This  EC focuses on a the geological timeline and geomorphology.   First a definition you will need:

• Geomorphology = The study of the Earth's landforms and topography in relation to the Earth's geology.

The title is a play on John McPhee's book, Annals of the Former World.  This EarthCache is about the way things use to be.  The most recent geological epoch is referred to as the Anthropocene because the rapid changes made by humans.  

The geological time line was developed before methods of actually determining the age of rocks.  The various eras, epochs, stages, etc, are almost all based on the first advent or disappearance of fossil assemblages.  The oldest era the Precambrian was originally defined as the time before fossils, although now soft body animals have been identified.  The Paleozoic Era is characterized by fossils prior to the advent of dinosaurs.  The Mesozoic Era is the time of dinosaur fossils.  And, the Cenozoic Era is the age of mammals.  A subdivision of the Cenozoic is the Quaternary Period, which includes the Pleistocene Epoch beginning about 1.6 million years ago which includes a series of ice ages and interglacial periods, and the following period the Holocene Epoch which is the "recent period" after the most recent ice age, beginning about 11,000 years ago.  By various names the concept of the "Anthropocene" has been around since the late 1980s.  The Anthropocene includes the period where humans have had a significant impact on geological processes.  Debates continue as to where to draw the line of the beginning of the Anthropocene, proposals varying from 250 years to 100 years before present.  Examples human effects during the Anthropocene include:

• Levees that prevent sediment depositing on the floodplains during flood.  An example of this is disappearance of the Mississippi River delta due to sediment being cut off, but lengthening the delta at its mouth as all the sediment shoots to the end (Kemp 1999)
• Dams on rivers that capture all the sediment.  An example of this is as the waves continuously erode Malibu Beach is not being offset by the sediment load from Malibu Creek because dams on Malibu Creek are capturing all the sediment (Knur 2000). 
• Hydraulic mining for gold in the Sierra Nevada Mountains generated an estimated approximately 139 million cubic yards of sediment just in the Feather River Basin (Gilbert 1917), and there 10 river basins draining the Sierras.  Major rain fall events from 1849 to 1852, and again in 1862 (NY Times 1862) washed these sediments into the rivers and bays.  These sediments chocked the rivers, flooding Sacramento and the average depth of the bay decreased 1 to 6 feet.   Honker Bay was created when a spit of sediment separated a large portion of this once contiguous bay (USGS 2016).  The shoreline of Martinez CA accreted approximately 3/4 mile (Confidential Engineering Report)(Aslo see the EarthCache GC3VGB9).   Prior to this river boats travelled up the Feather River >40 miles from Sacramento to Yuba City.  The Feather River remains so chocked with sediment that it remains impassable to all but the shallowest draft boats (USGS 2017).

You should standing on the southwest corner of Market Street & 1st Street (near where Battery St ends).  There is a rectangular brass plaque that tells of the former world.  This plaque tells of a geomorphic feature (geomorphology = study of the shape of the Earth's surface, features, or topography) that was formerly near this location.  You have certainly observed where this geomorphic feature is now, you can see it on any map.   

To keep you log from being deleted, in accordance with the Earthcaching rules, please message the answers to the following questions to the cache owner:

1) Name of the cache in the subject line.

2) What is the geomorphic feature that use to be about 25 feet from this plaque and in what compass direction?  This information is available in the text of the plaque.

3) When you look towards the ocean (southwest) along Market St, discuss the topography of Market Street.  This is best observed from the trolley island or the cross walk, Market is a very busy street.  Be safe.

4) When you look towards the bay (northeast) along Market St, discuss the topography of Market Street.  This is best observed from the trolley island or the cross walk, Market is a very busy street.  Be safe.

5) Two human actions resulted in the geomorphological change from the former feature to the where this feature is now.  One is included in the text above.  Speculate on the other, all good faith answers accepted.

Not a requirement, but for fun if you so choose, in your log please state the country and city do you call home.

REFERENCES

Gilbert, G.K. 1917.  "Hydraulic-Mining Debris in the Sierra Nevada".  United States Geological Survey: Professional Paper 105. 

Kemp, K 1999.  "The Mississippi Levee System and the Old River Control Structure." Tulane University.  http://www.tulane.edu/~bfleury/envirobio/enviroweb/FloodControl.htm

Knur, R. 2000.  "The effect of dam construction in the Malibu Creek Watershed on the Malibu coastline sediment budget, California."  [M.S. Thesis].  California State University, Los Angeles.  March.

NY Times 1862.  "THE GREAT FLOOD IN CALIFORNIA.; Great Destruction of Property Damage $10,000,000." January 21. 

http://www.nytimes.com/1862/01/21/news/the-great-flood-in-california-great-destruction-of-property-damage-10000000.html 

USGS 2017.  "San Francisco Bay Bathymetry."  https://sfbay.wr.usgs.gov/sediment/sfbay/bathy_change.html