Margaritifer Basin (Margaritifer Trilogy Book 1)
Page 88
“We could without the Genesis.”
“Yeah, but I’d rather not. We’d just have to turn around and come back. Come on, let’s go take a look at the map and see if can find an easier way down.”
“Okay.”
They returned to Amos and brought up several THEMIS and Viking Mola images. Jeff pointed to the western portion of the chaos boundary. “I don’t see anything promising to the north. Do you?”
“No, not unless we went all the way up and around this portion of the chaos.”
“God, that’s gotta be 40 kilometers, and we still wouldn’t be in it.”
“Okay, what about south; down here, west of this crater. The slope seems fairly gentle, not much more than 5º, and we can follow the contour out this ridge then drop straight in somewhere around here.”
“Alright. Plan B, or by now, Plan C, would be to follow the east slope of the volcano all the way down into the Valles, then turn back up into the chaos.”
“Works for me.”
“And if that doesn’t work, we go home and rethink the trip.”
“Okay. Jeff, since we’re not going to be able to climb these city-sized blocks, I suggest we take samples from any bedrock that we run across on the way down. From those, maybe somebody on Earth can figure out what went on here.”
“Sounds good to me. Let’s go.”
Another two hours and Jeff pulled to a stop beside their first chaos monolith, a rock the size of a small town and 200 meters tall. “Holy shit!”
Gabe stared at it. “Yeah, and this is just a pebble.”
“Uh huh. Okay, grab a camera and some baggies. I’ll get the drill. We need to do this and keep moving.”
“Okay.”
They collected their gear and walked up to the rock face. Jeff looked up. “Good grief, we may as well be standing in the Grand Canyon, and we’re nowhere near the bottom.”
“Impressive, isn’t it.”
“That would be one word for it.” He poked his finger at the rock wall ahead of them. “I say we drill here.”
“Drill away.”
“Okay, get a baggie underneath and catch the tailings.”
“Ready.”
Jeff drilled three inches into the stone. “Got it?”
“Yes, I have it.”
“Alright, tag it and let’s get going.” As he settled into his seat in Amos he said, “You know, it took the MSL about three months to do something like that.”
Gabe chuckled. “I just worked on it. It wasn’t my idea.”
Three hours and half a dozen samples later they finally arrived at the bottom of the chaos in a kilometer-wide valley bordered by 200 to 300 meter-high rock walls. Jeff stopped. “Okay, sweetie, we’re here.” They got out and looked around. “God, this reminds me of portions of Glen Canyon in Utah, but with sand instead of water.”
“Uh huh.”
Jeff glanced at his watch. “Alright, it’s a quarter to three and we’ve been in these suits for over seven hours. What say we climb inside, get some lunch, and call it a day? We can resume our sightseeing in the morning.”
“I was hoping you’d say that.”
Wednesday, February 1, 2017
MSD 50865.370 (Sol 115)
In the morning they again suited up, detached Amos from the Genesis trailer, and began exploring the hills, valleys, mesas, and buttes of the chaos.
“Gabe, why is this so… chaotic?”
“Uh, because it’s a chaos?”
He chuckled. “That’s not what I mean. The Aram Chaos, for example, has a certain symmetry to it. In some places it almost looks as though it was laid out with a ruler and cut with a knife. But this is a mess. There’s no geometry at all to it.”
“Aram is a crater. When the groundwater release event occurred, the water in Aram had no place to go; it just ponded. Here the water could flow downstream, so some erosion probably took place.”
“Aram has an outflow channel.”
“Yes, and the chaos around that channel is about like this.”
“Not on the south side. There’s still a large area of symmetrical blocks there.”
“Jeff, it’s Mars. Who knows what went on here?”
“Well, besides being space travelers we’re also scientists. Aren’t we supposed to try to figure this stuff out?”
“I suppose, but I’m a mathematician and physicist, not a geologist. I had one semester of geology in college, and Mars was never even mentioned.”
