WEBVTT 00:00:00.000 --> 00:00:02.980 What if a single, you know, relatively short 00:00:02.980 --> 00:00:06.519 river in the south of Spain could act as a literal 00:00:06.519 --> 00:00:08.660 time machine? Oh, I love that framing. Right. 00:00:08.900 --> 00:00:11.279 And I don't mean a metaphorical sit on the bank 00:00:11.279 --> 00:00:12.980 and just kind of think about the past kind of 00:00:12.980 --> 00:00:14.699 time machine. Sure, sure. I mean, a physical 00:00:14.699 --> 00:00:17.179 record of the Earth tearing itself open. Yeah, 00:00:17.280 --> 00:00:20.969 literally. A journey taking you from, like, Nine 00:00:20.969 --> 00:00:24.070 million year old geological escape rooms straight 00:00:24.070 --> 00:00:27.510 through to five thousand year old cliffside fortresses 00:00:27.510 --> 00:00:29.809 built by some of Europe's earliest settlers. 00:00:30.550 --> 00:00:32.810 Welcome to the deep dive. We're so glad you're 00:00:32.810 --> 00:00:36.009 here. It really is quite the the intricate journey 00:00:36.009 --> 00:00:38.350 we are mapping out today. It totally is. And 00:00:38.350 --> 00:00:41.009 today's mission is pulling apart a brilliantly 00:00:41.009 --> 00:00:44.090 dense Wikipedia article detailing the Cassin 00:00:44.090 --> 00:00:46.509 River. The Cassin River. Yeah. This is a waterway 00:00:46.509 --> 00:00:48.929 in Andalusia, Spain, down in the province of 00:00:48.929 --> 00:00:51.600 Grenada. But we aren't just doing a rote geography 00:00:51.600 --> 00:00:53.859 lesson today. No, definitely not. The goal is 00:00:53.859 --> 00:00:56.520 to truly understand the underlying mechanics 00:00:56.520 --> 00:00:59.840 of how water acts as the ultimate sculptor, you 00:00:59.840 --> 00:01:02.399 know, of both the earth and human history. Right. 00:01:02.619 --> 00:01:04.980 Because when you look at a river today, standing 00:01:04.980 --> 00:01:09.439 on its banks, it looks, well, permanent. Yeah, 00:01:09.439 --> 00:01:11.599 it really does. It gives the illusion that it 00:01:11.599 --> 00:01:14.159 has always been there, just quietly flowing in 00:01:14.159 --> 00:01:17.659 that exact path. But the Cason River's story... 00:01:17.760 --> 00:01:21.000 is fundamentally one of dramatic violent change. 00:01:21.200 --> 00:01:23.359 It's kind of crazy when you dig into it. What's 00:01:23.359 --> 00:01:26.200 fascinating here is the sheer scale of the river's 00:01:26.200 --> 00:01:28.620 journey from being trapped in a basin to eventually 00:01:28.620 --> 00:01:31.400 carving out a sanctuary for early humans. To 00:01:31.400 --> 00:01:33.920 understand the beautiful, rugged canyon environment 00:01:33.920 --> 00:01:36.459 that exists right now, we actually have to start 00:01:36.459 --> 00:01:38.280 our story at a time when this river couldn't 00:01:38.280 --> 00:01:40.560 go anywhere at all. Nowhere at all? Right. It 00:01:40.560 --> 00:01:42.519 was essentially trapped. OK, let's untack this. 00:01:42.579 --> 00:01:44.920 We have to go way back. Way back. We are looking 00:01:44.920 --> 00:01:47.980 at the Late Tortonian and the Middle and Late 00:01:47.980 --> 00:01:50.879 Tyrolean eras. Geologically speaking, we are 00:01:50.879 --> 00:01:55.000 talking roughly 9 .0 to 5 .3 million years ago. 00:01:55.079 --> 00:01:57.180 A massive stretch of time. Yeah. And during this 00:01:57.180 --> 00:02:00.079 massive stretch of time, the entire Granada Basin 00:02:00.079 --> 00:02:02.790 was what Geologists classify as an endorheic 00:02:02.790 --> 00:02:06.170 basin. That is the the crucial foundational term 00:02:06.170 --> 00:02:09.370 for this whole narrative endorheic And the best 00:02:09.370 --> 00:02:11.990 way I can think to visualize an Andorheic basin 00:02:11.990 --> 00:02:15.909 for you is to imagine a giant, regional -sized 00:02:15.909 --> 00:02:18.669 bathtub. A bathtub, right. But the drain has 00:02:18.669 --> 00:02:21.449 been completely plugged up with a rubber stopper. 