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74-548: The Calapooya Mountains are composed of volcanic rocks and newer sedimentary strata. The mountains have been deeply eroded by the Coast Fork Willamette River and its tributaries. In the southern drainage, the tributaries of the North Umpqua River have cut into the southern slopes. The soil is silty, clay loam formed from sandstone, sediment, and igneous rocks. The Calapooya Mountains and

148-457: A vesicular texture caused by voids left by volatiles trapped in the molten lava . Pumice is a highly vesicular rock produced in explosive volcanic eruptions . Most modern petrologists classify igneous rocks, including volcanic rocks, by their chemistry when dealing with their origin. The fact that different mineralogies and textures may be developed from the same initial magmas has led petrologists to rely heavily on chemistry to look at

222-743: A 6 percent grade to reach the Rogue Valley . The freeway passes through Ashland and Medford , running parallel to Oregon Route 99 , and turns west to follow the Rogue River to Grants Pass , where it intersects US 199 . I-5 then turns north and crosses a series of passes in the Klamath Mountains to reach the Umpqua Valley, where it follows the South Umpqua River to Roseburg . The highway enters

296-430: A black glassy substance called obsidian . When filled with bubbles of gas, the same lava may form the spongy appearing pumice . Allowed to cool slowly, it forms a light-colored, uniformly solid rock called rhyolite. The lavas, having cooled rapidly in contact with the air or water, are mostly finely crystalline or have at least fine-grained ground-mass representing that part of the viscous semi-crystalline lava flow that

370-410: A close analogy to hot solutions of salts in water, which, when they approach the saturation temperature, first deposit a crop of large, well-formed crystals (labile stage) and subsequently precipitate clouds of smaller less perfect crystalline particles (metastable stage). In igneous rocks the first generation of crystals generally forms before the lava has emerged to the surface, that is to say, during

444-474: A continuous 5 percent grade for 5 miles (8.0 km). After passing Pyramid Lake , I-5 makes several turns as it follows a series of narrow valleys to reach the second-highest point of its entire length, Tejon Pass (elevation 4,144 ft or 1,263 m) in the Tehachapi Mountains . The freeway then traverses the narrow Grapevine Canyon and descends for 12 miles (19 km) into

518-459: A good supplier will know what sort of volcanic rock they are selling. The sub-family of rocks that form from volcanic lava are called igneous volcanic rocks (to differentiate them from igneous rocks that form from magma below the surface, called igneous plutonic rocks ). The lavas of different volcanoes, when cooled and hardened, differ much in their appearance and composition. If a rhyolite lava-stream cools quickly, it can quickly freeze into

592-673: A major highway serving the Inland Northwest region. I-5 continues through Yreka in the Shasta Valley and follows the Klamath River into the Siskiyou Mountains , where it crosses into Oregon. I-5 enters Oregon near Siskiyou Summit , which sits at 4,310 feet (1,310 m) and is the highest point on the highway. From the summit, I-5 descends by 2,300 feet (700 m) over 6 miles (9.7 km) at

666-462: A paramorph of augite and magnetite, which may partially or completely substitute for the original crystal but still retains its characteristic outlines. The mechanical behaviour of volcanic rocks is complicated by their complex microstructure. For example, attributes such as the partitioning of the void space (pores and microcracks), pore and crystal size and shape, and hydrothermal alteration can all vary widely in volcanic rocks and can all influence

740-430: A pattern of wet winters and dry summers. Precipitation generally increases with elevation, ranging from an average of 40 to 50 inches (1,000 to 1,300 mm) per year in the valleys to 70 to 80 inches (1,800 to 2,000 mm) on the mountain peaks. Above 4,000 feet (1,200 m), a significant part of this falls as snow. Throughout the history of the region, the range has provided a geographic and cultural barrier between

814-529: A short spur into downtown Tacoma . The freeway turns north again after leaving Tacoma and its nearby seaport near Fife to traverse the suburbs of South King County . I-5 intersects its eastern bypass of Seattle , I-405 , in Tukwila near Seattle–Tacoma International Airport . The freeway generally follows the Green and Duwamish rivers into Seattle, passing Boeing Field and the industrial district in

