickly. After finishing the remaining stew plus an instant coffee, I went back to the river. As I did every day, I filled my backpack with samples and, like the cartoon character Obelix, carried them to the Land Rover. By about noon I finished and decided to drive farther on to the ocean. At some point I stopped then climbed onto the Rover’s roof to peer through the still-shimmering heat with binoculars. An inconsistent green and brown band of shrubbery lay in the distance. It was a line of acacia trees. From my map I knew that must be the boundary of the coastal settlement Hondeklip Bay—in English, Dog Rock Bay—named for a fifty-foot-tall rock that resembled a sitting dog until its head was struck off by especially fierce lightning. On the shore of the Atlantic Ocean and about fifty miles southwest of Springbok, it would be remarkably cold there in comparison to the hot interior I was coming from.
* * *
In the mid-1970s, the scanty tree boundary I drove to was interrupted by a chicken wire gate across the track. Trees had taken root around now-leaning wooden fence posts. Unlatching the sagging pipe and wire construction from an equally inclined metal support pole required strength. Straining, I had to lift the whole thing up and out of the sand. As I further struggled to drag it open, leaving a deep furrow, I realized there were no other furrows. No trace of other visitors. This had to be the only entrance from the land side, as there were no other roads leading to it. Of course, windblown sand could obscure recent tracks, but I had the feeling there were few anyway. Driving through, I dragged the gate closed and relatched its wire loop behind me. You never leave a closed gate open in Namaqualand, for fear enclosed animals like cows and sheep may escape. Though here, it seemed no one wanted to get in or, for that matter, out. So, why would you need a gate? It seemed a kind of Alice in Wonderland question.
A few hundred feet beyond, the track led to a huge rusting anchor propped up so that one of its two flanged arms pointed to the sky, signaling a fishing village. The smell of the ocean filled the air. The land had dramatically changed from bone-dry to water-covered, from intolerable heat to Atlantic Ocean–cold, from cattle to fish. And only a dilapidated chicken wire fence separated the extremes.
I followed the track until it gave way to smooth white and gray rocks weakly speckled with black minerals defining the shoreline. Polished smooth, they lay protruding from the swirling, angry water rising high in waves to form a natural harbor. Seals barked or lay contentedly while seagulls strutted and lifted off; their cai-ing filled the air. Waves washed the domelike rocks clean. They were periscope portions of the strong, stable, billion-year-old Precambrian shield rock on which Africa built itself.
Standing on the “dog cliffs,” I looked out to the beaten wreck of the Aristea, which resembled a small freighter. Only thirty years before, in 1945, she was beached when a massive storm swept her to her death on unforgiving rocks. Shipwrecks were not uncommon; I would see many more in the years following in places like the Wild, Skeletal, and Forbidden Coasts of southern Africa.
Not far away, on a windswept hill with a view of the vast, churning ocean, lay the village graveyard. I walked among the tombstones one day and spoke to another visitor. “The sea claims our sailors and we troll it for its fish. It’s the way it is,” he said looking at a weathered, tilted tombstone, standing among others. It read:
CAPT. KENNETH DEVENISH PARSONS,
WHO PERISHED WITH ALL HANDS
ON HIS SHIP “TEGWANI”
ON 26TH JUNE 1947,
IN HIS 36TH YEAR.
A long wooden pier penetrated deep into the very restless bay amid a tangled green mass of oscillating, ropelike kelp. The dock wearily but resolutely provided anchorage for a half-dozen aged wooden trawlers that sailed deeply into the sea’s body to capture pilchards each day. Processed at the adjacent canning factory, these finger-size sea creatures allowed the settlement to survive for a century.
Reaching the dock, I saw rope necklaces garnishing the uneven pillars jutting out from the churning water’s surface. Other ropes slapped rhythmically against wood hulls, adding their dull, wet, lulling sound to the aching groan offered by stretched lines and knots of wood in the crosstrees above. Beneath the waterline, a multitude of barnacles attached themselves to the anchorage supports like medals. It seemed a tribute to the partnership between man and sea.
It also looked like something that belonged to the past
.
