Recommendations For A "geology" Book

[sward]

I am new to geology and fossil hunting. I would like to find a good book that will help me understand the geology better, particularly of North Texas. But, I realize the book may not be specific to North Texas.

I have many of the geological maps and can use them "somewhat effectively" to determine what formation I'm in. What I feel I need help with is determining the different types of outcrops I find and their compositions. I read the different defintions such as "marl, brownish clays, flaggy sandstones" and don't really know what to look for.

I would like to find a book that may show color photos of these different materials so I can better understand what I'm looking at in an outcrop. The attached photo shows one of the outcrops that I found nautilus and plesioturrilites in. I was asked in one of the other forum categories about the outcrop and the distinct contrast in it. As you can tell, the bottom layers are solid rock (gray), while the top portion (brown) is composed of small rocks tighly embedded together. I would like to be able to better understand these different layers.

Any recommendations regarding a book that may help me to learn more about this will be very much appreciated. And, as usual, thanks for all of your help.

BRGDS,

sward

DFW, TX

[Texas-Tunnel Rat]

My recommendations as a starter kit for North Texas Geology would be.

1. A Earth Science or Physical geology lab manual or Audubon books. This will help you get used to IDing geologic formations on maps and other mechanics which can help you in the field.

2. Get the AAPG or some kind of geologic map of Texas

3. Finsley's field guide to fossils, great for beginners and experts then grow from there.

4. Roadside Geology guide of texas helps

Get these then specialize. I browse through the collections at any of the Unvsesity of Texas libaries. If you got any question PM me, we have all been in these shoes. And DFW is great becuse it effectivly can be split into 3 parts marine, shores, and terrestrial facies.

[MikeD]

You can check out the Geologic Atlas of Texas here:

http://www.twdb.state.tx.us/GwRD/GTA/GAT/index.htm

[vertman]

I believe the limestone containing the fossils is the Main Street Formation (but could also be Grayson Formation) from the Lower Cretaceous Washita Group. It is hard to say about the material above it. I am guessing the location is a creedbed? If so, then I believe the overlying material is a remix of stream washed and redsposited gravels, dirt, limestone pieces, etc. I believe the Woodbine Formation overlies the Main Street. Much of the material above the limestone may well belong to that formation as well. Much of the Woodbine is a redish dirt or clay. That may contribute to the color of the material.

[Tony Eaton]

In case you haven't seen these pages...

Lance Hall has a lot of great source material and pics on his page.

http://www.northtexasfossils.com/

And the DPS has a concise page here:

http://www.dallaspaleo.org/details/surface_geology.htm

[tracer]

from the way you described your objective, i'm not sure a book is the solution. what would seem most helpful would be if you could find a local geologist or paleontologist who would be willing to take you around to exposures of different formations and their contact points and tell you what you're looking at. text descriptions of formations can at times be very detailed, but still don't create a good picture in the mind's eye.

you can teach yourself a lot over time if you're diligent, but it's a much slower process. and sometimes you end up misinforming yourself.

[erose]

from the way you described your objective, i'm not sure a book is the solution. what would seem most helpful would be if you could find a local geologist or paleontologist who would be willing to take you around to exposures of different formations and their contact points and tell you what you're looking at. text descriptions of formations can at times be very detailed, but still don't create a good picture in the mind's eye.

you can teach yourself a lot over time if you're diligent, but it's a much slower process. and sometimes you end up misinforming yourself.

I agree with Tracer. I have many a geological report and over the many years have become somewhat familiar with the various terminology but nothing beats having an expert show you the ropes. One way to get that experience is to sign up and attend field trips given by various professional and semi-professional groups. Start with the Dallas Paleo Society and then see what is happening with any other local Geological societies and organizations. AAPG, GSA, etc. There are annual meetings that often include field trips. You might have to pay a fee or something but often they need to "fill the bus" and are happy to have folks outside the organization along. Museums, science centers, etc. may also offer trips. I wish I could offer more detail but you will have to do the actual searching.