Overnight Trip in the Talkeetna Mountains

[AK hiker]

My wife, dogs and I got out recently to camp overnight and hike in the Talkeetna Mountains. Still very cool for this time of year at 40 degrees in the late morning upon arriving with frost the next morning. The cool weather made for nice hiking weather and we put some miles in on caribou trails and ridges. At one point I checked out a gully with Cynthia staying up high where she collected two hands full of belamite pieces retaining two of the end pieces. I took pictures of the ammonites I saw in a 1/2 hour side hill jaunt returning to camp at our plane with 7.5 miles covered. I have been studying ammonite anatomy and nomenclature so getting closer to be able to make educated guesses as to what I have been seeing. I believe this area is in Member 3 of the Matanuska Formation probably the Pachydiscus kamishakensis zone per the reference recommended by FossilDAWG. I have several ammonites with the umbilcus cleaned out which will help with identification. A new one to me is ribbed, evolute and unfortunatly broken. Most of what I have been seeing are partially evolute or convolute if I am using the terms correctly, some being fairly large. Will post one picuture of a partially prepared one that I am going to make a grade school guess is from the genus Pachydiscus or Psendophyllites and when fully prepped will post better pictures to help identify. All of this is new to me so enjoying the education very much.

 

 

 

Reeeealy steep terrain

 

 

 I did not go out on the hard consolidated areas as poor grip with my boots.

 

 

Breath taking view and also don't slip here.

 

 

Belemnites deposit are above the ammonites

 

 

 

 

Orca our stylish Boston Terrier

 

 

 

Partially prepared ammonoid with an intact umbilcus

[t-tree]

Good finds, the location looks very peaceful .

 

John

[Ruger9a]

I agree with John.

[RJB]

  Maybe its just me, but you take some fantastic pictures!!!  

 

RB

[crabfossilsteve]

Wow, now that is a wonderful fossil hunting area.  Amazing scenery and amazing fossils all displayed out on the surface. Maybe a bit of a workout getting those ammonites home though..eh.

[AK hiker]

1 hour ago, crabfossilsteve said:

Wow, now that is a wonderful fossil hunting area.  Amazing scenery and amazing fossils all displayed out on the surface. Maybe a bit of a workout getting those ammonites home though..eh.

The workout is why we are doing the hikes and prefer to be in the mountains weather permitting. The fossils are a bonus and has rekindled my interest from when I was much younger. I did not pick any of the pictured fossils this trip as have seen these types before. I’m working on an ammonite anatomy terminology and nomenclature diagram to help me learn more about these fossils ultimately for definitive identification once I have a better understanding. 

[AK hiker]

1 hour ago, RJB said:

  Maybe its just me, but you take some fantastic pictures!!!  

 

RB

Thanks! My wife takes some great pictures too. All but the last one was from her iPhone 10 which has really good clarity.

 

The siltstone exposures in the background are where some of the fossils are located. The belamites are directly on top of the limestone and this area is very broken up by tectonic activity in the past. You can be standing the limestone layer like in this picture and looking up 500 elevation directly above and see the same layer. I am not even sure where the limestone layer falls in relation to the ammonite fossil layer due to the folding and displacements. Fun to ponder and figure out.

[Jackson g]

You would never get me to leave a place as beautiful as that. I am totally 

[Monica]

Gorgeous scenery and ammonites - amazing! 

[taj]

Crazy stuff...

 

[Oxytropidoceras]

Amazing fossils, great pictures.

 

Some related papers and PDF files are:

 

Hampton, B.A., Ridgway, K.D., O Neill, J.M., Gehrels, 

G.E., Schmidt, J., Blodgett, R.B., Trop, J.M. and Glen, 

J.M.G., 2007. Pre-, syn-, and postcollisional 

stratigraphic framework and provenance of Upper 

Triassic–Upper Cretaceous strata in the northwestern 

Talkeetna Mountains, Alaska (Hampton et al.), 

in Ridgway, K.D., Trop, J.M., Glen, J.M.G., and 

O’Neill, J.M., eds., Tectonic Growth of a Collisional 

Continental Margin: Crustal Evolution of Southern 

Alaska: Geological Society of America Special Paper 431.

https://www.researchgate.net/publication/262918413_Pre-_syn-_and_postcollisional_stratigraphic_framework_and_provenance_of_Upper_Triassic-Upper_Cretaceous_strata_in_the_northern_Talkeetna_Mountains_Alaska

https://www.researchgate.net/profile/Robert_Blodgett2/2

 

Imlay, R.W., 1960. Early Cretaceous (Albian) Ammonites 

from the Chitina Valley and Talkeetna Mountains, Alaska 

(pp. 87-114). USGS Professional Paper 354D

US Government Printing Office.

https://pubs.er.usgs.gov/publication/pp354D

 

Imlay, R.W., 1975. Stratigraphic distribution and 

zonation of Jurassic (Callovian) ammonites in 

southern Alaska. USGS Professional Paper 836

US Government Printing Office.

https://pubs.er.usgs.gov/publication/pp836

 

Jones, D.L. and Grantz, A., 1967. Cretaceous

ammonites from the lower part of the Matanuska

Formation, southern Alaska, with a stratigraphic

summary.USGS Professional Paper 547

US Government Printing Office.