“Right. But, what did this?”
“Subsurface ice, and perhaps liquid water, instantly evaporated, probably as a result of a giant meteorite strike, and the overlaying regolith collapsed.”
“Yeah, okay, I understand that part, but why is it so… chaotic. Why didn’t it collapse uniformly? Why isn’t it just a big flat sinkhole? This doesn’t look like a riverbed. Water takes the path of least resistance. The Samara Valles looks like a riverbed. This is chaos.”
“Probably because this geologic formation was here before the ice and water. Water flowed down the Loire Valles from the eastern highlands, and when it reached the volcano it ponded, then froze. And over who knows how many hundreds of millions of years, atmospheric dust formed a crust over it. Then when it was vaporized, the surface material collapsed between the monolithic structures that we’re looking at now.”
“So all this was here before the initial outflow from the Parana-Loire valley systems?”
“That would be my guess.”
“Okay, so again I ask, what caused it?”
“I dunno. But most of the bedrock on Mars that has been sampled so far is basaltic. So, volcanic activity during planetary formation as the crust cooled? The other possibility is that it’s ejecta from an impact. The Ladon Valles lowlands could very well be an ancient impact crater, and over 400 kilometers in diameter, and not that far away. If it is a crater, the impact almost certainly spewed city-sized rocks hundreds if not thousands of kilometers. In fact it probably spewed stuff into space.”
“Mind boggling.”
Gabe chuckled. “Yes, well, over the years that I have known you I have empirically determined that your mind is easily boggled.”
He laughed. “Ouch. Alright, wise-ass, why are all the valleys between this jumble of mesas and buttes sand dunes? Why sand dunes? Why not the remnants of the bedrock that covered the ice or water when it was evaporated?”
“I don’t know. Maybe because it’s been sitting here gathering dust for two or three billion years?”
“If that’s so, then the remains should be somewhere under this sand. Right?”
“Maybe.”
“Well, let’s see.”
“Huh?”
He pulled to a stop in a dune valley. “Grab a shovel.”
“Jeff, it could be tens or even hundreds of feet deep.”
“Yeah. Or it may only be a few inches. Let’s do a little digging and see.”
She sighed. “Oh, alright.”
Three feet down they struck rock. “That look basaltic to you?”
“Yes.”
“Well, there’s an extinct volcano about 15 klicks from here.”
“That doesn’t mean anything. This could be original bedrock that predates the chaos formation event.”
“True. Let’s get some samples. Maybe the geologists on Earth can make something of it.”
“Okay.”
For two sols they traversed as much of the chaos as they could, taking numerous samples and photos, and standing in awe at both the beauty and destruction nature had wrought on the planet.
On the morning of the third day they packed up and headed west, out of the chaos and down the Loire Valles toward the confluence of the Loire and Samara. As dusk began to set in, Jeff rubbed his eyes. “I’m tired.”
“Yeah, me too.”
“I’m gonna tell Amos to find a level spot and we’ll stop for the night.”
“Sounds good to me.”
Jeff stared at the video screen at the front of the Gen
esis module. “Wait a minute. What’s that?”
“What’s what?”
“Hang on.” He instructed Amos to stop, then zoomed in on a rock formation. “There. See that dark line running vertically through that rock formation?”
“Yeah.”
He zoomed in further. “Does that look like a crevice?”
“Hard to say in the shadow, but could be.”
“Hmmm. If it is, it would be interesting to see what’s inside one of these rocks.”
“Uh huh. But I really don’t feel like getting suited up right now.”
“Me neither. This looks like a pretty level spot. Let’s stop here for the night and go have a look in the morning.”
Saturday, February 4, 2017
MSD 50868.368 (Sol 118)
“Huh, it is a crevice,” said Jeff. “And it’s big enough to walk in.”
Gabe stopped at the mouth of the three-meter wide, thirty-meter high crevice.
“What?”
“It’s dark in there.”
“So switch on your helmet lights.”
