觀音山(Kuan-yin Mountain),舊稱新(xin)宜山,別名八(ba)(ba)里坌(ben)山(淡水廳(ting)志載)。位于臺灣省(sheng)新(xin)北市(shi)五(wu)股區(qu)、八(ba)(ba)里區(qu)交界,海拔標高(gao)616米,由淡水河北岸(an)向南遙(yao)望(wang),全(quan)區(qu)有十八(ba)(ba)連峰,區(qu)內有多座古剎,更增添觀音山的靈性(xing),其(qi)中有數間供奉(feng)觀世音菩薩的觀音寺。
觀(guan)音(yin)山(shan)(shan),亦有不少納骨塔及墓園(yuan)錯落其(qi)間,該山(shan)(shan)西臨臺(tai)灣(wan)海峽,東(dong)北隔(ge)淡(dan)(dan)水河遠望關(guan)渡(du),昔(xi)日(ri)的“坌嶺吐(tu)霧”為淡(dan)(dan)水八大景之一,山(shan)(shan)頂(ding)又稱“硬漢嶺”,全(quan)山(shan)(shan)屬北海岸及觀(guan)音(yin)山(shan)(shan)風景區。
觀(guan)音(yin)山自古便(bian)有登(deng)(deng)山活動,目前八里登(deng)(deng)觀(guan)音(yin)山的路(lu)線(xian)共(gong)有四條主(zhu)要路(lu)線(xian),其(qi)中以乘車至觀(guan)音(yin)山風景區管(guan)理處,由凌云禪(chan)寺旁鐵(tie)漢(han)(han)步(bu)道經(jing)硬漢(han)(han)嶺(ling)拾階(jie)而(er)上登(deng)(deng)頂(ding)為(wei)最熱門路(lu)線(xian)。硬漢(han)(han)嶺(ling)為(wei)1961年(nian)憲兵學(xue)校(xiao)300名學(xue)員開辟了(le)一條直達山頂(ding)的登(deng)(deng)山步(bu)道,為(wei)鼓勵學(xue)員學(xue)硬漢(han)(han)而(er)來(lai)作硬漢(han)(han)而(er)去,而(er)名硬漢(han)(han)嶺(ling)。
硬漢嶺為火(huo)山(shan)碎屑巖與凝灰角礫(li)巖所構成,1992,1993年來(lai)時(shi)有豪雨山(shan)崩(beng)土(tu)石滑動,步道毀壞(huai)并危及凌云禪寺(si)安(an)全。寄望能有效妥(tuo)當的維護整修以(yi)保持靈(ling)山(shan)古剎(cha)之原有古樸韻味。
由于季(ji)風吹來(lai)臺灣海峽的水汽(qi),遇到觀音山嶺的阻擋(dang),便降下化為(wei)云霧(wu)(wu),有(you)如飄綿滾絮、變幻無常,蔚為(wei)奇觀.被文人雅士命名為(wei)“坌嶺吐霧(wu)(wu)”,名列清代淡北八景(jing)之一(yi)。同治年間(jian)(jian)大龍峒舉人陳維英(ying)曾題(ti)詩贊曰(yue):“坌嶺微茫八里間(jian)(jian),連朝(chao)吐霧(wu)(wu)罩鴉鬟,此中定有(you)深藏(zang)貌(mao),未(wei)許分明見一(yi)斑”。
觀(guan)音山(shan)(shan)在淡水河(he)(he)河(he)(he)口南(nan)畔(pan),東與大(da)屯山(shan)(shan)群峰隔河(he)(he)相峙,西南(nan)毗(pi)接林(lin)口臺地。形似仰臥之觀(guan)音,山(shan)(shan)頂(ding)空曠怡人,立足其上可(ke)俯(fu)瞰河(he)(he)口及(ji)淡水鎮、臺北(bei)市(shi)郊景(jing)色,為(wei)淡水八(ba)景(jing)之一(yi)。凌云古剎坐落(luo)山(shan)(shan)腰(yao),后另(ling)建新(xin)廟于古剎后方約數(shu)百公尺處(chu)(即觀(guan)音山(shan)(shan)腹),名曰凌云禪寺,是游(you)人休憩處(chu)。
