diff --git "a/subtitle/74TEQfw6L60.srt" "b/subtitle/74TEQfw6L60.srt" new file mode 100644--- /dev/null +++ "b/subtitle/74TEQfw6L60.srt" @@ -0,0 +1,3672 @@ +1 +00:00:06,759 --> 00:00:11,920 +the Rocky Mountains the backbone of + +2 +00:00:09,599 --> 00:00:11,920 +North + +3 +00:00:12,080 --> 00:00:17,480 +America rugged spectacular and + +4 +00:00:17,520 --> 00:00:23,480 +Majestic today geologists are cracking + +5 +00:00:20,279 --> 00:00:25,720 +open these rocks to expose their + +6 +00:00:23,480 --> 00:00:27,920 +secrets how did the remains of sea + +7 +00:00:25,720 --> 00:00:31,960 +creatures end up in mountain peaks + +8 +00:00:27,920 --> 00:00:31,960 +thousands of feet in the air + +9 +00:00:32,880 --> 00:00:36,960 +when did the Rockies form are they still + +10 +00:00:35,520 --> 00:00:40,000 +Rising + +11 +00:00:36,960 --> 00:00:42,559 +today and if they are could the great + +12 +00:00:40,000 --> 00:00:46,160 +forces that built the Rockies one day + +13 +00:00:42,559 --> 00:00:46,160 +split North America in + +14 +00:00:47,200 --> 00:00:56,880 +[Music] + +15 +00:00:58,920 --> 00:01:01,519 +two + +16 +00:01:00,559 --> 00:01:03,680 +the + +17 +00:01:01,519 --> 00:01:05,920 +Rockies one of the greatest Mountain + +18 +00:01:03,680 --> 00:01:09,039 +chains on + +19 +00:01:05,920 --> 00:01:11,159 +Earth they stretch over 2,000 miles from + +20 +00:01:09,039 --> 00:01:14,400 +the northern tip of British Columbia to + +21 +00:01:11,159 --> 00:01:14,400 +the Rio Grand in New + +22 +00:01:14,600 --> 00:01:20,039 +Mexico up to 300 M wide they form the + +23 +00:01:18,479 --> 00:01:23,000 +continental + +24 +00:01:20,039 --> 00:01:25,280 +divide the Great Barrier between East + +25 +00:01:23,000 --> 00:01:25,280 +and + +26 +00:01:27,560 --> 00:01:34,759 +West in Colorado alone there are 58 + +27 +00:01:31,158 --> 00:01:39,680 +mountain peaks over 14,000 ft + +28 +00:01:34,759 --> 00:01:39,680 +tall that's around 2 and 1/2 mil + +29 +00:01:41,600 --> 00:01:48,640 +High the Rockies were created by the + +30 +00:01:44,360 --> 00:01:48,640 +most powerful geologic forces on + +31 +00:01:49,240 --> 00:01:55,158 +Earth their dramatic story takes us on a + +32 +00:01:52,240 --> 00:01:58,320 +journey from north to south through 200 + +33 +00:01:55,158 --> 00:02:02,000 +million years of geological + +34 +00:01:58,320 --> 00:02:04,520 +history from their birth birth place in + +35 +00:02:02,000 --> 00:02:06,960 +Canada to the youngest peaks in the + +36 +00:02:04,520 --> 00:02:06,960 +United + +37 +00:02:09,318 --> 00:02:15,520 +States it's a journey that takes us back + +38 +00:02:12,120 --> 00:02:15,520 +into the Earth's ancient + +39 +00:02:17,319 --> 00:02:24,400 +past 200 million years ago there were no + +40 +00:02:21,079 --> 00:02:27,400 +Rockies even the continents looked + +41 +00:02:24,400 --> 00:02:30,640 +different there was just one giant land + +42 +00:02:27,400 --> 00:02:32,800 +mass Pangia + +43 +00:02:30,640 --> 00:02:36,360 +but not for much + +44 +00:02:32,800 --> 00:02:38,959 +longer a vast Rift is opening up tearing + +45 +00:02:36,360 --> 00:02:42,120 +this super continent + +46 +00:02:38,959 --> 00:02:44,079 +apart over the next few million years + +47 +00:02:42,120 --> 00:02:46,840 +Pangia will break apart into many + +48 +00:02:44,079 --> 00:02:46,840 +smaller land + +49 +00:02:47,120 --> 00:02:52,560 +masses eventually forming the + +50 +00:02:49,200 --> 00:02:55,079 +present-day continent of North + +51 +00:02:52,560 --> 00:02:57,680 +America earth's surface is broken up + +52 +00:02:55,079 --> 00:02:59,840 +into vast pieces called + +53 +00:02:57,680 --> 00:03:02,799 +plates they sit on top of the the + +54 +00:02:59,840 --> 00:03:06,000 +Earth's warm dense + +55 +00:03:02,799 --> 00:03:08,040 +mantle as the planet gradually cools + +56 +00:03:06,000 --> 00:03:10,120 +convection currents in the mantle slowly + +57 +00:03:08,040 --> 00:03:11,239 +move these plates across the surface of + +58 +00:03:10,120 --> 00:03:14,480 +the + +59 +00:03:11,239 --> 00:03:17,400 +Earth where plates meet at their edges + +60 +00:03:14,480 --> 00:03:19,760 +there are often immense tectonic + +61 +00:03:17,400 --> 00:03:24,360 +forces these tensions can tear + +62 +00:03:19,760 --> 00:03:24,360 +continents apart but they also build + +63 +00:03:25,360 --> 00:03:30,120 +mountains Kirk Johnson Chief curator of + +64 +00:03:28,040 --> 00:03:32,159 +the Denver Museum of Nature and Science + +65 +00:03:30,120 --> 00:03:34,200 +explains the action of continents + +66 +00:03:32,159 --> 00:03:36,519 +crushing together or continents being + +67 +00:03:34,200 --> 00:03:39,680 +hit by oceanic plates those kinds of + +68 +00:03:36,519 --> 00:03:42,959 +forces create basically planetary + +69 +00:03:39,680 --> 00:03:45,439 +traffic accidents and the wrecks result + +70 +00:03:42,959 --> 00:03:45,439 +in Mountain + +71 +00:03:46,879 --> 00:03:51,599 +swarming evidence of the power of these + +72 +00:03:49,360 --> 00:03:53,599 +immense forces can be found in one of + +73 +00:03:51,599 --> 00:03:54,480 +the oldest and most Northerly parts of + +74 +00:03:53,599 --> 00:03:58,680 +the + +75 +00:03:54,480 --> 00:04:01,720 +Rockies yo National Park in British + +76 +00:03:58,680 --> 00:04:04,200 +Columbia here the fossils of thousands + +77 +00:04:01,720 --> 00:04:06,079 +of peculiar prehistoric creatures lie in + +78 +00:04:04,200 --> 00:04:10,640 +a cliff face near the peak of Mount + +79 +00:04:06,079 --> 00:04:10,640 +Steven 8,000 ft above sea + +80 +00:04:11,079 --> 00:04:16,160 +level geologist and Mountain guide Paul + +81 +00:04:13,879 --> 00:04:17,478 +mcneel specializes in the fossils of the + +82 +00:04:16,160 --> 00:04:20,798 +Burgess + +83 +00:04:17,478 --> 00:04:22,759 +Shale we see fossils here that we find + +84 +00:04:20,798 --> 00:04:26,000 +almost nowhere else in the fossil record + +85 +00:04:22,759 --> 00:04:28,800 +and unlike any animal that's alive + +86 +00:04:26,000 --> 00:04:31,600 +today this spiny creature is called + +87 +00:04:28,800 --> 00:04:31,600 +hucog Genia + +88 +00:04:31,680 --> 00:04:38,320 +and this bizarre specimen we + +89 +00:04:35,320 --> 00:04:40,720 +waxia these fossils offer Clues to how + +90 +00:04:38,320 --> 00:04:43,000 +the early Northern Rockies + +91 +00:04:40,720 --> 00:04:44,840 +formed because they're not the remains + +92 +00:04:43,000 --> 00:04:47,919 +of mountain dwelling + +93 +00:04:44,840 --> 00:04:50,159 +animals but of sea + +94 +00:04:47,919 --> 00:04:52,680 +creatures they lived and died in a + +95 +00:04:50,159 --> 00:04:54,479 +shallow tropical sea over half a billion + +96 +00:04:52,680 --> 00:04:57,000 +years + +97 +00:04:54,479 --> 00:05:01,240 +ago the rocks that contain these + +98 +00:04:57,000 --> 00:05:03,840 +extraordinary fossils formed on the sea + +99 +00:05:01,240 --> 00:05:06,680 +floor right around us all of the rocks + +100 +00:05:03,840 --> 00:05:09,680 +that we see used to be part of an + +101 +00:05:06,680 --> 00:05:12,120 +ancient seabed the limestones were part + +102 +00:05:09,680 --> 00:05:14,240 +of the continental shelf the shells were + +103 +00:05:12,120 --> 00:05:15,919 +part of the deeper ocean waters but it + +104 +00:05:14,240 --> 00:05:18,120 +was all + +105 +00:05:15,919 --> 00:05:20,680 +underwater long before the Rockies + +106 +00:05:18,120 --> 00:05:22,840 +formed the west coast of North America + +107 +00:05:20,680 --> 00:05:26,520 +was covered by a shallow + +108 +00:05:22,840 --> 00:05:29,600 +sea over millions of years clay mud and + +109 +00:05:26,520 --> 00:05:31,680 +gravel settled on this Coastal Shelf + +110 +00:05:29,600 --> 00:05:34,440 +trapping and fossilizing tens of + +111 +00:05:31,680 --> 00:05:37,000 +thousands of sea + +112 +00:05:34,440 --> 00:05:40,319 +creatures layers of sediment solidified + +113 +00:05:37,000 --> 00:05:43,400 +into rock up to 12 M + +114 +00:05:40,319 --> 00:05:48,199 +thick The Rock layers in this Cliff are + +115 +00:05:43,400 --> 00:05:48,199 +made from sediment laid down over 8,000 + +116 +00:05:48,840 --> 00:05:53,280 +years today these fossils are a mile and + +117 +00:05:51,600 --> 00:05:56,479 +a half above sea + +118 +00:05:53,280 --> 00:05:58,479 +level but once they were buried 6 miles + +119 +00:05:56,479 --> 00:06:01,240 +under other layers of + +120 +00:05:58,479 --> 00:06:04,319 +rock at their deepest point these + +121 +00:06:01,240 --> 00:06:06,479 +fossils were buried over 10 km under the + +122 +00:06:04,319 --> 00:06:09,680 +Earth's crust and since then they've + +123 +00:06:06,479 --> 00:06:12,479 +been thrust up to over 2 km up into the + +124 +00:06:09,680 --> 00:06:15,800 +air where we actually find them + +125 +00:06:12,479 --> 00:06:18,000 +now this ancient rock formed offshore + +126 +00:06:15,800 --> 00:06:20,319 +400 mil west of + +127 +00:06:18,000 --> 00:06:23,479 +here so what could have driven this + +128 +00:06:20,319 --> 00:06:27,039 +ancient seafloor so far inland and what + +129 +00:06:23,479 --> 00:06:28,880 +pushed it up almost 8 mil a force + +130 +00:06:27,039 --> 00:06:31,360 +powerful enough to transform a flat + +131 +00:06:28,880 --> 00:06:34,360 +ocean FL L into massive + +132 +00:06:31,360 --> 00:06:34,360 +mountains + +133 +00:06:35,199 --> 00:06:41,880 +subduction 180 million years ago the + +134 +00:06:39,360 --> 00:06:44,240 +North American Plate was moving West + +135 +00:06:41,880 --> 00:06:46,960 +driven by the breakup of + +136 +00:06:44,240 --> 00:06:48,120 +Pangia and the Pacific Ocean plate was + +137 +00:06:46,960 --> 00:06:53,080 +heading + +138 +00:06:48,120 --> 00:06:53,080 +east the two colossal plates met head + +139 +00:06:54,159 --> 00:06:59,680 +on in this Clash of the Titans the + +140 +00:06:57,280 --> 00:07:01,400 +denser Pacific ocean plate was forced + +141 +00:06:59,680 --> 00:07:03,879 +down beneath the more buoyant North + +142 +00:07:01,400 --> 00:07:03,879 +American + +143 +00:07:07,240 --> 00:07:13,199 +Plate professor John Gman from the + +144 +00:07:09,800 --> 00:07:13,199 +University of New Mexico + +145 +00:07:13,639 --> 00:07:18,879 +demonstrates what I'm going to do is + +146 +00:07:15,520 --> 00:07:21,440 +simply tap on one of the sides and I'm + +147 +00:07:18,879 --> 00:07:25,160 +going to create an instability now we + +148 +00:07:21,440 --> 00:07:28,639 +have oil starting to + +149 +00:07:25,160 --> 00:07:30,360 +Migrate move its way over the top of the + +150 +00:07:28,639 --> 00:07:33,199 +CD + +151 +00:07:30,360 --> 00:07:35,319 +ah voila it's happening all by itself I + +152 +00:07:33,199 --> 00:07:38,400 +don't have to nudge it anymore if you + +153 +00:07:35,319 --> 00:07:41,599 +see the oil moving its way across the CD + +154 +00:07:38,400 --> 00:07:45,199 +like so and the CD itself is going to be + +155 +00:07:41,599 --> 00:07:47,919 +begin to move like so into the oil and + +156 +00:07:45,199 --> 00:07:51,479 +the subduction process is + +157 +00:07:47,919 --> 00:07:54,400 +completed it's subducted into the + +158 +00:07:51,479 --> 00:07:58,319 +interior of our planet if you will and + +159 +00:07:54,400 --> 00:08:01,319 +it's a runaway process you can't stop + +160 +00:07:58,319 --> 00:08:01,319 +it + +161 +00:08:03,000 --> 00:08:08,400 +on top of the subducting Pacific Plate + +162 +00:08:05,479 --> 00:08:08,400 +sat offshore + +163 +00:08:09,479 --> 00:08:16,000 +Islands as the plate was pushed Eastward + +164 +00:08:12,400 --> 00:08:18,759 +it carried these islands like a conveyor + +165 +00:08:16,000 --> 00:08:20,599 +belt one particularly large island + +166 +00:08:18,759 --> 00:08:23,520 +reached the junction of the two plates + +167 +00:08:20,599 --> 00:08:25,680 +and coast of North America but it was + +168 +00:08:23,520 --> 00:08:28,039 +too large and buoyant to be pushed down + +169 +00:08:25,680 --> 00:08:30,680 +into the + +170 +00:08:28,039 --> 00:08:32,799 +mantle in instead it slammed into the + +171 +00:08:30,680 --> 00:08:34,799 +continental shelf on the western edge of + +172 +00:08:32,799 --> 00:08:38,200 +the + +173 +00:08:34,799 --> 00:08:41,240 +continent the seabed was shoved Eastward + +174 +00:08:38,200 --> 00:08:43,919 +it slowly folded up like a crumpled + +175 +00:08:41,240 --> 00:08:45,839 +carpet the fossils of the bures Shale + +176 +00:08:43,919 --> 00:08:49,000 +were pushed thousands of feet into the + +177 +00:08:45,839 --> 00:08:49,000 +air and Miles + +178 +00:08:49,080 --> 00:08:54,640 +Inland geologist and author Ben Gad has + +179 +00:08:52,399 --> 00:08:55,760 +spent 30 years studying the Rockies here + +180 +00:08:54,640 --> 00:08:58,399 +in British + +181 +00:08:55,760 --> 00:08:59,800 +Columbia one way to imagine this whole + +182 +00:08:58,399 --> 00:09:02,880 +pushing and shoving business business is + +183 +00:08:59,800 --> 00:09:05,279 +to is to uh is to do it on your hands so + +184 +00:09:02,880 --> 00:09:06,920 +you have the the Bony part of your hand + +185 +00:09:05,279 --> 00:09:09,279 +and then you have the skin over the top + +186 +00:09:06,920 --> 00:09:11,880 +right so imagine that the Bony part is + +187 +00:09:09,279 --> 00:09:13,640 +the continental plate and on top of that + +188 +00:09:11,880 --> 00:09:16,519 +you have all the sedimentary layers + +189 +00:09:13,640 --> 00:09:19,320 +right that's the Skin So when the big + +190 +00:09:16,519 --> 00:09:22,000 +push and shove comes you have the skin + +191 +00:09:19,320 --> 00:09:25,440 +being pushed along the Bony layer and as + +192 +00:09:22,000 --> 00:09:28,000 +it gets pushed along it wrinkles + +193 +00:09:25,440 --> 00:09:31,120 +up that's a good analogy for how the + +194 +00:09:28,000 --> 00:09:31,120 +Rockies were formed + +195 +00:09:31,519 --> 00:09:35,600 +the older I get the better this works + +196 +00:09:33,240 --> 00:09:38,760 +for some + +197 +00:09:35,600 --> 00:09:42,360 +reason over millions of years the plate + +198 +00:09:38,760 --> 00:09:42,360 +Collision forced up the northern + +199 +00:09:43,880 --> 00:09:48,680 +Rockies when the force of this Collision + +200 +00:09:46,320 --> 00:09:51,440 +lost its power the first wave of + +201 +00:09:48,680 --> 00:09:54,160 +mountain building came to an end but + +202 +00:09:51,440 --> 00:09:56,079 +that's not the end of the story 80 + +203 +00:09:54,160 --> 00:09:59,000 +million years after the first block of + +204 +00:09:56,079 --> 00:10:00,680 +land hit the coast a second one slammed + +205 +00:09:59,000 --> 00:10:03,800 +into into its + +206 +00:10:00,680 --> 00:10:04,690 +back it bulldozed everything Eastward + +207 +00:10:03,800 --> 00:10:06,120 +and + +208 +00:10:04,690 --> 00:10:08,760 +[Music] + +209 +00:10:06,120 --> 00:10:11,959 +upward layer after layer of rock was + +210 +00:10:08,760 --> 00:10:11,959 +shoved higher and + +211 +00:10:12,000 --> 00:10:17,200 +higher first into Hills and then into + +212 +00:10:18,880 --> 00:10:24,640 +mountains gentle folds of rock evolved + +213 +00:10:21,920 --> 00:10:24,640 +into the mighty + +214 +00:10:27,000 --> 00:10:32,200 +Rockies today these slabs of land called + +215 +00:10:30,079 --> 00:10:35,299 +terrains make up British + +216 +00:10:32,200 --> 00:10:35,299 +[Music] + +217 +00:10:37,000 --> 00:10:41,920 +Columbia as they continued to + +218 +00:10:39,519 --> 00:10:45,920 +rise the Rockies were continually + +219 +00:10:41,920 --> 00:10:48,720 +sculpted by the momentous force of the + +220 +00:10:45,920 --> 00:10:51,590 +elements even as they were pushed up + +221 +00:10:48,720 --> 00:10:56,219 +erosion was starting to tear them + +222 +00:10:51,590 --> 00:10:56,219 +[Music] + +223 +00:10:56,920 --> 00:11:04,800 +down the Canadian rocky + +224 +00:11:00,760 --> 00:11:07,760 +Jagged Peaks steep Cliffs and razor + +225 +00:11:04,800 --> 00:11:10,680 +sharp ridges carved from the sedimentary + +226 +00:11:07,760 --> 00:11:10,680 +rock of an ancient + +227 +00:11:12,760 --> 00:11:18,000 +seabed despite being caught in a mighty + +228 +00:11:15,440 --> 00:11:21,079 +plate collision and thrust up into + +229 +00:11:18,000 --> 00:11:24,000 +towering Peaks the layers of rock in + +230 +00:11:21,079 --> 00:11:26,800 +these mountains still lie almost + +231 +00:11:24,000 --> 00:11:30,959 +horizontally this provides a clue about + +232 +00:11:26,800 --> 00:11:30,959 +how they rose up + +233 +00:11:31,639 --> 00:11:36,240 +as the blocks of land drove into the + +234 +00:11:33,600 --> 00:11:38,399 +coast of North America slabs of + +235 +00:11:36,240 --> 00:11:42,399 +sedimentary rock were pressurized and + +236 +00:11:38,399 --> 00:11:42,399 +folded so much that they + +237 +00:11:45,720 --> 00:11:51,639 +snapped broken sheets of rock up to a + +238 +00:11:48,920 --> 00:11:54,200 +mile thick shunted forwards and slid + +239 +00:11:51,639 --> 00:11:57,959 +over each other again and again in a + +240 +00:11:54,200 --> 00:12:00,959 +process scientists call thrust + +241 +00:11:57,959 --> 00:12:00,959 +falting + +242 +00:12:03,440 --> 00:12:07,279 +so The Rock has actually been folded to + +243 +00:12:05,760 --> 00:12:09,680 +the point where it can't be folded + +244 +00:12:07,279 --> 00:12:11,279 +anymore and at that point the upper part + +245 +00:12:09,680 --> 00:12:14,199 +of the fold will literally break and + +246 +00:12:11,279 --> 00:12:17,240 +start sliding along that's what we call + +247 +00:12:14,199 --> 00:12:20,240 +a thrust fault and it's a a classic kind + +248 +00:12:17,240 --> 00:12:22,959 +of fault for the Canadian + +249 +00:12:20,240 --> 00:12:25,279 +Rockies sedimentary rock forms when + +250 +00:12:22,959 --> 00:12:27,040 +younger layers of sediment settle on top + +251 +00:12:25,279 --> 00:12:29,680 +of older + +252 +00:12:27,040 --> 00:12:32,480 +layers but here in the rock + +253 +00:12:29,680 --> 00:12:35,680 +layers of different ages are jumbled + +254 +00:12:32,480 --> 00:12:39,959 +up thrust falting pushed older layers of + +255 +00:12:35,680 --> 00:12:39,959 +sedimentary rock up and over younger + +256 +00:12:40,680 --> 00:12:46,440 +layers suppose that uh we think of this + +257 +00:12:43,720 --> 00:12:49,199 +book as being a continuation of the + +258 +00:12:46,440 --> 00:12:52,000 +layered rock that we see here now in a + +259 +00:12:49,199 --> 00:12:55,680 +thrust fault what happens is this part + +260 +00:12:52,000 --> 00:12:57,680 +will break up and it will slide along + +261 +00:12:55,680 --> 00:13:01,240 +like this and it can go rather a long + +262 +00:12:57,680 --> 00:13:03,560 +way until eventually it stops so now we + +263 +00:13:01,240 --> 00:13:06,800 +have layers that were down here pushed + +264 +00:13:03,560 --> 00:13:09,160 +up over these layers old rock pushed up + +265 +00:13:06,800 --> 00:13:12,519 +an over younger + +266 +00:13:09,160 --> 00:13:14,959 +rock in this laboratory sandbox the + +267 +00:13:12,519 --> 00:13:18,240 +layers of colored sand represent layers + +268 +00:13:14,959 --> 00:13:21,600 +of sedimentary rock as the sand pushes + +269 +00:13:18,240 --> 00:13:23,120 +Eastward to the right thrust faults form + +270 +00:13:21,600 --> 00:13:26,000 +one in front of the + +271 +00:13:23,120 --> 00:13:28,160 +other thrust fating pushes older rock + +272 +00:13:26,000 --> 00:13:30,320 +layers above younger to create the + +273 +00:13:28,160 --> 00:13:32,760 +distinctive Sawtooth ranges of the + +274 +00:13:30,320 --> 00:13:32,760 +northern + +275 +00:13:33,360 --> 00:13:38,399 +Rockies these mountains first emerged + +276 +00:13:36,639 --> 00:13:41,199 +140 million years + +277 +00:13:38,399 --> 00:13:42,279 +ago thrust falting first built the + +278 +00:13:41,199 --> 00:13:45,399 +Western + +279 +00:13:42,279 --> 00:13:48,680 +ranges and then crept Eastward forming a + +280 +00:13:45,399 --> 00:13:48,680 +new Range further in + +281 +00:13:49,240 --> 00:13:54,120 +land 120 million years ago the main + +282 +00:13:52,839 --> 00:13:57,040 +ranges + +283 +00:13:54,120 --> 00:14:01,800 +appeared and then even further east the + +284 +00:13:57,040 --> 00:14:01,800 +front ranges 85 5 million years + +285 +00:14:02,720 --> 00:14:11,240 +ago thrust fating began to slow down + +286 +00:14:05,880 --> 00:14:11,240 +until eventually 50 million years ago it + +287 +00:14:13,079 --> 00:14:19,279 +stopped at Mount yusa the mountains and + +288 +00:14:16,320 --> 00:14:22,170 +the Foothills meet Beyond lie the flat + +289 +00:14:19,279 --> 00:14:24,639 +Plains of Alberta and + +290 +00:14:22,170 --> 00:14:27,480 +[Music] + +291 +00:14:24,639 --> 00:14:31,070 +Montana immense forces pushed an ancient + +292 +00:14:27,480 --> 00:14:34,619 +seabed thousands of feet into the + +293 +00:14:31,070 --> 00:14:34,619 +[Music] + +294 +00:14:34,639 --> 00:14:41,279 +air but a very different Force sculpted + +295 +00:14:37,920 --> 00:14:41,279 +it into these striking + +296 +00:14:41,519 --> 00:14:44,519 +Peaks + +297 +00:14:45,279 --> 00:14:49,830 +erosion evidence of erosions power is + +298 +00:14:48,120 --> 00:14:53,219 +strewn all over the mountain + +299 +00:14:49,830 --> 00:14:53,219 +[Music] + +300 +00:14:55,160 --> 00:15:00,680 +side piles of broken shell + +301 +00:15:02,079 --> 00:15:06,680 +and heaps of ash-colored sediment called + +302 +00:15:08,399 --> 00:15:13,920 +scree erosion has been at least as + +303 +00:15:11,519 --> 00:15:16,160 +important uh as the mountain building + +304 +00:15:13,920 --> 00:15:18,519 +itself it's the mountain building + +305 +00:15:16,160 --> 00:15:20,759 +process the up piling that gives you the + +306 +00:15:18,519 --> 00:15:22,880 +elevation to give you the height of the + +307 +00:15:20,759 --> 00:15:25,519 +landscape but then the landscape itself + +308 +00:15:22,880 --> 00:15:27,480 +is carved downward differentially so + +309 +00:15:25,519 --> 00:15:30,839 +erosion is very important it actually + +310 +00:15:27,480 --> 00:15:30,839 +gives us the landscape we + +311 +00:15:31,199 --> 00:15:36,920 +see erosion is so powerful that it is + +312 +00:15:34,160 --> 00:15:39,440 +scraped up to 2 miles of solid rock off + +313 +00:15:36,920 --> 00:15:44,639 +the top of these mountain + +314 +00:15:39,440 --> 00:15:48,480 +peaks and the main force of erosion is + +315 +00:15:44,639 --> 00:15:51,560 +water uh water loosens material sends it + +316 +00:15:48,480 --> 00:15:54,880 +downhill water dissolves minerals uh + +317 +00:15:51,560 --> 00:15:57,440 +water freezes and and breaks up the + +318 +00:15:54,880 --> 00:16:00,319 +Rocks the northern Rockies are made of + +319 +00:15:57,440 --> 00:16:01,759 +sedimentary rock like Sandstone Shale + +320 +00:16:00,319 --> 00:16:05,120 +and + +321 +00:16:01,759 --> 00:16:07,940 +Limestone relatively soft and soluble + +322 +00:16:05,120 --> 00:16:11,039 +these are easy prey for + +323 +00:16:07,940 --> 00:16:11,039 +[Music] + +324 +00:16:11,120 --> 00:16:18,079 +erosion and here in Canada water's + +325 +00:16:14,240 --> 00:16:18,079 +erosive power takes on a new + +326 +00:16:19,959 --> 00:16:25,720 +dimension in this cold climate snowfall + +327 +00:16:23,240 --> 00:16:29,020 +freezes and compacts to form enormous + +328 +00:16:25,720 --> 00:16:35,230 +sheets of ice glaciers + +329 +00:16:29,020 --> 00:16:35,230 +[Music] + +330 +00:16:35,720 --> 00:16:40,880 +the glaciers here creep forward at 50 ft + +331 +00:16:38,720 --> 00:16:46,519 +per + +332 +00:16:40,880 --> 00:16:46,519 +year on a geologic time scale this is + +333 +00:16:48,160 --> 00:16:53,519 +fast glaciers pick up and carry loose + +334 +00:16:51,160 --> 00:16:56,120 +rocks and boulders which scour and + +335 +00:16:53,519 --> 00:16:59,279 +scratch the rock beneath + +336 +00:16:56,120 --> 00:17:02,840 +them like giant ice cream Scoops + +337 +00:16:59,279 --> 00:17:04,199 +glaciers gouge out distinctive u-shaped + +338 +00:17:02,840 --> 00:17:07,000 +[Applause] + +339 +00:17:04,199 --> 00:17:11,319 +valleys and when they melt they leave + +340 +00:17:07,000 --> 00:17:11,319 +behind deep gorges and steep-sided + +341 +00:17:15,760 --> 00:17:22,079 +Peaks erosion has worn down these rocks + +342 +00:17:19,000 --> 00:17:22,079 +over millions of + +343 +00:17:22,760 --> 00:17:27,280 +years but the Rockies are fighting + +344 +00:17:27,400 --> 00:17:33,320 +back while erosion attacks their Summits + +345 +00:17:31,120 --> 00:17:35,679 +deep below ground the mountains are + +346 +00:17:33,320 --> 00:17:35,679 +still + +347 +00:17:35,799 --> 00:17:40,600 +growing look at