MARK SMITH / PVT Geologist Lauren Wright heads cross-country toward the Crystal Spring formation east of the China Ranch Date Farm. MARK SMITH / PVT Marli Miller straddles 300 million years of geologic time. She has acted as Wright's photographer for years and has her own doctorate in geology. MARK SMITH / PVT Lauren Wright is elderly but still enthusiastic about the geologic history around Shoshone, Tecopa and Death Valley. MARK SMITH / PVT These stromatolites along a dry wash were deposited by single-celled creatures when they were the full extent of life on Earth. The photo covers about a foot and half horizontally. Advertisement

SHOSHONE, Calif. -- Like an informal patrol from Popski's Private Army in the Egyptian desert, we swung away from the road to the China Ranch Date Farm and headed east toward the War Eagle mine.

The group of a dozen and a half geologists, videographers, mining engineers and interested visitors from Pahrump was organized by Susan Sorrells of the Amargosa Conservancy and led by Lauren Wright and his assistant and photographer, Marli Miller.

Also with us was Nancy Cooper, widow of the late John Cooper, who devoted much of his life to the area and served as president of the Amargosa Museum board.

We were on our way to some of the oldest rocks around, not to mention evidence of single-celled life forms of an equal antiquity.

Wright, who has spent much of his life teaching geology at Penn State, began his close acquaintance with Death Valley and its surrounding area in the 1940s.

Miller gained her bachelor's degree in Colorado in 1982 and is a senior instructor and researcher at the University of Oregon in Eugene.

The two have worked closely in the Death Valley area for nearly two and a half decades and have hosted any number of geology tours.

At the first stop, where we could get to know each other and gain a foundation on what we will see, Miller mentioned casually that, just back down the road, were some of those ancient rocks. Rocks that were put into place 1.7 billion years ago.

As in billion with a "b."

We hastened back to the rocks that were exposed in a road cut, and one of the group asked if they were actually that old -- so old they would make dinosaurs seem like newcomers.

Yes, said Miller, they're that old.

The fellow immediately hauled out his geologist's hammer and went to work cracking stone.

Wright used a geologic map to explain the fault system that seems to converge east of Tecopa, and one gentleman explained that earthquakes are a matter of some significance to him -- he is building a house.

Miller said the record doesn't indicate any great worry, but then threw in that tremors happen only "on field trips."

Added Wright dryly, "You can hold onto your britches and wait 'til the next earthquake."

Wright explained that the area between the faults is "more strongly extended" due to the stretching experienced along Death Valley.

This "extreme crustal extension" allowed volcanic rocks to move vertically as the crust opened up.

To the south, yellowish noonday dolomite was exposed among a diversity of old talc mines. A sedimentary rock, the dolomite, Wright said, is "a kind of limestone." The sedimentary layers had metamorphosed through heat and pressure more than a billion years ago.

Or as one of the group put it, "slow roasting ... Earth's own crockpot."

According to Wright, it is somewhat surprising that rocks of such great age have been found so close to the continental margin.

For a moment Wright was taken back to his early days in the field, when the theory of plate tectonics, now thoroughly accepted, was still a relatively novel idea.

"It was exciting," he said, "because I had to change my lectures every year."

A winding, rough dirt track led us to a hump of high ground near the War Eagle mine, with the rocks interspersed with larkspur, beavertail and cholla cactus, and dying weak-stemmed Mariposa marigolds.

We were atop a mass of stromatolites, which originally, as described in Wright's notes, were "extensive mats of the microbe cyanothytes, a one-celled organism formerly referred to as blue-green algae."

Wright explained the formation and pointed out several more around us. He said they are "probably the largest stromatolites in the world."

Over time, as the slimy mats of algae rested in their shallow marine environment, they secreted carbonate rocks that left behind their distinct signatures.

We were standing on the noonday dolomite sea floor.

"These are almost unique in the world today," Wright said.

They were a considerable puzzle until examples were found in hypersaline pools off the western Australian coast in the mid 1950s.

Wright and the rest of us listened as Chick Joy, who was district mining engineer in the region, recollected the days of the War Eagle mine. It was thought to be played out at one point, but one miner thought there might be more ore and came upon a large vein of lead.

And there was the time when miners were deep in the earth and sent up the surprising word that they had found an "underground forest." Joy explained that they had unexpectedly come upon some even earlier workings and had run across some of the old wooden supports far beneath the surface.

Joy also allowed us to inspect some of the minerals in his personal collection, from chunks of brilliant green caledonite crystals to smooth raw talc.

Wright discussed the late paleontologist and geographer Preston Cloud, whom he described as the leading authority on precambrian life forms, those from the formation of the Earth around 4.5 billion years ago to the evolution of abundant hard-shelled animals.

"He sought out the earliest life forms around the world," Wright said. He added that, while Cloud may have been an intense student of such matters, he was no intellectual stargazer hidden behind the windows of the library. In the Navy, Wright said, Cloud was a tough bantamweight boxer.

Our convoy headed back west and, after passing several groups of ATV'ers, followed Western Talc Road to its end, whereupon Wright exited Sorrells' vehicle and strode off by himself for the Crystal Spring formation. The group straggled along in his sunlit wake, past greasewood and the occasional cholla as well as some red-eared blister beetles that appeared to be mating.

Well, said Sorrells, "it is springtime."

At the rock formation, Miller planted her right foot at one spot and extended the other to the rocks themselves, then explained her feet were straddling 300 million years, which Wright explained amounted to a major "unconformity" not unlike that near the base of the Grand Canyon. The term is used to describe any break in the sedimentary geologic record.

Heading back to the convoy, one of the visitors, conscious of the time, remarked, "We're having stromatolites for lunch."

"They're kind of crunchy," added another.

We drove farther into the back country to an abandoned talc mine, gaily passing a variety of worn no-trespassing signs along the way.

Miller asks whether we should go seek a group of stromatolites she photographed a decade ago, and we followed her into a small wash.

We quickly found some stromatolites, but they were not the ones she remembered, and we spread out but with no luck. Finally, about the time I figured someone was going to say it's time to get back to the cars and return to Shoshone, when only Sorrells and I were still with Miller, following her along the face of the rock, she called cheerfully, "Here they are."

We converged on her and were stunned.

They were just rocks, light gray, but they were the clearest, most vivid, most noteworthy rocks we'd seen that day, narrow gray accretion domes separated by the later fill from above.

Rocks that represented living things more than a billion years old

Miller looked around at the arid landscape. "They're right off the end of the wash," she said happily, committing the spot to memory.

We found a route down to the floor of the wash and made our way back to the vehicles and, in time, back to the present day.

Later on, Sorrells said Wright got back to Shoshone only to find his glasses had gone MIA. They turned and made their way all the way back to the mines area, with Sorrells and Cooper intently trying to visualize where the specs might be -- and there on the ground lay Wright's glasses, intact.

High fives all around.