Syndey Sandstone

Back in March and April 2015 my husband and I travelled to Australia for a couple of weeks for vacation. We went to visit some good friends who live in Sydney. We spent most of our time in Sydney and some of the surrounding areas, such as the Blue Mountains. We also spent a few days up in the Port Douglas area, including a couple of days on a boat out on the Great Barrier Reef.

While we were in Sydney, we were very impressed by all of the sandstone, which can be seen in outcrop at many places in Sydney, including along many of the beaches. We observed many interesting features in these sandstone outcrops, such as impressive cross-bedding structures, trace fossils, interesting erosional forms, and oxidation/coloring of various types and shades. We also observed that many buildings, walls, bridges, and other structures in Sydney are constructed out of sandstone blocks, which we assume were locally derived.

I’ve already shared some pictures of Sydney sandstone outcrops here, here, and here and of some sandstone building stones here. Today, I want to share some more pictures of Sydney sandstone and also briefly discuss its geology.

The sandstone that we observed around Sydney is known as the Syndey Sandstone or the Hawkesbury Sandstone. A nice scientific paper about the sandstone can be found here. The sandstone is Triassic in age and is interpreted to have been deposited in a fluvial environment by the ancient Hawkesbury River. Based on the scale and nature of features in the sandstone, such as cross-bedding and abandoned filled channels, this ancient river was likely a very large, sand-rich, braided river with deep main channels. Some of the abandoned channel fills are up to 18 m deep. The Hawkesbury Sandstone is extensively exposed in the Sydney area, outcropping over ~20,000 square kilometers in the Sydney Basin. The sandstone unit has a maximum thickness of ~290 m. The sandstone is a beautiful rock and has been used extensively as a building stone in Sydney, from the 1700s through to the present day.

Here’s a map showing the extent of the Hawkesbury Sandstone in the vicinity of Sydney:

Map showing the extent of the Hawkesbury Sandstone in the Sydney Area. Map from Rust and Jones (1987), Journal of Sedimentary Research, Vol. 57, No. 2: 222-333. Click to enlarge.

Here are some more pictures of this remarkable sandstone that we encountered pretty much everywhere in Sydney. The pictures below were all taken during a walk along the ocean, near Bondi Beach.

Sydney Sandstone #15. A bench amidst the cross-bedding.

Sydney Sandstone #16. Another view of the bench adjacent to the cross-bedding.

Sydney Sandstone #25. Sandstone being used as a building stone along the walking path... near an outcrop of the same sandstone. — Sydney Sandstone #25. Sandstone being used as a building stone along the walking path… near an outcrop of the same sandstone.

That’s all for today… stay tuned for some more pictures from our recent Australian travels!

Monday Geology Picture: Cross-Bedding Sandstone Bench, Sydney, Australia

Enjoying a stop at a bench in front of some Sydney sandstone with classic cross-bedding.

Goodness, I’ve been busy recently! I’m afraid that my blogging has been quite neglected… as it has been for the past few months.

However, things have finally calmed down a little now, so I’m going to make an effort over the next few weeks to share some geological pictures from some of my recent travels… and also possibly from some travels in 2014 that I neglected to blog about.

I’ll start with this quick “Monday Geology Picture” post. This week’s picture shows me sitting on a bench in front of some sandstone in Sydney, Australia. This particular sandstone displays some impressive cross-bedding. My husband took this picture when we were on a beachside walk near Bondi Beach back in March 2015. I wish that all benches had such great geological scenery in the vicinity!

Monday Geology Picture: More Sydney Sandstone

Sandstone with cro — Sandstone with iron oxidation coloration and bedding.

I’m still in Australia at the moment but will be home in a few days. I’m looking forward to writing up a few blog posts about some geological sights in Australia once I’m back home. For now, though, here’s a picture showing another beautiful example of sandstone in the Sydney area. This picture was taken at the Sydney Zoo. The red and orange colors are a result of iron oxidation. The white is sandstone that lacks a color change from iron oxidation. Some bedding is also visible in this sandstone outcrop.

Monday Geology Picture: Cross-Bedding Near Bondi Beach, Australia

I’m visiting Australia at the moment and will have a few blog posts to write up once I’m back at home. For now, though, here’s a sneak peek at some geology in Sydney. I took this picture close to Bondi Beach. There are some lovely exposures of sandstone outcrops near the beach.

Monday Geology Picture(s): Cross-Bedding in Ceres, South Africa

Posing with some pretty cross-bedding in Cape Fold Belt sandstones, Ceres, South Africa. — Posing with some pretty sandstone cross-bedding in the Cape Fold Belt, Ceres, South Africa.

Soon, I’ll continue with sharing more pictures from my geological wanderings in Mauritius earlier this year. However, for this week’s “Monday Geology Picture” I want to share some pictures from my recent visit to the little town of Ceres in the Western Cape of South Africa. Last Friday, I went to Ceres for the day with my husband and two friends visiting from America. Ceres is about an hour and a half north of Cape Town by car and is located in a geologic feature known as the Cape Fold Belt. In the Cape Fold Belt, sandstones and other sedimentary rocks have been extensively uplifted and folded. However, there are still many places where you can glimpse some primary sedimentary structures, such as the sandstone cross-bedding shown in the picture above. I posed with this cross-bedding when I was on a zipline adventure at Ceres Zip Slide Tours. If you like beautiful views of sedimentary rocks and aren’t afraid of heights, I highly recommend ziplining in Ceres. We had a great time!

Here are some more pictures from our ziplining adventure in Ceres:

Nervously preparing to launch myself on the first zipline of the day.

One of my friends on the first zipline. You can see vineyards in the background. — One of my friends on the first zipline. You can see some vineyards in the background.

On another zipline. What a view! What a great way to look at some uplifted sedimentary rocks!

Just stunning. — A friend on another zipline. This was a long one!

Posing with an interesting rock that is supposed to resemble a T-Rex head. — Posing with an interesting rock that resembles a dinosaur head.

A zipline with a view... — Another stunning zipline view.

Having fun... I think I'm (mostly) over my nervousness here. — Having fun… I think I’m (mostly) over my nervousness here.

What a fun day and a fun way to see some geology!

Monday Geology Picture: Sandstone Cross-bedding in Red Rock Canyon

A view of Red Rock Canyon, circa 2005. — A view of Red Rock Canyon, circa 2006.

This week’s Monday Geology Picture is a pretty shot that was taken several years ago in the Red Rock Canyon National Conservation Area, which is located just outside of Las Vegas. If you ever visit Las Vegas, I highly recommend making a trek out to Red Rocks– it’s a short drive away from the casinos and is a nice escape from the gaudy and glitzy Las Vegas strip. Also, you can see some very impressive sandstone cross-bedding, such as the bedding shown in the picture above.