the Rockies and it's + +348 +00:17:38,320 --> 00:17:43,520 +like seeing the tip of an + +349 +00:17:40,600 --> 00:17:47,640 +iceberg mountains have Roots which can + +350 +00:17:43,520 --> 00:17:50,919 +be five or six times deeper than their + +351 +00:17:47,640 --> 00:17:54,080 +height this mountain stands over 2 mi + +352 +00:17:50,919 --> 00:17:56,159 +high but its hidden rout could extend 13 + +353 +00:17:54,080 --> 00:17:58,520 +mil + +354 +00:17:56,159 --> 00:18:01,230 +underground these roots are the Rocky + +355 +00:17:58,520 --> 00:18:04,319 +secret defense against + +356 +00:18:01,230 --> 00:18:04,319 +[Music] + +357 +00:18:04,360 --> 00:18:08,640 +erosion structural geologist Carl + +358 +00:18:06,919 --> 00:18:11,840 +carlstrom from the University of New + +359 +00:18:08,640 --> 00:18:14,159 +Mexico demonstrates using blocks of + +360 +00:18:11,840 --> 00:18:16,200 +ice the red and green ice layers + +361 +00:18:14,159 --> 00:18:18,799 +represent the mountains above ground and + +362 +00:18:16,200 --> 00:18:21,280 +the white ice their Roots below + +363 +00:18:18,799 --> 00:18:23,120 +ground mountains are not static things + +364 +00:18:21,280 --> 00:18:26,080 +the earth's surface is continually being + +365 +00:18:23,120 --> 00:18:28,520 +reshaped by erosion by Rivers by + +366 +00:18:26,080 --> 00:18:30,200 +glaciers that tear the mountains down so + +367 +00:18:28,520 --> 00:18:32,159 +let's imagine I'm eroding the mountains + +368 +00:18:30,200 --> 00:18:34,760 +now and I'll just pull one of the blocks + +369 +00:18:32,159 --> 00:18:36,120 +off the overall surface has gone down + +370 +00:18:34,760 --> 00:18:38,240 +the continent has gotten thinner its + +371 +00:18:36,120 --> 00:18:39,960 +roots come up and now this rock which + +372 +00:18:38,240 --> 00:18:42,520 +was deep in the earth a minute ago + +373 +00:18:39,960 --> 00:18:44,880 +underneath the Green Layer has uh come + +374 +00:18:42,520 --> 00:18:47,919 +to the surface that's called Rock uplift + +375 +00:18:44,880 --> 00:18:50,520 +so I guess I'll Road off the pink layer + +376 +00:18:47,919 --> 00:18:52,159 +2 we're back down to a continent without + +377 +00:18:50,520 --> 00:18:56,200 +a without a major mountain belt + +378 +00:18:52,159 --> 00:18:58,440 +something like the eastern part of North + +379 +00:18:56,200 --> 00:19:00,880 +America when the heavy weight of the the + +380 +00:18:58,440 --> 00:19:02,240 +mountain is eroded away the route + +381 +00:19:00,880 --> 00:19:04,640 +rebounds + +382 +00:19:02,240 --> 00:19:09,559 +upward this process means that the + +383 +00:19:04,640 --> 00:19:12,880 +Rockies are constantly topped up from + +384 +00:19:09,559 --> 00:19:14,840 +beneath in Canada thrust falting and + +385 +00:19:12,880 --> 00:19:18,320 +erosion have shaped the + +386 +00:19:14,840 --> 00:19:21,080 +mountains but as we travel South this + +387 +00:19:18,320 --> 00:19:23,760 +distinctive landscape is about to + +388 +00:19:21,080 --> 00:19:26,360 +change just south of the US Border in + +389 +00:19:23,760 --> 00:19:30,080 +the state of Montana a new rock appears + +390 +00:19:26,360 --> 00:19:32,400 +among the Rockies + +391 +00:19:30,080 --> 00:19:35,000 +Granite this is the first clue that the + +392 +00:19:32,400 --> 00:19:37,520 +mountains of the American Rockies are + +393 +00:19:35,000 --> 00:19:37,520 +radically + +394 +00:19:43,720 --> 00:19:50,520 +different I think that's an interesting + +395 +00:19:46,280 --> 00:19:53,000 +thing this one piece will make 52 layers + +396 +00:19:50,520 --> 00:19:57,240 +watch on mobile devices or the big + +397 +00:19:53,000 --> 00:20:00,240 +screen all for free no subscription + +398 +00:19:57,240 --> 00:20:00,240 +required + +399 +00:20:00,770 --> 00:20:05,600 +[Music] + +400 +00:20:03,559 --> 00:20:07,720 +on our journey South along the Rocky + +401 +00:20:05,600 --> 00:20:09,679 +Mountains we're entering a very + +402 +00:20:07,720 --> 00:20:12,720 +different + +403 +00:20:09,679 --> 00:20:15,440 +landscape from Montana Southward the + +404 +00:20:12,720 --> 00:20:18,120 +Rockies are made from ancient Granite + +405 +00:20:15,440 --> 00:20:20,919 +1.7 billion years + +406 +00:20:18,120 --> 00:20:23,120 +old Granite makes up much of the deepest + +407 +00:20:20,919 --> 00:20:25,880 +part of the continental + +408 +00:20:23,120 --> 00:20:30,159 +crust that's why geologists call this + +409 +00:20:25,880 --> 00:20:30,159 +rock the basement + +410 +00:20:30,799 --> 00:20:34,840 +the Canadian Rockies are built from + +411 +00:20:32,520 --> 00:20:36,840 +sedimentary rocks piled up on top of the + +412 +00:20:34,840 --> 00:20:39,679 +Continental + +413 +00:20:36,840 --> 00:20:43,200 +foundations so why does granite suddenly + +414 +00:20:39,679 --> 00:20:43,200 +appear here in the American + +415 +00:20:45,320 --> 00:20:49,720 +Rockies but there's an even greater + +416 +00:20:49,919 --> 00:20:55,320 +puzzle mountains usually form close to + +417 +00:20:52,840 --> 00:20:57,400 +plate boundaries but the southern + +418 +00:20:55,320 --> 00:21:00,120 +Rockies sit a long way from the plate + +419 +00:20:57,400 --> 00:21:00,120 +margin + +420 +00:21:03,200 --> 00:21:07,919 +the Front Range in + +421 +00:21:05,159 --> 00:21:10,080 +Colorado is a th000 miles from where the + +422 +00:21:07,919 --> 00:21:12,230 +Pacific and North American plates + +423 +00:21:10,080 --> 00:21:14,520 +actually + +424 +00:21:12,230 --> 00:21:19,200 +[Music] + +425 +00:21:14,520 --> 00:21:19,200 +meet geologists have come up with an + +426 +00:21:19,559 --> 00:21:25,760 +explanation they believe that the + +427 +00:21:21,440 --> 00:21:25,760 +subducting Pacific Ocean plate is + +428 +00:21:27,039 --> 00:21:30,799 +responsible + +429 +00:21:28,600 --> 00:21:33,000 +ocean crust had been pushed deep into + +430 +00:21:30,799 --> 00:21:37,520 +the mantle beneath North America for a + +431 +00:21:33,000 --> 00:21:39,400 +100 million years when something unusual + +432 +00:21:37,520 --> 00:21:42,400 +[Music] + +433 +00:21:39,400 --> 00:21:44,720 +happened 70 million years ago the + +434 +00:21:42,400 --> 00:21:46,960 +Pacific Ocean plate started to subduct + +435 +00:21:44,720 --> 00:21:50,480 +at a shallower + +436 +00:21:46,960 --> 00:21:53,640 +angle instead of plummeting steeply it + +437 +00:21:50,480 --> 00:21:57,039 +sliced beneath North America + +438 +00:21:53,640 --> 00:21:59,120 +horizontally this change had dramatic + +439 +00:21:57,039 --> 00:22:00,960 +consequences + +440 +00:21:59,120 --> 00:22:03,360 +the big oceanic plate in the Pacific + +441 +00:22:00,960 --> 00:22:06,559 +didn't go deep down it went in Shallow + +442 +00:22:03,360 --> 00:22:08,520 +like a spatula under a pizza so + +443 +00:22:06,559 --> 00:22:10,840 +something happened 68 million years ago + +444 +00:22:08,520 --> 00:22:12,120 +over in California that plate drives + +445 +00:22:10,840 --> 00:22:14,640 +under North America but instead of + +446 +00:22:12,120 --> 00:22:16,960 +diving deeply it comes in shallow and a + +447 +00:22:14,640 --> 00:22:20,400 +thousand miles away from the coast up + +448 +00:22:16,960 --> 00:22:20,400 +from the ground Sprout the Rocky + +449 +00:22:21,559 --> 00:22:26,559 +Mountains for millions of years the + +450 +00:22:24,320 --> 00:22:29,240 +ocean plate scraped along the underside + +451 +00:22:26,559 --> 00:22:31,679 +of North America + +452 +00:22:29,240 --> 00:22:33,559 +it created friction breaking up the + +453 +00:22:31,679 --> 00:22:37,159 +basement Granite of the North American + +454 +00:22:33,559 --> 00:22:37,159 +Plate and punching it + +455 +00:22:40,960 --> 00:22:45,400 +upward structural geologist Carl + +456 +00:22:43,720 --> 00:22:47,279 +carlstrom + +457 +00:22:45,400 --> 00:22:49,360 +demonstrates because it was at a + +458 +00:22:47,279 --> 00:22:51,559 +shallower angle beneath North America it + +459 +00:22:49,360 --> 00:22:53,760 +was scraping along the base of North + +460 +00:22:51,559 --> 00:22:55,600 +America when that happens it puts the + +461 +00:22:53,760 --> 00:22:58,159 +plate under compression like this + +462 +00:22:55,600 --> 00:23:01,200 +because it's being both pushed at the + +463 +00:22:58,159 --> 00:23:03,159 +end and uh scraped along at the bottom + +464 +00:23:01,200 --> 00:23:04,960 +so it squeezes pushes up the mountains + +465 +00:23:03,159 --> 00:23:07,960 +and it transferred this mountain + +466 +00:23:04,960 --> 00:23:10,440 +building from The Edge to Great distance + +467 +00:23:07,960 --> 00:23:10,440 +from the plate + +468 +00:23:11,559 --> 00:23:16,720 +margin the shallow angle trajectory of + +469 +00:23:14,279 --> 00:23:19,440 +the Pacific Ocean plate explains why + +470 +00:23:16,720 --> 00:23:22,279 +these mountains formed so far + +471 +00:23:19,440 --> 00:23:23,960 +inland and it also explains the presence + +472 +00:23:22,279 --> 00:23:26,559 +of + +473 +00:23:23,960 --> 00:23:29,080 +granite thrust up through layers of + +474 +00:23:26,559 --> 00:23:32,760 +sedimentary rock the broken Granite + +475 +00:23:29,080 --> 00:23:32,760 +became the Rocky Mountains of the + +476 +00:23:36,440 --> 00:23:41,440 +South Red Rocks park Denver + +477 +00:23:41,600 --> 00:23:46,720 +Colorado a landscape forged by Granite + +478 +00:23:47,640 --> 00:23:52,039 +uplift Kirk Johnson demonstrates how + +479 +00:23:50,240 --> 00:23:55,159 +these Granite Peaks punched up through + +480 +00:23:52,039 --> 00:23:58,159 +the layers of Red Rock around + +481 +00:23:55,159 --> 00:24:01,840 +them I'm going to use my assistance + +482 +00:23:58,159 --> 00:24:04,200 +Veronica and Ian to help me explain how + +483 +00:24:01,840 --> 00:24:05,600 +the Rocky Mountains in Colorado formed + +484 +00:24:04,200 --> 00:24:09,520 +imagine if you will that Veronica and + +485 +00:24:05,600 --> 00:24:13,279 +Ian are composed of 1.7 billion year old + +486 +00:24:09,520 --> 00:24:15,960 +metamorphic rocks the basement rock of + +487 +00:24:13,279 --> 00:24:19,360 +Colorado before the mountains grew + +488 +00:24:15,960 --> 00:24:22,080 +layers of sedimentary rock covered the + +489 +00:24:19,360 --> 00:24:25,640 +granite and in about 68 million years + +490 +00:24:22,080 --> 00:24:27,720 +ago the mountain where Ian is starts to + +491 +00:24:25,640 --> 00:24:29,159 +break and lift up and move up so you see + +492 +00:24:27,720 --> 00:24:30,520 +the uplift forming and what's happening + +493 +00:24:29,159 --> 00:24:32,880 +is that layer of sediments being + +494 +00:24:30,520 --> 00:24:36,000 +deformed and bent and these are the flat + +495 +00:24:32,880 --> 00:24:39,320 +irons at Red Rocks as the mountain comes + +496 +00:24:36,000 --> 00:24:41,679 +up overlying sediments are eroded off + +497 +00:24:39,320 --> 00:24:44,640 +and deposited into the adjacent Basin + +498 +00:24:41,679 --> 00:24:46,760 +and eventually Ian's granitic back is + +499 +00:24:44,640 --> 00:24:49,080 +exposed as the core of the Rocky + +500 +00:24:46,760 --> 00:24:51,320 +Mountains Veronica remains deeply buried + +501 +00:24:49,080 --> 00:24:53,039 +beneath Denver still covered with deep + +502 +00:24:51,320 --> 00:24:55,880 +sediments and the sediments eroded off + +503 +00:24:53,039 --> 00:24:55,880 +the uplifting Rocky + +504 +00:24:56,240 --> 00:25:01,919 +Mountains Johnson is investigating + +505 +00:24:58,840 --> 00:25:04,039 +exactly when these events took place he + +506 +00:25:01,919 --> 00:25:07,840 +focuses on the Colorado Rockies Front + +507 +00:25:04,039 --> 00:25:10,200 +Range which runs 350 M between North and + +508 +00:25:07,840 --> 00:25:10,200 +South + +509 +00:25:10,320 --> 00:25:14,440 +Colorado dating the Rockies requires + +510 +00:25:12,880 --> 00:25:17,799 +real detective + +511 +00:25:14,440 --> 00:25:19,919 +work and like all detective work you get + +512 +00:25:17,799 --> 00:25:21,480 +Clues by digging up + +513 +00:25:19,919 --> 00:25:23,240 +dirt yes so it's sort of + +514 +00:25:21,480 --> 00:25:24,799 +counterintuitive to understand mountains + +515 +00:25:23,240 --> 00:25:27,399 +you don't look at the mountains in you + +516 +00:25:24,799 --> 00:25:29,200 +look at the debris from those mountains + +517 +00:25:27,399 --> 00:25:31,320 +so it's just like a detective would go + +518 +00:25:29,200 --> 00:25:32,799 +through a criminal's garbage can the + +519 +00:25:31,320 --> 00:25:34,600 +Basin adjacent to the mountain range is + +520 +00:25:32,799 --> 00:25:36,200 +sort of a garbage can of the adjacent + +521 +00:25:34,600 --> 00:25:38,799 +mountains the mountain goes up it sheds + +522 +00:25:36,200 --> 00:25:40,760 +all its garbage off to the side in this + +523 +00:25:38,799 --> 00:25:43,799 +case sedimentary rock and fossils + +524 +00:25:40,760 --> 00:25:46,320 +volcanic ash beds layers of lava we can + +525 +00:25:43,799 --> 00:25:48,920 +look at that garbage and reconstruct the + +526 +00:25:46,320 --> 00:25:52,279 +chronology of the uplifting mountain + +527 +00:25:48,920 --> 00:25:55,360 +[Music] + +528 +00:25:52,279 --> 00:25:57,960 +range today this debris forms layers of + +529 +00:25:55,360 --> 00:26:00,440 +sediment 10,000 ft thick beneath the + +530 +00:25:57,960 --> 00:26:00,440 +city of + +531 +00:26:00,919 --> 00:26:06,159 +Denver in their mission to date these + +532 +00:26:03,520 --> 00:26:08,600 +massive Peaks Johnson and his colleagues + +533 +00:26:06,159 --> 00:26:12,240 +search for the tiniest Clues like + +534 +00:26:08,600 --> 00:26:12,240 +fossilized leaves and + +535 +00:26:15,180 --> 00:26:19,440 +[Music] + +536 +00:26:16,480 --> 00:26:22,000 +pollen for Doug Nichols from the Denver + +537 +00:26:19,440 --> 00:26:24,279 +Museum of Nature and Science these + +538 +00:26:22,000 --> 00:26:25,520 +microscopic grains of pollen provide a + +539 +00:26:24,279 --> 00:26:28,799 +valuable + +540 +00:26:25,520 --> 00:26:32,120 +lead pollen can be used to date The + +541 +00:26:28,799 --> 00:26:34,360 +Uplift of mountains because plants that + +542 +00:26:32,120 --> 00:26:36,760 +were living at the time the mountains + +543 +00:26:34,360 --> 00:26:39,480 +were coming up were shedding their + +544 +00:26:36,760 --> 00:26:41,919 +pollen which was becoming incorporated + +545 +00:26:39,480 --> 00:26:44,399 +into sediment which was being eroded + +546 +00:26:41,919 --> 00:26:46,480 +from those same mountains and I'm + +547 +00:26:44,399 --> 00:26:51,120 +looking for the particular species of + +548 +00:26:46,480 --> 00:26:53,960 +pollen that can tell me the age of the + +549 +00:26:51,120 --> 00:26:56,600 +sample each sample of sediment can + +550 +00:26:53,960 --> 00:26:58,360 +contain thousands of fossilized pollen + +551 +00:26:56,600 --> 00:27:01,440 +particles + +552 +00:26:58,360 --> 00:27:04,679 +nichels examines a single + +553 +00:27:01,440 --> 00:27:05,919 +grain every plant genus has distinctive + +554 +00:27:04,679 --> 00:27:08,760 +shaped + +555 +00:27:05,919 --> 00:27:11,399 +pollen so by identifying the species of + +556 +00:27:08,760 --> 00:27:14,200 +plant and its age nickels can start to + +557 +00:27:11,399 --> 00:27:17,640 +date the exact uplift of Colorado's + +558 +00:27:14,200 --> 00:27:21,559 +Rockies we pretty well understand that + +559 +00:27:17,640 --> 00:27:25,279 +the uplift began 65 to 70 million years + +560 +00:27:21,559 --> 00:27:27,880 +ago because we find distinctive kinds of + +561 +00:27:25,279 --> 00:27:32,480 +pollen produced by plants that only + +562 +00:27:27,880 --> 00:27:32,480 +lived 65 to 70 million years + +563 +00:27:33,880 --> 00:27:41,600 +ago sometime during this 5 milliony year + +564 +00:27:37,120 --> 00:27:41,600 +period Colorado's Rockies began to + +565 +00:27:43,360 --> 00:27:48,960 +rise but geologists can narrow this + +566 +00:27:46,159 --> 00:27:52,559 +window even further thanks to one of the + +567 +00:27:48,960 --> 00:27:52,559 +most catastrophic events in + +568 +00:27:56,519 --> 00:28:02,159 +history + +569 +00:27:58,360 --> 00:28:02,159 +65.5 million years + +570 +00:28:04,519 --> 00:28:09,360 +ago and asteroid smashed into the + +571 +00:28:14,039 --> 00:28:19,799 +Earth it wiped out the dinosaurs and + +572 +00:28:17,600 --> 00:28:22,960 +left a distinctive line in the sediments + +573 +00:28:19,799 --> 00:28:25,600 +by Colorado's Rocky + +574 +00:28:22,960 --> 