GRB PG9603-0297

1

1

2

7

7

8

19

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27

31

35

I

II

2-1 15

III

IV

1-1 2

2-1 8

2-2 9

2-3

12

2-4 12

2-5 X 13

2-6 X 13

2-7 (A)

(B)

14

2-8 16

2-9

18

V

VI

X XRF

( )

plinthite 1

petroplinthite

( )

( )

( )

1 pl in th i t e

pe t ro-p l in th i t e

VII

VIII

IX

ABSTRACT

Keywords: coastal landform, petroplinthite, Lieyu, Kinmen

1. Purpose

The Lieyu, Kinmen has very diverse coastal landforms and

landscape. This project studied the coastal landscape and coastal geology

of Lieyu and their origin and geohistory to make available resources of

public education for tourism. The project also investigate potential

problem in coastal protection in order to provide the Kinmen National

Park a reference in landscape conservation and coast protection.

2. Methods

This project performed field investigation and sampling,

petrographical study, XRD mineralogy study and XRF elemental analysis

to document the coastal landform, coastal geology with a focus on the

famous Mau-gong-shi (petroplinthite) and discuss their origins.

3. Important results

(1) The origin of Mau-gong-shi at Huangcuo and Putou of Lieyu

is similar to that of Guningtou. Both were formed by iron

leached from the overlying red soil and re-precipitated in the

kaolinitic bed below the red soil, then developed into plinthite.

The kaolinitic bed resulted from weathering of granitic rocks or

arkosic sandstones derived from granitic rocks. Kaolinite in

plinthite may further be washed away by waves and evolved into

petroplinthite.

(2) The Mau-gong-shi of Lieyu differs from that of Guningtou in

geohistory of the host rock. At Guningtou, the kaolinitic bed

resulted from weathering of arkosic sandstones that were

derived from grduitic rocks, while at Huangcuo and Putou, the

kaolinitic bed resulted from weathering of granitic rocks.

(3) The main control of coastal development of Lieyu is lithology.

Hard igneous or metamorphic rocks developed into headlands

X

while sedimentary or weathered igneous rocks developed into

bays. The wave influence is not significant.

(4) The Kinmen Formation outcrops along coast near Dong-gang

reveals well developed sedimentary structures of storm

deposition. This has not been reported before. The sedimentary

characteristics of Kinmen Formation at this site are different

significantly from other outcrops.

4. Suggested strategies

This project comes to the immediate and long-term strategies.

For immediate strategies:

(1) Build a walking trail along the coast from the entrance to

Mau-gong-shi at the bicycle trail near Putou to a sight-seeing

platform is located at the bicycle trail about halfway toward

Huangcuo. This walking trail will allow visitors to walk along

the best part of the Mau-gong-shi coast, yet confine them stay

in the trail and not to damage the landscape. Panels should be

installed next to the trail to explain the origin of

Mau-gong-shi.

(2) Put a sign at a pavilion along the bicycle trail near Dong-gang to

guide the visitors to see the beautiful outcrops of storm beds in

the Kinmen Formation. Panels should be installed at to the site

to explain the origin of the sedimentary structures.

For long-term strategies:

Preserve the Mau-gong-shi (plinthite and petroplinthite) along the

coast from Putou to Huangcuo. Those iron-cemented formation serve as

natural wave-breaker and has successfully protected the northeast coast

of Lieyu for thousands years. Artificial levee or wave breaker is not

necessary in this area as far as coast protection is concerned, and will

only destroy the beautiful landscape at the site.

XI

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1

242428N1181216E 14.85

2 7 1-1

1-1 1965

19541995

2

22.8

1050 1680

2 3 4

20012005

5

19651970

1996

1965

1965

20042004

2

3

4

5

3

2004

2004

2006

plinthite

1965

2006

4

19901994

19972001

2003

5

6

X

X

7

96 5 96 9 23

23 2-1

2-1

1

8

2-2

2-2

2-2

9

2006

2.6

700 5% 35%

2006

2

X

2-3 2-5

10

2-4 2-6

3

2004

45

2-7

2-7 6

6

6 1

11

2-3

2-4

12

2-5 X

2-6 X

13

(A)

(B)

2-7(A)(B)

14

1.

7

2-1

2-8

0.25mm 1mm 2mm

2-8

16

2.

2-4

3. X

X 2-5

2-5

X X

amorphous

iron oxide

2-6

4. X

1

6

NIEA S322.60C 2-9

17

2006

2-9

18

19

20

(plinthite)

(petroplinthite)

21

22

(mg/kg)

0511-01 E1181345.5N242435.7 Quartz

Kaolinite

0511-02 E1181348.4N242439.3 Halloysite Beidellite

0511-03 E1181348.9N242439.9 Halloysite Montmorill

Sudoite

0507-01 E1181345.5N242435.7 Halloysite Hematite

0507-02 E1181342.9N242433.3

0507-03 E1181342.8N242432.3

0712-01 E1181440.0N242656.9 Quartz

Kaolinite Hematite

0712-02 E1181440.7N242658.6 Quartz

Kaolinite

0712-03 E1181443.6N242705.7 Quartz

Hematite

0508-03 E1181444.1N242706.3

PH-01 E1181444.9N242707.0 Quartz

Kaolinite 24750

PH-02 E1181444.9N242707.0 Quartz

Kaolinite Hematite

60300

PH-03 E1181444.9N242707.0 Quartz

Kaolinite Hematite

97030

PH-04 E1181444.9N242707.0 Quartz

Kaolinite Hematite

130410

PH-05 E1181444.9N242707.0 Quartz

Kaolinite

19650 94300 7600

23

PH-06 E1181444.9N242707.0

Quartz Kaolinite

18230 80900 7230

0621-1 E1181314.9N242551.7

0621-2 E1181316.4N242550.9

0621-3 E1181314.9N242549.8

0621-4 E1181320.6N242547.9

0621-5 E1181323.9N242546.6

0621-6 E1181325.7N242543.4

0621-7 E1181331.6N242544.0

24

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3 4

5 6

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96 7 18

27

10 10

28

5

1954-1995 1047mm

1684mm

29

30

96 11 27 14

1

31

2

3

1

2

3

4

1

2

3

15 10

32

petroplinthite

33

34

1996

2004 164~189

1997

2004

2001

2005 219

1998

1990

1994

2006 ( )52

196517 66-92

1970

1997

2001

2003

35

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