But geology at Harvard was not all history. When R. A. Daly and I were graduate students, we worked on Ascutney Mountain, studying ancient fire-made granites. The hills were lumps of the ancient pastes crystallized. The crystals were feldspars, mica, quartz, and iron oxides. Oldest prisms were lime phosphate, the mineral apatite containing imprisoned brown glass. How did the several kinds of red hot paste invade the altered sedimentary slates? Was brown glass the ancestor? Lava is brown glass. Some of the phosphate crystals contain gas bubbles and liquids. Daly, who published the work, found that ancient lava pushed up while deep in the claystones, and shattered a hole by heat and cracking. The pieces sank and the paste or gas foam was injected in successive lumps. Each new lump had more silica.
Apparently the fragments melted—some of the old sediments of Lower Silurian age were silica—and the invading magma was contaminated with more and more molten sand. So basalt turned into granite. Thus Ascutney Mountain in Vermont became a classic place for hot fluids squirting up and recrystallizing the under rock of New England. It made eventually, by erosion, the Connecticut River landscape.
Daly became a specialist on granites, I became a specialist on lavas. We became professors at Harvard and Massachusetts Institute of Technology.
Something new came into world geology when Wheeler, Hayden, King, Powell, Gilbert, and Dutton surveyed the Utah block fault mountains and the Rockies. They revealed the globe with a crust of gigantic cracked deep prisms, and an eroding surface. Davis of Harvard, the physical geographer, was at his zenith, and from Powell’s and Gilbert’s example came his classified river valleys. He devised systems of splendid topographic maps and models, and demonstrations of glacier steam beds and deltas. He made surface wear and dumping debris a living thing, and the land forms a record of it.
Thus I was overjoyed when, in 1893, I received the summons to go with Arnold Hague to the land of geysers, colorful canyon, old volcanoes, and the source rivers of the Mississippi. My job was to take pictures with a huge camera, but I posed as microscope man, too. I climbed the highest peaks of the Absaroka Range, and I traveled with Hague and a mule packtrain back and forth across the range, collecting specimens. Hague had been with Clarence King during the 40th Parallel Survey for the Union Pacific railroads.
Hague’s field method was to climb a peak, study the view, and ponder the visible strata, dikes, valleys, escarpments, and pinnacles for miles around, thus formulating each problem. Then we moved camp to a new place to solve the problem.
We sought the ancient craters. The volcanic tuffs and agglomerates covered thousands of square miles, dating from 30 million years ago and continuing outpourings until 2 million years ago, and there were lava flows, ropy or bouldery. Here were petrified trees; there could be found fossil leaves. The tree species told the formation ages of Tertiary time. Many peaks appeared but no volcano cones. The craters had been over what now were eroded dikes, or fissure fillings of lava, which stood out in crisscrossing walls. Where they clustered, ores were found: the Sunlight, Crandall Creek, and Stinking Water mining claims. These were the roots of lost volcanoes, lost by decay, tumble, rainfall, glaciers, and rivers. Underneath the mountainous lavas, appeared white marine limestone cliffs, and still lower appeared ancient granite gneiss.
The geology of ancient seabeds, fossils, eruptions, and glaciers was painted on a whole panorama of mountains and river basins. From a mountain top silently gazing through field glasses—which he was always losing and recovering—Hague would look around for hours. “That ledge is the Madison limestone, those are the Red Beds, those pink, rounded hills are Archean granites.”
After a day of packtrain travel I was free to fish or hunt. It was a privilege to hunt with Anderson, the old negro cook, whose gray beard and bushy white wool belied his keen eyes. He had been a slave, later a soldier in General Custer’s Big Horn expedition, and a pioneer and hunter. His father had been massacred by Indians, and Anderson swore he would kill any Indian on sight.
One of our hunting trips near Crandall Creek was especially memorable. “Mr. Jaggar, I smell sheep up on that shelf!”, said Anderson. And he climbed up a pine tree growing at the bottom against the limestone cliff. He laid his Winchester rifle on top of the steep slide rock slope at the foot of the tree, muzzle upward, butt end downhill. “You mind my gun, I’ll climb out on a limb against the cliff and get on the shelf, and yo’ all hand the gun up to me.” He reached the shelf, made of Cambrian limestone of trilobite fame, and sitting over on it immediately knocked down slabs of rock. They fell on the gun which started to slide down the slope. I grabbed for the muzzle pointed toward my throat, the stock wiggling right and left. The gun went off and I felt a nick in my ankle. Anderson had left a cartridge in the barrel with the hammer resting on it, but my nick was made by a pebble ploughed up by the bullet. So the trilobites took a shot at me. “Well, this is natural history,” I murmured. Old Anderson was less philosophical. He cussed me for letting the rifle kick itself far down among the trees.