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888-502: A volcanic rock's origin. The chemical classification of igneous rocks is based first on the total content of silicon and alkali metals ( sodium and potassium ) expressed as weight fraction of silica and alkali oxides ( K 2 O plus Na 2 O ). These place the rock in one of the fields of the TAS diagram . Ultramafic rock and carbonatites have their own specialized classification, but these rarely occur as volcanic rocks. Some fields of

962-401: Is a molten liquid and rock is solid). "Lava stone" may describe anything from a friable silicic pumice to solid mafic flow basalt, and is sometimes used to describe rocks that were never lava , but look as if they were (such as sedimentary limestone with dissolution pitting ). To convey anything about the physical or chemical properties of the rock, a more specific term should be used;

1036-716: Is at the Mexican border at the San Ysidro Port of Entry , the busiest land border crossing in the Western Hemisphere ; the crossing handles a daily average of 70,000 vehicles and 20,000 pedestrians crossing northbound and connects with Mexican Federal Highway 1 in Tijuana . The freeway splits in San Diego 's San Ysidro neighborhood, with I-5 traveling northwest through Chula Vista and National City on

1110-411: Is dependent on two things: the initial composition of the primary magma and the subsequent differentiation. Differentiation of most magmas tends to increase the silica ( SiO 2 ) content, mainly by crystal fractionation . The initial composition of most magmas is basaltic , albeit small differences in initial compositions may result in multiple differentiation series. The most common of these series are

1184-606: Is still listed as a control city on northbound I-5 between SR 99 and I-580. By the early 21st century, sections of I-5 had deteriorated due to a maintenance backlog as well as high traffic volumes. Several bridges in Oregon were reconstructed or repaired to accommodate use by heavy freight vehicles. On May 23, 2013, a bridge span collapsed over the Skagit River in Mount Vernon, Washington , sending two cars into

1258-679: Is the main north–south Interstate Highway on the West Coast of the United States , running largely parallel to the Pacific coast of the contiguous U.S. from Mexico to Canada . It travels through the states of California , Oregon , and Washington , serving several large cities on the West Coast, including San Diego , Los Angeles , Sacramento , Portland , and Seattle . It is the only continuous Interstate highway to touch both

1332-870: The Calapooya Divide are two parts of a spur of the Western Cascade mountains in the U.S. state of Oregon that form the divide between the watersheds of the Willamette and Umpqua rivers. At its southeastern end, the spur joins the Cascade Range near Cowhorn Mountain near the headwaters of the Middle Fork Willamette River and the North Umpqua River . A topographic map in the Atlas of Oregon shows

1406-600: The Central Pacific railroad also followed the route of the Siskiyou Trail. By the early 20th century, pioneering automobile roads were built along the path of the Siskiyou Trail, notably the Pacific Highway . The Pacific Highway ran from British Columbia to San Diego, California, and was the immediate predecessor of much of US 99. The route of US 99 was in turn used as a basis for much of

1480-755: The Columbia River into Washington state. The highway enters Vancouver at the north end of the Interstate Bridge and immediately intersects Washington State Route 14 near the Fort Vancouver National Historic Site . The freeway passes near downtown Vancouver and continues north through the city's suburbs before being rejoined by I-205 at Salmon Creek . I-5 travels north along the Columbia River to Kelso and Longview , where it switches to following

1554-754: The Cowlitz River between the Willapa Hills and Cascade foothills. The freeway then turns northwest to traverse a prairie and the adjacent cities of Chehalis and Centralia while concurrent with US 12 . I-5 continues north to a junction with US 101 in Tumwater , near Olympia and the state capitol campus . The freeway skirts the southeast side of downtown Olympia and turns east to cross Joint Base Lewis–McChord (formerly Fort Lewis and McChord Air Force Base ). I-5 then turns north to enter Tacoma but bends east to intersect I-705 ,

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1628-770: The East Los Angeles Interchange near downtown Los Angeles , I-5 intersects US 101 and begins a short concurrency with I-10 on a section of the Golden State Freeway . The freeway splits from I-10 and turns northwest to follow the Los Angeles River through Glendale and into Burbank . I-5 then leaves the river and travels across the San Fernando Valley , later crossing the Newhall Pass through

