What is Conglomerate?
Conglomerate is a clastic rock (fragments of pre-existing minerals and rock sedimentation) that contains large (greater than two millimeters in diameter) rounded clasts. The space between the clasts is generally filled with smaller particles and/or chemical cement that bind the rock together.
How Does Conglomerate Form?
Conglomerate forms where a sediment of rounded clasts at least two millimeters in diameter accumulates. It takes a strong water current to transport and shape particles this large. So the environment of deposition might be along a swiftly flowing stream or a beach with strong waves. There must also be a source of large-size sediment particles somewhere up current. The rounded shape of the clasts reveal that they were tumbled by running water or moving waves.
Alluvial Conglomerates:
Alluvial deposits are formed in areas of high relief and are typically coarse-grained. At mountain fronts individual alluvial fans merge to form braidplains and these two environments are associated with the thickest deposits of conglomerates. The bulk of conglomerates deposited in this setting are clast-supported with a strong AB-plane imbrication. Some matrix-supported conglomerates are present, a result of debris-flow deposition on some alluvial fans.
To log this EarthCache you have to answer the following questions and e-mail the answers to me:
1. Take a look at the rock speciman near the information panel and give a short description about the clasts you see.
2. What is clasts or clastic rock?
3. According to the panel, what is Geophagy?
Uploading photos to the cache page is the best way to say thank you to the cache developer and to encourage others to visit the location but is only optional.
NOTES:
- There are no other facilities along the trail except for very nice picnic spots.
- The distance is about 40km from Barberton on a narrow and winding road up to the Bulembu border post to Swaziland with no or limited cellphone reception.
- You can email me your answers in either Afrikaans or English.
Note that a handy guidebook specially compiled for this route is on offer at Barberton Tourism in town.
Enquiries: 013-712 2880 or www.barberton.co.za
Guided tours by Tony Ferrar on 072-376-2581 and Dave Mourant on 082-923-5366.
Thank you to the Barberton Chamber of Business and all those involved to develop this geotrail.
