Any Good Places Near San Marcos Texas For Giant Ammonites? I Used To Have A Spot...

[dt1028]

I am a Texas State student who grew up outside of San Marcos Texas. When I was a kid we used to play in an abandoned limestone quarry off of Hunter road.

We managed to find some giant Ammonites about the size of small car tires but they were to big for us to move on our BMX bikes. We did manage to carry one home weighing about 40 lbs and a giant sea snail that i found.

We had access to this quarry because a friend of mine lived on the property. Sadly when he moved away and more houses were constructed near the quarry the owner started really going after people trespassing. This put an end to our days of seeing these things.

The house i grew up in, which my parents still live in, has fossils all over the place. Tons of shells, and i think coral but no ammonites.

Does any one here have any sites near San Marcos Texas that has Ammonites. I would like to learn how to extract them and start a collection. I am willing to deal with the June/July heat if need be.

[mommabetts]

Welcome to the forum from Northeast Texas. I wish I could help you out but I am almost at the Red river so I know nothing about the area. If you knew who the owner of the quarry is, sometimes if you go up to them, explain what you are doing, I have found that they will let you go in. What they don't like is people going in without asking that makes them mad. It wouldn't hurt to ask. Good luck.

[dt1028]

The quarry is owned by a development firm now and they are paranoid about lawsuits. They destroyed the ramp that goes into the quarry. They also sold all the land around it.

So even if we could get down there, trying to bring these things back up a 30 foot wall is a feat in itself.

[tracer]

start searching for information on eopachydiscus and the duck creek formation.

[Seldom]

Welcome from Galveston Texas. I have not been to San Marcos in years, but do a Google search will get tons of info.

[LanceH]

The Geology of Texas - Vol. 1

DUCK CREEK FORMATION

Stratigraphic position and contacts.—The Duck Creek limestone overlies the Kiamichi marl as far south as Bell County. Farther south, the Kiamichi is absent and the Duck Creek, here the thinned basal member of the Georgetown limestone, directly and disconformably overlies the Edwards. The Duck Creek is everywhere overlain, apparently conformably, by the Fort Worth limestone.

...

Farther south it is consolidated with the Fort Worth limestone to form the lower Georgetown. At Fort Stockton, it is about 48 feet thick; at Kent, 50 feet; at El Paso, about 100 feet at Sierra Prieta, about 25 feet.

[LanceH]

So on the geologic map look for areas listed as Kgt. Since the ammos are in lowest Duck Creek up here (which in south Texas is actually lowest Georgetown) you would be searching areas that expose the lowest Kgt (ie, the most westernly exposures on the map). Good Luck finding Mr. Eopachydiscus .... this message will self destuct!

[Uncle Siphuncle]

The Kgt pinches pretty thin in the San Marcos anticline. If you found Eos in the Kgt of that area, you've done better than I have. I once found a few rough Mortoniceras ammonites and Macraster echinoids in the San Marcos area, but they were sparse and that is the farthest sound I've found them along the Balcones escarpment (but they do once again become much more common in far West Texas). I didn't catch whether you were east or west of I-35. If it was to the west you probably found Kgt limestone overlying the Ked, and the Kgt may have been treated as overburden. If it was east of 35 you were probably in the Austin Chalk which also has big ammonites, but productive exposures are much less common that those bearing Kgt ammonites. So if you have a good Kau site, work it hard as the stuff is more rare and therefore desirable to seasoned collectors. Morts and Eos (and Oxys in the Goodland and Plesioturrilites of the Del Rio, Grayson, and Pawpaw farther north) are somewhat of the "common currency" of Texas ammonites together probably constituting 90% of the ammonite finds in TX. That's why I get a kick out of the more rare Upper Cretaceous specimens.

[ShadyW]

I love exploring with Google Maps!

Is your quarry this one?

San Marcos quarry

[dt1028]

Its this one...doesnt look like a quarry but it is.

I dont know why Google maps claims there is a road there...those paths are from when they used to mine it

I am west of IH35.

From what i recall there is tons of small fossils in this thing embedded into the rocks. I am gonna have to see if they reopened since google maps claims its a street.

I know of a huge Quarry that I may be able to get access to....when i return from vacation i will fill you guys in. I will also post pictures of my findings from this place in the past.

[Evans]

Does any one here have any sites near San Marcos Texas that has Ammonites. I would like to learn how to extract them and start a collection. I am willing to deal with the June/July heat if need be.

If you travel south from San Marcos you will eventually be in the area of the house of Dan Woehr. You will find many nice sized ammonites at that location.

On a side note, you should check out the other postings from Dan with him, large caliber guns and dead mammals.

Welcome to the forum.

[Uncle Siphuncle]

My best defense against fossil theft is to roll ammonites into my house too large to cart off....mua ha ha!