The Forensic Geology Box Set

by Toni Dwiggins

  The debris stream fed into a larger creek that cut a channel into the canyon side.

  The canyon steepened.

  Waterfalls muscled down over boulders.

  The trail veered close to the tumbling creek and I thought, easy to lose your footing.

  Shelburne nimbly navigated the trail like he’d done it a thousand times before.

  We dropped until our trail bottomed out onto an oak-studded ledge overlooking a wide rocky river.

  The river ran like a boulevard through a high-rise canyon.

  I looked downriver, to the west, and then upriver, to the east. We were in the southern district of the Shelburne neighborhood.

  Walter said, “Which way would Henry have gone?”

  Shelburne said, “I’m sure he’s been all over this river canyon but which way now? I don’t know. From here, the trail goes east and west. From here, we follow the river. At least according to my grandfather’s letter, as interpreted by my father. The trail meets the waterway, at the southern grapes.”

  “Grapes?”

  “Early explorers found wild grapes growing along the banks and named the river for them. They spoke Spanish. Grapes in Spanish is uvas. My grandfather spoke Spanish. My father got a Spanish-English dictionary. Voila, the Yuba River. South fork.”

  “So from here,” I said, “Henry might go either direction.”

  Shelburne nodded. “Which way would you go?”

  CHAPTER 17

  Which way would I go?

  Up there, to the canyon rim just above us, where I swore I spotted a movement. A flash of brown. Bear, deer, daypack, backpack, tent being taken down, who the hell knew. As I looked again, as I squinted and stared, I saw nothing but the native trees and brush and rock.

  So the brown thing had moved on.

  Where?

  There were a thousand places to hide along the canyon rims, on the canyon slopes.

  Down here, we three stood out like dimes in a sluice box.

  Robert Shelburne in his red Arcteryx Altra backpack—might as well paint a target on it.

  I didn't like this. I didn't mind tracking Henry Shelburne, tracking the geology of the legendary rock, but I didn't like the feeling of being tracked, in turn.

  If that's what was going on here.

  Perhaps it was just the passing shadow of a cloud.

  Storm in the offing.

  I took out my cell phone and checked the River Forecast Center—all flood-forecast points were below critical stages. Normal.

  The weather wasn't giving us a reason to turn back.

  Shelburne repeated, “Which way?”

  I turned to the geology. We had studied the geologic maps back at the lab. Now, out in the field, it was show time.

  Which way?

  The Shelburne family blue lead offshoot splintered at the river. There were mapped outcrops west, and east. So the question became, in which direction lay the contact metamorphic zone with the chiastolite hornfels aureole? Because that was the landmark Henry Shelburne would have sought.

  Walter spread his hands, east and west. “In either direction we have a pluton invading metamorphic rock. A pluton, if you’ll recall Mr. Shelburne, is a large body of igneous rock that can cook the country rock to hornfels.”

  “Good, fine.” Shelburne looked ready to bolt. “Which way?”

  I jerked a thumb downriver. “South Yuba Rivers Pluton is thataway.”

  Walter jerked a thumb upriver. “Bowman Lake Pluton is up yonder.”

  “Although,” I said, “we’re not necessarily looking for a large mapped pluton.”

  Walter nodded. “Could be a small and unmapped igneous dike.”

  “So you're guessing?” Shelburne put in.

  “Don't knock guessing,” I said. “A good onageristic estimate can be useful.” I added, “An onager is a wild ass.”

  Shelburne tried for a smile.

  Walter said, “I don't think we're in need of a wild-ass guess, yet. I like the mapped unit up yonder.”

  As did I. The rock unit up yonder was known to have been intruded by numerous small igneous dikes. I said, “I tend to agree.”

  “Then let’s go.” Shelburne turned. “Upriver.”

  More like, above the river. The river was a good sixty feet below us.

  I paused to read a wooden interpretive sign staked into the ground. Once, the river had been level with the ground we now stood upon. And then debris had washed down from the mining pit above, elevating the river bed. And then, over time, the flowing water carved out its bed anew, leaving behind compacted-gravel benches like the one beneath our feet.

