10 Answered Questions for the topic sedimentology
The grains of the parabolic dunes?
My text book says that parabolic dunes consist of consolidated limestone grains, but I wondered if they have sand grains too, so I googled this issue and found that they consist of sands, but I am... more
Presence of cross stratified conglomerates in fan deltas?
Why are cross stratified conglomerates found in deposits of fan deltas? I know that fan deltas are alluvial fans that deposit directly into the sea, hence they are poorly sorted.But could not... more
Is Desert Sandstone a chemical sedimentary rock?
I gather that chemical sedimentary rocks are formed when minerals in solution are supersaturated and therefore they precipitate out. I also understand that desert sandstone is formed as Iron Oxide... more
What is the best way to mount white mica separates?
I have detrital mica separates that I would like to mount in EpoThin resin for microprobe analysis and I would simply like to know the best method for mounting them. With zircons you can mount on... more
Sediment layer chronology?
In the new Cosmos series, Neil DeGrass Tyson in explaining different ways the age of the world has been determined, shows how sedimentary layers at the Grand Canyon are a fossil record of a lot of... more
What are the differences between alluvial, eluvial and colluvial deposits?
There's always confusion and disagreement when these terms are mentioned. Need to be sure of their exact meanings.
Determining a rock age using volcanic ash layer?
I wanted to know if volcanic ash deposits found in the geologic record are most useful in correlating the age of rock layers if the volcanic ash was distributed over a large area during a short... more
How have global sedimentation rates changed over the last billion years?
Do we have a graph of how sedimentation rates changed over time?
A sedimentary rock with only minerals?
In my text book I came across this multiple-choice question>A sedimentary rock consists of only minerals and lacks fossils, it could be classified as:>i) a clastic sedimentary rock>ii) a... more
What is the difference between eluvium and alluvium?
I was reading about kimberlite on Wikipedia and it mentioned eluvium. I've heard of alluvium, alluvial fans, alluvial deposits, etc. However, when I looked up eluvium, it sounded exactly like... more