00:02:21.770 --> 00:02:24.270 You had rivers flowing in from the eastern mountains 00:02:24.270 --> 00:02:26.930 and rivers flowing in from the southwest, all 00:02:26.930 --> 00:02:30.289 pouring into the central lake in the basin. Pouring 00:02:30.289 --> 00:02:33.349 in, but not leaving. Exactly. There was absolutely 00:02:33.349 --> 00:02:35.789 no exit. Well, the bathtub visual works perfectly 00:02:35.789 --> 00:02:40.080 for the mechanics. scale that up to a terrifying 00:02:40.080 --> 00:02:43.580 degree. Oh, for sure. Imagine if the water evaporating 00:02:43.580 --> 00:02:47.199 from that closed tub left behind thousands of 00:02:47.199 --> 00:02:50.759 tons of heavy, mineral -rich sludge every single 00:02:50.759 --> 00:02:53.500 year. Yeah, that's a lot of sludge. In a closed 00:02:53.500 --> 00:02:55.280 system like that, the water has nowhere to flow 00:02:55.280 --> 00:02:57.300 out to the sea. It evaporates, sure, but all 00:02:57.300 --> 00:03:00.180 the sand, gravel, the loose clays. The heavy 00:03:00.180 --> 00:03:02.840 stuff. Right. The immense volume of sediment 00:03:02.840 --> 00:03:04.860 that those rivers carry down from the surrounding 00:03:04.860 --> 00:03:07.120 mountains, it all just settles at the bottom. 00:03:07.800 --> 00:03:10.180 Millions of years of rivers acting like, I don't 00:03:10.180 --> 00:03:13.039 know, delivery trucks, just dumping earth into 00:03:13.039 --> 00:03:15.460 this locked room, slowly filling it up to the 00:03:15.460 --> 00:03:18.860 brim. It's a landscape defined entirely by deposition. 00:03:19.259 --> 00:03:22.199 It is purely collecting. Just piling up. There 00:03:22.199 --> 00:03:25.389 is no carved terrain. Just an ever thickening 00:03:25.389 --> 00:03:28.069 layer of flat heavy sediment pressing down on 00:03:28.069 --> 00:03:30.150 the earth, but the earth rarely stays static 00:03:30.150 --> 00:03:32.719 forever, you know Eventually, it decides it's 00:03:32.719 --> 00:03:35.520 time for a breakout. A massive structural one. 00:03:35.979 --> 00:03:38.539 As we move out of those eras and into the Pliocene 00:03:38.539 --> 00:03:41.240 and eventually the earliest Pleistocene eras, 00:03:41.479 --> 00:03:44.199 the tectonic plunning of the entire Iberian region 00:03:44.199 --> 00:03:46.580 radically shifts. The Earth is actually moving. 00:03:46.840 --> 00:03:49.039 Exactly. The Earth's crust is moving. Mountains 00:03:49.039 --> 00:03:51.539 are pushing up. And because of this regional 00:03:51.539 --> 00:03:54.280 tilting, the western part of this basin started 00:03:54.280 --> 00:03:56.900 being drained by the Paleo -Casene River system. 00:03:57.000 --> 00:03:59.520 OK. It started pushing north and eventually hooking 00:03:59.520 --> 00:04:02.419 west. But the real game -changer, the mechanism 00:04:02.419 --> 00:04:04.680 that broke the bathtub, was the Janelle River. 00:04:05.259 --> 00:04:07.620 When I was looking into the Janelle River's role 00:04:07.620 --> 00:04:11.120 in this, I was just stunned by the sheer physics 00:04:11.120 --> 00:04:13.719 of it. Oh, it's wild. The Janelle River physically 00:04:13.719 --> 00:04:16.259 changed its course to flow west, linked up with 00:04:16.259 --> 00:04:18.920 the Paleo -Cassine system, and suddenly the entire 00:04:18.920 --> 00:04:21.779 basin flipped from being endorheic to completely 00:04:21.779 --> 00:04:25.089 exorheic. Exorheic. meaning it drains out. Right. 00:04:25.269 --> 00:04:28.089 The drain in the bathtub was violently unplugged. 00:04:28.329 --> 00:04:30.730 Well, the sheer scale of consequence from that 00:04:30.730 --> 00:04:34.430 single hydrogeological event is staggering. It 00:04:34.430 --> 00:04:36.430 flipped a switch in the Earth's mechanics for 00:04:36.430 --> 00:04:38.790 the entire region. It totally did. Think about 00:04:38.790 --> 00:04:41.829 the energy involved. For millions of years, the 00:04:41.829 --> 00:04:44.990 Granada Basin had been passively collecting sediments. 