  As soon as possible we’d need access to the river.

  Meanwhile, we were at the mercy of the trail.

  Save for Shelburne occasionally shouting his brother’s name, we hiked in silence. It was a roller-coaster trail that took our breath away. The trail paralleled the river but the rugged rock of the canyon walls forced the route to climb, traversing the descending ridges and knife-gullied canyons. Now and again the trail dipped down steep rock benches to skirt the river but there was no way down to the gravel banks, save a dicey scramble.

  We pushed on.

  Finally we got lucky. The trail jacked hard right and switchbacked down to the river’s rocky bench.

  “What do you think?” Walter asked me.

  I took in the lay of the land. “I think it’s prime.”

  “I think,” Shelburne said, “we should keep moving.”

  Walter turned to Shelburne. “We need to establish a baseline. This appears to be a natural catch-basin for anything coming downriver. Sediment, debris, minerals. Including, perhaps, float from a metamorphic contact upriver.”

  Shelburne gave a reluctant nod.

  I thought, something here doesn’t sit right with him. I wondered, what’s here?

  Nothing out of the ordinary, as far as I could see. The river bank was paved in cobbles and pebbles, armored with boulders. A gravelly sandbar extended halfway across the water.

  Shelburne sat on a boulder and folded his arms.

  Walter and I turned to our work. We shed backpacks and took out field kits. Walter claimed the rocky bank and I headed out on the gravel bar to sample the geology mid-river.

  I found a promising spot, a submerged bedrock hump that bridged the water and slowed its flow. A group of boulders gathered, forming deep crevices, a natural hydraulic trap on the river bottom where material coming downstream was likely to get lodged.

  I knelt to sample.

  The water was low. I wondered how much of a rainstorm was needed to saturate the watershed feeding this river. Right now, shafts of late afternoon sunlight glassed the surface. Where clouds shadowed, the river turned inky. A rainbow trout nosed the bottom, the fish multicolored as the gravel. I scanned the riverbed, noting how the rocks and sand acted as riffles, thinking geologically speaking this was an eminently likely site to find grains of gold. Nuggets, even. Nuggets by definition were water-worn pieces of gold, set free from the veins in which they formed. Taken hither and thither and yon by downflowing watercourses. And then dropped. Gold was heavy. Water needed a brute-force flow to suspend gold and move it along, and the moment the water slowed, the heaviest grains and nuggets bailed out and settled into pockets and crevices. I peered into a large crack. Looking, I abruptly realized, for the telltale metallic flash. I shifted position and did see a flash but it was silver—muscovite mica. Still, my mouth had gone a little dry. I moved on to the next crevice, the next little hollow. The gravel here was mostly buried under silt and sand that had settled out of the river flow. I bent lower and plunged my hands into the water, wetting my sleeves, running my fingers through the sandy bed, unearthing grains of quartz and chert and mica and every other freaking mineral that lived in this micro-niche but no gold.

  Hold on. What are you looking for again, lady? You’re looking for float. Diorite. Hornfels. That’s what should make your mouth go dry.

  Not gold.

  I g
lanced at Walter, who was examining a specimen under his hand lens, and then I glanced at Shelburne, who was still in that strange funk on his boulder, staring into the distance.

  They were paying me no attention.

  I recovered my dignity and paid heed to the little pool and riffle pocket where, in my professional opinion, something worth examination might be lodged. Upon closer examination I noticed a ledge. It was recessed, in shadow, and the riffling water was silty, but nevertheless I could make out the shape of a cobble in there. Hard to tell the texture and color but it was worth a closer look.

  I reached.

  My fingers closed on the cobble.

  I yelped.

  I’m not afraid of snakes but for a moment I thought this must be the hump of a coiled water snake, clammy and cold. If it were a snake it would have moved, would have recoiled from my touch, would have slunk out from the crevice and skedaddled or, worse, and wrapped itself onto my hand and given me a bite. This was no snake. This did not recoil. It simply pushed my fingers aside.