https://pubs.usgs.gov/pp/0547/report.pdf

https://pubs.usgs.gov/pp/0547/plate-10.pdf

 

Tropaff, J.M., Szuch, D.A., Rioux, M. and Blodgett, R.B., 

2005. Sedimentology and provenance of the Upper 

Jurassic Naknek Formation, Talkeetna Mountains, 

Alaska: Bearings on the accretionary tectonic history 

of the Wrangellia composite terrane. GSA Bulletin, 

117(5-6), pp.570-588.

http://mmtk.ginras.ru/pdf/Trop-Szuch-Rioux-Blodgett-2005 Sedimentology and provenance of the Upper Jurassic Naknek Formation, Talkeetna Mountains, Alaska.pdf

 

Trop, J.M., Ridgway, K.D. and Spell, T.L., 2003. 

Sedimentary record of transpressional tectonic and 

ridge subduction in the Tertiary Matanuska Valley–

Talkeetna Mountains forearc basin, southern Alaska. 

Geology of a transpressional orogen developed 

during ridge-trench interaction along the North 

Pacific margin: Geological Society of America 

Special Paper, 371, pp.89-118.

https://www.researchgate.net/publication/279339412_Sedimentary_record_of_transpressional_tectonics_and_ridge_subduction_in_the_Tertiary_Matanuska_Valley-Talkeetna_Mountains_forearc_basin_southern_Alaska

https://www.researchgate.net/profile/Jeffrey_Trop

 

yours,

 

PAul H.

[Ludwigia]

Thanks again for sharing this all with us. I'm enthused.

[AK hiker]

1 hour ago, Oxytropidoceras said:

Amazing fossils, great pictures.

 

Some related papers and PDF files are:

 

Hampton, B.A., Ridgway, K.D., O Neill, J.M., Gehrels, 

G.E., Schmidt, J., Blodgett, R.B., Trop, J.M. and Glen, 

J.M.G., 2007. Pre-, syn-, and postcollisional 

stratigraphic framework and provenance of Upper 

Triassic–Upper Cretaceous strata in the northwestern 

Talkeetna Mountains, Alaska (Hampton et al.), 

in Ridgway, K.D., Trop, J.M., Glen, J.M.G., and 

O’Neill, J.M., eds., Tectonic Growth of a Collisional 

Continental Margin: Crustal Evolution of Southern 

Alaska: Geological Society of America Special Paper 431.

https://www.researchgate.net/publication/262918413_Pre-_syn-_and_postcollisional_stratigraphic_framework_and_provenance_of_Upper_Triassic-Upper_Cretaceous_strata_in_the_northern_Talkeetna_Mountains_Alaska

https://www.researchgate.net/profile/Robert_Blodgett2/2

 

Imlay, R.W., 1960. Early Cretaceous (Albian) Ammonites 

from the Chitina Valley and Talkeetna Mountains, Alaska 

(pp. 87-114). USGS Professional Paper 354D

US Government Printing Office.

https://pubs.er.usgs.gov/publication/pp354D

 

Imlay, R.W., 1975. Stratigraphic distribution and 

zonation of Jurassic (Callovian) ammonites in 

southern Alaska. USGS Professional Paper 836

US Government Printing Office.

https://pubs.er.usgs.gov/publication/pp836

 

Jones, D.L. and Grantz, A., 1967. Cretaceous

ammonites from the lower part of the Matanuska

Formation, southern Alaska, with a stratigraphic

summary.USGS Professional Paper 547

US Government Printing Office.

https://pubs.usgs.gov/pp/0547/report.pdf

https://pubs.usgs.gov/pp/0547/plate-10.pdf

 

Tropaff, J.M., Szuch, D.A., Rioux, M. and Blodgett, R.B., 

2005. Sedimentology and provenance of the Upper 

Jurassic Naknek Formation, Talkeetna Mountains, 

Alaska: Bearings on the accretionary tectonic history 

of the Wrangellia composite terrane. GSA Bulletin, 

117(5-6), pp.570-588.

http://mmtk.ginras.ru/pdf/Trop-Szuch-Rioux-Blodgett-2005 Sedimentology and provenance of the Upper Jurassic Naknek Formation, Talkeetna Mountains, Alaska.pdf

 

Trop, J.M., Ridgway, K.D. and Spell, T.L., 2003. 

Sedimentary record of transpressional tectonic and 

ridge subduction in the Tertiary Matanuska Valley–

Talkeetna Mountains forearc basin, southern Alaska. 

Geology of a transpressional orogen developed 

during ridge-trench interaction along the North 

Pacific margin: Geological Society of America 

Special Paper, 371, pp.89-118.

https://www.researchgate.net/publication/279339412_Sedimentary_record_of_transpressional_tectonics_and_ridge_subduction_in_the_Tertiary_Matanuska_Valley-Talkeetna_Mountains_forearc_basin_southern_Alaska

https://www.researchgate.net/profile/Jeffrey_Trop

 

yours,

 

PAul H.

Wow!!!
Thanks. Guess what I’m doing for fun when it’s raining this summer.

Bob

[jort68]

Epic views, that must've been a wonderful couple days. Jealous to say the least <3