Misplaced Pages

#22977

89-479: The district is clearly subdivided into two parts; the first one, in the area of Via Cechov, has developed after the other one, enclosed between Via Cilea and Via Apennini; this latter, older part of the district is sometimes referred to as quartiere San Leonardo. These two parts are connected by a major shopping mall called Bonola. Gallaratese is one of the largest districts in Italy to have been built "from scratch" in

178-461: A palatificula civilization . According to some authors, part of these populations, following a demographic increase, migrated south settling along the Valle Olona . Further downstream, between 1926 and 1928, near the border between Castellanza and Legnano , an artifact dating back to a period between 3400 BC and the 2200 BC came to light It is a small fragment of a bell-shaped vase that

267-426: A distinctive landform known as karst , characterized by sinkholes and underground drainage. Limestone caves are often adorned with calcium carbonate formations produced through slow precipitation . These include flowstones , stalactites , stalagmites , helictites , soda straws and columns. These secondary mineral deposits in caves are called speleothems . The portions of a solutional cave that are below

356-578: A fountain in Misano Olona , a few kilometers upstream. Taking the old course and its name, the southern Olona flows into the Po at San Zenone al Po. The two Olona do not have an autonomous hydrography: at Rozzano, from the Lambro Meridionale, a branch take off towards the south-west, gaining vigor thanks to the water supply provided by springs and artificial canals. This stream then flows into

445-558: A hollow tube remains. Such caves can be found in the Canary Islands , Jeju-do , the basaltic plains of Eastern Idaho , and in other places. Kazumura Cave near Hilo , Hawaii is a remarkably long and deep lava tube; it is 65.6 km long (40.8 mi). Lava caves include but are not limited to lava tubes. Other caves formed through volcanic activity include rifts, lava molds, open vertical conduits, inflationary, blisters, among others. Sea caves are found along coasts around

534-420: A modern understanding of acoustics. Archaeologists have uncovered relationships between paintings of dots and lines, in specific areas of resonance, within the caves of Spain and France, as well as instruments depicting paleolithic motifs, indicators of musical events and rituals. Clusters of paintings were often found in areas with notable acoustics, sometimes even replicating the sounds of the animals depicted on

623-508: A pale or white coloration), a loss of eyes (or at least of optical functionality), an elongation of appendages, and an enhancement of other senses (such as the ability to sense vibrations in water). Aquatic troglobites (or stygobites), such as the endangered Alabama cave shrimp , live in bodies of water found in caves and get nutrients from detritus washed into their caves and from the feces of bats and other cave inhabitants. Other aquatic troglobites include cave fish, and cave salamanders such as

712-453: A range of early human species dating back to between three and one million years ago, including Australopithecus africanus , Australopithecus sediba and Paranthropus robustus . However, it is not generally thought that these early humans were living in the caves, but that they were brought into the caves by carnivores that had killed them. The first early hominid ever found in Africa,

801-406: A relatively short distance underground (such as rock shelters ). Caves which extend further underground than the opening is wide are called endogene caves . Speleology is the science of exploration and study of all aspects of caves and the cave environment. Visiting or exploring caves for recreation may be called caving , potholing , or spelunking . The formation and development of caves

890-618: A short distance: having reached the modern Lucernate at the Bozzente stream, the designers widened their bed to accommodate a greater water flow. As the final destination of the new Olona route, the moat of Milan's Roman walls was chosen, where it poured its water into the Canale Vetra (name given by the ancient Romans to the final stretch of the Nirone natural bed) at the height of the modern and homonymous piazza : to achieve this goal,

979-415: A stream sinks"), outflow caves ("from which a stream emerges"), and through caves ("traversed by a stream"). Solutional caves or karst caves are the most frequently occurring caves. Such caves form in rock that is soluble; most occur in limestone , but they can also form in other rocks including chalk , dolomite , marble , salt, and gypsum . Except for salt caves , solutional caves result when rock

SECTION 10

#1732781081023

1068-676: Is 71 km (44 mi) long and has a drainage basin of 1,038 km (401 sq mi). The drainage basin of the Olona extends over part of the province of Varese , the Metropolitan City of Milan and, to a lesser extent, province of Como , also affecting part of Switzerland . A small part of the Gaggiolo basin, its tributary, in fact belongs to the Canton Ticino . With its 1,038 km (401 sq mi),

