人类学学报 ›› 1985, Vol. 4 ›› Issue (01): 55-69.

• 人类学学报 • 上一篇    下一篇

禄丰古猿化石地点地层概述

祁国琴   

  • 出版日期:1985-03-15 发布日期:1985-03-15

Stratigraphic summarization of Ramapithecus fossil locality, Lufeng,Yunnan

Qi Guoqin   

  • Online:1985-03-15 Published:1985-03-15

摘要: 本文较详尽地记述了云南禄丰古猿化石地点附近的地质、地貌、地层情况以及产出古猿及大量脊椎动物化石的剖面。

关键词: 禄丰古猿化石地点;晚中新世褐煤沉积;石灰坝

Abstract: Lufeng is a county of Yunnan Province, about 60 km. to the west of Kunming city (Fig. 1) . Shihuiba locality (No. 75033 IVPP) (102°4' E, 25°1'N) is situated on the southern slope of Miaoshanpo Hill, about 9 km. north of Lufeng county.
Geomorphologically, Lufeng area is a small block basin, located in the east of the middle Plateau of Yunnan. Average height of it is about 1560 m. above sea level. The basin extends about 12 km. from south to north and about 2-3 km. from east to west. In its northern end, the most narrow part is only 0. 3-0. 5 km.
There are three rivers (the West River, the East River and the South River) in the basin. They join near Lufeng county and then is called Xingsu River (Fig. 2) .
The form and development of Lufeng basin were controled by a series of faults of south-north direction. The base and margin of the basin consist of strata of Presinian period mainly, in addition, Jurassic and Cretacious periods. The distribution of Cenozoic beds is only restricted to the piedmont or the center of the basin.
The strata of Presinian period called Kunyang Group, is a suite of thick metamorphic limestone and mudstone, topographically expressed as well-round, lowlying mountains and hills. The Mesozoic deposits are so called"Red Beds". They are identified as Fengjiahe (Early Jurassic) , Zhanghe (Middle Jurassic) and Jiongdihe (Late Cretacious) , Matoushan (Early Cretacious) formations respectively. In the Cenozoic strata, the Neogene beds are fluvial-laeustrine swamp deposits, consisting of sand, gravel, sandy clay, clay and lignite, about 30 m. or more in thickness, and exposed in Shihuiba, Tuguaneun, Taizicun, Lufeng and Xiabanqiao-Yangjiahuayuan. The Quarternary beds are fluvial gravels and terrace deposits, directly overlying on the old bedrock and the terraces of several rivers.
Miaoshanpo Hill on which Ramapithecus fossil locality lies consists of Kunyang Group, greyish white, greyish blue and in part pink microlitic dolomitic limestone and purplislh grey sericite slate intercalated with secondary belts of quartz. The Section A, B and C were exposed at different locations of a artificial road trough going to the back of the Miaoshanpo Hill for excavating limestone. In addition, the lignite deposits of lacustrine swamp face surrounding the Section D were exposed when Chengkun RaiIroad was built, the earthy crust of Miaoshanpo Hill was eradicated and pushed to the roadbed of the Railroad. The deposits have been excavated for 9 times since 1975 andthe location of the excavated section has been moved much westward.
The sequences of the Sections A and D are summarized from top to bottom in turn as following, mainly according to the observations of 1983, also refering to the sections over the years (Fig. 4 and 5) .
Section A:
1. Dark purple, purple, orange red weathering crust. Earthy deposits with porousities and plant roots. There are sands and gravels in the bottom. Average diameter of the gravels is 1-2 cm. The layer is 1. 5-3. 5 m. in thickness.
2. Yellow, yellowish drab calcareous clay and sandy clay with clear horizontal bedding. Deposits coarsen gradually from lower to upper. The clay is pure and hard, nearly without root casts and holes. It is demareated from the lower layer by a eleor erosin surface. The space occupied by the layer shows initial landform. Thickness is 2-6 m.