  Walter was suddenly beside me. “Cassie?”

  I let go of the thing and sat back on my haunches. Heart pounding.

  Shelburne sprinted across the gravel bar to flank me on the other side. “What is it?”

  It was a moment before I could speak. “Something’s down there.”

  CHAPTER 18

  Walter and Shelburne looked at the water.

  Looked back to me.

  “I touched it.”

  Neither of them made a move to put a hand in the water.

  “It’s not a snake.” I cast about, to explain my reaction. “But it felt...soft. It fit in my hand. About the size of my fist. It felt like...” The word came to me from some primitive zone in a dark corner of my mind. “Like a heart.”

  Shelburne went white.

  I bent back to the water, leaning farther, angling for a better view of the ledge down there, and now I got a straight-on look and saw the thing for what it was. It sat cupped on its ledge in the crevice. I understood my earlier confusion. It was indeed rounded as a river cobble, but not solid. It was big as a heart and it quivered slightly, fanned by the riffling water.

  “Cassie,” Walter said, “what the devil is down there?”

  I straightened. “Mercury.” A quivering heart of liquid mercury.

  Shelburne sucked in a deep breath, let it escape.

  “Well that’s not surprising,” Walter said.

  “It sure surprised me.”

  Walter said, “Millions of pounds were lost from the sluices. You’ll find it in the rivers and soils. You’ll certainly find droplets in catch-basins like this.”

  “Not droplets.” I held my hands apart, to demonstrate the size. A heart.

  His eyebrows lifted.

  I turned to Shelburne. “Did Henry put this here?”

  Shelburne looked taken aback. “Why would he do that?”

  “Why would he leave the dimes? His games.”

  “Even if he somehow set this up, how could he possibly know you would look down there?”

  I acknowledged the unlikelihood of the scenario but my heart rate had not yet gotten the message.

  “Look,” Shelburne said, “you get enough droplets caught in a hotspot, they coalesce. You can thank Mother Nature for that. I’ve heard of guys finding puddles big as pillows. When my dad brought us here panning, we sucked up mercury with a turkey baster. It’s all the hell over the place.”

  Big as pillows? Holy hell. A heart was big enough for me. I said, “You know a lot about it.”

  “Yes I do. As I’ve explained, Dad marched me and Henry up and down his trail.”

  “Here too?” I asked.

  “Sure. Here.” Shelburne got to his feet. “As you geologists point out, it’s a natural catch-basin. Good place for panning.”

  “Been here recently?”

  “Last time I panned for gold I was twelve years old.” Shelburne started to retreat across the gravel bar.

  “Hang on,” I said. He’d been on edge from the moment the trail brought us here, even before I’d said heart and freaked him out. “Anything else going on here?”

  Shelburne paused. “Like what?”

  “Like whatever’s been making you so edgy.”

  He turned. “Aside from the fact that my brother is missing?”

  “If there’s something else, yeah. Aside from that.”

  A shadow passed over his face. “It’s not relevant.”

  “I would like to be the judge of that,” Walter said. “Before we proceed.”

  Shelburne took a long moment and then he said, “My father died here.”

  Walter and I got to our feet. Scrambling to catch up.

  “This is news,” Walter said.

  “No kidding,” I said, “I thought your father died of a heart attack.”

  “Yes. Here. In fact, it wasn’t the heart attack that killed him. It was falling into the water and drowning.” He grimaced. “Animals got to him before the rangers found him.”

  I flinched. “That’s awful.”

  “Now you understand why this place gives me the creeps.”

  I nodded. That made two of us, now.

  “What was he doing here?” Walter asked. “Panning?”

  “No.”

  “Then?”

  “It’s not relevant.”

  “Indulge me,” Walter said.

  Shelburne shrugged. “He was sampling the water.”

  “Why?”