1157-647: Is also close to major thoroughfares such as the Tangenziale and the Strada del Sempione. A major landmark of the Gallaratese district is Monte Amiata , a complex of apartment blocks that were designed by Carlo Aymonino , and that are characterized by a futuristic architecture. The most typical buildings are the so-called "tower houses" ( case torri in Italian , tower-shaped apartment blocks. The project for

1246-453: Is determined on the basis of the lower limit of karst forming processes, coinciding with the base of the soluble carbonate rocks. Most caves are formed in limestone by dissolution . Caves can be classified in various other ways as well, including a contrast between active and relict: active caves have water flowing through them; relict caves do not, though water may be retained in them. Types of active caves include inflow caves ("into which

1335-444: Is dissolved by natural acid in groundwater that seeps through bedding planes , faults , joints, and comparable features. Over time cracks enlarge to become caves and cave systems. The largest and most abundant solutional caves are located in limestone. Limestone dissolves under the action of rainwater and groundwater charged with H 2 CO 3 ( carbonic acid ) and naturally occurring organic acids . The dissolution process produces

1424-775: Is due to the fact that originally it was two trunks of the same river, diverted by the ancient Romans in its upper stretch towards Milan to bring water to the moat of the defensive walls of the city. The principal source of the Olona is in the Fornaci della Riana locality, at the Rasa of Varese , part of the homonymous provincial capital , at the Sacro Monte di Varese , within the Campo dei Fiori regional park. The Fornaci della Riana owe their name to some ancient limestone furnaces that remained active until 1972. In addition to

1513-406: Is estimated that a cave cannot be more than 3,000 metres (9,800 ft) vertically beneath the surface due to the pressure of overlying rocks. This does not, however, impose a maximum depth for a cave which is measured from its highest entrance to its lowest point, as the amount of rock above the lowest point is dependent on the topography of the landscape above it. For karst caves the maximum depth

1602-559: Is founded in 1606, is the oldest irrigation consortium in Italy. The river is sometimes also referred to as "northern Olona" for the homonymy with another Olona, who was born in Bornasco and flows into the Po after having crossed the Province of Pavia . This second Olona, in turn, is designated as "inferior" or "southern". The homonymy is not of imitative or etymological origin, but it

1691-468: Is known as speleogenesis ; it can occur over the course of millions of years. Caves can range widely in size, and are formed by various geological processes. These may involve a combination of chemical processes, erosion by water, tectonic forces, microorganisms, pressure, and atmospheric influences. Isotopic dating techniques can be applied to cave sediments, to determine the timescale of the geological events which formed and shaped present-day caves. It

1780-496: The Ravenna Cosmography ). Instead, as far as local toponyms are concerned, it was assumed that Lonate Pozzolo and Lonate Ceppino derive from "Olona" (from "Olona" to "Lonate"). Since ancient times, the inhabitants of the Valle Olona lived mainly away from the river, on higher ground that certainly would not have been hit by seasonal floods . From the archaeological findings found, it can be deduced that

1869-723: The Alto Milanese , the Olona reaches Rho where it pours part of its water into the Canale Scolmatore Nord Ovest . After passing Pero , the river enters in Milan , where, at the exit of its underground route, it flows into the Lambro Meridionale , that flows into the Lambro at Sant'Angelo Lodigiano , in the quartier of San Cristoforo ending its course. Along the way, the water system formed by

SECTION 20

#1732781081023

1958-631: The Denisovans in southern Siberia. In southern Africa, early modern humans regularly used sea caves as shelter starting about 180,000 years ago when they learned to exploit the sea for the first time. The oldest known site is PP13B at Pinnacle Point . This may have allowed rapid expansion of humans out of Africa and colonization of areas of the world such as Australia by 60–50,000 years ago. Throughout southern Africa, Australia, and Europe, early modern humans used caves and rock shelters as sites for rock art, such as those at Giant's Castle . Caves such as

2047-717: The La Tène culture and which were brought to light along the lower Valle Olona. Even after the ancient Roman conquest, it took some time for the Romanization of the Valle Olona to take place; during this phase, a Celts -Roman cultural dualism coexisted. The complete Romanization of the Valle Olona occurred during the 1st century BC; after this phase, along the banks of the river, the findings of archaeological finds became more and more frequent. This abundance of furnishings continued for another two centuries, that is, until

