Keywords: altitudinal transect; Amazon headwaters; Branched and isoprenoid tetraether index; Branched GDGTs; Branched glycerol dialkyl glycerol tetraether, Ia, fractional abundance; Branched glycerol dialkyl glycerol tetraether, Ib, fractional abundance; Branched glycerol dialkyl glycerol tetraether, Ic, fractional abundance; Branched glycerol dialkyl glycerol tetraether, IIa, fractional abundance; Branched glycerol dialkyl glycerol tetraether, IIa', fractional abundance; Branched glycerol dialkyl glycerol tetraether, IIb, fractional abundance; Branched glycerol dialkyl glycerol tetraether, IIb', fractional abundance; Branched glycerol dialkyl glycerol tetraether, IIc, fractional abundance; Branched glycerol dialkyl glycerol tetraether, IIc', fractional abundance; Branched glycerol dialkyl glycerol tetraether, IIIa, fractional abundance; Branched glycerol dialkyl glycerol tetraether, IIIa', fractional abundance; Branched glycerol dialkyl glycerol tetraether, IIIb, fractional abundance; Branched glycerol dialkyl glycerol tetraether, IIIb', fractional abundance; Branched glycerol dialkyl glycerol tetraether, IIIc, fractional abundance; Branched glycerol dialkyl glycerol tetraether, IIIc', fractional abundance; Calculated from linear regression; Carbon, organic, total; Cyclization ratio of branched tetraethers; Degree of cyclisation; derived from pH; ELEVATION; in-situ production; Isomer ratio; LATITUDE; LONGITUDE; Madre_de_Dios_River_System; Madre de Dios River; MULT; Multiple investigations; Peru; pH, soil; Sample comment; Sample ID; soil inputs; Specific surface area; Sum branched glycerol dialkyl glycerol tetraether, per unit sediment mass; Suspended sediment concentration; Temperature, annual mean