A thin, resistant limestone escarpment is present just basinward.是什么意思？

A thin, resistant limestone escarpment is present just basinward.

薄层状的坚硬的石灰岩山崖正好位于靠盆地一侧.

thin

adj. 薄的，瘦的，稀少的，细的；vt. 使瘦，使淡，使稀疏；vi. 变薄，变瘦，变淡；adv. 稀疏地，微弱地；

例句
'But where could they have gone?' he demanded. 'They can't just vanish into thin air!'...
“但是他们可能去哪里呢？”他追问道，“他们不可能就神秘消失了!”

resistant

adj. 有抵抗力的，抵抗的，顽固的；n. 抵抗者，有抵抗力的东西，防染剂，防腐剂；

例句
The majority have a built-in Luddite mentality; they are resistant to change.
大部分人天生有种反对技术进步的心理。他们抗拒变革。

limestone

n. 石灰岩，石灰石；

例句
Between the white limestone and the greyish pink limestone is a thin bed of clay.
在白色石灰石和粉灰色石灰石之间是一层薄薄的黏土。

escarpment

n. 悬崖，断崖，绝壁，陡斜坡；

例句
The truck was trundling along the escarpment of the Zambesi valley.
卡车沿着赞比西山谷的绝壁缓缓行进。

is

vt.& vi. 是（be的三单形式；n. 存在；

例句
Bollinger 'RD' is a rare, highly prized wine.
博林格RD香槟是一种名贵的备受推崇的葡萄酒。

present

adj. 现在的，目前的，出席的，[语法学]现在时的；n. 现在，礼物；

例句
This could be an advance on the present situation.
这样可能会改善当前状况。

just

adv. 刚才，仅仅，只是，正好，刚要；adj. 公正的，合理的，恰当的，合法的，正确的；

例句
It became very clear that the incident was not just an aberration, it was not just a single incident.
事实已经很清楚，这件事不是偶发的，它并不是一起孤立的事件。