2136-399: The Lambro Meridionale . Until the entry into operation of the water purification system of Milan (2005), the Lambro Meridionale was a drain collector which collected the results of the western part of the city sewerage system. Subsequently, these sewage were diverted to the purifiers of San Rocco and Nosedo. From the same unloader, the Lambro Meridionale has its "clean source". The Olona

2225-783: The Madagascar dry deciduous forests and parts of Brazil contain many documented caves. As the world's expanses of soluble bedrock are researched by cavers, the distribution of documented caves is likely to shift. For example, China, despite containing around half the world's exposed limestone—more than 1,000,000 square kilometres (390,000 sq mi)—has relatively few documented caves. Cave-inhabiting animals are often categorized as troglobites (cave-limited species), troglophiles (species that can live their entire lives in caves, but also occur in other environments), trogloxenes (species that use caves, but cannot complete their life cycle fully in caves) and accidentals (animals not in one of

2314-665: The Milanese countryside: this passage had to be closed and strenuously defended to prevent the attack on Milan. For this reason, in Legnano, the Castle Visconteo was later built on a natural island of Olona river. Cave A cave or cavern is a natural void under the Earth 's surface . Caves often form by the weathering of rock and often extend deep underground. Exogene caves are smaller openings that extend

2403-616: The Po Basin , 71 kilometres (44 mi) long, that runs through the Province of Varese and Metropolitan City of Milan whose course is developed entirely in Lombardy . The river born at 548 meters above sea level in the Fornaci della Riana locality at the Rasa of Varese , at the Sacro Monte di Varese , within the Campo dei Fiori Regional Park . After crossing the Valle Olona and

2492-480: The Po Valley . Once there was also another natural branch which was indicated by the name of Olonella and which crossed Legnano passing behind the basilica of San Magno . The natural island that was formed by the two branches of the river was known as "Archbishop Braida". This legnanese branch was buried in the first part of the 20th century. After crossing San Lorenzo ( fraction of Parabiago ) and Nerviano ,

2581-756: The Quadronna , the Selvagna , the Mornaga , the Riale delle Selve and the Tenore . In Gorla Minore the river branches off into the Olonella , which joins the main riverbed after 1200 m. In this stretch, many artificial canals are born in the service of agriculture and of the industries that re-enter the Olona before Castellanza . After passing Castellanza, the waterway leaves the Valle Olona and heads towards

2670-605: The Taung Child in 1924, was also thought for many years to come from a cave, where it had been deposited after being predated on by an eagle. However, this is now debated (Hopley et al., 2013; Am. J. Phys. Anthrop.). Caves do form in the dolomite of the Ghaap Plateau, including the Early, Middle and Later Stone Age site of Wonderwerk Cave ; however, the caves that form along the escarpment's edge, like that hypothesised for

2759-406: The archbishop of Milan Theodorus II , "Aurona" (or "Orona"). In the latter case, the opposite has also been hypothesized, namely that the name of the monastery derives from the name of the river. Other toponyms that were used during the history to refer to the Olona are Ollona (appeared in a document dated 737 AD ), Oleunda (1033), Orona (mid-16th century) and Olonna (reported in 1688 on

Gallaratese - Misplaced Pages Continue

2848-613: The cattle station of the railways that stood there was built the Solari Park. The remaining part of the Darsena branch, and the canalized section along the ring road, were instead covered between 1950 and 1970. With the passing of the years, and with the increasing pollution of the river, the sluice of piazza Tripoli was not maneuvered only to divert the flow of water during the dry of the Navigli: at first it considerably reduced

2937-536: The olm and the Texas blind salamander . Cave insects such as Oligaphorura (formerly Archaphorura) schoetti are troglophiles, reaching 1.7 millimetres (0.067 in) in length. They have extensive distribution and have been studied fairly widely. Most specimens are female, but a male specimen was collected from St Cuthberts Swallet in 1969. Bats , such as the gray bat and Mexican free-tailed bat , are trogloxenes and are often found in caves; they forage outside of

