Table T2. Regression equations for carbonate content estimation, Leg 172.
 
Site Unit/Subunit N Adjusted
r2
RMSE (%) Prediction equation - CaCO3
(wt%)*

1054

I

63

0.994

4.99

= 380.59D465 - 9488.62(D455)2 + 494.79D435 + 844.46D655 + 18760.06(D695)2 + 940.74D455

1055

I

91

0.990

4.02

= 1.204R490 + 384.973D445

1056

I

594

0.983

5.32

= 1.104R580 + 418.649D445 + 3733.452(D675)2

1057

I

127

0.977

4.74

= 0.062(R610)2 - 10.930R400 + 9.994R470

1058

I

434

0.949

6.10

= 347.94D465 + 5681.51(D465)2 + 0.03(R630)2 + 304.52D575 + 15680.56(D675)2 - 22767.19(D575)2

1059

I

518

0.932

6.17

= 42.745D465 + 0.058(R550)2 + 7417.036(D455)2

1060

I

618

0.941

4.27

= -0.043(R550)2 + 9367.365(D435)2 + 0.093(R500)2

1061

I

421

0.950

4.32

= 0.042(R530)2 + 13009.538(D435)2 -11604.8(D485)2 + 199.2D405

1062

I

353

0.933

6.30

= 5965.94(D485)2 + 0.032(R640)2 - 15748.5(D605)2 + 7737.974(D415)2 + 192.354D405

1063

IA

629

0.944

5.27

= 5517.618(D455)2 + 679.051D405 + 311.074D595 + 0.087(R530)2 -1.504R400 -7836.977(D405)2

All

I

3862

0.934

7.09

= 603.751D465 + 0.056(R540)2 -0.873R420

All

II

165

0.949

6.70

= 343.692D465 + 8676.303(D415)2 +766.342D515 - 6092.993(D485)2 - 2296.044(D565)2

All

III

103

0.940

6.31

= 809.884D465 - 26491.2(D585)2 + 10140.34D655

All

All

4141

0.935

7.07

= 620.267D465 + 0.0536(R540)2- - 0.855R420

Notes: N = number of samples. Adjusted r2 = adjusted correlation coefficient. RMSE = root-mean-square error. * = the following abbreviations are used for the regression terms: Rxxx = percent reflectance at xxx nm wavelength; Dyyy = the first derivative of the reflectance at yyy nm wavelength (i.e., calculated as a first difference between reflectance at [yyy + 5] nm and reflectance at [yyy - 5] nm).