1702-727: The Eastside region. The freeway travels north through Everett , skirting the city's downtown and intersecting US 2 , and leaves the Seattle metropolitan area for the rural Skagit Valley . I-5 descends into the valley and travels through Mount Vernon and Burlington before climbing into the Chuckanut Mountains , where it turns west towards Bellingham Bay (part of the Salish Sea ). The freeway travels around downtown Bellingham and turns northwest to continue across

1776-616: The Mexican and Canadian borders. Upon crossing the Mexican border at its southern terminus, the highway continues to Tijuana , Baja California, as Mexican Federal Highway 1 (Fed. 1). Upon crossing the Canadian border at its northern terminus, it continues to Vancouver as British Columbia Highway 99 (BC 99). I-5 was originally created in 1956 as part of the Interstate Highway System, but it

1850-573: The Pacific coastline through the northern suburbs of San Diego. Between Oceanside and San Clemente , an 18-mile (29 km) stretch of the San Diego Freeway passes through Marine Corps Base Camp Pendleton before entering Orange County . At Dana Point , I-5 turns inland and heads north through Mission Viejo to the El Toro Y interchange in Irvine , where I-405 splits and carries

1924-758: The Ross Island Bridge (carrying US 26 ) before reaching an interchange with I-405 . I-5 and I-405 form a complete loop around downtown Portland , with I-5 crossing the Willamette River on the Marquam Bridge to run along the eastern riverfront. The freeway has interchanges with several major bridges crossing the Willamette, as well as the western terminus of I-84 near the Oregon Convention Center . From

1998-665: The San Joaquin Valley . At Wheeler Ridge near the south end of the valley, State Route 99 splits from the freeway to serve Bakersfield and other major cities in the Central Valley , while I-5 stays to the west. Now named the West Side Freeway, I-5 travels northwest along the edge of the Central Valley through farmland and avoids populated areas. The freeway is connected to several of

2072-633: The Santa Susana Mountains to reach the Santa Clarita Valley ; the Newhall Pass interchange with State Route 14 is notable for having separate lanes for truck traffic. The freeway passes the city of Santa Clarita and ascends into the Sierra Pelona Mountains , where the northbound and southbound lanes separate and cross sides for approximately 5 miles (8.0 km). The northbound ascent includes

2146-600: The Siskiyou Trail . This trail was based on an older network of Native American footpaths connecting the Pacific Northwest with California's Central Valley. By the 1820s, trappers from the Hudson's Bay Company were the first non-Native Americans to use the route of today's I-5 to move between today's Washington state and California. During the second half of the 19th century, mule trains, stagecoaches, and

2220-589: The University District near the University of Washington campus and Green Lake before leaving the city. The section between downtown Seattle and Northgate includes a set of reversible express lanes that add extra capacity in the peak direction of travel. I-5 continues through the northern suburbs of Seattle and turns northeasterly in Lynnwood , where it is rejoined by I-405, which serves

2294-664: The Willamette Valley and the Umpqua Valley , effectively separating Western Oregon from Southern Oregon . In the 19th century, it separated the tribal domains of the Kalapuya and Umpqua tribes of Native Americans . During the 1840s, the mountains proved a barrier to white settlers seeking to move into southern Oregon or to move southward to the California gold fields . The Applegate Trail , blazed in

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2368-586: The Willamette Valley near Cottage Grove and forms the boundary between the cities of Eugene and Springfield . After crossing the Willamette River , I-5 intersects Oregon Route 126 , which carries I-105 , and Oregon Route 569 ; both highways provide connections to Eugene and Springfield. I-5 then travels due north through farmland on the east side of the Willamette River, passing a junction with US 20 in Albany , and bisects eastern Salem near

2442-408: The pyroxenes . Bowen's reaction series correctly predicts the order of formation of the most common minerals in volcanic rocks. Occasionally, a magma may pick up crystals that crystallized from another magma; these crystals are called xenocrysts . Diamonds found in kimberlites are rare but well-known xenocrysts; the kimberlites do not create the diamonds, but pick them up and transport them to