3026-456: The very slow flow of the ice, which tends to collapse the caves again. Glacier caves are sometimes misidentified as " ice caves ", though this latter term is properly reserved for bedrock caves that contain year-round ice formations. Fracture caves are formed when layers of more soluble minerals, such as gypsum, dissolve out from between layers of less soluble rock. These rocks fracture and collapse in blocks of stone. Talus caves are formed by

3115-486: The water table or the local level of the groundwater will be flooded. Lechuguilla Cave in New Mexico and nearby Carlsbad Cavern are now believed to be examples of another type of solutional cave. They were formed by H 2 S ( hydrogen sulfide ) gas rising from below, where reservoirs of oil give off sulfurous fumes. This gas mixes with groundwater and forms H 2 SO 4 ( sulfuric acid ). The acid then dissolves

3204-518: The yaodong in China were used for shelter; other caves were used for burials (such as rock-cut tombs ), or as religious sites (such as Buddhist caves ). Among the known sacred caves are China's Cave of a Thousand Buddhas and the sacred caves of Crete . Paleolithic cave paintings have been found throughout the world dating from 64,800 years old for non-figurative art and 43,900 years old for figurative art. The importance of sound in caves predates

3293-468: The 13th century BC were identified that are referable to the recent Bronze Age The culture of Canegrate, which has an importance that goes beyond local boundaries, developed up to the Iron Age . The chronologically later furnishings, two bronze spearheads linked to the archaic Golasecca culture and always found in Legnano, date back to between the 9th and 8th centuries BC (early Iron Age). Along

3382-515: The 20th century (between the 1960s and 1980s) in a previously rural area. The Olona river, which traverses the district, has been laid underground. The first buildings to be created in Gallaratese were large apartment blocks; smaller palaces were added later. Today, the district has a population of about 60,000. The district is well connected by public transportation; it has four stops of the Milan Metro subway and five bus lines traversing it. It

3471-554: The Darsena was maintained. The detour to the latter took place in Piazza Tripoli : here there was a lock that diverted the river by Via Roncaglia , starting what was called the "Darsena branch". In the two dry periods of the Navigli annual, the sluice was maneuvered in such a way as to completely close the Darsena branch causing the entire flow of the Olona water to flow into Lambro Meridionale. The Lambro Meridionale, which at

3560-533: The Gallaraterse district was first laid down by architect Piero Bottoni in the mid 20th century. The objective was to create a low-income housing district with green areas, effective traffic connection to the city, and functional public services. Construction began in 1957, from a first core of the district named "Gallaratese G.1". The original plan by Bottoni was then refined and developed by over 60 architects, led by Gianluigi Reggio . A second and third part of

3649-487: The Olona and the Lambro Meridionale crosses or laps 45 towns receiving the water of 19 tributaries . The Olona is known for the waterfalls and caves of Valganna and for having been one of the most polluted rivers in Italy. The valley carved by the river, thanks to the system of water wheels that exploited the driving force originated by the water, was one of the cradles of Italian industrialization . The Olona river consortium (it. Consorzio del fiume Olona ), that

Gallaratese - Misplaced Pages Continue

3738-455: The Olona drainage basin occupies 5% of the Lombardy area and hosts approximately 1,000,000 inhabitants (which corresponds to around 10% of the residents in the region). The catchment area of Olona instead measures 370 km². Any hydrographic engineers describe the Olona and the Lambro Meridionale as a single stream that flows into the Lambro at Sant'Angelo Lodigiano and which has an overall length of 121 km (75 mi). One of

3827-611: The Olona river receives its two main tributaries, the Bozzente and the Lura , at Rho . In Rho there is also the "deviator of the Olona", completed in the 1980s, which flows into Lambro Meridionale . This work has always been a source of controversy: on the one hand it has not avoided all the floods as it was designed and, on the other hand, it carries polluted water towards the Ticino . In November 2002, in particular climatic conditions,

3916-462: The Olona were also discovered other finds that belong to the Golasecca culture; these furnishings, which are more recent than those previously mentioned, date back to the 6th-5th century BC. The archaeological findings found along the Olona then become more and more frequent as they approach the ancient Roman conquest of the Po valley . Among them, numerous finds stand out which are connected to

4005-618: The Olona, the Seveso , the spillway and the Ticino overflowed. From Lucernate (fraction of Rho) onwards the river no longer flows into the natural riverbed, but follows the path deviated by the ancient Romans towards the Bozzente. Entering Pero , after an initial stretch still outdoors, the Olona begins to flow under the road surface and reaches Milan by first crossing the Gallaratese , Lampugnano and QT8 districts, where it collects