  “All right.” Shelburne looked at us squarely. “It’s irrelevant but let’s get it out of the way. My father, the auto mechanic, was a handy guy. He developed a piece of technology and brought it to me, looking for funding for a startup. Venture capital, it’s what I do. Dad had a plan to build a super-dredge to suck up mercury, clean up the gold country riverbeds.” He shot me a look. “You saw for yourself what’s down there.”

  I nodded. Saw, and felt.

  “Environmental remediation is the big-bucks term. There’s your new gold rush. Turns out my firm was already working with a deep-pockets company looking to get into the business. So I hooked Dad up with the company, which I’m going to call Deep Pockets. I helped bring the plan to product. I helped Dad come up with a catchy name for his subsidiary—AquaHeal. And yes, I came out here with Dad and a Deep Pockets guy a couple of times. Site survey, checking out hotspots, up and down the river. We packed in, stayed awhile.” He held up a hand. “By the way, I did mention my site scouting, earlier.”

  Walter said, evenly, “You didn’t elaborate.”

  “It wasn’t relevant. Don’t know how else I can put that.”

  “It involved your father,” I said. “He died and Henry found the ore sample and that kicked off what’s going on now.”

  “He wasn’t out here hunting gold when he died. He was here, on his own, taking water samples—as I said. I was in Sacramento trying to get the permit for a second round of tests. Had a few problems with the first round.”

  “What kind of problems?” Walter asked.

  Shelburne sighed. “Dredging is a violent process. It sucks up the riverbed—sediment and gravel along with the mercury. Breaks up large drops into smaller ones.”

  Relevant or not, I flinched. “It floured? Into reactive mercury?”

  “Yes.”

  Jesus. “You’re talking methylation.”

  “Yes. Bacteria convert the inorganic mercury into the nasty form, and that gets into the food chain.”

  I glanced at the river.

  “I wouldn’t eat the fish.” He gave a tight smile. “In fact, you can take that advisory all the way downriver to the San Francisco Bay.”

  I said, “Methylated mercury is a neurotoxin.”

  “Yes. Hence the word problems. Hence the need to tweak the technology. Hence the need for a second round of tests.”

  I shook my head.

  “By the way, storm waters rile up mercury-laden sediments all the time. Mercury gets methylated all the time. It�
�s already in the state’s water transport system. We just added to the problem.”

  “And Henry?” Walter asked. “Was he involved with the startup?”

  “No, of course not. He had no money to invest, no skills to offer. He’s hardly a company man, anyway.”

  “But he was aware of it?”

  Shelburne shifted. “Actually, no. Henry and I hadn’t been in touch. And then, at Dad’s place, I didn’t bring it up—no point until I knew if the technology would work. As far as Dad goes, he and Henry had nothing to do with one another for years. In any case, once the estate is settled, Henry will inherit half the company.”

  I said, “Did Henry know his dad died here? How he died?”

  “He read the report. Didn’t seem to rattle him. Remember, he spends his life in the wild. Hey, we Shelburnes are hunters. Dad was a hunter. Dad died as he lived, hunting the new gold rush. And he was hunted, in death.” Shelburne put his hand to his neck, as if there were a tie to adjust. “Admittedly, that’s all too wild-kingdom for me.”

  ~ ~ ~

  Walter had moved to sample upstream of the gravel bar when he shouted, “Oh dear.”

  CHAPTER 19

  I sprinted across the bar to the rocky bank.

  Shelburne was already sprinting along the bank.

  We joined Walter and looked where he was looking. Into the river.

  The water was clearer here than at the gravel bar. It ran over bedrock and it ran fast and everything on the river bed was glaringly visible. A metal bottle lay on the bottom. It was cylindrical with a screw-cap top lying alongside. It was open. It was rusted. It was about the size of an extra-large water bottle but you wouldn’t want to drink from it. A word came to mind. Flask. In my reading during the drive across the Sierra, I’d come across that word. Heavy iron flasks were needed to hold heavy liquid mercury. Seventy-six pounds of quicksilver per flask.