Re: Trachilos footprints ~6 Ma


Marine sediments form in all depths of sea water. From a thin film such as in a calm lagoon to deep water. I worked in interdigitated marine and terrestrial sediments with months in the field in those types of deposits in the Caliente Formation Miocene. Most of what I studied for marine was shallow water marine, sometimes with poor mammal ichnofossils and sometimes with fossil terrestrial mammals. Some locals with both marine fossils and terrestrial mammals mixed.


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From: Gareth Morgan
Sent: Thursday, October 14, 2021 8:14 AM
Subject: Re: [AAT] Trachilos footprints ~6 Ma


 Marine sediment settles deep on the sea floor.

Estuarial sediment happens in estuaries.

Palaeoichnological sites, per link...

alternated layers of clay and sand formed in shallow water bodies, with more or less marine influence.


 hunters-gatherers in an estuary 

 In England, Severn Estuary, Formby Point can be found; in South Wales, Mersey and Kenfig estuaries. All of them belong to the Mesolithic and Neolithic.

The Trachilos prints are in carbonate–siliciclastic tidal sedimentation

Google it for tracks of camels and horses



From: <> on behalf of Allan Krill <krill@...>
Sent: Thursday, October 14, 2021 2:12 PM
To: <>
Subject: Re: [AAT] Trachilos footprints ~6 Ma


On Thu, Oct 14, 2021 at 01:02 AM, Gareth Morgan wrote:

The fossils and fossil footprints in your reference are in fluvial sedimentary rocks, not marine sedimentary rocks. Here is the paragraph that explains this:

Rocks were formed in a moment of the history of the Earth when the climate was cold and dry, and the sea was not where it is today; it had gone back dozens of kilometres towards the South-East of its current position. The former Pehuén co was a great valley of an ancient river and, in its lowest parts, fresh water accumulated during periods of heavy rains that swept along the mud from the nearest ravines. As a consequence, ponds were formed, that were inhabited by waterfowls, and where pumas, deer, guanacos, bears, horses and strange huge animals that are extent today (Megatherium, Macrauchenia, Stegomastodon) came to drink water.

The tracks of all these creatures were marked on the mud, which after drying and covering with layers of sand and new mud mantles, they were transformed slowly in a succession of semi-consolidated rocks. 



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