Multivariate Analysis, Mass Balance Techniques, and Statistical Tests as Tools in Igneous Petrology: Application to the Sierra de las Cruces Volcanic Range (Mexican Volcanic Belt)

Table 1

Petrographic information of the Sierra de las Cruces volcanic rocks^a.

Sample

Locality

Lat. (N)°

Long. (W)°

Texture

Phenocrysts

Groundmass texture

Rock

Disequilibrium evidence

Ol

Opx

Cpx

Plg

Qtz

Amp

Type

Ol + Qtz

Qtz-R

Plg-N + S

E

SC03

Cantimplora

99°14′34′′

19°11′35′′

VP

94

6

M

I

SC16

Rancho Agustín

99°19′40′′

19°11′30′′

P

70

2

2

6

20

M

IDE

⨀

⨀

⨀

SC22

Volcán Negro

99°23′06′′

19°10′00′′

VT

85

15

T

I

SC46

Los Puercos

99°28′04′′

19°31′36′′

P

4

58

20

18

M

FDE

⨀

SC51

Cerro Prieto

99°16′55′′

19°18′42′′

P

3

3

59

10

25

V

FDE

⨀

⨀

SC52

S Miguel Tecpan

99°24′33′′

19°31′12′′

VP

27

41

4

28

M

FDE

⨀

⨀

⨀

SC52a

S Miguel Tecpan

99°24′33′′

19°31′12′′

VP

23

77

M

ME

SC53

Santiago

99°16′53′′

19°15′48′′

VP

69

7

24

V

FDE

⨀

⨀

SC58

Garambullos

99°15′56′′

19°15′03′′

P

3

2

58

6

31

V

FDE

⨀

⨀

SC60

Quellamecal

99°14′25′′

19°10′33′′

P

5

3

62

30

V

F

aModal data are percentages of phenocrysts + microphenocrysts calculated on a vesicle and groundmass free basis. Texture: P: porphyritic, VP: vesicular-porphyritic, and VT: vesicular trachytic. Groundmass represents 60–90% of the rocks. Groundmass texture: M: microlithic, T: trachytic, and V: vitreous. Phenocrysts: Ol: olivine, Opx: orthopyroxene, Cpx: clinopyroxene, Plg: plagioclase, Qtz: quartz, and Amp: amphibole. Rock types: I: intermediate magmas without disequilibrium evidence, F: felsic magmas without disequilibrium evidence, IDE: intermediate comingled lava, FDE: felsic comingled lava, and ME: magmatic enclave. Disequilibrium evidences: Ol + Qtz: olivine + quartz, Qtz-R: quartz with a reaction rim, Plg-N + S: plagioclases with normal and sieved texture, and E: ellipsoidal chilled andesitic enclave.