Yuan, F., Koran, M. R. and Valdez, A.: Late Glacial and Holocene record of climatic change in the southern Rocky Mountains from sediments in San Luis Lake, Colorado, USA, Palaeogeography, Palaeoclimatology, Palaeoecology, 392, 146–160, doi:10.1016/j.palaeo.2013.09.016, 2013.

Late Glacial and Holocene record of climatic change in the southern Rocky Mountains from sediments in San Luis Lake, Colorado, USA

These lines of evidence strongly suggest that conditions favor- able for B. braunii growth occur during moderate-to-strong El Nin?o events and thus that C34 botryococcene ?D records the hydrologic conditions of the lake during these events. In contrast, the avail- able evidence suggests that the dinoflagellate population persists throughout the varying hydrologic conditions experienced by El Junco Lake and thus that sedimentary dinosterol ?D records the long-term (decadal-to-centennial) mean lake conditions.

AA: This record is a duplicate of LS14ZHJU (and is a shorter version of the latter record). This study's unique record is dinosterol d2H, which LS14ATJU01A.

All botryococcene dD values were highly correlated with water dD values (R2>0.99). And, Zhang and Sachs 2007, Organic Geochemistry, 38: 582-608.

changes in rainfall amount are imprinted in the isotopic composition of botryococcenes, with negative (posi- tive) ?D values co-occurring with wetter (drier) periods.

Semipreparative HPLCMS to isolate dinosterol, which was then acetylated and injected on a GC, Delta V IRMS system. From Supplemental Methods: "Hydrogen isotope measurements of dinosterol were performed on a Finnigan Delta V Plus Isotope Ratio Mass Spectrometer (IRMS) coupled to a Thermo Trace GC Ultra with a Varian VF17ms FactorFour capillary column (60 m x 0.32 mm x 0.25 ?m) and a pyrolysis reactor according to the methods described in Atwood and Sachs (2012). Samples were injected into a split/splitless inlet in splitless mode at 310 �C. The oven temperature was ramped from 100 �C to 220 �C at a rate of 20 �C/min, then at 2 �C /min up to 325 �C where it was held for 17 min. The carrier gas, He, was held constant at 2.6 mL/min. The pyroloysis reactor was maintained at 1400 �C. Isotope values, expressed as ?D values, were calculated in Isodat software relative to VSMOW using a coinjection standard containing nC32, nC40, and nC44 of known ?D values (obtained from A. Schimmelmann, Indiana University, Bloomington, IN, USA). The measured isotope values of dinosterol were corrected for the addition of hydrogen atoms (of known ?D value) that occurred during acetylation. Triplicate analyses were typically performed on each sample and mean values and standard deviations reported. Instrument performance was evaluated using H2 reference gas and a prepared standard of nalkanes of known ?D values."