觀音山(shan)(shan)(shan)(shan)為一錐狀火(huo)(huo)山(shan)(shan)(shan)(shan),是大(da)屯火(huo)(huo)山(shan)(shan)(shan)(shan)匯最西的(de)一部分(fen),其(qi)北側以火(huo)(huo)山(shan)(shan)(shan)(shan)熔(rong)(rong)巖(yan)為主(zhu),南側以火(huo)(huo)山(shan)(shan)(shan)(shan)碎屑流(liu)為主(zhu),火(huo)(huo)成巖(yan)以安山(shan)(shan)(shan)(shan)巖(yan)為主(zhu),另外(wai)含有一些早期噴(pen)發(fa)的(de)玄武巖(yan),越晚期的(de)噴(pen)發(fa)則形成含角閃(shan)石的(de)安山(shan)(shan)(shan)(shan)巖(yan)。淡水河沿著觀音山(shan)(shan)(shan)(shan)麓流(liu)入(ru)臺灣海(hai)峽,因兩側的(de)火(huo)(huo)山(shan)(shan)(shan)(shan)熔(rong)(rong)巖(yan)與碎屑物漫流(liu)入(ru)海(hai),而形成火(huo)(huo)山(shan)(shan)(shan)(shan)海(hai)岸。
山(shan)(shan)上(shang)坐落著不少(shao)名(ming)剎古寺,并可溯溪觀(guan)瀑、觀(guan)鷹賞鳥(niao)、眺望(wang)半個臺北(bei)和壯麗的(de)大屯(tun)山(shan)(shan)列(lie),是(shi)一處(chu)豐富的(de)自(zi)然(ran)觀(guan)賞去(qu)處(chu)。觀(guan)音山(shan)(shan)上(shang)的(de)山(shan)(shan)徑(jing)溪谷四通八達(da),登(deng)山(shan)(shan)路(lu)線(xian)林(lin)林(lin)總總、難易不同(tong),登(deng)山(shan)(shan)客可以(yi)(yi)揀挑適合(he)自(zi)己體力(li)的(de)山(shan)(shan)徑(jing)上(shang)山(shan)(shan)。其(qi)中(zhong)最大眾化的(de)路(lu)線(xian)是(shi)從五股的(de)觀(guan)音山(shan)(shan)站(zhan)牌出發,沿山(shan)(shan)階上(shang)登(deng)凌(ling)云禪寺,再由寺后的(de)牌樓往上(shang)走,約1小(xiao)時可抵硬漢(han)嶺。在此登(deng)高(gao)眺覽,視野遼闊(kuo),整個臺北(bei)市(shi)自(zi)新光大樓以(yi)(yi)北(bei)的(de)市(shi)景都在眼下,而對面的(de)大屯(tun)山(shan)(shan)列(lie)及淡水河口山(shan)(shan)海相映的(de)景象更是(shi)壯觀(guan)。
白天上觀音山,可(ke)隔著門(men)墻老樹感受(shou)楞嚴(yan)閣(ge)、開山院(yuan)的古樸(pu)莊嚴(yan),遠(yuan)眺淡水(shui)八景之一的“坌領吐霧”;傍晚時分(fen)坐(zuo)觀落日晚霞,淡水(shui)暮色最令人心動;或于夜(ye)幕低垂(chui)時看(kan)淡水(shui)河(he)畔夜(ye)景,萬家燈(deng)火閃爍明滅,另有一番擾攘人間之美。
在荷(he)蘭人(ren)統(tong)治(zhi)時代(dai),觀音山(shan)叫淡(dan)水山(shan)(出現在1654年荷(he)蘭人(ren)‘淡(dan)水與其附(fu)近村(cun)社(she)暨雞籠島略(lve)圖’中編號37的Tamswijse berch),但漢人(ren)習稱八(ba)(ba)里分(坌(ben))山(shan),系因山(shan)邊的原住(zhu)民部落八(ba)(ba)里坌(ben)社(she)而得名。
康熙年(nian)間,乃延(yan)用八里(li)坌(ben)山的(de)地(di)名(康熙二(er)十(shi)四年(nian)蔣毓(yu)英“臺灣府志”)。清朝雍正年(nian)間(西(xi)(xi)元1710年(nian)代)也曾改為“興直山”,但在(zai)各地(di)方史籍中仍以(yi)“八里(li)坌(ben)山”稱之。后來改為觀音山的(de)說法有二(er):一說是乾隆17年(nian)(西(xi)(xi)元1752年(nian))客(ke)家籍貢生胡焯猷(福建汀州永定(ding)人)在(zai)山路西(xi)(xi)云巖(yan)籌建大(da)士(shi)觀(今五股區西(xi)(xi)云巖(yan)寺(si))而(er)得名,一說是由于山棱起(qi)伏變化(hua),從關渡一帶眺望(wang)時,山型起(qi)伏貌似(si)觀音菩薩的(de)面容仰天的(de)側(ce)面而(er)得名。