4094-780: The Taung Child, are formed within a secondary limestone deposit called tufa . There is numerous evidence for other early human species inhabiting caves from at least one million years ago in different parts of the world, including Homo erectus in China at Zhoukoudian , Homo rhodesiensis in South Africa at the Cave of Hearths ( Makapansgat ), Homo neanderthalensis and Homo heidelbergensis in Europe at Archaeological Site of Atapuerca , Homo floresiensis in Indonesia, and

4183-492: The Valle Olona connecting Milan to the northwest of Lombardy . The Olona river maintained its strategic importance for another reason over the centuries: the river was a precious source of provisioning due to the presence, along its course, of numerous water mills . The latter continued to be strategic even in the following centuries thanks to their use for agricultural purposes. In fact, the ground wheat in these mills provided food for tens of thousands of inhabitants. In 1176

4272-427: The Valle Olona was - already in antiquity - a significant communication route. The water of the Olona have been used for centuries by the local population to irrigate the fields , for fishing , for the breeding of livestock , to move the wheels of water mills and, with the industrialization of its banks, to operate the hydraulic turbines serving the establishments. The oldest prehistoric finds found in

4361-600: The Verbanus Lacus ( Lake Maggiore ), and from here to the Simplon Pass (lat. Summo Plano ). The stretch of river that followed this road was channeled: there are those who hypothesize that it was this work that promoted the deviation of the Olona towards Milan. The road built by the ancient Romans along the river kept its strategic importance even in the Middle Ages . This transit route always came from

4450-504: The ancient Romans extended and enlarged the Vetra canal towards the aforementioned Pudiga natural meander so as to also collect the Olona water. With the deviation of the Olona towards the wall of the city, the water continuity of the ancient bed of the Pudiga disappeared, whose southern section (the future "Lambro Meridionale") was intercepted remaining devoid of clean water, which came from

4539-400: The ancient natural beds of two streams , Bozzente and Pudiga . Before the deviation of the Olona towards Milan the Pudiga stream, after having lapped on the western side of the city, continued south following its natural bed, corresponding to what is now called Lambro Meridionale , which ended its course, like the ancient Pudiga, in the Lambro near Sant'Angelo Lodigiano . Originally, at

SECTION 50

#1732781081023

4628-529: The areas around the natural Olona riverbed are bos primigenius bones dating back to the Würm glaciation . Unearthed in Legnano in the locality of Costa San Giorgio, they are kept in the Museo civico Guido Sutermeister . As for the presence of man , the oldest finds discovered around the river have been found in the area of the springs . The Lake Varese was in fact frequented, between 4300 BC and 800 BC, from

4717-530: The avenues of the ring road bypass. The path under the ring road, which was designed for the first time on the General Plan of Milan in 1884 (the so-called Piano Beruto ), was channeled in the first two decades of the 20th century and covered in a period from 1950 to 1970. At the exit from this covered stretch, after passing under the Naviglio Grande , the Olona ends its course flowing into

4806-468: The banks of the river were theater of the decisive phases of the battle of Legnano . The Carroccio , escorted by hundreds of knights, was placed along an escarpment flanking the Olona with the aim of having a natural defense on at least one side. The decision to place the Carroccio in Legnano was not fortuitous. At the time the village of Milan represented, for those coming from the north, the gateway to

4895-593: The branch of Valganna is increased by four torrents (the Margorabbia, Valfredda, Valpissavacca and Pedana della Madonna). The Valganna branch also gives rise to the Fonteviva lake, dedicated to sport fishing , and to the Valganna waterfalls , which in winter, due to the harsh climate, are often frozen. They are found in the municipality of Induno Olona and are close to the famous and homonymous caves . On

4984-586: The caves utilized for reverberation, but for the dampening qualities of their abnormal faces as well. The irregularities in the walls of the Cumberland Caverns diffuse sounds bouncing off the walls and give the space an almost recording studio-like quality. During the 20th century musicians began to explore the possibility of using caves as locations as clubs and concert halls, including the likes of Dinah Shore , Roy Acuff , and Benny Goodman . Unlike today, these early performances were typically held in