00:04:45.269 --> 00:04:48.129 But once that river system broke out and found 00:04:48.129 --> 00:04:51.250 a downward path to the sea, the flowing water 00:04:51.250 --> 00:04:53.329 gained incredible kinetic power. It's moving 00:04:53.329 --> 00:04:56.829 fast now. Very fast. The basin went from collecting 00:04:56.829 --> 00:04:59.350 sediments to aggressively eroding them. So the 00:04:59.350 --> 00:05:01.709 river stops being a delivery truck dropping off 00:05:01.709 --> 00:05:04.350 dirt and suddenly becomes a massive excavator 00:05:04.350 --> 00:05:06.410 digging it all back up. That's a great way to 00:05:06.410 --> 00:05:09.000 put it. And erosion isn't just water lightly 00:05:09.000 --> 00:05:11.759 touching rock. It's water carrying abrasive sand 00:05:11.759 --> 00:05:14.339 and gravel, acting like liquid sandpaper at high 00:05:14.339 --> 00:05:17.240 speed. Wow! Liquid sandpaper! Yeah. That shift 00:05:17.240 --> 00:05:19.660 from deposition to aggressive erosion is what 00:05:19.660 --> 00:05:22.040 sets the stage for the dramatic landscapes that 00:05:22.040 --> 00:05:25.139 define the region today. The water was now slicing 00:05:25.139 --> 00:05:28.019 straight down through millions of years of that 00:05:28.019 --> 00:05:30.970 soft, accumulated sediment. So this river spends 00:05:30.970 --> 00:05:33.410 millions of years acting like a buzzsaw, creating 00:05:33.410 --> 00:05:36.850 these massive steep drops. Exactly. Geologically, 00:05:37.269 --> 00:05:40.550 that is a violent process, but biologically it 00:05:40.550 --> 00:05:43.589 creates a fortress. Which brings us to the present 00:05:43.589 --> 00:05:46.449 -day geography and the river's most spectacular 00:05:46.449 --> 00:05:52.089 feature. Yes. The word tajos refers to these 00:05:52.089 --> 00:05:55.910 sheer, steep cuts or gorges. And the scale of 00:05:55.910 --> 00:05:59.110 this specific gorge is just breathtaking. Let's 00:05:59.110 --> 00:06:01.129 trace the water from the very top, because the 00:06:01.129 --> 00:06:03.230 contrast between where it starts and where it 00:06:03.230 --> 00:06:05.790 ends up is amazing. It really is night and day. 00:06:06.170 --> 00:06:09.029 The Cansin River originates high up, over a thousand 00:06:09.029 --> 00:06:11.550 meters above sea level in the Sierra de la Almejada. 00:06:11.850 --> 00:06:14.529 The water filters down from these high -altitude 00:06:14.529 --> 00:06:17.410 aquifers made of limestone, shale, and quartzite. 00:06:17.529 --> 00:06:20.230 Which is an important detail. Limestone and quartzite 00:06:20.230 --> 00:06:23.029 act almost like giant natural sponges. Oh, really? 00:06:23.149 --> 00:06:25.410 Yeah, they hold the water and release it slowly 00:06:25.410 --> 00:06:27.730 and consistently. That's why the river can flow 00:06:27.730 --> 00:06:29.970 year -round and continue its work of erosion 00:06:29.970 --> 00:06:32.180 rather than just flashing and drying up. That 00:06:32.180 --> 00:06:34.139 makes sense. It bursts out into the world through 00:06:34.139 --> 00:06:36.540 these wilderness springs with beautifully evocative 00:06:36.540 --> 00:06:40.100 names. You have Agujerio Caliente, Manticana 00:06:40.100 --> 00:06:42.980 Las Gondrinas. Very poetic. They sound perfectly 00:06:42.980 --> 00:06:46.040 serene and they run through these pristine, high 00:06:46.040 --> 00:06:49.459 altitude wilderness areas. The runoff from the 00:06:49.459 --> 00:06:51.500 north face of those mountains eventually collects 00:06:51.500 --> 00:06:54.300 in what is now the Los Bermejales Reservoir. 