A log with distinct tree rings is found buried in a sequence of Ice Age varves. What would you learn about the log by counting the tree rings? What would you learn about the log by counting the varves? What assumption is made when either method is used to determine absolute time?
2007-02-09 05:23:20 · 2 answers · asked by cassandra 1 in Science & Mathematics ➔ Earth Sciences & Geology
tree rings tell age of tree. ring thickness tells growth rate. climate can be interferred by ring thickness: narrow slow growth = colder climate/stress, thick fast growth = warmer climate/better growing conditions. counting varves shows time as varves are deposited cyclically. compare varve thickness to ring thickness for climate and # tree rings in a varve cycle to interpret time scale of varve deposition. of course this only applies to varves deposited before the tree died. also, the number of varves deposited around and over the log will show rate of deposition of varves. this analyses requires assumption and application of principals of superposition. another factor is if the tree died in-situ or was transported to it present location. interesting project!
2007-02-09 07:37:01 · answer #1 · answered by TheRockLady 4 · 0⤊ 0⤋
that the reings and varves are based upon a calendar year
2007-02-09 13:37:58 · answer #2 · answered by Jason C 2 · 0⤊ 0⤋