據(ju)臺灣著名(ming)的地名(ming)學(xue)者-陳國章(zhang)教授(shou)所著的臺灣地名(ming)詞典,認為該地的地名(ming)是因“形(xing)似觀(guan)音菩(pu)薩的山(shan)”而得名(ming)。
1937年12月27日,日本殖民當(dang)局以臺灣寶(bao)島山水風(feng)光秀麗籌劃成(cheng)立(li)大屯觀音山、次高山太(tai)魯閣和新高阿里(li)山三座公園,并于(yu)1941年3月10日發行紀念(nian)郵票(piao)、小全張及臺灣公園寫真集,可(ke)惜因戰爭而延宕。
二次世界大戰結束后,臺灣回(hui)歸中國,觀音山(shan)優良的(de)屏障、視野的(de)寬闊好山(shan)好水(shui),為國人(ren)所(suo)認為風水(shui)寶地(di),濫(lan)挖濫(lan)葬,一片零(ling)亂有礙視野觀瞻。相較(jiao)之(zhi)下,景觀資(zi)源大不(bu)如(ru)往昔,已失去(qu)了成為公園之(zhi)基(ji)本要件,十分可(ke)惜。
觀音(yin)山是臺灣北(bei)部火(huo)(huo)成巖(yan)(yan)區中最西北(bei)側(ce)之(zhi)火(huo)(huo)山單(dan)元,以淡水河與大屯火(huo)(huo)山群(qun)遙遙相望,基本上為(wei)單(dan)一中心(xin)噴發(fa)(fa)的火(huo)(huo)山碎屑、凝(ning)灰巖(yan)(yan)與熔巖(yan)(yan)交替(ti)組成之(zhi)復(fu)式火(huo)(huo)山。觀音(yin)山火(huo)(huo)山之(zhi)主體可能是一中央(yang)噴發(fa)(fa)之(zhi)錐(zhui)狀(zhuang)火(huo)(huo)山,錐(zhui)體半徑約(yue)1~2公里,噴發(fa)(fa)中心(xin)在觀音(yin)山主峰(feng)之(zhi)東南方。在凌(ling)云山一帶之(zhi)半環(huan)形之(zhi)連(lian)峰(feng)可能是火(huo)(huo)山口(kou)壁(bi)之(zhi)西側(ce)。
在此(ci)以(yi)(yi)東,于(yu)石(shi)(shi)壁坑附近之(zhi)(zhi)地(di)形,呈(cheng)馬蹄狀之(zhi)(zhi)半圓(yuan)形凹陷可能(neng)是火(huo)(huo)(huo)山(shan)(shan)口(kou)所在,但火(huo)(huo)(huo)山(shan)(shan)口(kou)之(zhi)(zhi)東壁已經爆(bao)破或(huo)熔巖溢(yi)流(liu)(liu)巖漿(jiang)庫(ku)匱空塌(ta)陷而(er)(er)崩塌(ta),其部(bu)分碎(sui)(sui)屑(xie)(xie)構(gou)成(cheng)分布(bu)于(yu)凌云山(shan)(shan)以(yi)(yi)東地(di)區之(zhi)(zhi)集塊巖或(huo)原先之(zhi)(zhi)火(huo)(huo)(huo)山(shan)(shan)碎(sui)(sui)屑(xie)(xie)流(liu)(liu)與火(huo)(huo)(huo)山(shan)(shan)礫(li)巖。觀音山(shan)(shan)火(huo)(huo)(huo)山(shan)(shan)活動時(shi)可能(neng)不猛烈,因而(er)(er)出露之(zhi)(zhi)主(zhu)(zhu)體(ti)并未含有可觀的(de)火(huo)(huo)(huo)山(shan)(shan)碎(sui)(sui)屑(xie)(xie)巖,仍(reng)以(yi)(yi)厚層(ceng)的(de)巖流(liu)(liu)為(wei)主(zhu)(zhu)。觀音山(shan)(shan)噴出熔巖流(liu)(liu)也(ye)和大屯(tun)火(huo)(huo)(huo)山(shan)(shan)群相(xiang)似,均以(yi)(yi)安山(shan)(shan)巖為(wei)主(zhu)(zhu)。