2516-640: The state capitol campus . It is connected to downtown Salem by Oregon Route 22 and the Salem Parkway , which joins I-5 as the freeway crosses the 45th parallel near Keizer . From Salem, I-5 turns northeast and passes Woodburn before crossing the Willamette River on the Boone Bridge in Wilsonville , at the south end of the Portland metropolitan area . The freeway travels through

2590-562: The tholeiitic , calc-alkaline , and alkaline . Most volcanic rocks share a number of common minerals . Differentiation of volcanic rocks tends to increase the silica (SiO 2 ) content mainly by fractional crystallization . Thus, more evolved volcanic rocks tend to be richer in minerals with a higher amount of silica such as phyllo and tectosilicates including the feldspars, quartz polymorphs and muscovite . While still dominated by silicates, more primitive volcanic rocks have mineral assemblages with less silica, such as olivine and

2664-549: The Calapooya Mountains curving northwest from near Potter, McGowan, and Balm mountains past Bohemia Mountain to Holland Point, south of Oakridge . From near Bohemia Mountain, a block of mountains connected to the Calapooya Mountains runs due west along the border between Lane and Douglas counties to the vicinity of Interstate 5 (I-5) near Rice Hill . This block is known as the Calapooya Divide. To

2738-810: The Coast Fork Willamette River or its major tributary, the Row River , are Brice, Layng, and Mosby creeks and Big River . The Umpqua flows west through the Oregon Coast Range to the Pacific Ocean at Reedsport , while the Willamette flows north to the Columbia River , which flows northwest to the Pacific Ocean at Astoria . The highest peaks in the range include Balm Mountain at 6,165 feet (1,879 m) above sea level , Potter Mountain at 6,145 feet (1,873 m), and McGowan Mountain at 6,130 feet (1,870 m), all near

2812-479: The Earth's current land surface. Volcanic rocks are usually fine-grained or aphanitic to glass in texture. They often contain clasts of other rocks and phenocrysts . Phenocrysts are crystals that are larger than the matrix and are identifiable with the unaided eye . Rhomb porphyry is an example with large rhomb shaped phenocrysts embedded in a very fine grained matrix. Volcanic rocks often have

2886-657: The I-84 interchange to a second junction with I-405 near the Fremont Bridge , I-5 is concurrent with US 30 , which continues west towards Astoria . Through North Portland , the freeway runs below street level until it crosses the Columbia Slough to bisect Delta Park . I-5 continues across Hayden Island to the Interstate Bridge , a pair of vertical-lift bridges which carry the highway over

2960-500: The John J. Montgomery Freeway and I-805 serving the eastern neighborhoods. I-5 follows the shore of San Diego Bay and intersects State Route 15 (a continuation of I-15 ) near Naval Station San Diego . The freeway then travels around downtown San Diego and San Diego International Airport before reaching a junction with I-8 . I-5 bisects the University of California, San Diego campus, merging with I-805 nearby, and follows

3034-774: The San Diego Freeway designation. I-5 continues northwest as the Santa Ana Freeway through several Orange County and Los Angeles County suburbs and passes near Disneyland in Anaheim . The freeway intersects I-605 in Downey and I-710 in Commerce before reaching the city of Los Angeles . Southern Californians often refer to I-5 as "the 5" or as the Santa Ana Freeway in the Los Angeles area. At

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3108-575: The TAS diagram are further subdivided by the ratio of potassium oxide to sodium oxide. Additional classifications may be made on the basis of other components, such as aluminum or iron content. Volcanic rocks are also broadly divided into subalkaline, alkaline, and peralkaline volcanic rocks. Subalkaline rocks are defined as rocks in which SiO 2 < -3.3539 × 10 × A + 1.2030 × 10 × A - 1.5188 × 10 × A + 8.6096 × 10 × A - 2.1111 × A + 3.9492 × A + 39.0 where both silica and total alkali oxide content (A) are expressed as molar fraction . Because

3182-436: The TAS diagram uses weight fraction and the boundary between alkaline and subalkaline rock is defined in terms of molar fraction, the position of this curve on the TAS diagram is only approximate. Peralkaline volcanic rocks are defined as rocks having Na 2 O + K 2 O > Al 2 O 3 , so that some of the alkali oxides must be present as aegirine or sodic amphibole rather than feldspar . The chemistry of volcanic rocks