“Are you sure there’s nothing living in there?”
He laughed. “Pretty sure. Come on.” He switched on his helmet lights and entered the crevice. About ten meters in Jeff checked his external temperature gauge. “Hey, it’s not only dark in here, it’s cold. It’s nearly 35ºF out in the valley, but it’s only 17ºF in here. I’ll bet sunlight never reaches down in here.”
“If it does, it’s only for a couple minutes a day, and even then only in mid-summer.”
Another twenty meters in and the crevice began to narrow. “Looks like we won’t be going too much farther. Look at these walls. They’re much rougher than anything we’ve seen out in the open.”
“Limited erosion.”
“Uh huh. Get some samples from the walls. Look for any kind of interesting veins. I’m gonna dig a hole in this sand and see if I can find bedrock. Let’s see if the bedrock and the walls are the same thing.”
“Okay.”
Jeff started digging. A couple feet down he hit something hard. “Pay dirt.” He dug out a bit more sand, then got down on his knees, reached down, and swiped sand off the surface. He stared at the hard glossy white substance for a moment, then gasped. “Oh my god!”
“What?”
“Come here.”
Gabe got down on her knees beside him. “What is it?”
“Ice.”
“It can’t be. Not at this latitude.”
He picked up the rock hammer, chipped out a chunk, and held it out in the palm of his glove. “Sure looks like ice.”
“Carbon dioxide?”
“No. Water.”
“How do you know?”
“If it was CO2, at this temperature it’d be sublimating in my hand. This is water ice.”
“Good god.”
“Yeah. Jackpot.”
“How much do you think there is?”
“No way of knowing. Could be a couple cubic meters, or a couple cubic miles.”
“Jesus.”
“Go get half a dozen of those gallon-sized sample bags from Amos. I’ll chip out some ice cubes.”
“Roger that.”
A few minutes later Gabe returned. “Here.”
“Hold one open.” Jeff dropped chunks of ice in until the bag was full. “Okay, squeeze as much air out as you can, then double bag it. It’ll probably melt by the time we get back, but at least we will have captured the essence of it. Then get another bag.”
Gabe sealed the last bag. “Alright, that’s it”
“Okay, grab the other shovel and help me bury this.”
“Why?”
“Oh, let’s be environmentally responsible, and do what we can to see that it doesn’t sublimate. Who knows? We may want to come back for more.”
After they stowed their samples and equipment, they returned to the Genesis and got out of their suits. Then Jeff got on the radio. “Abby, Sue, somebody there?”
A moment later Abby got on the radio. “Hi, how’s it going? What’s up?”
“You are never going to believe what we just found?”
“What?”
“Water ice.”
“You’re kidding?!”
“Nope.”
“How much?”
“A couple gallons worth, and there’s no way of telling how much is still there underground.”
“Oh my god, hydrogen.”
“Yeah.”
“Are you on your way back?”
“No, not yet. We still have a few more stops to make. Probably be another three days, but we’ll keep in touch. We’re gonna head on over to the confluence and check that out. We’ll call you again tomorrow.”
“Roger that.”
Late in the afternoon Jeff pulled to a stop in a large plain south of two peaks, about 35 kilometers southwest of the station. “That slope’s too steep. Let’s stop here for the night, then take Amos and go down there in the morning. It’s only three or four kilometers.”
Gabe smiled. “Alright.”
Sunday, February 5, 2017
MSD 50869.341 (Sol 119)
Jeff delicately negotiated his way down the 500-meter slope into the 5-kilometer wide notch carved in the mountainside at the confluence of the Loire and Samara valles. “Good god, the west face at its apex has to be the better part of half a mile high. That’s like Yosemite.”
“Yes, but it’s not. Yosemite Valley was cut by a glacier, this wasn’t. Yosemite’s faces are sheer and mostly vertical; this looks more like it was scooped out. This was cut by water, and whole lot of it.”
