VOLCANOLOGICAL EXCURSION TO ISCHIA ISLAND

The bibliography is reported in the general section on Ischia.

1 - Introduction

The morphology of the island is dominated in the central part by the Monte Epomeo, 785 m asl high, around which are located numerous other reliefs of volcanic nature. The flat part of the island is located between Casamicciola, Barano and Ischia Ponte.

The recent volcanic activity of the Island is subdivided into 5 phases. The first two (old cycle) occurred before the emission of the Green Tuff forming much of Monte Epomeo. The last three (younger cycle) are younger than the Green Tuff.

Phase 1- older than 150.000 years ago (prevailing explosive activity (picture in italian): Formation of Carrozza; Lower and Upper Formations of Scarrupata di Barano)

Phase 2 - between 150.000 - 75.000 years ago (prevailing effusive activity (picture in italian): lava domes of Punta Imperatore, Capo Negro, Punta Chiarito, Sant'Angelo, Punta della Signora, Capo Grosso, La Guardiola, Monte Vezzi, Castello d'Ischia, Monte Vico). After this phase there is a period of quiescence

Phase 3 - between 55.000 - 33.000 years ago: (Pignatiello Formation, Green Tuff of Monte Epomeo, Citara Formation)

Phase 4 - between 28.500 - 18.000 years ago (Lava dome of Grotta del Mavone; lava flows of Pilaro; explosive products of Scarrupo di Panza and lower formation of Cava Pelara; effusive activity of Schiappa and Pomicione. A quiescence follows this activity. The activity starts again with the explosive eruptions of Punta Imperatore, Upper Formation of Cava Pelara and volcano of Campotese. Scoria cone (picture in italian) of Ciglio, Cava Petrella, Monte Cotto, Monte Vezzi and Grotta di Terra.

Phase 5 - after 10.000 years ago until 1302 AD (scoria cone of Punta della Cannuccia; volcano of Zaro; Formation of Piano Liguori; volcanic complexes of Monte Rotaro and Montagnone-Monte Maschiatta; eruptive centers of Porto d'Ischia, Vateliero-Molara-Cava Nocelle; Arso volcano).

2 - Excursion

The excursion can be made by private car or public transportation in one or (preferably) two days. The different stops can be reached from the statal road around the island.

1 - Porto d'Ischia.

The present port was, until the last century, a lake (Lago del Bagno), separated from the sea by a small piece of land that was cutted in 1853-54. The circular structure has a diameter of 400 m and is the remains of a crater formed around the III century BC. The products erupted in this eruption are mostly black scoria and lavas visible on the hill of S.Pietro and at S. Alessandro to the back of Spiaggia degli Inglesi. On S.Pietro hill, archeological findings dated at the VI and V century BC were found; they testify the presence of a settlement possibly destroyed by the eruption.

From Porto d' Ischia take the road toward Casamicciola. After about 700 m stop at S.Alessandro, park your car and go down to Spiaggia degli Inglesi following a small road. At the beach reach the rocks along the sea and go toward Cafiero beach.

2 - Cafiero Beach

Marine erosion evidenced a volcanic conduit filled with lava on the cliff facing the beach. A lava flow, 3.5 m thick with a massive interior bounded by two scoria levels, originated from this conduit. Some deposits at Cafiero are of sedimentary origin and contain marine fossils. The sedimentary strata have a green color and are made of reworked ash. In the top part of the cliff there is an hanging beach (the original sea level was higher than the present one, or the ground uplifted) in which were found artifacts of Bronze age.

Go back to the main road and go toward Casamicciola. 100 meters after the Spa of Castiglione, on the left along the main road, there is small road toward the soccer field of Casamicciola.

3 - Soccer Field (Campo sportivo) of Casamicciola.

Rotaro Crater is visible in the background of the soccer field . Rotaro emitted a lava flow presently covered by pine trees. Recent datings obtained for this eruption a date around the III century AC. The lava flow is 650 m long and ends into the sea at Punta la Scrofa.

The volcanic complex of Monte Rotaro is made up of different vents alligned along a euptie fracture. The volcanic activity moved from south to north. The older vent is Bosco della Maddalena, a regular cone approximately 200 m high and 800 m wide on top of which is Fondo d'Oglio. The northern side of the crater has been breeched by the eruption that formed the lava dome of Monte Rotaro 175 m high and 500-600 m wide. In the northern part at the base of Monte Rotaro there are some lava flows 30 m thick. The oldest flow is the one of Punta della Scrofa. The other flows ends in the vicinity of the cemetery of Casamicciola and are separated each other by some scoria levels.

Go back onto the main road and proceed toward Lacco Ameno, in the port of Lacco Ameno there is a rock eroded in the form of a mushroom. During clear days it is possible to see the italian coast from Monte di procida to Circeo.l

4 - The Mushroom of Lacco Ameno is made up of the Green Tuff of Epomeo eroded by the action of the sea.

Stop in the center of Lacco Ameno in the square of the church of S. Restituta. Below the church there is the Archeological Museum.

5 - Church and Archeological Museum.

The church of S. Restituta, has been rebuilt after the earthquake of 1883, it has a nice policrome marble altar originally belonging to the church of Rosario, destroyed by the same earthquake. Below the church there is the Archeological Museum made by an ancient settlement which included furnaces and tumbs discovered in the '50. The archeological items belong to findings in the Site of Santa Restituta and from other excavations in the locality of Monte Vico near Lacco Ameno. This site was inhabited since XV century BC. In the VIII century BC, it became the site of the Greek colony named Pithekoussa (island of monkeys); this name was subsequently given to the all island. The necropolis and part of the acropolis (Locality Mazzola) were excavated during the years '20 by the archeologist Giorgio Buchner and Don Pietro Monti. The thermal springs named Isabella, Romana and Greca are located on the coast in the front of the church. The flow rate totals 74 m3/day and the water temperature are comprised between 50 and 70°C. The Greca thermal spring is mildly radioactive.