00:06:54.620 --> 00:06:56.879 But once the water leaves that reservoir and 00:06:56.879 --> 00:07:01.079 heads north, the serene sanctuary vibe abruptly 00:07:01.079 --> 00:07:04.660 ends. It's over. Completely. The underlying geology 00:07:04.660 --> 00:07:08.680 changes and the terrain gets intense. The river 00:07:08.680 --> 00:07:11.519 hits the Tajos de los Bremahalas. Wait, so when 00:07:11.519 --> 00:07:13.860 we say the earth here is made of quaternary sandstones, 00:07:14.060 --> 00:07:16.339 clays, and conglomerates, what kind of rock are 00:07:16.339 --> 00:07:18.620 we actually dealing with? Good question. Is this 00:07:18.620 --> 00:07:21.100 like the crumbly stuff left over from the bathtub 00:07:21.100 --> 00:07:23.360 era? That is exactly what it is. Because these 00:07:23.360 --> 00:07:25.459 were loosely packed sediments from when the basin 00:07:25.459 --> 00:07:29.220 was a giant lake, they lack the solid heat -forged 00:07:29.220 --> 00:07:31.779 crystalline structure of older rocks like granite. 00:07:31.779 --> 00:07:34.759 So they're soft. Very. They are highly susceptible 00:07:34.759 --> 00:07:38.360 to rapid water erosion. So when the newly energized 00:07:38.360 --> 00:07:41.720 river hit this soft quaternary layer, it didn't 00:07:41.720 --> 00:07:44.100 just casually flow over it. It carved it up. 00:07:44.519 --> 00:07:47.389 It dug straight down, almost like a knife. through 00:07:47.389 --> 00:07:50.990 an incredibly dense layer cake. Wow. It created 00:07:50.990 --> 00:07:54.350 this incredibly narrow canyon with sudden, sheer 00:07:54.350 --> 00:07:57.529 100 -meter drops. If you were standing at the 00:07:57.529 --> 00:08:00.129 edge of the Tajos today, you'd be looking down 00:08:00.129 --> 00:08:03.889 a 330 -foot vertical plunge of raw, exposed clay 00:08:03.889 --> 00:08:07.209 and sandstone. It is a harsh, raw, deeply eroded 00:08:07.209 --> 00:08:09.370 environment. And apparently people hike this. 00:08:09.430 --> 00:08:11.600 They do. There is a walking trail through the 00:08:11.600 --> 00:08:13.819 gorge, but it's officially classified as a difficult 00:08:13.819 --> 00:08:15.399 route. You aren't just taking a stroll, you are 00:08:15.399 --> 00:08:18.040 dealing with sections of hanging bridges, literal 00:08:18.040 --> 00:08:20.699 metal ladders bolted directly into the rock face. 00:08:20.860 --> 00:08:23.000 Not for the think of heart. No, and there are 00:08:23.000 --> 00:08:25.079 support ropes you have to grip just to navigate 00:08:25.079 --> 00:08:28.220 the narrowest cuts. Oh, and there is a hilarious 00:08:28.220 --> 00:08:30.019 historical quirk on this trail. Oh, I know what 00:08:30.019 --> 00:08:32.059 you're gonna say. You are hiking through this 00:08:32.059 --> 00:08:34.860 treacherous prehistoric gorge, gripping a rope 00:08:34.860 --> 00:08:38.080 for dear life, and you arrive at a majestic landmark 00:08:38.080 --> 00:08:40.940 known as the Roman Bridge, which, as it turns 00:08:40.940 --> 00:08:43.840 out, was actually built in the 1940s. A slight 00:08:43.840 --> 00:08:46.299 branding error by the local tourism board, perhaps. 00:08:46.539 --> 00:08:48.679 Just a bit. I mean, missing the fall of the Roman 00:08:48.679 --> 00:08:52.100 Empire by roughly 1 ,500 years is quite the stretch. 00:08:52.159 --> 00:08:55.200 It is. But 1940s concrete bridge doesn't have 00:08:55.200 --> 00:08:57.799 the same romantic ring to it when you're marketing 00:08:57.799 --> 00:09:00.080 a rugged adventure trail. It really doesn't. 00:08:59.980 --> 00:09:03.000 but the human infrastructure is really just a 00:09:03.000 --> 00:09:06.440 footnote here. What is truly remarkable about 00:09:06.440 --> 00:09:09.100 this gorge is the natural adaptation happening 00:09:09.100 --> 00:09:12.320 on those sheer walls. The wildlife. Yes. This 00:09:12.320 --> 00:09:15.299 deep, harsh canyon with its 100 -meter vertical 00:09:15.299 --> 00:09:18.159 drop somehow became a thriving, heavily protected 00:09:18.159 --> 00:09:20.559 ecosystem. I mean, how does anything survive 00:09:20.559 --> 00:09:23.720 on a sheer, crumbly clay cliff? There's no ground 00:09:23.720 --> 00:09:26.460 to stand on. By entirely utilizing the verticality. 