Opposite the pier and shore were about thirty whitewashed concrete-block homes lining dead-end streets. Lacking further architectural distinction, they were generally placed parallel to the seashore in several unevenly spaced rows. A web of pathways led from the homes to a prominent row of battered concrete outhouses, presumably shared, perched high on rocks at the sea’s edge. They provided a spectacular view of the churning, cold sea. I imagined the user sitting in the very brisk air, contemplating life. Frequent storms had blown doors and roofs off, however. Necessary usage during such angry events was no doubt made more exhilarating by flapping toilet paper, some of which clung to the sparse adjacent foliage.
Few people were outside in the middle of the day. Pecking chickens, lurking dogs, and goats with clanking neck bells wandered freely. I stopped at a small whitewashed building, which housed a very tidy restaurant—the only one around. Inside were six tables covered with red-and-white checkered tablecloths. No one else was there. The owner was a very pleasant lady who spoke with an accent. She told me she’d come here years ago with her husband. I asked if she found life difficult. “Nay,” she replied, “I accepted it, I dinnae have much in Scotland and I’ve nay gone back. My husband, a sailor, passed on years ago. Ach, he loved the sea and sound of seagulls. This restaurant is how I support myself. I know what’s here; I have nowhere else to go.”
Years later, when I looked at my notes, I wondered if Capt. Kenneth Devenish Parsons could have been her husband.
I drove to the gas station that doubled as a general store. Pumping a worn metal handle, an older man dressed in faded jeans and shirt gazed at me guardedly and silently filled my tank. He asked me to help him pump and why I didn’t speak Afrikaans. “You should learn it,” he added with conviction. Inside the store was a crank-up telephone and penny candy in a large jar. Shovels, enamel plates, bolts of bright cloth, hats, lanterns, rows of tinned food, shoes made from rubber tires (I bought a pair), bars of blue washing soap, tin kettles, and bags of mealie meal (corn) and flour were all neatly stacked.
One Sunday I saw people walking to the one-room whites-only church. The restaurant lady had told me that some Sundays a traveling Dutch Reformed dominee2 would provide the service, other times one of his disciples. Given the dangerous occupation of the sailors, “release from earthly bonds” was a common topic. Ladies attended the service carrying large baskets and wearing enormous bonnets and long, grandmother-style dresses that protected them from the sun and the blowing sand. Men, awkward in their best clothes, accompanied them. They shuffled out of the church and down the silent streets ready for life.
Isolated settlements like this started with a few families. Often, such societies chose to keep to themselves. There really didn’t seem to be much reason for people to visit. It wasn’t on the way to anywhere. The children married each other, and the next generation did the same. Inbreeding could lead to deficiencies. Later, on one occasion I met a young man in the settlement who had married his cousin. I asked him why he hadn’t looked elsewhere for a bride.
“Because I know what I’m getting,” he replied.
I went back to the settlement each time I visited my field area over the next four years, lugging that gate open and closed and rarely seeing any other tire tracks. I told myself it was to escape the interior’s heat, to sit in the chilly ocean’s breeze on the periscope Precambrian rock and stare at the restless, clawing ocean.
But more so, I think it fascinated me to return to a place that didn’t change, a place that was tranquil and survived without influence from the rest of the world.
_____________
1Afrikaans term for boss or master; used by blacks when referring to white supervisors
2A minister of the Dutch Reformed Church
Chapter 6
Preparing a Rock, Finding a Woman
Two months of hot, dry living in Namaqualand collecting rocks and creating a geological map was exhausting work. There came a point when I had to stop gathering data and start reviewing what I had. That meant a return to UCT, where I would conduct certain tests and hopefully have a little social life. But how do you test rocks? And how can you meet women if you’re in the lab all day?
Rock specimens are examined by cutting off a very thin slice of the rock in question. That slice is then cemented onto the middle of a two-inch-long glass slide. The sample is then sanded down and made so thin light can pass through most of the minerals the rock is composed of. This is called a thin section. When viewed through a polarizing microscope and magnified hundreds of times, mineral details emerge, allowing the rock to be correctly categorized. Knowing I was the first person ever to see that tiny bit of nature in these thin sections fascinated me.
