#hartzburgite

[geoworldtravel]

Our first full day of touring started with at Wadi al Abyad, the best place in the world to see the #Moho – the boundary between the earth’s crust and mantle. Here we could see a sharp contrast between the #mantle rocks, consisting of a type of #peridotite called #hartzburgite, and the ocean crust rocks made of layered #gabbro. So how is it possible to see such rocks at the surface of the earth and on land? This because in the late Cretaceous these rocks which form part of the #Semail #Ophiolite were conducted onto Arabia as an ocean basin was closed.The Semail Ophiolite is the best exposed ophiolite anywhere in the world. We then moved onto the Gubrah Bowl this is a beautiful amphitheatre that technically is a basement core anticline, or a #geological window. The upper rocks of the anticline have been eroded away leaving the older rocks exposed in the base of the bowl. After this we had a picnic lunch in Wadi Mistal. Here we were able to observe Cretaceous coral #fossils as well as lake deposits formed from a Quaternery lake that filled the wadi in a wetter climate and when it was dammed by a landslide. Next we saw an angular #unconformity between precambrian rocks and late #Permian rocks.We then moved on to Wadi Haslan where we examined Snowball Earth deposits. These deposits formed at a time when it is thought that the whole Earth was glaciated. The deposits we saw were 712ma tillites and glacial lake deposits with dropstones (rocks that fall out of icebergs) immediately overlain by tropical dolomites. These tropical dolomites are known as the cap carbonates and can be found all over the world on #SnowballEarth deposits, showing when the climate very rapidly warmed at the end of Snowball Earth. (at Oman) https://www.instagram.com/p/B9RwWjyJcPN/?igshid=atae9lykc5yv

[geoworldtravel]

Oman 2020: Ocean Crust and Mountains of Mantle

We've just published the blog of our recent trip to Oman - hope you enjoy reading it!

Day one – Muscat to Al Mussanah

Our first full day of touring started at Wadi al Abyad, the best place in the world to see the Moho – the boundary between the earth’s crust and mantle. Here we saw a sharp contrast between the mantle rocks, consisting of a type of peridotite called hartzburgite, and the ocean crust rocks made of layered gabbro. So how is it possible to see such rocks at the…