00:09:26.600 --> 00:09:28.860 The canyon walls offer perfect protection from 00:09:28.860 --> 00:09:31.179 land -based predators that simply cannot navigate 00:09:31.179 --> 00:09:33.960 the drops. You say they'd fall. Exactly. It creates 00:09:33.960 --> 00:09:37.299 an aerodynamic haven. You have an incredible 00:09:37.299 --> 00:09:40.340 array of bird colonies that make their home right 00:09:40.340 --> 00:09:43.600 on the sheer walls, utilizing the updrafts created 00:09:43.600 --> 00:09:46.539 by the narrow gorge. Oh, wow. You have raptors 00:09:46.539 --> 00:09:49.019 soaring through the corridor, common kestrels, 00:09:49.360 --> 00:09:51.990 and the Eurasian eagle owl. scientifically known 00:09:51.990 --> 00:09:55.049 as bubo bubo. The bubo bubo. It thrives here 00:09:55.049 --> 00:09:57.389 because it can nest in the inaccessible crags 00:09:57.389 --> 00:10:00.370 high up and use the narrow river corridor below 00:10:00.370 --> 00:10:03.149 as a concentrated hunting ground. That's brilliant. 00:10:03.330 --> 00:10:06.250 And alongside the massive raptors you have colonies 00:10:06.250 --> 00:10:09.870 of western jackdaws, rock doves, bee eaters, 00:10:10.110 --> 00:10:13.009 barn swallows, and Eurasian crag martens. It 00:10:13.009 --> 00:10:15.629 is a veritable high -rise of avian life. Just 00:10:15.629 --> 00:10:18.110 a wall of birds. Pretty much. Yeah. But it's 00:10:18.110 --> 00:10:20.330 not just birds taking advantage of the verticality. 00:10:20.360 --> 00:10:22.460 The gorge is also navigated by the southeastern 00:10:22.460 --> 00:10:25.279 Spanish Ivex. Wild mountain goats just casually 00:10:25.279 --> 00:10:28.139 defying gravity on a 330 -foot drop. It's amazing 00:10:28.139 --> 00:10:30.220 to watch. They have highly specialized cloven 00:10:30.220 --> 00:10:32.879 hooves with rubbery pads that allow them to grip 00:10:32.879 --> 00:10:35.299 the almost vertical clay and sandstone walls. 00:10:35.440 --> 00:10:37.360 Gripping clay. Yeah, they use the sheer drops 00:10:37.360 --> 00:10:39.620 as a shield against predators. It paints such 00:10:39.620 --> 00:10:42.639 a vivid, almost contradictory picture. You have 00:10:42.639 --> 00:10:45.399 this river that spent millennia violently tearing 00:10:45.399 --> 00:10:48.159 the earth open, destroying the flat landscape. 00:10:48.740 --> 00:10:52.120 But in doing so, it accidentally carved out this 00:10:52.120 --> 00:10:55.820 perfect fortified sanctuary for an entire vertical 00:10:55.820 --> 00:10:58.379 biome. Exactly. And that concept of a fortified 00:10:58.379 --> 00:11:01.320 sanctuary brings us to the human element of the 00:11:01.320 --> 00:11:04.000 Cassian River story. Because wildlife weren't 00:11:04.000 --> 00:11:07.480 the only ones to look at those towering, unscalable 00:11:07.480 --> 00:11:11.659 walls and realize the strategic value of an inaccessible 00:11:11.659 --> 00:11:13.820 fortress. Here's where it gets really interesting. 00:11:14.039 --> 00:11:15.799 We're zooming forward from millions of years 00:11:15.799 --> 00:11:19.169 ago to about 5 ,000 years ago. The Neolithic 00:11:19.169 --> 00:11:22.230 era. The early humans. Early humans look at the 00:11:22.230 --> 00:11:24.850 Tajos de los Bermejales with its sheer cliffs 00:11:24.850 --> 00:11:26.970 and its flowing water, and they decide to move 00:11:26.970 --> 00:11:29.149 right in. Literally into the walls of the canyon. 00:11:29.309 --> 00:11:32.090 Yes. They lived sheltering under the overhanging 00:11:32.090 --> 00:11:34.409 walls. And to me, this isn't just seeking shelter. 00:11:34.710 --> 00:11:37.850 This is a prehistoric high -rise apartment complex. 