一(yi)般安山(shan)(shan)巖常呈(cheng)灰或(huo)灰黑色,且多呈(cheng)斑(ban)狀結(jie)構(gou),由結(jie)晶(jing)較(jiao)粗大之(zhi)(zhi)斑(ban)晶(jing)散布(bu)在石(shi)(shi)質細(xi)密(mi)之(zhi)(zhi)石(shi)(shi)基(ji)中(zhong)。斑(ban)晶(jing)礦(kuang)物(wu)(wu)以(yi)(yi)鎂鐵礦(kuang)物(wu)(wu)為(wei)多,包括橄欖石(shi)(shi)、輝石(shi)(shi)、紫蘇輝石(shi)(shi)、角閃石(shi)(shi)、黑云母等礦(kuang)物(wu)(wu),此(ci)外(wai)還有灰白(bai)色的(de)斜(xie)長石(shi)(shi)。石(shi)(shi)基(ji)以(yi)(yi)斜(xie)長石(shi)(shi)和一(yi)些鎂鐵礦(kuang)物(wu)(wu)的(de)微晶(jing)(肉眼不能(neng)分辨的(de))和無(wu)結(jie)晶(jing)的(de)火(huo)(huo)(huo)山(shan)(shan)玻璃(li)所組成(cheng)。
本區安山巖熔巖依噴發(fa)之先后,由下而上可分別為三層,各(ge)層巖石在組(zu)織上和(he)成分上都有(you)多(duo)少不同。
底層(或第一層)是(shi)(shi)粗(cu)粒普(pu)通輝(hui)(hui)石(shi)(shi)(shi)(shi)(shi)玄(xuan)武(wu)巖(yan)(yan)或玄(xuan)武(wu)巖(yan)(yan)質安(an)(an)山(shan)(shan)巖(yan)(yan)熔巖(yan)(yan)。主(zhu)要露出于火山(shan)(shan)錐(zhui)體(ti)之(zhi)(zhi)(zhi)中(zhong)心地帶,包括石(shi)(shi)(shi)(shi)(shi)壁坑(keng)及(ji)其東側(ce)之(zhi)(zhi)(zhi)米倉村、烏山(shan)(shan)頭,至福隆山(shan)(shan)等地。安(an)(an)山(shan)(shan)巖(yan)(yan)顏(yan)色深灰,呈(cheng)斑(ban)(ban)狀(zhuang)結構有許(xu)多(duo)黑(hei)綠色之(zhi)(zhi)(zhi)普(pu)通輝(hui)(hui)石(shi)(shi)(shi)(shi)(shi)斑(ban)(ban)晶(jing)(jing)(jing)(jing)(jing)(jing),散布(bu)在灰色細晶(jing)(jing)(jing)(jing)(jing)(jing)之(zhi)(zhi)(zhi)石(shi)(shi)(shi)(shi)(shi)基(ji)中(zhong),斑(ban)(ban)晶(jing)(jing)(jing)(jing)(jing)(jing)大者可達(da)5公里左右。在顯(xian)微鏡下觀(guan)察巖(yan)(yan)石(shi)(shi)(shi)(shi)(shi)薄(bo)片,這些(xie)斑(ban)(ban)晶(jing)(jing)(jing)(jing)(jing)(jing)多(duo)成(cheng)雙晶(jing)(jing)(jing)(jing)(jing)(jing)或叢晶(jing)(jing)(jing)(jing)(jing)(jing)(由(you)數個晶(jing)(jing)(jing)(jing)(jing)(jing)體(ti)結集而(er)成(cheng)),輝(hui)(hui)石(shi)(shi)(shi)(shi)(shi)之(zhi)(zhi)(zhi)外還(huan)有多(duo)數斜長(chang)石(shi)(shi)(shi)(shi)(shi)和少數橄(gan)欖石(shi)(shi)(shi)(shi)(shi)。中(zhong)層(或第二層)的熔巖(yan)(yan)是(shi)(shi)由(you)兩輝(hui)(hui)安(an)(an)山(shan)(shan)巖(yan)(yan)構成(cheng)。