3256-446: The West Coast Clean Transit Corridor Initiative. The program is a collaboration of nine utilities and two agencies representing municipal utilities, and aims to enable electric freight and delivery trucks to operate along the entire West Coast corridor. I-5 will have a complete set of auxiliary routes (i.e. 105, 205, 305, 405, 505, 605, 705, 805, 905), with the completion of I-905 in San Diego County . Currently, I-80 and I-90 are

3330-420: The West Coast Electric Highway, a partnership between the states of California, Oregon, and Washington to build and maintain a network of charging stations for electric vehicles . The pact was formed in 2009 and the first charging stations—spaced 25 to 50 miles (40 to 80 km) apart—opened in 2011. In 2019, the three states also broke ground on a similar charging network for electric trucks along I-5 called

3404-428: The ascent from the subterranean depths to the crater of the volcano. It has frequently been verified by observation that freshly emitted lavas contain large crystals borne along in a molten, liquid mass. The large, well-formed, early crystals ( phenocrysts ) are said to be porphyritic ; the smaller crystals of the surrounding matrix or ground-mass belong to the post-effusion stage. More rarely lavas are completely fused at

3478-520: The context of Precambrian shield geology, the term "volcanic" is often applied to what are strictly metavolcanic rocks . Volcanic rocks and sediment that form from magma erupted into the air are called "pyroclastics," and these are also technically sedimentary rocks. Volcanic rocks are among the most common rock types on Earth's surface, particularly in the oceans. On land, they are very common at plate boundaries and in flood basalt provinces . It has been estimated that volcanic rocks cover about 8% of

3552-433: The crystal. It is clear that after the mineral had crystallized it was partly again dissolved or corroded at some period before the matrix solidified. Corroded phenocrysts of biotite and hornblende are very common in some lavas; they are surrounded by black rims of magnetite mixed with pale green augite. The hornblende or biotite substance has proved unstable at a certain stage of consolidation, and has been replaced by

3626-472: The edge of downtown . I-5 intersects two transcontinental highways in the Sacramento area: US 50 (and unsigned I-305 ) south of downtown and I-80 in the northern suburbs. After an unsigned concurrency with State Route 99 in northern Sacramento, the freeway turns west to pass the city's airport and resumes its northwestern path at Woodland . It then intersects I-505 , another Bay Area connector, near Dunnigan . The freeway continues north along

3700-404: The ground-mass . Microscopic examination of the phenocrysts often reveals that they have had a complex history. Very frequently they show layers of different composition, indicated by variations in color or other optical properties; thus augite may be green in the center surrounded by various shades of brown; or they may be pale green centrally and darker green with strong pleochroism (aegirine) at

3774-409: The late 1840s, provided the first reliable path for white settlement through the western end of the mountains. Interstate 5 essentially follows the route of the trail between Eugene and Roseburg. The mountains have been an important timber source in the 20th century. The eastern end of the mountains are largely within the Umpqua National Forest in the south and Willamette National Forest in

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3848-456: The mechanical behaviour of volcanic rocks can help us better understand volcanic hazards, such as flank collapse. Volcanic rocks : Subvolcanic rocks : Plutonic rocks : Picrite basalt Peridotite Basalt Diabase (Dolerite) Gabbro Andesite Microdiorite Diorite Dacite Microgranodiorite Granodiorite Rhyolite Microgranite Granite Interstate 5 Interstate 5 ( I-5 )

3922-714: The moment of ejection; they may then cool to form a non-porphyritic, finely crystalline rock, or if more rapidly chilled may in large part be non-crystalline or glassy (vitreous rocks such as obsidian, tachylyte , pitchstone ). A common feature of glassy rocks is the presence of rounded bodies ( spherulites ), consisting of fine divergent fibres radiating from a center; they consist of imperfect crystals of feldspar, mixed with quartz or tridymite ; similar bodies are often produced artificially in glasses that are allowed to cool slowly. Rarely these spherulites are hollow or consist of concentric shells with spaces between ( lithophysae ). Perlitic structure, also common in glasses, consists of