00:11:37.970 --> 00:11:39.940 That's a really good analogy. They didn't just 00:11:39.940 --> 00:11:42.860 find deep caves to hide in. They found shallow 00:11:42.860 --> 00:11:45.399 natural cavities and overhangs in the canyon 00:11:45.399 --> 00:11:49.100 walls. And they actively built physical dry stone 00:11:49.100 --> 00:11:51.460 walls across the front to enclose them, making 00:11:51.460 --> 00:11:54.200 them into secure elevated homes. They were engineering 00:11:54.200 --> 00:11:55.940 their environment. And think about the brilliant 00:11:55.940 --> 00:11:58.860 strategy of it. You live high up in an enclosed 00:11:58.860 --> 00:12:02.860 rock cavity where no rival group or large predator 00:12:02.860 --> 00:12:05.580 can easily reach you. Right. Because of the drop. 00:12:05.820 --> 00:12:08.039 But you have this conveyor belt of resources. 00:12:08.360 --> 00:12:11.120 Fresh water, fish, hunting grounds flowing right 00:12:11.120 --> 00:12:13.080 past you at the bottom of what is essentially 00:12:13.080 --> 00:12:16.399 a massive natural fortress moat. And the wild 00:12:16.399 --> 00:12:18.860 thing is, you can still see the traces of some 00:12:18.860 --> 00:12:21.279 of these built walls today. You can, but this 00:12:21.279 --> 00:12:23.460 raises an important question about the physical 00:12:23.460 --> 00:12:26.340 logistics of living there. It's a detail that 00:12:26.340 --> 00:12:28.720 is easy to gloss over if you aren't speaking 00:12:28.720 --> 00:12:32.090 about the scale of geological time. Those Neolithic 00:12:32.090 --> 00:12:34.370 dwellings, those high -rise apartments. Today, 00:12:34.450 --> 00:12:37.110 they sit about 10 meters above the present river 00:12:37.110 --> 00:12:39.149 level. 10 meters. That's like over 30 feet in 00:12:39.149 --> 00:12:41.429 the air. Over 30 feet. Lugging water and supplies 00:12:41.429 --> 00:12:45.149 up a 30 -foot sheer cliff every single day sounds 00:12:45.149 --> 00:12:48.970 exhausting, even with ladders. It would be. If 00:12:48.970 --> 00:12:51.250 we connect this to the bigger picture of the 00:12:51.250 --> 00:12:54.509 river's geological history, that constant relentless 00:12:54.509 --> 00:12:56.990 erosion we talked about earlier, we realize the 00:12:56.990 --> 00:13:00.269 canyon floor wasn't 30 feet down 5 ,000 years 00:13:00.269 --> 00:13:02.259 ago. Wait, are you saying the physical river 00:13:02.259 --> 00:13:05.320 was higher up the cliff face? Yes. The river 00:13:05.320 --> 00:13:07.740 was physically much closer to those dwellings 00:13:07.740 --> 00:13:09.620 when the Neolithic people actually lived there. 00:13:09.799 --> 00:13:12.960 Oh, wow. They absolutely built their homes slightly 00:13:12.960 --> 00:13:15.960 elevated for defensive reasons, using stairways 00:13:15.960 --> 00:13:17.740 and ladders to reach them, keeping themselves 00:13:17.740 --> 00:13:21.200 safe. But over the last five millennia, the Cassine 00:13:21.200 --> 00:13:23.360 River just kept doing what it does. Which is 00:13:23.360 --> 00:13:26.110 digging. It kept digging. That is a mind -bending 00:13:26.110 --> 00:13:28.789 concept. So the human history stayed bolted to 00:13:28.789 --> 00:13:31.570 the wall, but the earth itself moved. The river 00:13:31.570 --> 00:13:33.509 literally dropped the floor out from under their 00:13:33.509 --> 00:13:36.929 history. It excavated roughly 30 feet of solid 00:13:36.929 --> 00:13:40.250 quaternary sandstone and clay over 5 ,000 years 00:13:40.250 --> 00:13:42.590 while those abandoned walls just sat up there 00:13:42.590 --> 00:13:44.570 watching the water get further and further away. 00:13:44.669 --> 00:13:47.450 That's so much rock. If you do the math on that, 00:13:47.850 --> 00:13:50.809 it means the river has been carving away about 00:13:50.809 --> 00:13:54.500 two millimeters of solid rock every single year 00:13:54.500 --> 00:13:57.960 since the Neolithic era. Two millimeters a year. 00:13:58.120 --> 00:14:00.620 It is the perfect illustration of water as a 00:14:00.620 --> 00:14:03.620 slow, unstoppable sculptor. And because the river 00:14:03.620 --> 00:14:05.620 was the center of their lives and physically 00:14:05.620 --> 00:14:08.519 closer to their homes, their artifacts naturally 00:14:08.519 --> 00:14:10.820 found their way into the water. They did. Which 00:14:10.820 --> 00:14:13.340 brings us to perhaps the most significant historical 00:14:13.340 --> 00:14:16.120 discovery in this entire area. The Cassine Pot. 00:14:16.440 --> 00:14:19.039 or the Olla de Cacín as it is known in Spanish. 