巖(yan)(yan)石(shi)(shi)(shi)(shi)(shi)外觀(guan)灰色,普(pu)通輝(hui)(hui)石(shi)(shi)(shi)(shi)(shi)之(zhi)(zhi)(zhi)斑(ban)(ban)晶(jing)(jing)(jing)(jing)(jing)(jing)雖粗(cu)大易見但(dan)甚稀(xi)少,細長(chang)之(zhi)(zhi)(zhi)紫蘇輝(hui)(hui)石(shi)(shi)(shi)(shi)(shi)晶(jing)(jing)(jing)(jing)(jing)(jing)體(ti)頗多(duo)但(dan)均(jun)細小(xiao)。本巖(yan)(yan)石(shi)(shi)(shi)(shi)(shi)之(zhi)(zhi)(zhi)石(shi)(shi)(shi)(shi)(shi)基(ji)占(zhan)量較多(duo),由(you)斜長(chang)石(shi)(shi)(shi)(shi)(shi)和紫蘇輝(hui)(hui)石(shi)(shi)(shi)(shi)(shi)細晶(jing)(jing)(jing)(jing)(jing)(jing)以及(ji)火山(shan)(shan)玻璃所組成(cheng)。本層是(shi)(shi)觀(guan)音(yin)山(shan)(shan)中(zhong)露出面積最(zui)廣的熔巖(yan)(yan),主(zhu)要分(fen)布(bu)于觀(guan)音(yin)山(shan)(shan)主(zhu)峰(feng)北(bei)側(ce)之(zhi)(zhi)(zhi)山(shan)(shan)坡。
第二(er)層(ceng)斑晶(jing)(jing)稀疏之(zhi)(zhi)(zhi)兩輝(hui)(hui)安(an)(an)山(shan)(shan)(shan)(shan)(shan)(shan)(shan)巖(yan)(yan)(yan)(yan)(yan),常含(han)第一(yi)(yi)層(ceng)輝(hui)(hui)石(shi)斑晶(jing)(jing)多(duo)而(er)聚(ju)集成叢的(de)(de)(de)普通輝(hui)(hui)石(shi)安(an)(an)山(shan)(shan)(shan)(shan)(shan)(shan)(shan)巖(yan)(yan)(yan)(yan)(yan)之(zhi)(zhi)(zhi)捕(bu)獲巖(yan)(yan)(yan)(yan)(yan)塊(kuai),根據(ju)年代對比的(de)(de)(de)包裹定律,即可(ke)(ke)(ke)(ke)知其(qi)發(fa)生之(zhi)(zhi)(zhi)先后順序(xu),乃輝(hui)(hui)石(shi)安(an)(an)山(shan)(shan)(shan)(shan)(shan)(shan)(shan)巖(yan)(yan)(yan)(yan)(yan)(第一(yi)(yi)層(ceng))早于兩輝(hui)(hui)安(an)(an)山(shan)(shan)(shan)(shan)(shan)(shan)(shan)巖(yan)(yan)(yan)(yan)(yan)(第二(er)層(ceng))。頂(ding)層(ceng)(第三(san)層(ceng))紫蘇輝(hui)(hui)石(shi)安(an)(an)山(shan)(shan)(shan)(shan)(shan)(shan)(shan)巖(yan)(yan)(yan)(yan)(yan)與(yu)一(yi)(yi)部(bu)分角(jiao)閃(shan)石(shi)紫蘇安(an)(an)山(shan)(shan)(shan)(shan)(shan)(shan)(shan)巖(yan)(yan)(yan)(yan)(yan)為(wei)其(qi)特征,顏色淡灰色或(huo)灰紫,斑晶(jing)(jing)細小(xiao)(xiao)不(bu)顯著。有(you)時可(ke)(ke)(ke)(ke)見有(you)細長(chang)之(zhi)(zhi)(zhi)紫蘇輝(hui)(hui)石(shi)或(huo)角(jiao)閃(shan)石(shi)之(zhi)(zhi)(zhi)小(xiao)(xiao)晶(jing)(jing),石(shi)基較多(duo)包含(han)微(wei)晶(jing)(jing)與(yu)玻(bo)璃質(zhi)(zhi)(zhi)。