strattotimepointcont {DAIME} | R Documentation |
This function takes a continuous deposition rate and reconstructs at what time a given stratigraphic height was deposited.
This can be used to create age models, determine the time of deposition of single samples in the outcrop, and transform isotope ratios from stratigraphic height into time (see examples).
strattotimepointcont(x, xdep, ydep, hiatuslist = list(), unit = "sediment per time")
x |
Vector containing the stratigraphic heights whose time of deposition are to be determined |
xdep |
Vector of strictly increasing real numbers |
ydep |
Vector of the same length of |
hiatuslist |
OPTIONAL, default is an empty list. A list of hiatuses to insert. Every entry in the list corresponds to a hiatus, which is given as a vector of length two. The first entry of the vector is the stratigraphic height of the hiatus, the second entry is the duration of the hiatus. |
unit |
OPTIONAL, default is "sediment per time". Either "sediment per time" or "time per sediment". Determines the unit that is assumed for the deposition rate. |
Returns a list containing
time |
vector containing times of deposition of the stratigraphic heights given by the input |
height |
vector containing the heights that were deposited at the times given by |
Output of NA
in time
indicates that some values coincide with a hiatus or are located at places where the deposition rate is undefined.
Niklas Hohmann
Hohmann, Niklas. 2018. Quantifying the Effects of Changing Deposition Rates and Hiatii on the Stratigraphic Distribution of Fossils. <doi:10.13140/RG.2.2.23372.51841>
strattotimeratecont
for the transformation of rates from stratigraphic height into time,
timetostratpointcont
for the transformation of single samples or isotope ratios from time into stratigraphic height.
For an overview of the functions in the DAIME package, see its vignette (available via vignette("DAIME")
)
##define deposition rate xdep=seq(0,12,length.out=100) ydep=splinefunH(x=c(0,2,4,6,8,10,12),y=c(1,5,6,1,0.5,1,6),m=c(0,1.5,-0.5,-0.5,0,0.5,0))(xdep) #unit of deposition rate is sediment per time unit (default setting) usedunit="sediment per time" #unit of deposition rate is sediment per time unit (default setting) #Plot deposition rate plot(xdep,ydep,type='l',main='Deposition Rate',xlab='Stratigraphic Height',ylab=usedunit) ##at what time was the point with tratigraphic height 9 deposited? strattotimepointcont(9,xdep,ydep) ##create an age model stratheight=seq(min(xdep),max(xdep),length.out=100) usedunit="sediment per time" reslist=strattotimepointcont(stratheight,xdep,ydep,unit=usedunit) #plot age model plot(reslist$time,reslist$height,xlab='Time',ylab='Stratigraphic Height', main=paste('Age model with unit',usedunit)) #create age model but with other units for sedimentn input usedunit='time per sediment' reslist=strattotimepointcont(stratheight,xdep,ydep,unit=usedunit) #plot age model (note the difference this setting makes) plot(reslist$time,reslist$height,xlab='Time',ylab='Stratigraphic Height', main=paste('Age model with unit',usedunit)) ##create age model with a hiatus stratigraphicheight=5 #strat. height of the hiatus duration=2 #duration of the hiatus hiatuslist=list(c(stratigraphicheight,duration)) #required input format for hiatuses reslist=strattotimepointcont(stratheight,xdep,ydep,hiatuslist=hiatuslist) #!using default setting for units again! plot(reslist$time,reslist$height,xlab='Time',ylab='stratigraphic height') ##Transform isotope ratios #create fake oxygen isotope curves samplelocation=sort(runif(20,min=min(xdep),max=max(xdep))) #where the samples are taken isotoperatio=sin(samplelocation)*rnorm(length(samplelocation)) #isotope ratios of the samples plot(samplelocation,isotoperatio,type='l',xlab='Stratigraphic Height',ylab='Isotope Ratio') #transform only (!) sample locations, NOT values reslist=strattotimepointcont(samplelocation,xdep,ydep) #Isotope ratios in time plot(reslist$time,isotoperatio,type='l',xlab='Time',ylab='Isotope Ratio')