5073-565: The caves. Some species of cave crickets are classified as trogloxenes, because they roost in caves by day and forage above ground at night. Because of the fragility of cave ecosystems, and the fact that cave regions tend to be isolated from one another, caves harbor a number of endangered species, such as the Tooth cave spider , liphistius trapdoor spider , and the gray bat. Caves are visited by many surface-living animals, including humans. These are usually relatively short-lived incursions, due to

5162-465: The city of Mediolanum then, from the 12th century, in the defensive moat around the medieval walls and later (1603) in the Darsena of Porta Ticinese . In particular Olona river, during the Middle Ages , flowed into the moat of medieval defensive walls of the city in correspondence of the modern Piazza della Resistenza Partigiana , while in ancient Roman times it continued the city route reaching

5251-495: The crisis of the 3rd century AD , when a dramatic decline occurred. In Roman times, the shores of the Olona assumed significant importance due to their strategic position with respect to the communication routes between the Po valley and the Alps . In the 1st century AD, along the route drawn by the course of the river, an ancient Roman road was built, the via Severiana Augusta , which connected Mediolanum (modern Milan ) with

5340-752: The derivation of the Canale Ticinello , we arrive then a little further south, in the territory of Lacchiarella , where the Colombana and Carona irrigation channels bring water to the irrigation network giving rise to the Roggione . The Roggione, when at the Settimo di Bornasco receives the Olonetta canal, changes its name to lower or Olona . The Olonetta, together with the Misana canal, comes from

5429-422: The district, named "Gallaratese G.2" and "San Leonardo" respectively, were developed between 1964 and 1974. In those years, the "tower houses" that now characterize the Gallaratese' skyline were built. The final outcome was quite different from the original plans; the district was in fact developed with less green areas and less services than it had been planned, resulting in a definitely "satellite" district. In

SECTION 60

#1732781081023

5518-413: The flow of the Darsena branch and, at the end of the 1980s, it was resetted for "hydrogeological risk and danger of pollution" of the Darsena and the water that came out for irrigation or navigation purposes. There are three hypotheses on the origin of the toponym Olona . The first supposes that the name of the river is connected to the Celtic root Ol- , which means "large", "valid" in reference to

5607-499: The height of the inhabited center of Milan, the Pudiga made a wide bend towards the east, which led it to touch the city at the height of the modern Piazza Vetra , near the natural and ancient bed of the Nirone stream, and then bend towards the south following the bed of the modern Lambro Meridionale. Originally, on its hydrographic left, the Pudiga, in place of the Olona, received the Bozzente stream. The Bozzente originally had in fact an autonomous natural bed that led him to collect

5696-442: The inhabited centers located on the hills overlooking the river bed, the so-called pianalti . The slopes are mostly covered with woods , while in the valley bottom there are cultivated areas, meadows and heaths . The main tributary on Olona in the province of Varese is the Bevera ; other important tributaries of this stretch of the river are the Vellone , the Gaggiolo (also called Rio Lanza , Ranza , Anza or Clivio ),

5785-562: The lack of light and sustenance. Cave entrances often have typical florae. For instance, in the eastern temperate United States, cave entrances are most frequently (and often densely) populated by the bulblet fern, Cystopteris bulbifera . People have made use of caves throughout history. The earliest human fossils found in caves come from a series of caves near Krugersdorp and Mokopane in South Africa. The cave sites of Sterkfontein , Swartkrans , Kromdraai B, Drimolen , Malapa , Cooper's D, Gladysvale, Gondolin and Makapansgat have yielded

5874-410: The last decades of the 20th century the district has grown larger, gradually extending north up to the borders of Pero; the Bonola shopping mall was also created. 45°29′39″N 9°07′03″E  /  45.49417°N 9.11750°E  / 45.49417; 9.11750 Olona The Olona ( Olona in Italian ; Ulona , Urona or Uòna in Western Lombard ) is an Italian river belonging to

5963-413: The limestone from below, rather than from above, by acidic water percolating from the surface. Caves formed at the same time as the surrounding rock are called primary caves . Lava tubes are formed through volcanic activity and are the most common primary caves. As lava flows downhill, its surface cools and solidifies. Hot liquid lava continues to flow under that crust, and if most of it flows out,