00:28:30,000 +Mountains this pale yellow layer in the + +575 +00:28:25,600 --> 00:28:30,000 +Rock contains the remains of the a huge + +576 +00:28:30,510 --> 00:28:35,240 +[Music] + +577 +00:28:32,760 --> 00:28:37,320 +asteroid because it's sandwiched between + +578 +00:28:35,240 --> 00:28:39,600 +layers of debris that eroded off the + +579 +00:28:37,320 --> 00:28:41,760 +Rockies we know that the Rockies must + +580 +00:28:39,600 --> 00:28:46,960 +have been up and eroding at the time of + +581 +00:28:41,760 --> 00:28:46,960 +impact 65.5 million years + +582 +00:28:48,120 --> 00:28:52,799 +ago Kirk Johnson specializes in dating + +583 +00:28:51,480 --> 00:28:55,559 +fossilized + +584 +00:28:52,799 --> 00:28:58,640 +leaves he uses them to date the Rocky's + +585 +00:28:55,559 --> 00:29:01,360 +birth even more precisely + +586 +00:28:58,640 --> 00:29:05,519 +geologists know that 69 million years + +587 +00:29:01,360 --> 00:29:08,320 +ago Colorado was covered by a shallow + +588 +00:29:05,519 --> 00:29:10,720 +sea but Johnson's fossil leaves show + +589 +00:29:08,320 --> 00:29:12,840 +that just a million years later there + +590 +00:29:10,720 --> 00:29:15,720 +were plants + +591 +00:29:12,840 --> 00:29:18,080 +here Johnson combines his findings with + +592 +00:29:15,720 --> 00:29:20,320 +Nichols pollen evidence to come up with + +593 +00:29:18,080 --> 00:29:23,120 +a million-year window during which the + +594 +00:29:20,320 --> 00:29:24,240 +Colorado Rockies must have + +595 +00:29:23,120 --> 00:29:26,320 +[Music] + +596 +00:29:24,240 --> 00:29:28,679 +[Applause] + +597 +00:29:26,320 --> 00:29:32,500 +emerged compared with the northern + +598 +00:29:28,679 --> 00:29:34,559 +Rockies these mountains grew up + +599 +00:29:32,500 --> 00:29:38,279 +[Music] + +600 +00:29:34,559 --> 00:29:41,039 +fast we know that 69 million years ago + +601 +00:29:38,279 --> 00:29:43,559 +Colorado was covered by a shallow sea we + +602 +00:29:41,039 --> 00:29:45,120 +know that at 68 million years ago the + +603 +00:29:43,559 --> 00:29:47,760 +Rocky Mountains were up so sometimes in + +604 +00:29:45,120 --> 00:29:49,799 +that 1 million period 1 million years + +605 +00:29:47,760 --> 00:29:51,760 +the Rocky Mountains came up it may have + +606 +00:29:49,799 --> 00:29:53,799 +taken all the 1 million years it may + +607 +00:29:51,760 --> 00:29:55,600 +have happened in 200,000 years we don't + +608 +00:29:53,799 --> 00:29:59,320 +know that yet but we're working on that + +609 +00:29:55,600 --> 00:29:59,320 +particular question + +610 +00:30:04,559 --> 00:30:09,720 +although Johnson's team can't yet say + +611 +00:30:07,000 --> 00:30:12,760 +how quickly the mountains grew they are + +612 +00:30:09,720 --> 00:30:12,760 +certain of one + +613 +00:30:13,360 --> 00:30:20,039 +thing 68 million years ago the American + +614 +00:30:17,279 --> 00:30:20,039 +Rockies had + +615 +00:30:21,799 --> 00:30:29,240 +arrived as we continue South through the + +616 +00:30:24,519 --> 00:30:29,240 +Rockies the landscape evolves once again + +617 +00:30:30,080 --> 00:30:35,039 +in 35 million years ago at the southern + +618 +00:30:33,559 --> 00:30:38,679 +tip of the mountain + +619 +00:30:35,039 --> 00:30:42,880 +chain volcanoes appeared among the Peaks + +620 +00:30:38,679 --> 00:30:42,880 +triggered by changes deep beneath + +621 +00:30:43,919 --> 00:30:49,279 +America a new explosive era had + +622 +00:30:52,919 --> 00:30:58,600 +begun as we travel South 2,000 miles + +623 +00:30:56,399 --> 00:31:01,880 +through the Rockies and forward through + +624 +00:30:58,600 --> 00:31:04,799 +their 200 milliony year history we reach + +625 +00:31:01,880 --> 00:31:07,240 +Albuquerque New + +626 +00:31:04,799 --> 00:31:09,039 +Mexico here a dramatic change deep + +627 +00:31:07,240 --> 00:31:13,200 +beneath America triggered the most + +628 +00:31:09,039 --> 00:31:13,200 +explosive phase in the evolution of the + +629 +00:31:20,200 --> 00:31:25,480 +Rockies 70 million years ago the + +630 +00:31:23,000 --> 00:31:27,840 +subducting Pacific Ocean plate punched + +631 +00:31:25,480 --> 00:31:31,200 +up huge blocks of basement Granite + +632 +00:31:27,840 --> 00:31:31,200 +forming the Rockies of New + +633 +00:31:35,840 --> 00:31:41,279 +Mexico 35 million years later the + +634 +00:31:39,080 --> 00:31:44,600 +Pacific Ocean plate began to peel away + +635 +00:31:41,279 --> 00:31:48,080 +from the underside of the North American + +636 +00:31:44,600 --> 00:31:50,080 +continent as the ocean plate sunk deeper + +637 +00:31:48,080 --> 00:31:52,639 +warm mantle came into contact with the + +638 +00:31:50,080 --> 00:31:55,039 +underside of the North American + +639 +00:31:52,639 --> 00:31:59,159 +Plate right underneath parts of the + +640 +00:31:55,039 --> 00:31:59,159 +Southern Rocky Mountains + +641 +00:32:06,399 --> 00:32:11,080 +just as the burner on a hot air balloon + +642 +00:32:08,399 --> 00:32:12,639 +makes the air less dense causing the + +643 +00:32:11,080 --> 00:32:15,240 +balloon to float upward through the + +644 +00:32:12,639 --> 00:32:18,639 +cooler air around + +645 +00:32:15,240 --> 00:32:20,480 +it so warm buoyant mantle rose up + +646 +00:32:18,639 --> 00:32:22,600 +through the cooler denser mantle beneath + +647 +00:32:20,480 --> 00:32:22,600 +the + +648 +00:32:25,279 --> 00:32:31,159 +mountains Carl Carl thinks that this + +649 +00:32:28,080 --> 00:32:32,559 +caused the Rockies to grow even taller + +650 +00:32:31,159 --> 00:32:34,919 +well let's think about uplift of + +651 +00:32:32,559 --> 00:32:37,399 +mountains in the context of this analogy + +652 +00:32:34,919 --> 00:32:39,799 +of a hot air balloon we're floating High + +653 +00:32:37,399 --> 00:32:42,279 +because we're more buoyant than the air + +654 +00:32:39,799 --> 00:32:44,559 +around us and if we want to go up + +655 +00:32:42,279 --> 00:32:47,720 +actually get still higher uh we'll just + +656 +00:32:44,559 --> 00:32:50,080 +turn on the burner and uh fire it up and + +657 +00:32:47,720 --> 00:32:52,720 +then the air becomes lighter within the + +658 +00:32:50,080 --> 00:32:54,600 +balloon causing a dynamic or an active + +659 +00:32:52,720 --> 00:32:57,519 +uplift and we can think of that in the + +660 +00:32:54,600 --> 00:33:00,559 +context of mountains as if an upwelling + +661 +00:32:57,519 --> 00:33:03,039 +of warm and buoyant mantle is actually + +662 +00:33:00,559 --> 00:33:05,039 +pushing up the + +663 +00:33:03,039 --> 00:33:07,039 +mountains but it's not just the + +664 +00:33:05,039 --> 00:33:09,760 +mountains that were + +665 +00:33:07,039 --> 00:33:13,000 +affected the upwelling mantle also + +666 +00:33:09,760 --> 00:33:13,000 +stretched the crust + +667 +00:33:13,360 --> 00:33:18,320 +Above This sandbox simulation + +668 +00:33:16,000 --> 00:33:21,360 +demonstrates the stretching + +669 +00:33:18,320 --> 00:33:23,760 +process as the continent pulled apart + +670 +00:33:21,360 --> 00:33:26,240 +the crust thinned and fractured an + +671 +00:33:23,760 --> 00:33:29,600 +immense crevice called the Rio Grand + +672 +00:33:26,240 --> 00:33:32,440 +Rift opened up in the heart of the + +673 +00:33:29,600 --> 00:33:35,720 +Rockies in parts of the Southern Rockies + +674 +00:33:32,440 --> 00:33:40,799 +the crust is over 30 m thick but in + +675 +00:33:35,720 --> 00:33:43,320 +places beneath the rift it's just 17 Mi + +676 +00:33:40,799 --> 00:33:44,600 +thick this thin crust triggered + +677 +00:33:43,320 --> 00:33:46,840 +something + +678 +00:33:44,600 --> 00:33:49,279 +[Music] + +679 +00:33:46,840 --> 00:33:53,840 +dramatic under immense pressure from + +680 +00:33:49,279 --> 00:33:53,840 +rising heat in the mantle it gave + +681 +00:33:54,960 --> 00:34:01,120 +Way Red Hot magnet blasted out onto the + +682 +00:33:58,320 --> 00:34:01,120 +New Mexico + +683 +00:34:03,360 --> 00:34:08,960 +landscape and volcanos punctured the Rio + +684 +00:34:06,519 --> 00:34:08,960 +Grand + +685 +00:34:11,719 --> 00:34:16,918 +Rift scientists believe that hot magma + +686 +00:34:14,719 --> 00:34:19,560 +has surged up from the mantle many times + +687 +00:34:16,918 --> 00:34:22,159 +over the past 