Can anyone please critique on my first attempt at creating a theorem?

[LexonTheDragon]

I spent two days observing the coast of half moon bay along a 2 mile stretch of land. I made this because if it is true, it would place an extinction event between 2 recorded ones.

[DPS Ammonite]

Hello Lexon.

 

I wonder if you mean that you are formulating a hypothesis.

 

Fossil bivalves with both shells in their original living position could have been buried under feet of sediment due to a tsunami, underwater landslide or storm surge which cut them off from food and oxygen. You see a lot of them in the Merced Formation around Daly City, especially around Bivalve Point.

 

Fossil shells found well above current sea level can also get there by the land rising due to nearby faults such as the San Andreas. The Palos Verdes Peninsula near Los Angeles has 13 abandoned marine terraces up to 1,300 feet about sea level due to tectonic forces. Some of the terraces probably have shells. Current uplift is about 1 foot per thousand years.

 

Gary Griggs, Our Ocean Backyard: Why marine terraces, By Gary Griggs Published in the Santa Cruz Sentinal

PUBLISHED: January 23, 2016 at 12:00 a.m. | UPDATED: September 11, 2018 at 12:00 a.m.

 

https://www.santacruzsentinel.com/2016/01/23/gary-griggs-our-ocean-backyard-why-marine-terraces/amp/

 

[Al Dente]

 

Bivalve shells are hard and easily preserve in the fossil record. Shell beds are common and are found worldwide. You don’t need an event like an earthquake to explain how a bivalve becomes preserved in the fossil record.

[Kane]

At the very least, one of the many different possible indicators of an extinction event is in measuring the biostratigraphy in such a way as to do faunal counts and diversity markers. This would be plotted statistically for each layer. A study of the lithology would also prove beneficial to see some kind of connection to bathymetry (for instance, a lower count of fauna and biodiversity does not necessarily signal an extinction event any more than the ocean levels dropping for a time -- and thus showing an absence of marine fauna -- does not signal a major marine faunal extinction event). It is all well and good to speculate about earthquakes and plate movements, but it remains conjecture without a very dedicated study on the geology for that area. 

 

In terms of preservation, that is also something that has many different taphonomic causes. Something like catastrophic abrution (mudslides) that bury organisms quickly need not have something seismological as its cause, for it could also be explained by storms or other environmental phenomena. At other times, it can linked to topography of the marine bed, the presence of scavengers, tidal flows, and mineral availability.

[Mark Kmiecik]

And sometimes large groups of organisms that were spawned at the same time die off at the same time due to old age. They may have just dug down as the tide went out and died because it was their time to go. This would have created a localized mass death event but way short of mass extinction. Mass extinction is generally a reference to the entire species globally, and requires sampling most, if not all, of the known locations of a species' distribution to formulate that hypothesis. Three fossil bivalves don't provide enough data -- three hundred thousand or million would be more convincing.