6052-473: The main source, the river also flows from five other small springs, two in Val di Rasa and three in Valganna ; these springs give rise to two branches joining downstream from Bregazzana ( fraction of Varese). The branch that is born to the west, in Val di Rasa, is the most important; the two springs that originate this waterway are located at the Varrò pass (between Monte Legnone and Monte Pizzella ) and on Monte Chiusarella . The main source, and

6141-417: The modern Piazza Vetra , where it poured its water into the moat of Roman walls thanks to the homonymous canal, the Canale Vetra . The Cerchia dei Navigli then originated from the medieval moat of walls, while the two branches of the Roman moat became the Grande Sevese and the Piccolo Sevese , two canals still existing today in the Milan underground. The Milanese stretch of the Olona corresponds to

6230-456: The most important studies on hydrography of Milan was carried out by engineer Felice Poggi. In 1911 Poggi affirmed that the two Olona, the one that flows into the Lambro Meridionale and the stream that flows into the Po at San Zenone al Po , constituted until the first years of the Common Era a single river that had a total length of 120 km (75 mi). This hypothesis has also been confirmed by subsequent studies. The place where

6319-408: The neighboring towns of Cesano Boscone, Corsico and Trezzano sul Naviglio, all three of which rise on the Naviglio Grande , it is possible to identify two waterways that could flow - towards the south - into the ancient natural riverbed of the Olona to Binasco : at Trezzano sul Naviglio and Cesano Boscone would be the Belgioioso canal, while in Corsico would be the Vecchia roggia. From Binasco, with

6408-556: The north, thus becoming in a sewer collector. Until 1704 the river had only one terminal arm, while on a map of 1722 it is reported that the Olona forked into two almost parallel branches that met before entering Darsena of Milan: the Olona Nuova (en. "New Olona"), that is the northern one that later will be called roggia Molinara , and the Olona Vecchia (en. "Old Olona"), that it was the southern one. The Molinara canal

6497-560: The one located at the Varrò pass, join upstream from the inhabited area of the Rasa di Varese, while the spring that flows from Monte Chiusarella flows into the Olona downstream. The branch of the Valganna, which is located to the east, was born instead south of Monte Martica . The branch of the Rasa is fed by seven small tributaries (more precisely, the torrents Legnone, Grassi, Boccaccia, Brasché, Pissabò, Valle del Forno and Sesnini), while

6586-465: The openings among large boulders that have fallen down into a random heap, often at the bases of cliffs. These unstable deposits are called talus or scree , and may be subject to frequent rockfalls and landslides . Anchialine caves are caves, usually coastal, containing a mixture of freshwater and saline water (usually sea water). They occur in many parts of the world, and often contain highly specialized and endemic fauna. Caves are found throughout

6675-428: The previous categories). Some authors use separate terminology for aquatic forms (for example, stygobites , stygophiles , and stygoxenes ). Of these animals, the troglobites are perhaps the most unusual organisms. Troglobitic species often show a number of characteristics, termed troglomorphic, associated with their adaptation to subterranean life. These characteristics may include a loss of pigment (often resulting in

6764-595: The river was diverted to Milan by the ancient Romans is Lucernate, a fraction of Rho . From here, to find the ancient bed of the Olona following the minimum undulations and the very small altimetric variations of the terrain, we arrive at Cascina Olona (a locality of Settimo Milanese ; the toponym is indicative), in Baggio and in Corsico , with a possible variant that from Settimo Milanese would lead to Muggiano and Trezzano sul Naviglio (or Cesano Boscone ). In

6853-413: The southern Olona. The reconnection of the two Olona is being planned with the construction of an artificial riverbed that would resume the ancient course of the river. Until ancient Roman times, at La Maddalena , today's quartier of Milan, the Olona was diverted towards the city with the aim of bringing water to it: in ancient Roman times it flowed into the moat of the republican defensive walls of

6942-558: The time was a veritable sewer collector, was also known as "Lambro Merdario" (en. "Shiter Lambro"). The new channeled route, which was also envisaged by the Beruto Plan of 1884, the first regulatory plan of Milan, did not come into operation until the early 1930s. The first covering carried out in Milan on the course of the Olona occurred in 1935 on part of the Darsena branch (from Via Valparaiso to Viale Coni Zugna ), when instead of

