Laguna Niguel Geologist Tours History Underfoot

For those who say Orange County has no history, Mark Koestel has a retort.

As do all historians, Koestel pieces together available clues to assemble a story--but his story is not of people, but of the landscape. A geologist, Koestel works in a time frame where man’s time on Earth is the blink of an eye, and a century or two is an instant too small to consider.

Orange County, Koestel said, has plenty of stories to tell, and he operates a company offering local geology tours to the curious. The Laguna Niguel resident will be speaking Thursday in Santa Ana about the local landscape.

“We’ve got everything. There’s fascinating geology out here,” Koestel said.

Earthquake faults crisscross the terrain. There are remnants of volcanoes on the beach in Laguna. Along the edge of the Santa Ana Mountains, sandstones reveal fossilized reminders of a sea that once covered this land.

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Also, Koestel said, the igneous rock that forms the backbone of the Santa Anas (formed by cooling magma deep beneath the surface) is still being uplifted at a rate faster than erosion. The mountains are growing, which underlines a point Koestel likes to make.

“The only constant in geology is change,” Koestel said, standing at the edge of a tide pool at Little Corona del Mar State Beach. Crouching down, he traced with his finger the twisted layers of shale at his feet. Some 12 million years ago, he said, it was mud at the bottom of a shallow sea, which became buried beneath other sediments and solidified into rock.

Later, intense heat and pressure contorted the once-even layers and eventually pushed the shale back to the surface, where it was cut and smoothed by waves. Such “wave-cut terraces” extend inland like steps in Southern California, marking the boundaries of an ocean that has retreated or expanded with the comings and goings of the ice ages.

Piecing together the clues offered up by the land has been Koestel’s life work.

For the first 10 years of his professional career, Koestel traveled the country as an exploration geologist for a major oil company, searching for deposits of titanium, rare earths, cobalt and other metals. For the past seven years, he has continued his travels as a consultant for the environmental industry.

Through all that time, he has often found himself sharing his knowledge of geology. “Friends would like to go out with me and hear about their local environment,” Koestel said. Strangers too--sometimes, on walks with park rangers or naturalists while on vacation, Koestel would find himself answering the questions that inevitably come up about geology.

The rangers, he said, “do a good job, but they are not geologists.”

Not long ago, Koestel decided that there might be a way to “try and make this my business,” taking people out on geology-oriented day tours and longer trips. About five months ago, he created his own company, Adventures in Geology.

He now offers a series of local programs, which can be customized to fit personal interests. And because “geology is everywhere,” as Koestel said, the walks and hikes take in some of the most scenic spots in the county and beyond.

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The day trips include two-hour beach walks ($30), four-hour hikes in Trabuco Canyon ($40) and eight-hour hiking or driving tours of the Santa Ana Mountains ($65). Koestel, an experienced hiker, camper and backpacker, also offers multiday trips, ranging from two-day tours of the Elsinore fault zone ($150) to four-day camping tours of southeastern Utah ($850, including air fare and ground transportation).

Koestel hopes to launch international tours as well, to such areas as Australia and Mexico’s Copper Canyon. He is also planning classroom courses.

At a time when “eco-travel” is a buzz word and many people are looking for more active vacations that include a natural history element, Koestel said he has developed a niche with his geology-oriented tours. He said interest so far is strong, but he’s getting the business off the ground and continues to do consulting work on the side.

Even in his shorter walks, Koestel starts with an overview of geology and an introduction to the distinction between igneous, sedimentary and metamorphic rocks. He also tries to fit the local landscape into the bigger picture, talking about plate tectonics, the theory that describes the motion of huge continental “plates” across the surface of the Earth.

That has particular relevance in earthquake-prone Southern California. The part of the state we live on--which is part of the Pacific plate--is inching northward, while the rest of North America is sliding south. The boundary of that movement: the infamous San Andreas fault.

His goal, Koestel said, is to give people some kind of unifying sense of the landscape, rather than a few isolated facts. “One thing about geology, it’s an interpretive science,” he said. “I don’t feel I’ve done my job if I just go out there and point out some rocks.”

Koestel will speak Thursday at 7 p.m. at REI, 1411 Village Way, Santa Ana. Admission is free. Information: (714) 543-4142. For information on Koestel’s tours, call (714) 586-3328.