3996-448: The north along I-5 are Cottage Grove and Eugene and to the south are Sutherlin and Roseburg . Streams flowing south from the Calapooyas into the North Umpqua River include Steamboat, Canton, and Rock creeks, while Calapooya Creek flows west from the divide into the Umpqua main stem. Streams flowing north or east into the Middle Fork Willamette River include Tumblebug, Staley, Coal, and Packard creeks. Flowing northwest or west into

4070-498: The north. Volcanic rock Volcanic rocks (often shortened to volcanics in scientific contexts) are rocks formed from lava erupted from a volcano . Like all rock types, the concept of volcanic rock is artificial, and in nature volcanic rocks grade into hypabyssal and metamorphic rocks and constitute an important element of some sediments and sedimentary rocks . For these reasons, in geology, volcanics and shallow hypabyssal rocks are not always treated as distinct. In

4144-409: The periphery. In the feldspars the center is usually richer in calcium than the surrounding layers, and successive zones may often be noted, each less calcic than those within it. Phenocrysts of quartz (and of other minerals), instead of sharp, perfect crystalline faces, may show rounded corroded surfaces, with the points blunted and irregular tongue-like projections of the matrix into the substance of

4218-454: The presence of concentric rounded cracks owing to contraction on cooling. The phenocrysts or porphyritic minerals are not only larger than those of the ground-mass; as the matrix was still liquid when they formed they were free to take perfect crystalline shapes, without interference by the pressure of adjacent crystals. They seem to have grown rapidly, as they are often filled with enclosures of glassy or finely crystalline material like that of

4292-524: The process. I-5 intersects I-90 near Seattle's Chinatown–International District on the south side of downtown Seattle . The freeway turns northwest and bisects downtown Seattle in a trench, with some sections covered by Freeway Park and the Washington State Convention Center . It then turns north to intersect Washington State Route 520 near Eastlake and crosses the Ship Canal Bridge over Portage Bay , which lies between Lake Union and Lake Washington . I-5 continues through northern Seattle, passing

4366-561: The product of explosive volcanism. They are often felsic (high in silica). Pyroclastic rocks are often the result of volcanic debris, such as ash , bombs and tephra , and other volcanic ejecta . Examples of pyroclastic rocks are tuff and ignimbrite . Shallow intrusions , which possess structure similar to volcanic rather than plutonic rocks, are also considered to be volcanic, shading into subvolcanic . The terms lava stone and lava rock are more used by marketers than geologists, who would likely say "volcanic rock" (because lava

4440-432: The rest of the San Francisco Bay Area. Original plans called for a loop Interstate with a directional suffix, I-5W. This route now roughly corresponds to I-580 from I-5 south of Tracy to Oakland, I-80 from Oakland to Vacaville , and I-505 from Vacaville to I-5 near Dunnigan. I-5W and most of the other Interstates around the country with directional suffixes were eventually renumbered or eliminated. Nevertheless, San Francisco

4514-478: The resultant mechanical behaviour (e.g., Young's modulus, compressive and tensile strength, and the pressure at which they transition from brittle to ductile behaviour ). As for other crustal rocks, volcanic rocks are brittle and ductile at low and high effective confining pressures, respectively. Brittle behaviour is manifest as faults and fractures, and ductile behaviour can either be distributed (cataclastic pore collapse) or localised (compaction bands). Understanding

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4588-404: The route of today's I-5. A major deviation from the old US 99 route is the Westside Freeway portion of I-5 in California's Central Valley. To provide a faster and more direct north–south route through the state, the decision was made to build a new freeway to the west and bypass Fresno, Bakersfield, and the rest of population centers in the area instead of upgrading the existing highway (which

4662-405: The rural Fraser Lowland . I-5 terminates at the Peace Arch Border Crossing on the Canadian border , adjacent to the eponymous monument , in Blaine . The highway becomes British Columbia Highway 99 , which continues northwest to Vancouver . An extensive section of this highway (over 600 mi (970 km)), from approximately Stockton, California, to Portland, Oregon, follows the track of

4736-426: The southeastern end of the range. Along the divide, Huckleberry Mountain in the east rises to 4,754 feet (1,449 m), while Ben More Mountain near I-5 is only 2,480 feet (760 m) high. Bohemia Mountain and its close neighbor Fairview Peak reach identical peak elevations of 5,933 feet (1,808 m), while Holland Point near Oakridge is 5,048 feet (1,539 m) high. The climate in the Calapooya Mountains follows

