Teide Volcanism

Site #1

Point #1 

These photographs are views to the northeast of pyroclastic deposits, which are fragmental rocks formed through explosive eruptions of stratovolcanoes and calderas. They are typically deposited as clouds of ash, pumice, and rock that race along the ground from the volcano. The pumice and ash are lighter colored, which gives these deposits their lighter-colored appearance. The first picture appears to show cross-bedding (middle of image), which is indicative of pyroclastic flow deposits and not fall deposits. 

Examples of pyroclastic flows similar to those that created the deposits you are observing:

(1) https://www.youtube.com/watch?v=-iSFM-T-F_0

(2) https://www.youtube.com/watch?v=Cvjwt9nnwXY 

Point #2: Boca Tauce

This picture is of columnar joints, which are a type of feature or structure that commonly occurs in igneous rocks as they cool and solidify. This columnar joint has formed so that it is parallel to the ground, which typically happens in narrow bodies of magma that solidify inside the Earth. We refer to such bodies of magma as intrusions. Go into street view to see a broader view of this feature. 

Point #3

These pictures are views to the north of a lava flow with two stratovolcanoes in the background (the two volcanoes are best seen in the first image; the lava flow is best seen in the second image). When a lava flows, it will typically take on either a smooth ropy appearacne (texture) or a rough blocky appearance (texture); lava that is smooth we refer to as a pahoehoe texture and lava that is blocky we refer to as an a'a' texture - the lava flow that you see in the foreground at this stop is an example of an a'a' flow.

The stratovolcanoes in the background are Pico Viejo (to the left) and Teide (to the right); note that stratovolcanoes are relatively tall and have steep slopes. There are numerous bumps on the flanks of Pico Viejo that are smaller volcanoes called cinder cones. 

Example of how the a'a' flow observed at this stop was likely emplaced (the video is of an a'a' flow in Hawaii): http://www.youtube.com/watch?v=iyIV5fd1Aww

Example of a video showing how stratovolcanoes erupt, check out this video of Mt. St. Helens erupting in Washington State in 1980: http://www.youtube.com/watch?v=pGImksoOwtU&feature=fvsr 

Site #2

Point #4: Los Azulejos

This is a view to the east of a roadcut that shows a fault (bright orange layer that is at an angle) that has cut through pyroclastic deposits (light gray patches on the right hand side of the picture) and a breccia (purple patch on the left side of the picture). The fault is a normal fault with the pyroclastic deposits sittiing in the footwall and the breccia making up the hanging wall. The orange layer is actually a dike that has intruded along the fault. 

Point #5: Roques de García

Photographs that highlight two textures within a lava flow that can be observed at this stop. The first texture can be observed in the photographs with the finger and coin - the finger is pointing at a mineral called feldspar, which is much larger than any other grains that make up this rock. We call such a texture porphyritic and the feldspar is what we call a phenocryst. The second texture are the rope-like features that can be seen next to the foot - these ropes indicate a smooth texture that occurs within some lava flows. We call such a texture pahoehoe. 

https://es.wikipedia.org/wiki/Roques_de_Garc%C3%ADa

Point #6

This is a photograph to the south of the same lava flow seen at Stop 5. The surface of this lava flow is smooth making the texture of this flow pahoehoe. 

Video showing how this type of lava flows: http://www.youtube.com/watch?v=4SBIGMyGG7I&feature=related 

Point #7

Weakly indurated pyroclastic deposits similar to those observed at Stop 1. White particles in deposit are pumice and dark clasts are lithic pieces of volcanic material. 

Point #8

Photographs looking to the northeast of the pahoehoe flow from Stops 5 and 6 where it has flowed down a hillside. 

Point #9

Photographs of columnar joints that can be seen within the rocks at this stop. Note that the columnar joints are all parallel to the ground. 

Site #3

Point #10

Two photographs towards the east that show a channel that formed within a lava flow. The flow has has a blocky texture that we call a'a'. Note the tall boundaries or walls that line the channel - we refer to such walls as levees. The flow erupted from the vent at the very top of Teide. The second photo is a view of this channel from Stop 12. 

Point #11

A single piece of 'fresh' lava that is part of an a'a flow on the summit of Teide. Note white marks, which are crystals of the mineral plagioclase feldspar. There are two textures represented within this rock. The first consists of the plagioclase crystals, which are much larger than any other minerals in the rock - this is called a porphyritic texture where the plagioclase crystals are called phenocrysts. The second texture consists of the holes within the rock; these holes form as gasses escape from the lava as it flows. Holes within a rock like this are what we refer to as a vesicular texture. 

Point #12

This photograph is to the north and shows the blocks that make up the front of a lava flow that erupted from the summit of the stratovolcano Teide. This is part of the same lava flow observed at stops 10 and 11. 

Point #13

This is a photograph to the west of a lava flow that has a smooth ropy texture. This lava flow is ~2000 years old. 

Point #14: Minas de San José

View to the south part of the Canadas Caldera wall. Light colored layers in the wall represent pyroclastic deposits and dark colored layers likely represent lavas and/or magma intrusions that hava paralleled the pyroclastic deposits. The dark lens in the center of the picture at the top of the wall represents the ancient interior of an old volcano. 

Site #4

Point #15: Montaña del Portillo Nuevo

View to the east of a cinder cone. Note that the front of the cone (west side) is lower than the rest of the cone. These are the same types of volcanoes that you can observe on the flanks of Pico Viejo at Stop 3. The eruption of cinder cones is not nearly explosive as the eruption of stratovolcanoes, but it is still slightly explosive. Cinder cones typically erupt in a style called fire fountaining (Strombolian eruption), though they do release some ash; most material is lapilli-sized tephra . 

The following are links to videos of a volcano on the island of La Palma (to the west of here) in 2021; this would have been a similar eruption to what would have occured at this cinder cone: 

https://www.youtube.com/watch?v=CmQVquojJfo

https://www.youtube.com/watch?v=2KTkTDKw6kY 

Site #5

Point #16

Road cut of a mafic lava flow that unconformably overlies layered pyroclastic deposits (tephra). Note that the tephra overlay another lava flow in the second picture. 

Point #17: Mirador de Igueque

Road cut of mafic pyroclastic deposits that consist of pieces of scoria and other lithic clasts. This roadcut is undergoing variable amounts of erosion, which highlights various grain sizes making up the various layers of the deposit. 

Point #18: La Tarta

Road cut of a pyroclastic deposit that consists of alternating mafic and more sliceous pyroclastic deposits. The orientation of the beds here may be primary (i.e., not caused by faulting) and may therefore be reflective of where they were emplaced in relation to the vent.