I apologize for any confusing abbreviations, misspellings or typos. This was created primarily for me to use
| Date | Events |
| Late PC and Early PZ | Rodina begins to separate. Wide continental shelf across BC, WA, OR, ID, NV |
| 1bil to 400 mil | and N. CA. 30,000 ft of marine sediments accumulate. Chrt,sh,slts,volcanics,Ls. |
| Known as Lt. PC Belt-Purcell Sediments. Include brachios, trilos. In BC includes | |
| Burgess shale. Shallow seas in NW at this time | |
| Late PZ through MZ | Smaller coastal oceans develop as archipelagos collide with N. Amer. Islands |
| 300 to 70 mybp | and basins associated with them developed some distance off shore. Durring |
| this time most accreation occurred. Parallel belts of rocks form | |
| from accreation and sediments eroded from continent accumulate on | |
| shelf. Off shore seds accumulating on volcanic islands represent tropical environment. | |
| PZ & MZ terrane fragments include: Blues in OR WA ID, Klamaths in OR and CA | |
| Insular and Intermontane regions of BC and N. WA. N. Cascades of WA, & BC | |
| Smaller terrans are in Basin & Range of OR, ID and N central NV | |
| Blues are linked to Klamaths rocks in N.WA and BC. Oldest rocks in N. Cascad. | |
| are platform of terranes over 500mybp. Smaller terranes in Vancouver Island | |
| strait of Juan de Fuca and in the Olympic peninsula were annealed in Tertiary | |
| Accretion wrinkled and folded western margin of N. Amer into the Omineca | |
| and coast range. San Juans, N. Cascades, Klamaths and blues have many | |
| faults. Fore-arc depressions formed between trenches and volcanic islands. Ex// | |
| Bowser basin in BC, Queen Charlotte basin, Naniamo on VanCouver island, and | |
| Chuckanut trough in WA . All filled in with sediment and debris and interlaid | |
| with fossils and plants to create coal. | |
| Granitic batholiths were emplaced and sutured the Blues. Biggest emplacements in | |
| Idaho, coast range in BC, and Sierra Nevada. Average 5 miles in thickness | |
| Idaho: 100 mybp. Coast range between Jurassic to Miocene. | |
| CZ | Cretaceous seaway withdraws & mnt uplift. NW coastline looks similar to today |
| Eocene: warm and humid. Miocene & Pliocene cool and dry. Pleistocene: ice age | |
| Early Eocene | Shifting plates created volcanism, intrusions, faulting, erosion and rapid sedimentation |
| ~55mybp | localized volcanics and sedimentation and older rocks highly eroded then covered |
| Ruptures in crust offshore between Kula and Farallon plates. Kula plate pulled N and | |
| Farallon plate subducted. Spreading center between two developed. Linear volcanic | |
| platform developed where seds accum from Klamaths and eventually the W. Casc. | |
| Created the foundation for Coast range of OR and WA | |
| Mid Eocene | Subduction of Farallon plate slows and angle steepens. Local volcanics & basins form |
| Across MT WY ID &NE WA andesitic and rhyolitic activity (Challis episode). Overlaps | |
| with Clarno formation in OR. Trop plants and mammals buried in mudflows | |
| Kula plate pulling against edge of N. American plate created many small basins | |
| in BC and N WA. Basins run N-S. Variety of flora and fauna preserved in ash/lava | |
| mixed with freshwater seds. Other basins developed coal deposits: | |
| Swauk, Chumstick in WA, Great Valley in CA, Tyee in OR to Puget sound | |
| Kula plate motion also caused exposures of core complexes and domed older rocks | |
| upwards. Many smaller mtns in NW have older crustal rocks beneath surface | |
| End Eocene | More volcanism. Beginning of Western cascade formation (~40 mybp). Offshore |
| plate change and subduction angle flattens out. | |
| Oligocene-Miocene | eruptions continue. Miocene (35-20 mybp) tilting and uplift created rainshadow effect. |
| Savannahs dominate inland regions. Upward arching of blues in OR depress John Day. | |
| Ignimbrites preserve plants in animals in JD basin. | |
| Miocene (20-5mybp) | Coast range, Olympic Pen. and Coastal Mtns in BC Slowly rise due to subducting |
| Plate. (continues today). Platform created in Eocene off shore was elevated in E to L | |
| Miocene so by Pliocene it was well above sealevel. This uplift depressed regions to | |
| east and the Willamette and Puget basins werer created. | |
| Lavas from this time: Steens, Warner Range (CA), Snake River Plain, CRBs, and 5 | |
| provences across BC. | |
| Widespread rhyolite and lava in Owyhee highlands marks start of Yellowstone hot spot. | |
| eastward propagating Owyee-McDermitt, Bruneuau -Jarbridge, Magic Reservoir, & | |
| Heise volcanic fields show track of speed and direction of N American plate since Mid | |
| Miocene | |
| CRBs of this time related to crustal stretching vetween archipelago and mainland. | |
| Environmental changes due to CRBS: changing drainage patterns of rivers, ponds | |
| developed, soils develop between flows to show record of grass, animals and trees | |
| Late Oligocene to | Five volcanic chains in BC and Alaska triggered by combo of subduction, hotspot and |
| pleistocene | extension. Include: Wangell, Stikine, anahim, Pemberton, & Garibaldi volc. Zones |
| Created intrusive rocks, volcanic calderas and lava and ash (very widspread) | |
| Pliocene to | Continuing volcanics and many glaciers and ice sheets. Often the two interacted |
| Pleistocene | Plate motion changed and violent eruptions dominate emerging High Cascades. |
| Change in Plate motion caused extension and contributed to basalts of snake river | |
| plain and Basin & R. ex// Craters of the Moon, Newberry, Medicine lake | |
| Change in Juna de Fuca slab (9 mybp) pushed volcanic arc to east | |
| Pleistocene | Ice age dominates. Most BC covered in ice at some point. Several major cycles |
| beginning ~ 2mybp continental glacers in BC move south to Puget sound, Okanagan | |
| and Pend Oreille. Ice caps in high summets and valley glaciers also further south. | |
| Time of Missoula Floods. |