4810-399: The southern suburbs of Portland , intersecting I-205 in Tualatin and Oregon Route 217 in Tigard before entering the city proper. I-5 then turns northeast to follow Barbur Boulevard (part of Route 99W) and navigate the Terwilliger curves . The freeway continues north through the South Waterfront neighborhood, crossing under the Portland Aerial Tram and the western approach to

4884-455: The surface of the Earth. Volcanic rocks are named according to both their chemical composition and texture. Basalt is a very common volcanic rock with low silica content. Rhyolite is a volcanic rock with high silica content. Rhyolite has silica content similar to that of granite while basalt is compositionally equal to gabbro . Intermediate volcanic rocks include andesite , dacite , trachyte , and latite . Pyroclastic rocks are

4958-419: The valley's main cities, including Fresno , Merced , and Modesto , by other highways. Near Tracy , I-580 splits from I-5 to provide the first of several connections to the San Francisco Bay Area ; I-205 northeast of Tracy also provides a connection through I-580. The freeway continues north through Stockton to Sacramento , where it follows the Sacramento River through the southern suburbs and along

5032-463: The water and requiring traffic in both directions to bypass the crossing. The Washington State Department of Transportation used a temporary structure to restore access across the river while a permanent bridge replacement was built. That process was completed September 15, 2013. On December 18, 2017, an Amtrak train derailed on an overpass crossing I-5 near Tacoma, Washington, and blocked several lanes of traffic. The I-5 corridor forms part of

5106-471: The western edge of the Sacramento Valley , passing through farmland and several small towns before reaching the end of the valley at Red Bluff . I-5 then traverses the rugged Shasta Cascade region, passing through Redding and crossing Shasta Lake before beginning its ascent towards Mount Shasta . The freeway follows the Sacramento River upstream to the southwestern slopes of the mountain and turns northwest to reach Weed , where it intersects US 97 ,

5180-653: Was built in segments between 1956 and 1978, including expressway sections of US 99 that were built earlier to bypass various towns along the route. US 99 was removed in 1972. I-5 is a major Interstate Highway that spans 1,381 miles (2,223 km) and runs north–south through the West Coast states of California , Oregon , and Washington . It connects several major metropolitan areas as well as agricultural regions, seaports, and freight destinations. The freeway ranges from four lanes in some rural sections to 22 lanes in Orange County, California , where it had been widened and reconstructed. The southern terminus of I-5

5254-453: Was going on while the mass was still creeping forward under the surface of the Earth, the latest formed minerals (in the ground-mass ) are commonly arranged in subparallel winding lines that follow the direction of movement (fluxion or fluidal structure)—and larger early minerals that previously crystallized may show the same arrangement. Most lavas fall considerably below their original temperatures before emitted. In their behavior, they present

5328-425: Was predated by several auto trails and highways built in the early 20th century. The Pacific Highway was built in the 1910s and 1920s by the states of California, Oregon, and Washington, and was later incorporated into U.S. Route 99 (US 99) in 1926. I-5 largely follows the route of US 99, with the exception of portions south of Los Angeles and in the Central Valley of California. The freeway

5402-648: Was re-designated as part of SR 99). This re-route through California's Central Valley was the last section of I-5 to be constructed, with the final segment dedicated and opened to traffic near Stockton, California, on October 12, 1979. Representatives from both Canada and Mexico attended the dedication to commemorate the first contiguous freeway connecting the North American countries. It cost an estimated $ 2.3 billion in 1979 dollars (equivalent to $ 7.79 billion in 2023 dollars) to construct all of I-5. This direct route also bypasses San Francisco and

5476-480: Was still liquid at the moment of eruption. At this time they were exposed only to atmospheric pressure, and the steam and other gases, which they contained in great quantity were free to escape; many important modifications arise from this, the most striking being the frequent presence of numerous steam cavities ( vesicular structure) often drawn out to elongated shapes subsequently filled up with minerals by infiltration ( amygdaloidal structure). As crystallization

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