“Uh huh. Well, let’s get out and have a look around. See if we can find anything that was brought down from the highlands and deposited here. That would pretty much prove the water theory.”
“Okay.”
They climbed out, grabbed a couple small folding shovels, and began poking around. Jeff dug a hole about a foot deep, extracted a small sample from the bottom, put it in a plastic bag, and labeled it. “Hey Gabe, this isn’t dust atop bedrock, and it’s not sand. This is… for lack of a better word, dirt. And it’s easy to dig in.”
“Uh huh, it’s a flood plain. This is alluvium, with a thin layer of dust on top.”
“Wish we had Big Jake down here and could dig eight or ten feet into this stuff. See what it’s really made of.” He heard Gabe gasp softly. “What?”
She walked over to him and held out her hand. “Look.”
He took the rock and slowly turned it over in his hand, staring at it in disbelief. “This isn’t iron pyrite.”
“No.”
“It’s gold.”
“Uh huh. A nugget.”
“I’ll be damned. Let’s look around, see if we can find some more.” After a minute of searching, Jeff found one. “Found another.”
“So did I.”
He slowly looked around. “Good god, Gabe, this is a placer deposit; a five square mile placer deposit. Including what’s buried, there could be hundreds of tons of the stuff in here.”
“Yeah. And that doesn’t include what’s upstream and further downstream to the west. This is unbelievable. Can we take some home?”
“Uh, sure, that would be a good idea. But remember, the sample return MAV has a load limit of 1,500 pounds. If we take back nothing more than three-quarters of a ton of gold, JPL may be interested, but a little disappointed.”
“You think?”
“On the other hand, 1,500 pounds of Martian gold nuggets on eBay might pay for the trip.”
For three hours they walked around the area picking up nuggets and taking samples. While Gabe hiked over to the west wall of the notch and took some drill tailing samples, Jeff returned to Amos, pulled out one of their signboards and, with a broad marker, made up a sign.
Gabriel Mine
Trespassers
will be shot.
He attached the sign to a plastic stake, and drove it into the ground. When Gabe returned he gave her a handful of n
uggets and said, “Go stand by the sign.”
She turned around, looked, and laughed. “You think we’ll have many trespassers?”
“No, not for a while. But someday they’ll come.”
Jeff took some pictures of her and the sign, then had Amos take pictures of both of them with his MastCam. “Alright, let’s make sure we’ve got all this stuff tagged and bagged, and head on back. I don’t know about you, but I’m hungry.”
Tuesday, February 7, 2017
MSD 50871.686 (Sol 121)
The four of them stood silently in the lab, staring at the pile of plastic-bagged gold nuggets.
Abby picked one up and eyed it carefully. “You’re sure this is really gold.”
Jeff nodded. “That’s what Amos’ laser spectrometer says, alloyed with about 8% silver and a few trace elements. Roughly 22 carat.”
“And it’s just lying around on the ground?”
“Uh huh.”
“And there’s more?”
“Yeah, lots. Probably tons of it.”
“Jesus.”
“Yeah.”
“What’s this worth?”
Jeff shrugged. “Beats me. Gabe?”
Gabe shook her head. “I don’t know. What is gold selling for these days?”
“Oh, around $2,000 an ounce, I think.”
“Well, we’ve got about eight kilos, 22 carat, so about 0.92 fine. That’s roughly 260 ounces… $520,000, give or take.”
Abby chuckled. “Not bad wages for a couple hours work.”
Jeff shook his head. “Yeah, but it’ll cost a lot more than that just to get it back to Earth.”
“It can’t cost that much.”
“Gabriel?”
Gabe sighed. “Well, if upon our return to Earth the only tangible item we have to show for the trip is 17.6 pounds of gold, the net cost to get it home is roughly the cost of the trip, $3 billion, or around $10.6 million per ounce.”
Abby rolled her eyes. “Oh, details. Can I have one?”
Jeff held his hand out toward the stack. “Help yourself.” He chuckled. “You can write me a check when we get home.”