00:14:19.200 --> 00:14:21.620 It's an ancient clay vessel that was found right 00:14:21.620 --> 00:14:24.120 down there in the riverbed. The water had essentially 00:14:24.120 --> 00:14:26.759 swallowed it and held onto it for millennia and 00:14:26.759 --> 00:14:29.009 preserved it. It's such a significant find that 00:14:29.009 --> 00:14:31.149 it was carefully extracted from the gorge and 00:14:31.149 --> 00:14:33.409 is now preserved in the National Archaeological 00:14:33.409 --> 00:14:36.429 Museum in Madrid. Its significance goes far beyond 00:14:36.429 --> 00:14:39.750 simply being an old clay pot. The Oia de Cassin 00:14:39.750 --> 00:14:42.590 is a specific type of artifact known as cardium 00:14:42.590 --> 00:14:45.230 pottery. Okay. And it represents the most southern 00:14:45.230 --> 00:14:47.850 example of this specific pottery found in all 00:14:47.850 --> 00:14:50.929 of Europe. Which begs the question, What exactly 00:14:50.929 --> 00:14:54.149 makes cardium pottery so special to archaeologists? 00:14:54.730 --> 00:14:57.649 Why does this one pot in Madrid matter so much 00:14:57.649 --> 00:14:59.929 to the timeline of human history? Well, cardium 00:14:59.929 --> 00:15:02.330 pottery is named after the Cerastoderma edul, 00:15:02.789 --> 00:15:05.549 which is a type of marine cockle shell. A seashell? 00:15:05.690 --> 00:15:08.350 Yes, a seashell. During the Neolithic period, 00:15:08.769 --> 00:15:11.690 a specific culture of early humans would press 00:15:11.690 --> 00:15:13.929 these cockle shells into the wet clay of their 00:15:13.929 --> 00:15:16.990 pottery to create distinct decorative imprints 00:15:16.990 --> 00:15:19.590 before firing it. It's often called impressed 00:15:19.590 --> 00:15:22.809 wear. But a cockle shell is a marine shell. That's 00:15:22.809 --> 00:15:25.769 a coastal resource. The Cassine River Gorge is 00:15:25.769 --> 00:15:28.149 tucked away inland deep in the rugged mountains 00:15:28.149 --> 00:15:31.490 of Andalusia. Exactly the point. This pottery 00:15:31.490 --> 00:15:33.629 technique originated along the coastlines of 00:15:33.629 --> 00:15:36.159 the Mediterranean. It tracks the maritime expansion 00:15:36.159 --> 00:15:38.639 of early farming cultures. Oh, I see. So when 00:15:38.639 --> 00:15:40.940 archaeologists find a pot stamped with coastal 00:15:40.940 --> 00:15:43.460 shells buried deep inside an inland river gorge, 00:15:43.740 --> 00:15:46.220 it becomes a massive archaeological marker. Proof 00:15:46.220 --> 00:15:48.580 of movement. Right. It proves that these Neolithic 00:15:48.580 --> 00:15:51.000 people didn't just stay on the beaches. They 00:15:51.000 --> 00:15:53.519 migrated inland, navigating these treacherous 00:15:53.519 --> 00:15:56.159 mountain passes. Or they established complex, 00:15:56.320 --> 00:15:58.419 long -distance trade networks with coastal groups. 00:15:58.879 --> 00:16:03.159 That is incredible. These people pushed inland. 