本層(ceng)主(zhu)要(yao)分布在火(huo)山(shan)(shan)(shan)(shan)(shan)(shan)(shan)中(zhong)央之(zhi)(zhi)(zhi)頂(ding)部(bu),由(you)(you)觀音(yin)山(shan)(shan)(shan)(shan)(shan)(shan)(shan)主(zhu)峰至崩山(shan)(shan)(shan)(shan)(shan)(shan)(shan)一(yi)(yi)帶。在本地(di)(di)(di)區內(nei)除上述之(zhi)(zhi)(zhi)三(san)層(ceng)熔巖(yan)(yan)(yan)(yan)(yan)流之(zhi)(zhi)(zhi)外,還有(you)兩處(chu)獨(du)立之(zhi)(zhi)(zhi)小(xiao)(xiao)規模火(huo)山(shan)(shan)(shan)(shan)(shan)(shan)(shan)巖(yan)(yan)(yan)(yan)(yan)體,一(yi)(yi)是在觀音(yin)山(shan)(shan)(shan)(shan)(shan)(shan)(shan)站北側公路(lu)旁出露之(zhi)(zhi)(zhi)黑云母角(jiao)閃(shan)安(an)(an)山(shan)(shan)(shan)(shan)(shan)(shan)(shan)巖(yan)(yan)(yan)(yan)(yan)脈(mo),為(wei)一(yi)(yi)厚約20~40公尺之(zhi)(zhi)(zhi)脈(mo)狀小(xiao)(xiao)侵入(ru)體(或(huo)稱觀音(yin)坑巖(yan)(yan)(yan)(yan)(yan)脈(mo)),穿(chuan)入(ru)觀音(yin)山(shan)(shan)(shan)(shan)(shan)(shan)(shan)層(ceng)之(zhi)(zhi)(zhi)粉砂(sha)巖(yan)(yan)(yan)(yan)(yan)之(zhi)(zhi)(zhi)中(zhong)。另(ling)一(yi)(yi)處(chu)是突出于成子寮附近低地(di)(di)(di)上之(zhi)(zhi)(zhi)萬(wan)年塔小(xiao)(xiao)山(shan)(shan)(shan)(shan)(shan)(shan)(shan),巖(yan)(yan)(yan)(yan)(yan)石(shi)是橄欖石(shi)玄(xuan)武(wu)巖(yan)(yan)(yan)(yan)(yan),可(ke)(ke)(ke)(ke)能(neng)是一(yi)(yi)火(huo)山(shan)(shan)(shan)(shan)(shan)(shan)(shan)側噴發(fa)之(zhi)(zhi)(zhi)巖(yan)(yan)(yan)(yan)(yan)體。萬(wan)年塔所(suo)產出者,其(qi)橄欖石(shi)含(han)量較普通輝(hui)(hui)石(shi)為(wei)多(duo),與(yu)福隆山(shan)(shan)(shan)(shan)(shan)(shan)(shan)玄(xuan)武(wu)巖(yan)(yan)(yan)(yan)(yan)略(lve)有(you)不(bu)同(tong)。根據(ju)結(jie)晶(jing)(jing)分化的(de)(de)(de)效應,玄(xuan)武(wu)質(zhi)(zhi)(zhi)巖(yan)(yan)(yan)(yan)(yan)漿(jiang)經由(you)(you)橄欖石(shi)、輝(hui)(hui)石(shi)與(yu)斜長(chang)石(shi)的(de)(de)(de)結(jie)晶(jing)(jing)分化可(ke)(ke)(ke)(ke)以(yi)產生安(an)(an)山(shan)(shan)(shan)(shan)(shan)(shan)(shan)巖(yan)(yan)(yan)(yan)(yan)。