Tjörnes

Tjörnes is a large peninsula in the north of Iceland.

Name

The name is a composite of isl. Tjörn ( dt = pond ), and nes ( = headland ).

Geography

The peninsula is located in the north of Iceland, on the west by the Skjálfandi Bay on the north by the Arctic Ocean and to the east by the Öxarfjörður.

On it is the same community Tjörnes. The largest town is located on the west side of the Skjálfandi Húsavík.

Geology

Tjörnes lies on the western wing named after the peninsula Tjörnes transform zone. This geologically connects the Northern volcanic zone of Iceland ( NVZ ) with the Kolbeinsey - back. Thus Tjörnes is part of the active rift and volcanic zone of the Mid-Atlantic Ridge.

This means that Tjörnes can be affected both by plate movements and volcanic eruptions.

The main actors in this respect are a great tectonic column, called Húsavík - Flatey -Fault, also Húsavík Transform Faultsowie the volcanic system of Theistareykir.

The tectonic column cuts through the urban area of ​​Húsavík, where she is also clearly visible and forms a natural harbor, and then runs into the mountains to the east, ending in central volcano Þeistareykjabunga. In its submarine continuation it forms a 5-10 km wide and 3-4 km deep valley towards Kolbeinsey. Over the last nine million years here there has been an overall shift by 60 km.

The manifests itself in partly violent earthquakes. The date last severe earthquake in the area was in 1976 held as part of the volcano- tectonic episode at Krafla. The hypocenter was near the place Kópasker and the tremors reached a magnitude of 6.2 Magn.

Paleontology

It has been found on the Tjörnes peninsula about 1200 m thick sedimentary layers, whose origin dates back approximately 4 million and since then documented phases of Earth's history.

Based on the found there fossilized traces of shells and micro-organisms to climate change in the Arctic can be reconstructed.

The subsoil consists of approximately 8 million year old basalt layers.

On these three clearly distinguishable sediment layers build on. It involves shallow sea deposits that are clay and sand rich, as well as fluvial sandstones, some of which were formed in former estuaries.

The oldest group, the tape layers are 4-3,5 million years old. Since the fossilized shells found there today live in the North Sea, it can be concluded on warmer climate at the time.

The next layer is the Mactra layer. Your age is 3.5 to 2.5 million years. The fossils of these rocks occupy a position still considerably warmer climate, yet live in them mussel species found today in the mid-Atlantic to the Canary Islands.

The upper layer of sediments molluskenhaltigen called Seripes, is evidence of a further climate change: although here the climate was warmer than today, but colder than in the previous phase. Most striking, however, is that shellfish from the Pacific are found in this layer, which speak for a then- opening of the Bering Strait.