00:16:03.289 --> 00:16:06.710 found this violently carved gorge, recognized 00:16:06.710 --> 00:16:09.250 it as a natural fortress, built their ladders, 00:16:09.490 --> 00:16:12.230 set up their high rises, and brought their distinct 00:16:12.230 --> 00:16:14.590 coastal pottery traditions with them. And then 00:16:14.590 --> 00:16:16.909 they left. And then they left. And the river 00:16:16.909 --> 00:16:18.970 just kept cutting deeper and deeper into the 00:16:18.970 --> 00:16:21.309 earth, preserving the traces of their homes high 00:16:21.309 --> 00:16:24.169 up on the canyon walls while burying their pottery 00:16:24.169 --> 00:16:27.129 deep in the riverbed. It truly functions as a 00:16:27.129 --> 00:16:30.149 time machine. The geology and the human anthropology 00:16:30.149 --> 00:16:32.490 are completely intertwined. So what does this 00:16:32.490 --> 00:16:35.179 all mean? We started this deep dive looking at 00:16:35.179 --> 00:16:38.139 the documentation of a river in Andalusia that 00:16:38.139 --> 00:16:41.259 flows north to join the Genual River. On paper, 00:16:41.440 --> 00:16:43.759 it is just another geographical line on a map. 00:16:43.799 --> 00:16:45.720 Sure. But when you really look at the mechanics 00:16:45.720 --> 00:16:48.480 of it... The Cassine River is a living, flowing 00:16:48.480 --> 00:16:50.919 record of the Earth's sheer power and consequence. 00:16:51.440 --> 00:16:54.360 It is the story of an ancient, trapped lake finally 00:16:54.360 --> 00:16:56.759 breaking its boundaries. Unplugging the bathtub. 00:16:57.019 --> 00:17:00.080 Exactly. It's the story of water violently carving 00:17:00.080 --> 00:17:03.019 a 100 meter gorge out of soft clay, dropping 00:17:03.019 --> 00:17:05.799 the floor millimeter by millimeter. And it's 00:17:05.799 --> 00:17:08.279 the story of a defensive sanctuary that kept 00:17:08.279 --> 00:17:11.359 ancient Europeans safe five thousand years ago, 00:17:11.740 --> 00:17:13.859 holding on to their secrets until we were ready 00:17:13.859 --> 00:17:15.950 to find them. It serves as a powerful reminder 00:17:15.950 --> 00:17:18.250 for all of us, the landscapes you drive past, 00:17:18.650 --> 00:17:20.990 the wilderness trails you might hike, even the 00:17:20.990 --> 00:17:24.750 difficult ones with ironically named 1940s concrete 00:17:24.750 --> 00:17:28.509 bridges, they are not static painted backdrops. 00:17:28.509 --> 00:17:32.289 They are active ongoing processes. They are the 00:17:32.289 --> 00:17:34.710 result of millions of years of hidden geological 00:17:34.710 --> 00:17:37.750 drama and ancient human adaptation. The earth 00:17:37.750 --> 00:17:39.849 is still moving. The tectonic plates are still 00:17:39.849 --> 00:17:42.069 shifting and the rivers are absolutely still 00:17:42.069 --> 00:17:44.400 digging. And that leaves us with one final thought 00:17:44.400 --> 00:17:46.539 for you to take away. Think about that constant 00:17:46.539 --> 00:17:48.740 relentless digging. It never stops. The water 00:17:48.740 --> 00:17:50.779 is still rushing down from the high aquifers. 00:17:50.900 --> 00:17:53.259 It is still carving through the rock. If the 00:17:53.259 --> 00:17:55.559 Cassian River has eroded the canyon floor 10 00:17:55.559 --> 00:17:58.200 entire meters deeper since those Neolithic people 00:17:58.200 --> 00:18:00.559 lived there just five thousand years ago, what 00:18:00.559 --> 00:18:02.920 is it carving into right now? That's a great 00:18:02.920 --> 00:18:06.000 question. Upstream, the river cuts through the 00:18:06.000 --> 00:18:09.740 Alpujarid reliefs. These are complex, much older 00:18:09.740 --> 00:18:12.170 mountain structures full of folded rock and and 00:18:12.170 --> 00:18:15.089 hidden history. What undiscovered artifacts, 00:18:15.390 --> 00:18:18.049 what pieces of forgotten human or geological 00:18:18.049 --> 00:18:20.470 history are currently being washed down from 00:18:20.470 --> 00:18:22.589 those high reliefs today? We don't know. Right 00:18:22.589 --> 00:18:25.289 now, entirely hidden beneath the flowing water, 00:18:25.529 --> 00:18:27.450 just tumbling along the bottom of the gorge, 00:18:27.869 --> 00:18:30.009 waiting to be found by whoever wanders the Tajos 00:18:30.009 --> 00:18:32.369 thousands of years from now. The time machine 00:18:32.369 --> 00:18:34.470 is still running, and it's still collecting data. 00:18:34.849 --> 00:18:36.410 Thanks for taking the deep dive with us today.