同(tong)樣的(de)(de)(de)由(you)(you)混(hun)染作(zuo)用,也就是由(you)(you)基性(xing)的(de)(de)(de)巖(yan)(yan)(yan)(yan)(yan)漿(jiang)與(yu)酸性(xing)的(de)(de)(de)巖(yan)(yan)(yan)(yan)(yan)漿(jiang)混(hun)合,或(huo)是由(you)(you)玄(xuan)武(wu)質(zhi)(zhi)(zhi)巖(yan)(yan)(yan)(yan)(yan)漿(jiang),混(hun)雜了沈積物(wu)(wu)或(huo)地(di)(di)(di)殼物(wu)(wu)質(zhi)(zhi)(zhi)都可(ke)(ke)(ke)(ke)能(neng)衍生成安(an)(an)山(shan)(shan)(shan)(shan)(shan)(shan)(shan)巖(yan)(yan)(yan)(yan)(yan)。在觀音(yin)山(shan)(shan)(shan)(shan)(shan)(shan)(shan)地(di)(di)(di)區安(an)(an)山(shan)(shan)(shan)(shan)(shan)(shan)(shan)巖(yan)(yan)(yan)(yan)(yan)或(huo)玄(xuan)武(wu)巖(yan)(yan)(yan)(yan)(yan)中(zhong),常含(han)有(you)火(huo)山(shan)(shan)(shan)(shan)(shan)(shan)(shan)體基底的(de)(de)(de)砂(sha)巖(yan)(yan)(yan)(yan)(yan)或(huo)硅質(zhi)(zhi)(zhi)片(pian)巖(yan)(yan)(yan)(yan)(yan),顯示地(di)(di)(di)殼物(wu)(wu)質(zhi)(zhi)(zhi)的(de)(de)(de)混(hun)染作(zuo)用具有(you)舉足(zu)輕(qing)重的(de)(de)(de)角(jiao)色。
觀音(yin)(yin)山(shan)(shan)各火山(shan)(shan)體的(de)噴(pen)(pen)發(fa)時代,根據鉀-氬法定年(nian)的(de)結(jie)果來(lai)看,觀音(yin)(yin)山(shan)(shan)火山(shan)(shan)之活動盛行于第四(si)紀。由(you)六(liu)十(shi)余(yu)萬年(nian)前開始;接著是五十(shi)余(yu)萬年(nian)前底層輝(hui)石(shi)玄(xuan)(xuan)武巖(yan)(yan)(yan)(yan)或玄(xuan)(xuan)武巖(yan)(yan)(yan)(yan)質(zhi)熔巖(yan)(yan)(yan)(yan)之噴(pen)(pen)發(fa);其次(ci)則(ze)為(wei)四(si)十(shi)余(yu)萬年(nian)前,第二(er)(er)層兩(liang)輝(hui)安山(shan)(shan)巖(yan)(yan)(yan)(yan);再依次(ci)為(wei)三(san)十(shi)余(yu)萬年(nian)前第三(san)層紫(zi)蘇輝(hui)石(shi)與(yu)紫(zi)蘇輝(hui)石(shi)角閃安山(shan)(shan)巖(yan)(yan)(yan)(yan)之噴(pen)(pen)發(fa);最后以二(er)(er)十(shi)余(yu)萬年(nian)前橄欖玄(xuan)(xuan)武巖(yan)(yan)(yan)(yan)落幕。由(you)火山(shan)(shan)噴(pen)(pen)發(fa)年(nian)代與(yu)塌陷破火山(shan)(shan)口地貌看來(lai),觀音(yin)(yin)山(shan)(shan)非為(wei)活火山(shan)(shan),有可能是座(zuo)休眠火山(shan)(shan)或死火山(shan)(shan)。
1937年12月27日(ri)成(cheng)立(li)大(da)屯公園,觀音(yin)山(shan)(shan)亦(yi)在其中(zhong)。但(dan)戰后成(cheng)立(li)的陽明山(shan)(shan)公園剔(ti)除觀音(yin)山(shan)(shan)(2002年方另(ling)成(cheng)立(li)北海岸及(ji)觀音(yin)山(shan)(shan)風(feng)景(jing)區管理(li)),以及(ji)民(min)間認(ren)為此山(shan)(shan)為風(feng)水(shui)寶地,埋(mai)下日(ri)后濫墾濫葬(zang)及(ji)水(shui)土保持的問題。據估計(ji)目前山(shan)(shan)上非法墓計(ji)4萬處,成(cheng)為發展阻礙。