Hot answers tagged

12

One can only speculate based upon a photograph - however they look very much like mineralized fractures. At some time in the past this rock mass may have fractured in response to thermal or tectonic stresses. Fluid may have then penetrated relatively long distances along the fractures into the area and infiltrated shorter distances into the wall rock along ...


7

It depends on which classification system you're using, which varies by country. According to the USDA Soil Taxonomy, R is used to designate bedrock. Other countries and classification systems may (or may not) use different letters. Check out the Compendium of On-Line Soil Survey Information for other classification systems. To answer your second ...


7

According to Wikipedia and Nature.com, "R Horizon" is the official letter for bedrock. CAPTION: Example soil with designations that communicate the soil formation processes occurring in each horizon.


5

Basically a formation is just a layer or group of layers of rock that is both distinct enough to be identifiable in the field and large enough to show up on a geological map. Usually it is many nearly identical layers grouped together or just one large layer. Its not a hugely precise definition but it is a lot like the term "species" in biology, it's a ...


4

No such thing exists. Some of the data you're looking for may be available from government geological surveys. For example, the Australian state of New South Wales provides this in their online map tool: https://minview.geoscience.nsw.gov.au Click "Add layer", then "Geochemistry", then "All surface geochemistry". MinView from ...


3

The two geological faults that may be responsible of large earthquake in proximity of the museum are: Hollywood fault; Santa Monica fault (actually many branches, but they all go together as Santa Monica fault). The museum seems to be enough far away from the fault trace (the surface expression of the fault itself), so it is unlikely that there will be a ...


3

This answer is based on a cursory look at the 1:50000 Foglio Appiano, from the Geologic Map of Italy (in Italian Language only, as far as I can tell). As I pointed out in comment, I intend it as just a start for further investigations, which should be done with more detailed geological works and possibly more field work. I'd recommend contacting the office ...


3

A small scale seismic survey as well. I remember as students we found the water table using a 100m refraction line and a sledge hammer sound source. Scale that up from ~5m to 100m you're going to need a longer line and a larger sound source. Reflection might also become more convenient. Still a lot smaller than a typical 2d survey line though!


2

According to Wikipedia, and perfectly consistent with basic historical geological textbooks, a formation is: ...the fundamental unit of lithostratigraphy. A formation consists of a certain number of rock strata that have a comparable lithology, facies or other similar properties. ... The concept of formally defined layers or strata is central to the ...


2

There are three possible sources for the reported limestone nodules from the clay horizon from colluvium and alluvium. First, as noted before, they could be either detrital gravel of limestone either eroded from limestone bedrock. Given that the bedrock source from which this gravel was eroded and transported from could be either local or regional, such ...


2

If you were hoping for a smooth succession from Archean all the way down to Quaternary, you're going to be disappointed. Geology is messier than rocks being serenely laid down continuously through time like that. A drive from the Appalachians to the East Coast would get you everything but the Archaean rocks, although the only Proterozoic rocks would be found ...


1

Sonar (passive or active) or ground penetrating radar with both work, it can also be estimated from a published geologic profile of the area which are often built from both in addition to drill data.


1

I can offer a counter-example. What if your soil sample is taken from the site of some lost ancient Roman buildings? The Romans built plenty in northern Tunisia, and like using travertine limestone. A few long-destroyed buildings would explain the presence of limestone nodules in the soil while saying nothing about the bedrock. The point is there are many ...


Only top voted, non community-wiki answers of a minimum length are eligible