3. Grey, greyish yellow, greyish brown clay with intercalations of sand and gravel. Deposits coarsen gradually from upper to lower. There are 2-3 belts of blackish brown carbonaceous clay. The thickness of each belt is 15-20 cm. About 1. 5-3m. in thickness.
4. Purple sandy clay with sands and gravels and clear bedding. Deposits coarsen downward. The diamater of gravels is 5-25 cm. The elements of them are quartz, sandstone, slate and limestone and so on. There are usually pollution motley and casts of root in the layer. The surface of the deposit was washed and wearthered, it looks like columnar. Exposed thickness is 5 m.
The sequences of the Sections B. and C are similar to that of the Section A. Any fossil of vertebrate has not been found from sections mentioned above yet.
Section D:
1. Yellow sandy clay with sand and gravel lenses. The color of the clay is brown contaminated by ferro-magnesium. The element of the gravel is mainly quartz with mediate roundness and diameter 1-—2 cm. The layer is demarcated by a clear erosin surface from the lower layer and lost at the northeast of the Section. About 0. 5-2m. in thickness. Dip SW 210°-220°, dip angle 5°.
2. Interbedding of blackish brown carbonaceous clay and greyish white fine sand. In general, there are four continued belts of carbonaceous clay and five small sand layers. Each elay belt and small sand layer is about 10-15 cm. in thickness. Their thickness and continued degree are various with the difference of section position. The sand contains abundant shell fragments of mullosc. Dip SW 210°, dip angle 5°-10°. Thickness 0. 7-3 m.
3. Blackish brown massive lignite with compact and solid texture. Partialy intercalating with blackish grey laminated sand and sandy clay. There are some burrows in the lignite occasinally. White spots and greyish green epiphytes are common in the bed. Dip Sw 210°-220°, dip angle 5°—12°. Thickness 0. 3-1. 4 m.
4. Interbedding of black carbonaceous clay and grey fine sand with clear texture of microstratifications. There are small and irregular lenses of lignite. About 0. 21. 8 m. in thickness. Dip SW 210°, dip angle 5°—10°.
5. Grey, uniform and pure fine sand with intercalations or lenses. of black carbonaceous clay and lignite. The color of the sand is more and more dark from upper tolower. There are a lot of shell fragments of molluse and quartz pebbles of diamater about 1-2 cm. Dip SW 210°, dip angle 5°-10°. Thickness 1. 5-2. 5 m.
6. Lignite consisting of two or three laminated layers. There are grey fine sand and blackish grey carbonaceous clay between the lignites. Containing plant fossil and woody fragments in the lignite. White and greyish blue epiphytes are common. Dip SW 210°—220°, dip angle 10°. Thickness 0. 5 m.
7. Greyish white, blackish grey clay with white small pebbles of quartz and nodules of pyrite. Exposed thickness in test pit of 1981 is 1. 6 m. No any vertebrate fossil has been found from the layer.
8. Purplish red, orange red, yellowish brown sandy elay. The layer has not been excavated during the excavations over the years. The thickness exposed in test pit of 1981 is 0. 8 m. Any vertebrate fossil has not been found from the layer.
These sections and their correlativities are shown in Fig. 4. Approximate 110 forms of vertebrate fossil have been found from the layers 1-6 of the Section D. The list of the fauna is shown in the chinese text.
Except Shihuiba, the Neogene strata have been also found in many places of the basin such as: Lufeng, Tuguancun, Taizicun and Xiabanqiao-Yangjiahuayuan and so on. The deposits can be divided into main two parts: the upper sand with gravel lenses and lower sandy clay with carbonaceous clay or lignite It is considered that the upper sand layer can correspond to the layer 1 of the Section D and the lower sandy clay layer can correspond to the layers 2-7 of the Section D.

Key words: Ramapithecus fossil locality of Lufeng; Late Miocene lignite deposits; Shihuiba