Geology 1023 Geological maps

Geological maps Draw a map based on fragmentary data Using samples and map descriptions interpret environments as they existed in the past Make a list of the events that occurred

Map

If you extend all the boundaries… You get contradictions/inconsistencies

Look for youngest contact(s) Extending this doesn’t produce inconsistencies

Then add gradually older ones Which stop at the younger contact

And the next… Which again stops at the younger contact

Pattern or colour

Pattern or colour

Pattern or colour

Pattern or colour

Add structural or bedding info.

Add structural or bedding info.

Example given here much simpler then the example in the lab

Map interpretation Look at the geological map of the Wolfville Area The rock descriptions for each unit are given (on the map) There are examples given in the lab of each unit (samples are numbered according to the unit number on the map)

Map interpretation Q2: Give the depositional environments (c.f. list in Lab. 3, e.g., beach, lagoon, etc.) Q3: Insofar as possible, indicate the likely topography and climate that operated in the area over different times Note: North Mountain Basalt, and Scots Bay Formation are Jurassic NOT Triassic Q4: Indicate the evidence present for various geological features: folding, faulting, intrusion, extrusion (mostly about the nature of the contacts)

Map interpretation Deduce a geological history. Put in numerical order starting at # 1 for the oldest

The most basic geological sequence of events must have: Deposition (put the rocks there in the first place) Uplift and erosion (so we can see them) Repeat

Adding a few wrinkles Deposition (must have) Folding/faulting Metamorphism Intrusion Uplift and erosion (must have) Repeat These can be in any order (or may be missing altogether)

The Wolfville sheet has 3 of these cycles.

Questions?