Proceed in the direction of Forio till to the deviation to Punta Caruso. Along this road you may notice the lava dome from which was emitted the lava flow of Zaro. The road is in a bad condition and it is better to proceed without car.

6 - Punta Caruso.

The volcanic center of Zaro is one of the few center of activity of the recent cycle in the north-western part of Ischia. The last activity produced some lava domes (Monte Marecocco and Caccaviello) and the viscous lava flow of Zaro, dated at about 10000 years before present. The lava flow has a surface of 1.2 km2 is 800-1000 m wide and 100 m thick. The base of the flow and the underlaying level of pumice deposit (pertaining to the same eruption) are visible in the east side of the beach of S.Montano. Large white crystals of sanidine are visible within the lava flow.

Go back to the main road and proceed to Forio. Along this road you may notice the steepest flank of Mt Epomeo. Forio is the area with the highest number of thermal springs. At Citara there are the Spa "Terme di Poseidon" and at Sant'Angelo those named "Afrodite". Numerous fumaroles are found in the locality "Il Cuotto". From Forio go toward Panza. From here follow the road signals to "Baia di Sorgeto".

7 - Baia di Sorgeto.

In this locality there are several fumaroles heating marine water. The products of Citara formation have here a thickness of 40 m. They were emitted during eruptions occurred in the South-Western part of the island. The deposits alternate pumice fall levels and surge levels. At Sorgeto there are breccia layers with pumice bombs, and lithic blocks as big as 1 m with impact sags (deformation of the underlaying ground caused by the impact).

From Panza go to Sant'Angelo

8 - Peninsula of S. Angelo.

The peninsula of S. Angelo extends for about 400 meters toward the south, it is 104 m high and is bounded to Ischia by a narrow isthmus. The base of Sant'Angelo is made up by a lava dome, approximately 50 m thick. The lava is compact with columnar jointings of a dark grey colour. A deposit , formed by two levels of pumice and litified tuffs, covers the lava dome and fills the fractures of its surface. Black welded scorias for a thickness of about 2-3 m are visible in the eastern part. The products of Sant'Angelo are covered by the deposits of the green Tuff of Monte Epomeo. The presence of the lava dome at the base of Sant'Angelo, made it difficult the marine erosion giving to the peninsula its peculiar form.

Back to the road, go to Serrara Fontana. During clear days it is possible to see the Pontine Island (Ponza and Ventotene). At the Belvedere you may stop to rest (and eventually to have lunch). Proceed to Barano. Park your car about 500 m after the fraction of Buonopane in correspondance of a white road that goes to the Spa of Nitrodi.

9 - Terme di Nitrodi.

The Nitrodi spa is renown for the terapeutic effects of its water. The first historical references go back from the I century BC to the III century AC. In the Archeological Museum of Naples there are bas-relief dedicated to the Ninphs of Nitrodi.

After Barano, proceed to Testaccio from where you can reach the beach of Maronti.

10 - Maronti.

The beach is 2 km wide, and is affected by an intese geothermal activity. The thermal springs of Olmitello and Cava Scura have temperatures of 65°C and 72° C and are the springs exploited since longer time in the island. Above the beach there are loose materials of the landslides that affect this side of Monte Epomeo. An hanging beach is at about 10-20 m above sea level.

FromMaronti go back toTestaccio and then proceed to the volcanic center of Vateliero. From the square of Testaccio it is possible to see the crater of Fondo del Vateliero dated at about 2000 years ago. From Testaccio take the road toward Monte Barano where you park and walk along the trail to Scarrupata di Barano. The trail is difficult. The way back may be difficult during sunny day. You may spend an halfday in this place including swimming.

11 - Scarrupata di Barano.

The area goes from Punta S. Pancrazio to Capo Grosso. With the back to the sea, you may see, to the right, the lavas of Monte Vezzi covered by the explosive products of the eruption of Pignatiello and the Green Tuff of Epomeo. Above the deposits of the Green tuff there are the products of a younger eruption.

The products outcropping along the Scarrupata have been subdivided into lower Formation and Upeer Formation. The lower one belongs to the first cycle of activity of Ischia. There are the products of at least three different explosive eruptions separated by paleosols and erosional surfaces. The upper formation is 85 m thick (up to 200 m on Monte Vezzi) and is made of layers of pumice fall deposits, and stratified breccia and scoria deposits. In correspondance of Monte vezzi there are also lava flows.

Proceed to Fiaiano above Porto d'Ischia on the lava flow of Arso,

12 - Lava flow of Arso.

This lava flow was emitted during the last eruption on Ischia in 1302. It destroyed the middle age village of Geronda. The crater is to the east of Fiaiano and it is surrounded by black and red scoriae. The lava flow is 2.7 km long , and 1 km wide in its largest point near Punta Molina. In this point it is 15-17 m high. The lava flow is presently covered by pine trees planted between 1853-1855.

From Fiaiano you can take the road to Cretaio. At the end of this road there is a two-lane road circling for 500 m the crater of Fondo Ferraro. At the left there is the volcanic edifice of Posta Lubrano and then Bosco della Maddalena, Moschiata and the top of Montangone.Following the road it is possible to reach the crater of Fondo d'Oglio. Park where possible, and proceed by walking.

13 - Fondo d'Oglio crater.

The crater of Fondo d'Oglio belongs to the volcanic complex of Monte Rotaro. At about 30 m from the entrance on the left there are some fumaroles. Continue walking and after an enlargement of the road you find Fondo d'Oglio, erupted about 2300 years ago.


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