35 million + +688 +00:34:19,560 --> 00:34:25,760 +years these surges led to renewed + +689 +00:34:22,159 --> 00:34:25,760 +volcanism in the Rio Grand + +690 +00:34:25,879 --> 00:34:32,000 +Rift + +691 +00:34:28,440 --> 00:34:32,000 +but this is not ancient + +692 +00:34:34,280 --> 00:34:40,399 +history the last eruption just 1500 + +693 +00:34:38,119 --> 00:34:45,280 +years ago flooded New Mexico with a + +694 +00:34:40,399 --> 00:34:45,280 +river of molten lava 44 miles + +695 +00:34:45,918 --> 00:34:50,639 +long could such recent eruptions mean + +696 +00:34:48,719 --> 00:34:53,280 +that hot magma is ballooning beneath + +697 +00:34:50,639 --> 00:34:56,199 +Earth surface + +698 +00:34:53,280 --> 00:34:59,200 +today could the Rockies of New Mexico + +699 +00:34:56,199 --> 00:34:59,200 +still be on On The + +700 +00:34:59,280 --> 00:35:04,920 +Rise Laura crossy a geologist at the + +701 +00:35:02,359 --> 00:35:06,599 +University of New Mexico is on a mission + +702 +00:35:04,920 --> 00:35:10,000 +to find + +703 +00:35:06,599 --> 00:35:11,880 +out working with Carl carlstrom crossy + +704 +00:35:10,000 --> 00:35:13,960 +is focusing on a fault where the Rio + +705 +00:35:11,880 --> 00:35:16,680 +Grand Rift meets the + +706 +00:35:13,960 --> 00:35:18,800 +Rockies here hot springs bubble up to + +707 +00:35:16,680 --> 00:35:21,480 +the surface from deep + +708 +00:35:18,800 --> 00:35:23,800 +below gases in the water can provide a + +709 +00:35:21,480 --> 00:35:27,200 +clue to the activity in the + +710 +00:35:23,800 --> 00:35:28,680 +mantle this point along this fault is a + +711 +00:35:27,200 --> 00:35:30,440 +place where these fluids are finding + +712 +00:35:28,680 --> 00:35:33,200 +their way to the surface because of the + +713 +00:35:30,440 --> 00:35:35,640 +extension the tectonic activity we're + +714 +00:35:33,200 --> 00:35:37,400 +able to come here and have a window into + +715 +00:35:35,640 --> 00:35:40,880 +that deep deep + +716 +00:35:37,400 --> 00:35:44,040 +world all the way to the + +717 +00:35:40,880 --> 00:35:46,200 +mantle beneath earth's surface gases are + +718 +00:35:44,040 --> 00:35:49,040 +under immense pressure and dissolve in + +719 +00:35:46,200 --> 00:35:50,520 +water when they reach the surface they + +720 +00:35:49,040 --> 00:35:53,079 +escape as + +721 +00:35:50,520 --> 00:35:56,160 +bubbles analyzing samples of the gas + +722 +00:35:53,079 --> 00:35:58,160 +bubbles crossy discovers carbon dioxide + +723 +00:35:56,160 --> 00:36:01,760 +and traces of helium + +724 +00:35:58,160 --> 00:36:04,119 +3 carbon dioxide and helium 3 are both + +725 +00:36:01,760 --> 00:36:06,560 +byproducts of activity in the + +726 +00:36:04,119 --> 00:36:08,720 +mantle their presence indicates that + +727 +00:36:06,560 --> 00:36:10,960 +deep beneath the surface Rock in the + +728 +00:36:08,720 --> 00:36:14,440 +mantle is melting and on the + +729 +00:36:10,960 --> 00:36:16,839 +move like a rising hot air balloon hot + +730 +00:36:14,440 --> 00:36:19,800 +buoyant magma is slowly surging up + +731 +00:36:16,839 --> 00:36:22,160 +beneath both the rift and the + +732 +00:36:19,800 --> 00:36:24,880 +Rockies this is evidence that here in + +733 +00:36:22,160 --> 00:36:25,720 +New Mexico the Rocky Mountains are far + +734 +00:36:24,880 --> 00:36:27,800 +from + +735 +00:36:25,720 --> 00:36:30,200 +dead + +736 +00:36:27,800 --> 00:36:33,240 +they could still be growing thrust + +737 +00:36:30,200 --> 00:36:33,240 +Higher by Rising + +738 +00:36:33,520 --> 00:36:38,319 +mantle carlstrom believes that in the + +739 +00:36:35,880 --> 00:36:42,000 +future there will be a wider Rift and + +740 +00:36:38,319 --> 00:36:42,000 +taller more spectacular + +741 +00:36:42,520 --> 00:36:47,000 +Rockies I think portions of the Rocky + +742 +00:36:44,680 --> 00:36:48,480 +Mountains are going up dynamically and + +743 +00:36:47,000 --> 00:36:51,440 +that they were getting higher and the + +744 +00:36:48,480 --> 00:36:53,200 +Rockies are getting higher and in + +745 +00:36:51,440 --> 00:36:56,680 +certainly in the million-year time frame + +746 +00:36:53,200 --> 00:36:59,880 +we will have a more interesting High + +747 +00:36:56,680 --> 00:37:02,960 +higher and more rugged mountains I would + +748 +00:36:59,880 --> 00:37:04,839 +predict having investigated their past + +749 +00:37:02,960 --> 00:37:07,359 +geologists are now looking to their + +750 +00:37:04,839 --> 00:37:10,560 +future and it's + +751 +00:37:07,359 --> 00:37:14,480 +Bleak the Rockies are doomed and North + +752 +00:37:10,560 --> 00:37:14,480 +America's Destiny hangs in the + +753 +00:37:17,760 --> 00:37:22,240 +balance on this journey through the + +754 +00:37:19,920 --> 00:37:24,800 +Rocky Mountains 200 milliony year + +755 +00:37:22,240 --> 00:37:27,960 +history we've witnessed their dramatic + +756 +00:37:24,800 --> 00:37:31,040 +birth and examined their Complex + +757 +00:37:27,960 --> 00:37:34,079 +Evolution now we turn to their uncertain + +758 +00:37:31,040 --> 00:37:35,560 +future a future that goes hand inand + +759 +00:37:34,079 --> 00:37:37,480 +with the fade of the whole North + +760 +00:37:35,560 --> 00:37:40,000 +American + +761 +00:37:37,480 --> 00:37:42,640 +continent this is the Columbia ice field + +762 +00:37:40,000 --> 00:37:46,040 +in Alberta Canada where geologists are + +763 +00:37:42,640 --> 00:37:48,880 +already seeing how the mountains are + +764 +00:37:46,040 --> 00:37:51,880 +changing within a 100 years it could + +765 +00:37:48,880 --> 00:37:51,880 +look something like + +766 +00:37:53,880 --> 00:37:58,720 +this human activity is altering the the + +767 +00:37:56,760 --> 00:38:01,440 +course of geological + +768 +00:37:58,720 --> 00:38:04,240 +history increasing global temperatures + +769 +00:38:01,440 --> 00:38:06,760 +are taking their toll on the mountains + +770 +00:38:04,240 --> 00:38:08,839 +glaciers they're + +771 +00:38:06,760 --> 00:38:11,240 +melting Brian Luckman from the + +772 +00:38:08,839 --> 00:38:14,040 +University of Western Ontario wants to + +773 +00:38:11,240 --> 00:38:14,040 +know how + +774 +00:38:14,440 --> 00:38:21,640 +fast during the winter glaciers + +775 +00:38:18,520 --> 00:38:25,520 +grow an advancing Glacier pushes a pile + +776 +00:38:21,640 --> 00:38:27,359 +of eroded Rubble ahead of itself called + +777 +00:38:25,520 --> 00:38:29,880 +aine + +778 +00:38:27,359 --> 00:38:32,000 +when the glacier shrinks back in summer + +779 +00:38:29,880 --> 00:38:35,359 +it leaves behind this pile of debris in + +780 +00:38:32,000 --> 00:38:37,640 +its wake it's a Telltale sign that the + +781 +00:38:35,359 --> 00:38:40,640 +glacier is melting + +782 +00:38:37,640 --> 00:38:42,119 +away because the glacier over time is + +783 +00:38:40,640 --> 00:38:45,000 +retreating + +784 +00:38:42,119 --> 00:38:48,000 +continuously then what you have left are + +785 +00:38:45,000 --> 00:38:50,160 +a series of these annual Marine ridges + +786 +00:38:48,000 --> 00:38:53,119 +which Mark the furthest point of Advance + +787 +00:38:50,160 --> 00:38:53,119 +during the previous + +788 +00:38:54,040 --> 00:38:59,960 +winter Luckman walks between the marins + +789 +00:38:57,359 --> 00:39:00,880 +using GPS to map the distance between + +790 +00:38:59,960 --> 00:39:03,359 +each + +791 +00:39:00,880 --> 00:39:07,359 +one the greater the distance between + +792 +00:39:03,359 --> 00:39:07,359 +them the faster the glacier is + +793 +00:39:08,400 --> 00:39:13,400 +melting Glaciers are one of the most + +794 +00:39:10,720 --> 00:39:15,960 +effective ways to demonstrate the people + +795 +00:39:13,400 --> 00:39:19,640 +that the climate is changing you've only + +796 +00:39:15,960 --> 00:39:21,680 +got to come here twice or look at some + +797 +00:39:19,640 --> 00:39:24,720 +of the older photographs to realize + +798 +00:39:21,680 --> 00:39:27,280 +something radically is + +799 +00:39:24,720 --> 00:39:30,400 +changing these two photo graphs of the 3 + +800 +00:39:27,280 --> 00:39:32,359 +and 1/2 Mile Long Athabasca Glacier show + +801 +00:39:30,400 --> 00:39:33,800 +how far it has retreated over the past + +802 +00:39:32,359 --> 00:39:36,160 +30 + +803 +00:39:33,800 --> 00:39:38,400 +years and these photos of the grenell + +804 +00:39:36,160 --> 00:39:41,920 +glacier in Montana show that America's + +805 +00:39:38,400 --> 00:39:41,920 +Glaciers are disappearing as + +806 +00:39:42,040 --> 00:39:47,960 +[Music] + +807 +00:39:44,880 --> 00:39:50,200 +well one day the glaciers that have + +808 +00:39:47,960 --> 00:39:54,160 +shaped these steep-sided Peaks and + +809 +00:39:50,200 --> 00:39:54,160 +ushaped valleys will + +810 +00:39:55,079 --> 00:39:59,839 +disappear but water erosion will + +811 +00:39:57,480 --> 00:40:02,400 +continue to sculpt these mountains + +812 +00:39:59,839 --> 00:40:04,839 +beating them down and softening their + +813 +00:40:02,400 --> 00:40:04,839 +Jagged + +814 +00:40:05,240 --> 00:40:09,560 +edges the the future of the Rockies is + +815 +00:40:07,720 --> 00:40:12,760 +that they're eroding at the rate of + +816 +00:40:09,560 --> 00:40:15,040 +about 600s of a millimeter per year this + +817 +00:40:12,760 --> 00:40:16,960 +is based on taking a sample of river + +818 +00:40:15,040 --> 00:40:18,720 +water measuring the sediment in it and + +819 +00:40:16,960 --> 00:40:21,520 +seeing how fast the Rockies are being + +820 +00:40:18,720 --> 00:40:21,520 +carried off to the + +821 +00:40:22,160 --> 00:40:27,440 +Sea the Relentless force of erosion has + +822 +00:40:25,119 --> 00:40:30,839 +sealed the fade of The Rock mountains + +823 +00:40:27,440 --> 00:40:30,839 +since they first began to + +824 +00:40:31,599 --> 00:40:37,760 +rise one day they will erode away to + +825 +00:40:37,790 --> 00:40:41,010 +[Music] + +826 +00:40:41,200 --> 00:40:46,319 +nothing the Rockies that we see today + +827 +00:40:44,440 --> 00:40:48,400 +the beautiful mountains why tourists + +828 +00:40:46,319 --> 00:40:51,319 +come here why it's just uh one of the + +829 +00:40:48,400 --> 00:40:53,440 +most dramatic places on the earth uh + +830 +00:40:51,319 --> 00:40:55,560 +they're eroding away and so if we look + +831 +00:40:53,440 --> 00:40:58,119 +at all the rivers draining off of them + +832 +00:40:55,560 --> 00:41:02,160 +they're full of silt and sand and that + +833 +00:40:58,119 --> 00:41:04,640 +is our Rockies slowly bleeding to + +834 +00:41:02,160 --> 00:41:07,200 +death the Rockies will eventually + +835 +00:41:04,640 --> 00:41:07,200 +dissolve + +836 +00:41:08,400 --> 00:41:13,839 +away but far in the distant future there + +837 +00:41:11,520 --> 00:41:15,839 +could be a final devastating twist to + +838 +00:41:13,839 --> 00:41:20,280 +their + +839 +00:41:15,839 --> 00:41:20,280 +story a continent ripped in + +840 +00:41:24,800 --> 00:41:31,760 +two the future of the Rocky Mountains is + +841 +00:41:29,640 --> 00:41:36,119 +inevitable thanks to the Relentless + +842 +00:41:31,760 --> 00:41:36,119 +force of erosion they will one day + +843 +00:41:37,000 --> 00:41:42,920 +disappear but they will leave a + +844 +00:41:39,720 --> 00:41:46,119 +legacy the Rio Grand + +845 +00:41:42,920 --> 00:41:48,760 +Rift a great tear in the Earth's + +846 +00:41:46,119 --> 00:41:51,599 +crust that could one day split North + +847 +00:41:48,760 --> 00:41:51,599 +America in + +848 +00:41:51,680 --> 00:41:56,520 +two geologist Mizumi Roy and her + +849 +00:41:54,640 --> 00:41:58,920 +colleague Nicholas George both both from + +850 +00:41:56,520 --> 00:42:02,079 +the University of New Mexico are taking + +851 +00:41:58,920 --> 00:42:05,280 +part in an ambitious 5-year + +852 +00:42:02,079 --> 00:42:08,319 +project its aim to monitor the widening + +853 +00:42:05,280 --> 00:42:08,319 +of the Rio Grand + +854 +00:42:09,040 --> 00:42:14,040 +Rift the team is setting up GPS stations + +855 +00:42:12,040 --> 00:42:18,640 +along the length of the rift like this + +856 +00:42:14,040 --> 00:42:18,640 +one in remote New Mexico 3 hours from + +857 +00:42:19,480 --> 00:42:26,480 +Albuquerque the GPS receivers are buried + +858 +00:42:22,240 --> 00:42:29,280 +in the Bedrock to a depth of around 5 ft + +859 +00:42:26,480 --> 00:42:31,960 +when the Earth moves the receivers move + +860 +00:42:29,280 --> 00:42:34,880 +too Roy + +861 +00:42:31,960 --> 00:42:36,880 +explains if you have two GPS stations + +862 +00:42:34,880 --> 00:42:39,200 +then you have information about relative + +863 +00:42:36,880 --> 00:42:41,440 +motion along a line that connects the + +864 +00:42:39,200 --> 00:42:41,440 +two + +865 +00:42:41,920 --> 00:42:46,599 +stations a network of GPS stations + +866 +00:42:44,640 --> 00:42:49,960 +allows the team to build up a much more + +867 +00:42:46,599 --> 00:42:49,960 +detailed map of the rift's + +868 +00:42:50,920 --> 00:42:55,839 +Motions by looking at the difference + +869 +00:42:53,599 --> 00:42:58,440 +between the coordinates between the GPS + +870 +00:42:55,839 --> 00:43:00,680 +station through time we get a good idea + +871 +00:42:58,440 --> 00:43:02,599 +of the relative motion between each of + +872 +00:43:00,680 --> 00:43:05,880 +these + +873 +00:43:02,599 --> 00:43:08,839 +stations the team has set up 24 GPS + +874 +00:43:05,880 --> 00:43:12,000 +stations along the Rio Grand + +875 +00:43:08,839 --> 00:43:13,559 +Rift it's early days but the team + +876 +00:43:12,000 --> 00:43:18,520 +expects to find that the rift is + +877 +00:43:13,559 --> 00:43:22,280 +widening between .5 and 2 mm every + +878 +00:43:18,520 --> 00:43:25,079 +year it's a very slow + +879 +00:43:22,280 --> 00:43:28,079 +process but little by little the + +880 +00:43:25,079 --> 00:43:28,079 +continent is being + +881 +00:43:28,680 --> 00:43:34,480 +unzipped the r Grand Rift is a rift + +882 +00:43:31,800 --> 00:43:37,319 +system that's causing a continent to + +883 +00:43:34,480 --> 00:43:39,359 +split and if this process continues uh + +884 +00:43:37,319 --> 00:43:41,400 +for tens of millions of years you could + +885 +00:43:39,359 --> 00:43:43,200 +eventually Rift the North American + +886 +00:43:41,400 --> 00:43:45,559 +continent + +887 +00:43:43,200 --> 00:43:47,400 +apart there's a lot of indications that + +888 +00:43:45,559 --> 00:43:49,040 +there's some action happening maybe some + +889 +00:43:47,400 --> 00:43:51,440 +more as in the future for the Rocky + +890 +00:43:49,040 --> 00:43:53,160 +Mountains and uh another few million + +891 +00:43:51,440 --> 00:43:55,319 +years and there will be greater Tales to + +892 +00:43:53,160 --> 00:43:57,160 +tell of active tectonism further to the + +893 +00:43:55,319 --> 00:43:59,760 +north where this real grand Rift is + +894 +00:43:57,160 --> 00:44:02,040 +trying to work its way and crack the + +895 +00:43:59,760 --> 00:44:03,400 +continent I think it'll be unsuccessful + +896 +00:44:02,040 --> 00:44:05,559 +in that attempt but it's giving it a + +897 +00:44:03,400 --> 00:44:05,559 +good + +898 +00:44:05,640 --> 00:44:10,160 +show the story of the Rocky Mountains + +899 +00:44:08,599 --> 00:44:12,440 +began with the birth of the North + +900 +00:44:10,160 --> 00:44:16,920 +American + +901 +00:44:12,440 --> 00:44:16,920 +continent and it could end with its + +902 +00:44:18,160 --> 00:44:24,240 +death one day the real grand Rift May + +903 +00:44:21,520 --> 00:44:28,000 +split a continent North America might + +904 +00:44:24,240 --> 00:44:28,000 +become east and west + +905 +00:44:28,960 --> 00:44:34,280 +America but all this is hundreds of + +906 +00:44:31,520 --> 00:44:37,200 +millions of years into the uncertain + +907 +00:44:34,280 --> 00:44:41,119 +[Music] + +908 +00:44:37,200 --> 00:44:43,330 +future today the iconic Rockies are in + +909 +00:44:41,119 --> 00:44:46,520 +their + +910 +00:44:43,330 --> 00:44:49,079 +[Music] + +911 +00:44:46,520 --> 00:44:53,160 +Prime the mountains that divide a + +912 +00:44:49,079 --> 00:44:53,160 +continent unite us all in + +913 +00:44:53,559 --> 00:44:58,119 +admiration dramatic and resilient they + +914 +00:44:56,319 --> 00:45:02,599 +will remain the backbone of North + +915 +00:44:58,119 --> 00:45:02,599 +America for millions of years to + +916 +00:45:04,580 --> 00:45:21,789 +[Music] + +917 +00:45:24,880 --> 00:45:31,580 +come + +918 +00:45:27,370 --> 00:45:31,580 +[Music] +