7031-431: The use of its water. The second conjecture hypothesizes that the name derives from the ancient Greek "oros" (ὄρος), which means "relief", "mountain". The last hypothesis supposes instead that the toponym of the water course is connected to a Milanese monastery founded in the 8th century that was known as Aurona . The latter name perhaps derives, in turn, from the name of the founder of the convent, as well as sister of

7120-462: The walls. The human voice was also theorized to be used as an echolocation device to navigate darker areas of the caves where torches were less useful. Dots of red ochre are often found in spaces with the highest resonance, where the production of paintings was too difficult. Caves continue to provide usage for modern-day explorers of acoustics. Today Cumberland Caverns provides one of the best examples for modern musical usages of caves. Not only are

7209-492: The water of the Lura stream and the Merlata stream and then flow into the Pudiga. As already mentioned, it was the ancient Romans who diverted the Olona to Lucernate, a quartier of Rho, in the bed of Bozzente and then to the Pudiga riverbed. The Milanese stretch of the Olona therefore corresponds to the ancient natural beds of Bozzente and Pudiga. The new artificial riverbed of the Olona was then excavated from scratch only for

7298-603: The water of the Merlata river (also called Fugone ), to then skirt the southern slope of Monte Stella . Once in Piazza Stuparich it receives the confluence of the Pudiga (known as Mussa in his Milanese section). Merlata and Pudiga are the water collectors that come from the area north of Milan, the so-called "groane". The Olona then runs along the Lampugnano and San Siro districts, and then continues under

7387-417: The water, such as a fault or joint. A subtype of the erosional cave is the wind or aeolian cave, carved by wind-born sediments. Many caves formed initially by solutional processes often undergo a subsequent phase of erosional or vadose enlargement where active streams or rivers pass through them. Glacier caves are formed by melting ice and flowing water within and under glaciers. The cavities are influenced by

7476-418: The waterfalls, which were artificially created at the beginning of the 20th century to improve water withdrawal, one can admire the phenomenon of travertine surfacing. After the initial stretch, the river begins to travel the valley of the same name, the Valle Olona . This valley originated from the Olona and the retreat of the glaciers during the last ice age ; it looks like a valley deeply engraved with

7565-667: The world, although the distribution of documented cave system is heavily skewed towards those countries where caving has been popular for many years (such as France, Italy, Australia, the UK, the United States, etc.). As a result, explored caves are found widely in Europe, Asia, North America and Oceania, but are sparse in South America, Africa, and Antarctica. This is a rough generalization, as large expanses of North America and Asia contain no documented caves, whereas areas such as

7654-791: The world. A special case is littoral caves, which are formed by wave action in zones of weakness in sea cliffs. Often these weaknesses are faults, but they may also be dykes or bedding-plane contacts. Some wave-cut caves are now above sea level because of later uplift. Elsewhere, in places such as Thailand 's Phang Nga Bay , solutional caves have been flooded by the sea and are now subject to littoral erosion. Sea caves are generally around 5 to 50 metres (16 to 164 ft) in length, but may exceed 300 metres (980 ft). Corrasional or erosional caves are those that form entirely by erosion by flowing streams carrying rocks and other sediments. These can form in any type of rock, including hard rocks such as granite. Generally there must be some zone of weakness to guide

7743-420: Was founded, a multi-sports club in Milan, winner of an Italian men's water polo championship, based in the Darsena of Porta Ticinese. In 1919, as part of the complex hydrophobic revision of Milan, the channels of the current Olona route began to be built, which involved the deviation of part of the river's water towards the Lambro Meridionale passing through the outer ring road . However, the branch that led to

7832-633: Was made in the Copper Age and that can be connected to the Remedello culture . It was found during construction work on the Bustese highway 527 in the "Paradiso" quartier of Castellanza. This furniture is also kept in the Museo civico Guido Sutermeister. Further down the valley, archaeological finds belonging to Canegrate culture have been discovered. During the excavations, 165 tombs dating from

7921-421: Was then buried at the end of the 19th century before the river was channeled. The so-called "Brera island", which was located between the present-day Via George Washington and Via Vincenzo Foppa , had a longer life. Originated from another fork in the river, it took its name from the homonymous farmhouse that once stood there. It is still marked in a paper from 1925. In this context, in 1894, Canottieri Olona

#22977