The physical or structural conditions under which these metamorphic minerals were formed can also be deduced by viewing them in thin sections. If elongated minerals are orientated (lined up) as opposed to random, it shows they have been subjected to pressure as they lay deep under the earth’s surface where massive surrounding movement occurs. It’s similar to a group where each person is being pushed in the same direction; they fall lined up and according to the direction and the force of the shove.
As I noted earlier, minerals form under different conditions of temperature and pressure. Some minerals form when it’s hot, some when it’s cold. The appearance of certain mineral assemblages reveals the approximate temperature conditions that were occurring when the minerals reached a state of stable chemical equilibrium. That is to say, they were content with each other (like happy neighbors) and not reacting to form new (“baby”) minerals. Most metamorphic rocks are in equilibrium, as the conditions they were formed under were stable for long periods.
Sometimes there are tiny fragments (inclusions) of older formed minerals enclosed in younger mineral bodies. That speaks of a previous life for those older minerals. It can mean the younger mineral had begun to eat or dissolve the older one. If not for it being inorganic, it might be considered macabre.
We also look at delineations. Were boundaries between different minerals sharp or irregular? If irregular and blending into each other, this may suggest they were reacting or “mating” to create a new mineral made from both of their chemistries. This took place because they were not happy with the physical conditions they had ended up with. The new mineral “baby” would feel more adjusted and stable.
The chemistry of rocks and minerals is determined by sophisticated laboratory equipment, such as the electron microanalyzer and the X-ray fluorescence machine. Data from my rocks, obtained by using these machines, was vital to understanding the area’s geology.
My plan was that after four years or so, I would have enough information to prove something insightful to my science and present a new, original thought in order to submit my PhD dissertation.
There were no desktop computers at UCT in the mid-1970s, just a mainframe located in an isolated building. We used punch cards initially to enter the programs required to interpret larger quantities of data. If I lost one card from a deck or (heaven help me) dropped a deck of hundreds of cards, I would be in for days of work to sort out the disorder. Every card had to be perfectly punched and in sequence, or the program would not work. Scientists then sent decks of cards, aggressively bound, to one another via post.
New electronic typewriters were scarce and, as a student, I used a manual typewriter to compile reports. Our photocopy machines were primitive. It was standard procedure to send out recent publications as hard copy to other workers. If I needed research from other authors, I wrote to them via land mail and asked for copies. Fax machines and cell phones were still twenty or so years in the future. Libraries did not normally contain all recent, pertinent information. Everything took time.
After reviewing locations, I selected certain rocks from my collection for chemical analysis. As is still done today, each one had to be broken down into golf ball–size pieces with a sledgehammer and rock splitter. This after I’d broken much larger pieces off fro
m their parent rocks in the field. A double handful of golf ball–size specimens from a single rock were fed into a strong jaw crusher, which was first cleaned with distilled water to lessen the possibility of contamination. The pulverized results went into a decontaminated agate grinder until reduced to a powder. This was then mixed and quartered again and again to get a thimble-size sample representative of the huge rock’s chemistry. That specimen was prepared for X-ray diffraction analysis that magically churned out percentages of the elements present.
I primarily analyzed distinctive metabasite rock, which originated initially with the melting of rock deep within the earth’s surface. After forming, these igneous (basite) rocks, while remaining in their solid state, endured additional extreme heat and pressure a billion years ago by a process called metamorphism. I was most excited by the resulting dark minerals formed; the work with thin sections made it clear they would provide specific evidence of the temperature and pressure conditions under which the metabasite had been formed. And the resulting abnormally hard rock made a unique bell-ringing sound when struck with a sledgehammer. I could identify the rock blindfolded just by the sound it made. It was not crushed to powder easily.
However, metapelite rocks also were found in my semidesert study area. These were formed underwater and as such were of sedimentary (pelite) origin. Later, they too suffered metamorphism by the same metamorphic event that affected the metabasites. Finding these metapelites meant there once had been a lake or large body of water where I searched. Composing some of these pelite rocks were extraordinarily big, prominent minerals like “round” red garnet, “thin and tall” colorless sillimanite, and blue kyanite, which could easily be seen with the naked eye. These minerals had the ability to grow (or crystallize) in a large and distinguishable characteristic manner, unlike most other minerals, which remained small and without a visible form. They were like weight lifters among children.
A Rock and a Hard Place Page 5
