Here's a short story:

Norfolk () is a county in East Anglia in England. It borders Lincolnshire to the west and north-west, Cambridgeshire to the west and southwest, and Suffolk to the south. Its northern and eastern boundaries are the North Sea and, to the north-west, The Wash. The county town is Norwich. With an area of and a population of 859,400, Norfolk is a largely rural county with a population density of 401 per square mile (155 per km²). Of the county's population, 40% live in four major built up areas: Norwich (213,000), Great Yarmouth (63,000), King's Lynn (46,000) and Thetford (25,000). 

The Broads is a network of rivers and lakes in the east of the county, extending south into Suffolk. The area is not a National Park although it is marketed as such. It has similar status to a national park, and is protected by the Broads Authority. 

Norfolk was settled in pre-Roman times, with camps along the higher land in the west, where flints could be quarried. A Brythonic tribe, the Iceni, inhabited the county from the 1st century BC to the end of the 1st century AD. The Iceni revolted against the Roman invasion in AD 47, and again in 60 led by Boudica. The crushing of the second rebellion opened the county to the Romans. During the Roman era roads and ports were constructed throughout the county and farming was widespread. (End of story)

Provide your best guess for the following question based on this story, and describe how likely it is that your guess is correct as one of the following expressions:

Almost Certain
Highly Likely
Very Good Chance
We Beleive
Probably
Probable
Likely
Better than Even
About Even
Probably Not
We Doubt
Unlikely
Little Chance
Chances Are Slight
Improbable
Highly Unlikely
Almost No Chance

Give ONLY the guess and your confidence, no other words or explanation. For example:

Guess: <most likely guess, as short as possible; not a complete sentence, just the guess!>
Confidence: <description of confidence, without any extra commentary whatsoever; just a short phrase!>

Here are a few examples of questions and answers:

Question: When does the habitation of Norfolk date back to?
Guess: 1st century BC
Confidence: <appropriate level of confidence in this guess>

Now answer the following question in the same format.

Question: What was mined there?

unknown