grommit Posted April 23, 2008 Share Posted April 23, 2008 As I've been driving around, I've been trying to take the advice to always look around. I've been pretty lucky. Now I'd like to be more methodical. People have suggested several types of geography, and I'd like to figure out the details. 1. Creeks. Anything special needed, or are they all worth looking at? Fossils on the creek banks, or creek bottom, or both? 2. Cliffs. Assuming need rocky outcroppings. 3. Fields. I guess grassy fields are no good. Looking for gravelly/exposed fields with no topsoil? 4. Construction sites. It's been tricky to figure out where I am allowed to go. No fences on new roads = ok? Any / all advice appreciated. Link to comment Share on other sites More sharing options...
TheFossilHunter Posted April 23, 2008 Share Posted April 23, 2008 As I've been driving around, I've been trying to take the advice to always look around.I've been pretty lucky. Now I'd like to be more methodical. People have suggested several types of geography, and I'd like to figure out the details. 1. Creeks. Anything special needed, or are they all worth looking at? Fossils on the creek banks, or creek bottom, or both? 2. Cliffs. Assuming need rocky outcroppings. 3. Fields. I guess grassy fields are no good. Looking for gravelly/exposed fields with no topsoil? 4. Construction sites. It's been tricky to figure out where I am allowed to go. No fences on new roads = ok? Any / all advice appreciated. Your question is a little too broad to asnwer, you are asking like 35 quaestions at the same time, and too many unknowns in the equasion. A lot of it depends on what kind of fossils you are looking for. Some, are more likely to be found in creeks, for example, than the other. basically, if you don't want to go by looking up the geology of the area or particular formation and just want to drive around and look, the deal is basically any place where sedimentary rocks are exposed. It may be a creek, a river bank, outcrop, cliff, roadcut, construction sites etc. Again, if you are talking about sharks teeth, then you might need to look in the creek bottom of sift the gravel to find them, or just pick up what's been weathered from the creek shore. What I usually do with creeks is see if there is the right type of rock exposed at the points where i can get access to the creek - intersection with roads. If i see the right rock I go down and explore, If I don't , I dont investigate any more ( unless i have a lead about fossils found in a particular section of the creek). Construction sites can be a good place to look. You cant automatically assume that if there are no fences around a construction site, then you can go in. Look for no trespassing signs and if it appears risky to go in, then maybe its better to ask permission. if they blow things up in a quarry, then most likely there will be no trespassing signs. even if there are no signs you can still get in trouble. Cliffs and outcrops can in many cases be igneous rock, you should be able to see it by the look of the rock, and then you dont need to look for fossils. I don't think that gravelly fields is what you need to look for. You need the right type of sedimentary rock exposed. Also, remember, that even in the right type of rock and rock formation one spot can be fossiliferous and another next to it completely devoid of fossils. Thats why I dont think your approach is going to be very effective. What you should rather do ( untill you feel comfortable using a geologic map) is try to find out about the well known sites, research the internet, ask other collectors, join a paleo society in your area, look for info in books. Then when you are in the area try to look for exposures near the sites - you will have better chances of finding something. Driving around blindly looking for rock exposures will not be effective ( for most fossils) and you will spend a fortune on gas. There arer cases when it will be effective but not for the type of fossils you are probably trying to find. Once again, your question is way to broad to answer in one post. Mike Link to comment Share on other sites More sharing options...
Uncle Siphuncle Posted April 23, 2008 Share Posted April 23, 2008 All of the above features can be productive exposures if and only if they incise or expose the right formations. Pick up geo maps for your favorite areas from the UT Bureau of Economic Geology for 6 bucks each then target the named exposures within the mapped aerial outcrop of the formation of interest. Grüße, Daniel A. Wöhr aus Südtexas "To the motivated go the spoils." Link to comment Share on other sites More sharing options...
grommit Posted April 23, 2008 Author Share Posted April 23, 2008 All of the above features can be productive exposures if and only if they incise or expose the right formations. Pick up geo maps for your favorite areas from the UT Bureau of Economic Geology for 6 bucks each then target the named exposures within the mapped aerial outcrop of the formation of interest. That's where I am trying to close the loop. I have the maps, but no knowledge of which formations contain anything. So I know the main formation in Mansfield (name escapes me now) but have no idea if that formation contains anything useful. I have another thread asking about where to find information about the formations. Not where they are, but in general, what they have. I think I'll take the advice and join the Dallas Paleo society soon. Grommit Link to comment Share on other sites More sharing options...
Uncle Siphuncle Posted April 23, 2008 Share Posted April 23, 2008 I can't think of a dead formation in the DFW area. They all have something. The Woodbine to me seems the hardest to hunt as I don't know many zones in it, however it gives up Calycoceras ammonites, dinosaur, croc, and plant material in certain spots. The Austin Group is also hard to hunt in your area and may in fact be the most devoid of collectible fossils even though big Parapuzosia ammonites have been found east of Dallas. The Goodland through Upper Britton sequence all have distinctive fauna. Most have ammonites. Most have echinoids. Some have crabs. Some have more shark teeth than others. In general the Washita group will give up lots of ammonites and echinoids while the Atco fm has the most shark teeth. The prettiest ammonites in my opinion come from the Pawpaw, Woodbine, Arcadia Park and Upper Britton. The best marine vert material in my opinion comes from the Lower Britton, which is the yellow stuff in the Mansfield area. The best crabs are in the Upper Britton and Pawpaw. The best pyritized fossils come from the Grayson and Pawpaw. Most of the echinoids range from Goodland through Mainstreet. Hope this helps. The problem is that some areas are mapped as groups and not as formations. For instance the Eagle Ford, Woodbine, and Austin are not mapped as individual members or formations, so some field work is required to nail all this down. Grüße, Daniel A. Wöhr aus Südtexas "To the motivated go the spoils." Link to comment Share on other sites More sharing options...
LanceH Posted May 24, 2008 Share Posted May 24, 2008 Grommit, Go to my website: Lance's fossil page Scroll the left menu bar down about half way and you'll see my pages on individual North Texas geological formations with pictures of representative fossils Link to comment Share on other sites More sharing options...
emtilt Posted May 24, 2008 Share Posted May 24, 2008 Be careful what construction sites you look in. I don't know what the laws are in Texas, but in Florida, trespassing on certain kinds of construction areas without permission is a felony offense. Link to comment Share on other sites More sharing options...
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