(This post first appeared on En Tequila Es Verdad. I republish it here for the handful of you who might have missed it there - I'd really like you to get to know Lockwood. The Accretionary Wedge, of course, is a geoblog carnival, which has been responsible for some of my best and whackiest writing, and always includes fabulous posts by amazing geologists.)

Everyone I've learned geology from has been "the most important" in some respect. But when Simon Wellings at Metageologist offered up this theme for Accretionary Wedge #44, one name sprang to the head of the line: Lockwood DeWitt.

It began with gabbro.

Until then, Lockwood had been one of the many amazing folks in the geoblogosphere who'd been giving me support and encouragement. Then he tweeted about some leftover gabbro from a counter installation at a Corvallis restaurant. I asked him to save me some. Then, instead of him mailing it, we decided I'd come down and pick it up. We'd go out and look at some of the local geology whilst I was there. "How neat," I thought. "I get to see some stuff with an actual geologist."

That trip pretty much changed everything. I'd been doing this all on my own, picking up what I could from books and blogs and nuggets of wisdom from folks in the geoblogosphere, but none of that can do what getting out on the rocks with someone who knows them can do. And Lockwood isn't in to this "Look at that feature, isn't that great?" sort of geological sightseeing. He wouldn't tell me what we were seeing. He'd give me a few hints and wait for me to painfully piece some of it together before he'd tell me what we were looking at. I'd been out of school for well over a decade, I was a complete amateur at geology, and here was this dude who looked a little like Santa Claus giving me bags of gorgeous geology and expecting me to figure it out.

I saw my first slickensides, some of the greatest pillow basalts in the universe, actual gabbro in the wild, tide pools threaded with dikes, and Devils Churn. I saw flesh-eating plants. I saw dunes. I saw more than you could imagine a person could in two days, and learned more than I realized. Moments from that trip pop up all the time, as I recognize a feature and put it together with something Lockwood showed me.

I often wished, when I got home, that I'd had some way to record everything he said. So I bought a digital recorder for the second trip we took, a several-day extravaganza through the Oregon interior. This was the trip where I saw Crater Lake for the first time, learned about lineaments, found faults, enormous fault scarps, and the greatest rhyolite outcrop in the universe.

This is the trip where I learned to look more closely at seemingly-boring brown desert rocks, because you never knew what might be hiding:

I'd had no idea until then that rhyolite could do such things.

And what about eruptions under Pleistocene lakes? Yeah, we had that covered, too.

That's not just a tuff ring, mind. It's also got wave-cut platforms, and the place is lousy with old shorelines. Which, because of Lockwood, I can now spot at 60 mph. We've done a lot of geology at x-mph.

Being out with Lockwood challenges my brain and my car. We took that Honda Civic of mine all the way up to the top of Paulina Peak. This may not sound impressive until you realize it's a one-lane road that's washboard and practically vertical in places. But we made it, and from there, we could see a huge variety of volcanism.

We're on top of a shield volcano, with stratovolcanoes in the background, and the whole place is littered with cindercones. (If I ever move to Oregon, I want to move to Bend. It's like coming home. And it has got a cindercone right in the middle of town.)

After that trip, even without listening to the recordings, I realized I'd picked up far more than I'd realized. When I'm out with Lockwood, it's like drinking from a firehose. I feel like I'm not learning a damned thing, it's all going by so fast. Then, a month or two later, I run across some concept he'd taught me, things go click, and once again I'm thanking the internets Lockwood and I ran across each other.

Our most recent trip through the central-southern Oregon coast and inland through the Coast Range was just the two of us - I left my poor intrepid companion home. And it's another of those trips where I'm boggled by the sheer amount of stuff I learned without realizing. It's got to the point now where I can sometimes contribute an intelligent bit to the conversation. I recognized some fine slickensides all by me lonesome. That, I have to tell you, was a moment of bliss. All of you who've ever studied the sciences know that feeling, the one that comes when you can show your teacher that you're really getting this stuff.

I've already talked about the strike-and-dip revelation. That's the kind of thing Lockwood does: points me to features, lets me guess at the answer, then demonstrates how to solve the puzzle. It's okay to make mistakes in his presence. Like the best teachers, he doesn't make me feel like an idiot for getting things wrong. He just shows me how to get them right. And he's taught me it's okay to say, "I don't know." Nobody knows it all. We can admit that, and work to fill in the gaps.

He's brought me to the point where I'm comfortable playing the geological host me own self. A lot of what I recognized at Seward Park this last time came from him. And who knows what'll happen after this next trip we've got in the works: a wild ride through the Josephine Ophiolite in California and then back up through Quartzville in Oregon. If I ever do go back for a formal degree, one of the reasons it won't be hellaciously difficult is because I'll be saying, "Oh, I saw something like that with Lockwood" about every three minutes.

It's not just me. There's a considerable contingent of the geoblogosphere that relies on him. He's one of the most knowledgeable folks around, and always willing to share that knowledge. Drop by Corvallis, and he'll be more than happy to take you round the local delights. Talk to one of the Northwest geobloggers, and you'll hear his name come up with a reverence usually reserved for scientists like Carl Sagan or Stephen J. Gould. We loves us our Lockwood.

I owe him more than he'll ever admit to. One of the main reasons I felt comfortable writing for Scientific American was because I'd learned from him, and I know he'll be there to answer questions. Jim Bennett got me started on this whole geology addiction. Lockwood's brought it to a whole new level. I can't wait to see what he teaches me next!